DE102013210024A1 - Notched connector for a solid electrolytic capacitor - Google Patents

Abstract

A capacitor including a solid electrolytic capacitor element comprising a porous anode body and an anode terminal having a relatively large thickness and / or width (e.g., wire / ribbon) is provided. The connection part is electrically connected to the anode body for connection to an anode end part. The connector has a thickness that is at least about 10% of the height of the porous anode body and / or a width that is at least about 20% of the width of the anode body to improve the contact points between the anode body and the connector and thereby to reduce the ESR. A part of the connection part extends from a surface of the anode body in the longitudinal direction. At least one notch may be formed in the part of the terminal part extending from the anode body, such as by laser, cutting, punching or sawing, and may serve as a point of electrical connection between the anode end part and the terminal part.

Description

Background of the invention

Solid electrolytic capacitors (eg, tantalum capacitors) have mainly contributed to the miniaturization of electronic circuits and have enabled the use of such circuits in extreme environments. The anode of a typical solid electrolytic capacitor includes a porous anode body, with a terminal portion extending beyond the anode body and connected to an anode end portion of the capacitor. The anode may be formed by first pressing a tantalum powder into a compact, which is then sintered to form fused connections between individual powder particles. A problem with many conventional solid electrolytic capacitors is that the volumetric contact between the anode body and the connector may decrease due to the small size of the tantalum particles. In fact, it can be difficult to find many points of contact between the connector and the powder particles. As the contact area between the anode body and the terminal member decreases, there is a corresponding increase in resistance at the location where the terminal and the anode meet. This increased equivalent series resistance (ESR) results in a capacitor that has reduced electrical capabilities. While several efforts have been made to improve the connection between the anode body and the anode termination, these efforts involve additional processing steps that may be detrimental from a manufacturing standpoint. Therefore, there is currently a need for an improved solid electrolytic capacitor in which the contact points between the anode body and the connector are increased, thereby significantly improving the electrical properties by achieving extremely low ESR values.

Brief description of the invention

According to one embodiment of the present invention, a solid electrolytic capacitor is disclosed which comprises a capacitor element. The capacitor element comprises a sintered porous anode body having a width and a height, an anode terminal, a dielectric layer covering the sintered porous anode body, and a cathode covering the dielectric layer and comprising a solid electrolyte. Furthermore, the anode terminal part has a first part located inside the anode body and a second part extending longitudinally from a surface of the anode body. The second part has a notched area in which there is at least one notch.

According to another embodiment of the present invention, there is disclosed a method of forming a solid electrolytic capacitor comprising a sintered porous anode body having a width and a height. The method includes positioning a first portion of an anode fitting within a powder formed from a valve metal composition such that a second portion of the anode fitting extends longitudinally from a surface of the anode body. The method further comprises compacting the powder around the first portion of the anode termination, sintering the compacted powder and the first portion of the anode termination to form the porous anode body, anodizing the sintered porous anode body to form a dielectric layer, applying a solid electrolyte to the anodized anode sintered body to form a cathode, forming a notched portion in the second part of the anode terminal in which at least one notch is located, and welding the anode terminal to an anode end portion the notched portion to form an electrical connection between the anode terminal and the anode end portion.

Further features and aspects of the present invention are set forth in more detail below.

Brief description of the drawings

In the remainder of the specification and with reference to the accompanying drawings, a complete and reproducible disclosure of the present invention, including the best mode of realization thereof, will be specifically presented to those skilled in the art; are:

1 a perspective view of an embodiment of the electrolytic capacitor of the present invention;

2 a perspective view of another embodiment of the electrolytic capacitor of the present invention;

3 a plan view of an embodiment of the electrolytic capacitor of the present invention;

4 a plan view of another embodiment of the electrolytic capacitor of the present invention;

5 a plan view of still another embodiment of the electrolytic capacitor of the present invention;

6 a plan view of still another embodiment of the electrolytic capacitor of the present invention;

7 a side view of an embodiment of the electrolytic capacitor of the present invention;

8th a side view of another embodiment of the electrolytic capacitor of the present invention;

9 a side view of still another embodiment of the electrolytic capacitor of the present invention;

10 a side view of still another embodiment of the electrolytic capacitor of the present invention;

11 a perspective view of another embodiment of the electrolytic capacitor of the present invention;

12 a perspective view of an embodiment of the electrolytic capacitor of the present invention;

13 a perspective view of yet another embodiment of the electrolytic capacitor of the present invention;

14 a plan view of an embodiment of the electrolytic capacitor of the present invention;

15 a plan view of another embodiment of the electrolytic capacitor of the present invention;

16 a plan view of still another embodiment of the electrolytic capacitor of the present invention;

17 a plan view of still another embodiment of the electrolytic capacitor of the present invention;

18 a side view of an embodiment of the electrolytic capacitor of the present invention;

19 a side view of another embodiment of the electrolytic capacitor of the present invention;

20 a side view of still another embodiment of the electrolytic capacitor of the present invention; and

21 a side view of yet another embodiment of the electrolytic capacitor of the present invention.

When multiple references are used in the present specification and drawings, they are intended to represent the same or analogous features or elements of the present invention.

Detailed description of representative embodiments

It should be understood by those skilled in the art that the present discussion is only a description of exemplary embodiments and is not intended to limit the broader aspects of the present invention.

Generally speaking, the present invention relates to a solid electrolytic capacitor including a capacitor element comprising a sintered porous anode body, a dielectric layer covering the sintered porous anode body, and a cathode covering the dielectric layer and comprising a solid electrolyte. An anode termination (eg, a wire or ribbon) may be electrically connected to the anode body for connection to an anode termination. The anode termination may have a relatively large thickness (eg, diameter when in the form of a ribbon), width, or both to improve the contact points between the anode porous body and the anode termination, and thereby the ESR of the capacitor to reduce.

For example, if in the form of an anode lead wire, the thickness of the anode lead wire may be from about 10% to about 95% of the height of the porous anode body. In other embodiments, the thickness of the anode lead wire may be from about 20% to about 90% of the height of the porous anode body, and in still other embodiments, the thickness of the anode lead wire may be from about 30% to about 85% of the height of the porous anode body. Furthermore, the thickness of the anode lead can be from about 5% to about 65% of the width of the porous anode body. In other embodiments, the thickness of the anode terminal wire may be about 10% to 60% of the width of the porous anode body, and in still other embodiments, the thickness of the anode terminal wire may be about 15% to 55% of the width of the porous anode body.

Meanwhile, if it is in the form of an anode lead tape, the thickness (eg, height) of the anode lead tape may be about 5% to about 70% of the height of the porous anode body. In other embodiments, the thickness of the anode lead tape may be from about 10% to about 65% of the height of the porous anode body, and in yet other embodiments, the thickness of the anode lead tape may be from about 15% to about 60% of the height of the porous anode body. Furthermore, the width of the anode lead tape may be about 20% to about 75% of the width of the porous anode body. In other embodiments, the width of the anode termination strap may be from about 25% to about 70% of the width of the porous anode body, and in still other embodiments, the width of the anode termination strap may be from about 30% to about 65% of the width of the porous anode body.

A part of the anode terminal may be inside the anode body, and a part of the anode terminal may extend longitudinally from a surface thereof. At least one notch may be formed in the part of the anode terminal which extends from one surface of the anode body. The anode termination may be electrically connected to an anode termination or lead frame, while the cathode may be electrically connected to a cathode termination by any method well known in the art. Regardless of the technique used, the connection between the anode terminal and the anode terminal can be formed in the notched portion of the terminal. In addition, the notch may be located anywhere along the portion of the anode termination extending away from the face of the anode body as long as there is sufficient clearance between the face and the notch so that the bond can be made without the capacitor to damage. Furthermore, the presence of the notch on the anode termination allows for a decrease in the energy required to form an electrical connection between the anode termination and the anode termination. Various embodiments of the solid electrolytic capacitor of the present invention will be discussed in more detail below.

In 1 is a particular embodiment of a capacitor element 100 shown, consisting of a porous anode body 33 and an anode lead wire 34 is formed. Generally speaking 1 a perspective View of the porous anode body 33 that around the anode lead wire 34 is formed around and the dimensions of the porous anode body 33 and the anode terminal wire 34 shows. Another embodiment of a capacitor element 1100 is in 11 shown where the capacitor element 1100 is also formed of a porous anode body, but an anode connection tape 84 instead of the anode terminal wire 34 from 1 includes. Generally speaking 11 a perspective view of the porous anode body 33 which is around the anode connection tape 84 is formed around and the dimensions of the porous anode body 33 and the anode connection tape 84 shows. As well in 1 as well as in 11 may be the porous anode body 33 a first side surface 31 , a second side surface 32 , a front surface 36 , a back surface 37 , an upper surface 38 and a lower surface 39 exhibit. The porous anode body 33 can also have a width W, for example, on the width of the front surface 36 can relate, and a height H, for example, to the height or thickness of the front surface 36 can relate. The width W of the front surface 36 of the porous anode body 33 may range from about 400 microns to about 6000 microns, in some embodiments, about 800 microns to about 4500 microns, and in some embodiments, about 1200 microns to about 3000 microns. In addition, the height H of the front surface 36 of the porous anode body 33 in the range of about 200 microns to about 4000 microns, in some embodiments about 400 microns to about 3000 microns and in some embodiments about 600 microns to about 2000 microns.

In the particular embodiments that are in the 1 and 11 are shown, the porous anode body is located 33 in the form of a rectangular compact. In addition to a rectangular shape, however, the anode may also have a cube-shaped, cylindrical, circular or any other geometric shape. The anode may also be "corrugated" in that it may contain one or more ridges, grooves, depressions or indentations to increase the surface area to volume ratio thereby minimizing the ESR and extending the frequency response of the capacitance. Such "corrugated" anodes are for example in the U.S. Pat. Nos. 6,191,936 (Webber et al.), 5,949,639 (Maeda et al.) And 3,345,545 (Bourgault et al.) And US Patent Application Publication No. 2005/0270725 (Hahn et al.), Which are hereby incorporated by reference for all purposes.

We now turn specifically to the embodiments in which the anode termination is in the form of an anode lead. Even though 1 shows that the anode lead wire 34 is circular and has a thickness D, the anode lead disclosed herein can be used 34 have any cross-sectional shape, such as elliptical, square, rectangular, etc., possess. As in 1 can be shown, the anode lead wire 34 a first part M located within the anode body 33 located, and a second part L, extending from a surface of the porous anode body 33 like the front surface 36 , from extending. The thickness of the anode connection wire 34 may vary depending on the total size of the anode body 33 vary. In any case, the greater the thickness D, the greater the number of contact points between the porous anode body 33 and the anode lead wire 34 along the first part M, resulting in a lower ESR and improved electrical capabilities of the capacitor.

As in 1 is shown, the anode lead wire extends 34 from the front surface 36 of the porous anode body 33 out; however, it should be understood that the anode lead wire 34 also from any other surface of the porous anode body 33 can extend out. Furthermore, the second part L of the anode connection wire 34 extending from a surface of the porous anode body 33 out, a thickness D, which, as mentioned above, also on the thickness of the first part M of the anode connection wire 34 which is located within the porous anode body 33 located. The size of the anode connection wire 34 may vary depending on the total size of the anode body 33 vary.

As continues in 1 is shown, the thickness D of the anode connection wire 34 be uniform along the first part M and the second part L except that at the anode lead wire 34 in the notch region N along the second part L at least one notch 50 can be present. The at least one notch 50 may be rectangular, square, circular, elliptical, triangular, stepped, U-shaped, V-shaped, or any other suitable shape. Because of the score 50 indicates the anode lead wire 34 along the notch area N of the anode lead wire 34 a smaller thickness D 'on.

As discussed above, the anode lead wire 34 a thickness D along the first part M and the second part L on. The thickness D is uniform over the entire anode lead, except in the notch region N, which has a thickness D '. The thickness D may be at least about 10% of the height H of the front surface 36 of the porous anode body 33 be. For example, the thickness D may generally be about 10% to about 95% of the height H of the front surface 36 of the porous anode body 33 be. Further, the thickness D may be about 5% to about 65% of the width W of the front surface 36 of the porous anode body 33 be. For example, the thickness D may range from about 20 microns to about 3800 microns, in some embodiments, from about 40 microns to about 2850 microns, and in some embodiments, from about 60 microns to about 1900 microns. In still other embodiments, the thickness D may be about 20% to about 90% of the height H of the front surface 36 of the porous anode body 33 , like about 30% to about 85% of the height H of the front surface 36 of the porous anode body 33 , amount. In addition, in still other embodiments, the thickness D may be about 10% to about 60% of the width W of the front surface 36 of the porous anode body, such as about 15% to about 55% of the width W of the front surface 36 of the porous anode body 33 , amount.

Meanwhile, the thickness D 'of the notch portion N of the anode lead wire is 34 due to the removal of material from the anode lead wire 34 along the notch area N to form at least one notch 50 smaller than the thickness D of the anode terminal wire 34 , The thickness D 'of the notch region N is generally about 20% to 90% of the first diameter D of the anode lead wire 34 , For example, the thickness of the notch region D 'may range from about 4 microns to about 3425 microns, in some embodiments, from about 8 microns to about 2600 microns, and in some embodiments, from about 12 microns to about 1700 microns. In other embodiments, the thickness of the notch region D 'may be from about 30% to about 80% of the thickness D, such as from about 40% to about 70% of the thickness D.

We now turn to embodiments in which the anode termination is in the form of a lead ribbon. Even though 11 shows that the anode connection tape 84 is rectangular in shape and generally has a width W 'and a thickness / height H', the anode termination strap disclosed herein may be used 84 have any cross-sectional shape, such as circular, elliptical, square, etc. As in 1 can be shown, the anode connection tape 84 a first part M located within the anode body 33 located, and a second part L, extending from a surface of the porous anode body 33 like the front surface 36 , from extending. The thickness / height H and / or the width W 'of the anode connection tape 84 may vary depending on the total size of the anode body 33 vary. In any case, the greater the thickness H 'and / or the width W' of the band, the greater the number of contact points between the porous anode body 33 and the anode connection tape 84 along the first part M, resulting in a lower ESR and improved electrical capabilities of the capacitor.

As in 11 is shown, the anode terminal strip extends 84 from the front surface 36 of the porous anode body 33 out; however, you should be aware that the anode connector tape 84 also from any other surface of the porous anode body 33 can extend out. Furthermore, the second part L of the anode connection band 84 extending from a surface of the porous anode body 33 from, a width W 'and a thickness / height H', which also on the width and thickness / height of the first part M of the anode terminal strip 84 which is located within the porous anode body 33 located. The size of the anode connection tape 84 may vary depending on the total size of the anode body 33 vary. In any case, the greater the width W 'and / or the height or thickness H' of the anode connection tape 84 , the greater the number of contact points between the porous anode body 33 and the anode connection tape 84 , which leads to a lower ESR.

As continues in 11 is shown, the width W 'of the anode connection tape 84 be uniform along its length including the first part M and the second part L, except that at the anode terminal strip 84 in the notch region N along the second part L at least one notch 50 can be present. The at least one notch 50 may be rectangular, square, circular, elliptical, triangular, stepped, U-shaped, V-shaped, or any other suitable shape. Because of the score 50 has the anode connection band 84 along the notch region N of the anode lead tape 84 a smaller second width E on. Further shows 11 though a notch 50 located on an X-axis facing surface of the anode lead strap 84 (eg on the right side) is formed, so that the anode connection tape 84 at the notch 50 along the notch portion N has a reduced width E, but the at least one notch 50 also on a Y-axis facing surface of the anode connection tape 84 (eg, on the upper surface), so that the anode connection tape 84 at the notch 50 along the notch region N has a reduced thickness / height G, as in the capacitor 200 from 2 is shown. Furthermore, a plurality of notches on both the X-axis facing surface and the Y-axis facing surfaces of the anode terminal strip 84 so that the anode terminal tape has a reduced width E and a reduced thickness / height G along the notch area N, as in FIG 3 is shown and discussed in more detail below.

As discussed above, the anode termination strap 84 a width W 'along the first part M and the second part L on. The width W 'is uniform over the entire anode terminal tape, except in the notch area N, which has a width E. The width W 'may be generally about 20% to about 75% of the width W of the front surface 36 of the porous anode body 33 be. For example, the width W 'of the anode connection tape 84 in the range of about 80 microns to about 4500 microns, in some embodiments about 160 microns to about 3500 microns, and in some embodiments, about 240 microns to about 2500 microns. In still other embodiments, the width W 'of the anode lead strap 84 about 25% to about 70% of the width W of the front surface 36 of the porous anode body 33 , such as about 30% to about 65% of the width W of the front surface 36 of the porous anode body 33 , amount.

Furthermore, the thickness / height H 'of the anode lead tape is 84 also over the entire anode terminal strip uniformly, except in the notch area N, which has a thickness / height G (see 2 ). The thickness / height H 'may be at least about 5% of the height or thickness H of the front surface 36 of the porous anode body 33 be. For example, the thickness / height H 'may generally be from about 5% to about 70% of the height or thickness H of the front surface 36 of the porous anode body 33 be. Furthermore, the thickness / height H 'of the anode connection tape 84 in the range of about 10 microns to about 2800 microns, in some embodiments about 20 microns to about 2100 microns and in some embodiments about 30 microns to about 1500 microns. In still other embodiments, the thickness / height H 'of the anode termination strap 84 about 10% to about 65% of the thickness / height H of the front surface 36 of the porous anode body 33 such as about 15% to about 60% of the front panel thickness / height H 36 of the porous anode body.

Besides, as in 11 and discussed above, in some embodiments, the width E of the notch region N of the anode lead tape 84 due to the removal of material from the anode connection tape 84 along the notch area N to form at least one notch 50 smaller than the width W 'of the connection tape 84 , The width E of the anode connection tape 84 may be about 20% to 90% of the width W 'of the anode lead tape 84 be. For example, the width E in the notch region N can range from about 16 microns to about 4050 microns, in some embodiments, from about 32 microns to about 3375 microns, and in some embodiments, from about 48 microns to about 2700 microns. In other embodiments, the width E of the notch region N may be about 30% to about 80% of the width W ', such as 40% to about 70% of the width W'.

In another embodiment, as in 12 2, the thickness / height G of the notch portion N of the anode lead tape is due to the removal of material from the anode lead tape 84 along the notch area N to form at least one notch 50 smaller than the thickness / height H 'of the anode terminal strip 34 , The thickness / height G of the anode connection tape 34 is generally about 20% to 90% of the thickness / height H 'of the anode lead tape 34 , For example, the thickness / height G may range from about 2 microns to about 2520 microns, and in some embodiments, from about 4 microns to about 1890 microns, and in some embodiments, from about 6 microns to about 1575 microns. In other embodiments, the thickness / height G may be from about 30% to about 80% of the thickness / height H ', such as from about 40% to about 70% of the thickness / height H'.

Even though 11 shows that the anode connection tape 84 at the notch 50 a smaller width E than and the same height H 'as the rest of the anode lead tape 84 and 12 shows that the anode connection tape 84 at the notch 50 a smaller thickness / height G than, but having the same width W 'as the rest of the anode lead strap, one skilled in the art should be aware that material can also be removed such that the anode lead strap 84 at the notch 50 both a smaller width E and a smaller thickness / height G than the remainder of the anode lead strap 84 having. For example, shows 13 that the anode connection tape 84 at the notch 50 both a width E that is less than the width W 'of the remainder of the anode lead strap 84 , as well as a thickness / height G which is less than the thickness / height H 'of the remainder of the anode terminal strip 84 , may have. Furthermore, the skilled person should be aware that the at least one notch 50 not on the in the 11 - 13 shown configurations and that any combination of changed heights and widths of the anode connection tape 84 on the side surfaces or the upper and lower surface is possible, as long as the thickness / height and / or width at the notch 50 is less than the thickness / height or width of the remainder of the anode lead strap 84 ,

We now refer to the 1 - 2 and 11 - 13 , The notch region N may be anywhere along the second part L of the anode lead 34 or the anode connection tape 84 (ie along the Z axis) as long as the notch region N is at a sufficient distance F from the porous anode body 33 is located so that the capacitor is not damaged when the anode lead wire 34 or the anode connection tape 84 to an anode end part 35 is welded, as will be discussed in more detail below. In general, the ratio of the length of the second part L to the distance F, where the notch 50 is about 1.1 to about 20 in some embodiments, about 1.5 to about 15 in other embodiments, and about 2 to about 10 in yet other embodiments be. For example, in one embodiment, the second part L may have a length that is about 200 microns to about 50 millimeters, in some embodiments, about 400 microns to about 30 millimeters, and in some embodiments, about 1000 microns to about 10 millimeters. The distance F to the notch 50 Thus, it may be about 10 microns to about 45 millimeters when the second part L has a length that is about 200 microns to about 50 millimeters. Meanwhile, the distance F to the notch 50 from about 20 microns to about 27 millimeters when the second portion L has a length that is about 400 microns to about 30 millimeters. Furthermore, the distance F to the notch 50 from about 50 microns to about 9 millimeters when the second portion L has a length that is about 1000 microns to about 10 millimeters.

The notch area N (ie the length of the notch 50 ) may have a length that is about 10% to about 90% of the second part L of the anode lead wire 34 or the anode connection tape 84 is what refers to the total distance to which the anode lead wire 34 or the anode connection tape 84 from the front surface 36 of the porous anode body 33 extends out. As discussed above, in one embodiment, the second portion L may be about 200 microns to about 50 millimeters, in some embodiments, about 400 microns to about 30 millimeters, and in some embodiments, about 1000 microns to about 10 millimeters. Thus, the notch region N may have a length of about 20 microns to about 45 millimeters, in some embodiments about 40 microns to about 27 millimeters, and in some embodiments about 100 microns to about 9 millimeters.

If a connecting wire 34 In addition, the at least one notch may be used 50 even at different locations around the center of the anode lead wire 34 be oriented around. For example, the notch 50 be oriented along the X-axis or the Y-axis or at any point in between. In the in 1 and 2 For example, although the notch may be oriented along the X-axis, for example, although other possible orientations for the at least one notch may be found in more detail below with reference to FIGS 3 - 10 to be discussed.

Likewise, if a connection tape 84 is used, the notch 50 be oriented along the X-axis or the Y-axis or at any point in between. In the in 11 For example, in the embodiment shown, the notch is oriented along the X-axis while the notch in the in 12 embodiment is oriented along the Y-axis. Regardless of whether material from the anode connection tape 84 is removed to provide a smaller width E, a lower height G, or both, when material along the notch area N from the anode terminal tape 84 is removed, at least one notch 50 in the anode connection tape 84 as discussed above. In addition, the at least one notch 50 at various locations around the center of the anode lead strap 84 be oriented around.

As in 11 the notch can be shown 50 on an X-axis facing surface of the anode lead strap 84 be formed, resulting in a smaller width E of the anode connection tape 84 along the notch region N where the anode lead strap 84 to an anode end part 35 can be welded (as in 12 is shown). In another embodiment, as in 12 the notch can be shown 50 be formed on a Y-axis facing surface of the anode terminal strip, resulting in a smaller thickness / height G of the anode terminal strip 84 along the notch region N where the anode lead strap 84 to an anode end part 35 can be welded (as in 12 is shown). In yet another embodiment, as in the 13 pictured capacitor 300 shown can have multiple notches 63 - 66 on both the X-axis and the Y-axis facing surfaces of the anode lead strap 84 be formed, resulting in a smaller width E and a smaller thickness / height G of the anode connection tape 84 in the notch area N leads. For example, a notch 63 formed on the right side of the tape, a notch 64 is formed on the upper surface of the band, a notch 65 is formed on the right side of the band, and a notch 66 is formed on the lower surface of the band. Other possible orientations for the at least one notch are described in greater detail below with reference to FIGS 14 - 21 discussed.

Furthermore, as already described with reference to 13 and discussed in more detail below with reference to the 4 - 5 . 8th - 9 . 15 - 16 and 19 - 20 is discussed, more than one notch in the notch area N be formed. For example, two notches may be formed at different locations around the center of the anode lead wire. In a particular embodiment, a notch may be on an x-axis facing surface 70 of Anode lead wire 34 or the anode connection tape 84 may be formed, and another notch on an opposite, the X-axis-facing surface 71 of the anode connection wire 34 or the anode connection tape 84 be formed. In another embodiment, a notch may be on a surface facing the Y-axis 72 of the anode connection wire 34 or the anode connection tape 84 may be formed, and another notch on an opposite, the Y-axis-facing surface 73 of the anode connection wire 34 or the anode connection tape 84 be formed. Regardless of where the two notches are formed on the anode lead wire or ribbon, the notches may be symmetrically disposed about the center of the wire or ribbon.

Regardless of the way in which the one or more notches center around the anode lead wire 34 are oriented, leads, as in the 1 - 2 shown is the presence of at least one notch 50 to a reduction in the thickness D of the anode lead wire 34 to a smaller thickness D 'in the notch region N, that is, where the anode lead wire 34 to an anode end part 35 can be welded (as it is in 2 is shown). Due to the removal of material in the notch area N is the density of the anode lead wire 34 in the notch region N lower than in the remainder of the second part L of the anode lead wire 34 that extends from the front surface 36 of the porous anode body 33 extends out.

We will relate again 1 , Regardless of their geometry or orientation around the center of the anode lead wire 34 around is the at least one notch 50 by removing material in the notch area N of the anode lead wire 34 educated.

Furthermore, regardless of the manner in which the one or more notches guide about a center of the anode lead tape 84 are oriented around, as in the 11 - 13 shown is the presence of at least one notch 50 to a reduction of the thickness / height H 'and / or the width W' of the anode terminal strip 84 to a smaller thickness / height G and / or a smaller width E in the notch region N, that is, where the anode connection tape 84 to an anode end part 35 can be welded (as it is in the 12 and 13 is shown). Due to the removal of material in notch area N, the density of the anode lead tape is 84 in the notch region N lower than in the remainder of the second part L of the anode lead tape 84 that extends from the front surface 36 of the porous anode body 33 extends out.

We refer back to the 11 - 13 , Regardless of their geometry or orientation around the center of the anode lead strap 84 around is the at least one notch 50 by removing material in the notch area N of the anode lead tape 84 educated.

The material may be cut, punched or sawed from the anode lead wire 34 or the anode connection tape 84 under formation of the notch 50 be removed. Any technique known to those skilled in the art may be used. For example, material from the anode lead wire 34 or the anode connection tape 84 forming a notch 50 cut away, a cutting tool can be used. On the other hand, the score can 50 also be formed with a punching tool. The design of the punch tool can provide high accuracy with minimal presets. The specially designed punches may typically consist of tungsten carbide, hardened steels or derivatives. A common Brinell hardness value for stamped materials may range from about 1500 MN / m ² to about 1900 MN / m ² , which may be compared to the hardness value of sintered tantalum material, which may be 500 MN / m ² , for example.

The notch may also be formed by a saw using, for example, strong diamond blades for accurate shape and depth control. The specially designed blades may be made of hardened resin coated diamond grain (75%). The thickness of the sheets may range from about 50 microns to about 1500 microns. Meanwhile, the size of the diamond grain may range from about 80 microns to about 1200 microns.

The material can also be removed with a laser to the notch 50 to build. For example, a scanning mode laser may be used to erode the anode terminal wire in the notch area N. For example, the erosion caused by the laser treatment can give rise to a rough surface, like that in the 6 . 10 . 17 and 21 shown stepped notch, the laser welding of the anode lead wire 34 or the anode connection tape 84 to the anode end part 35 can facilitate. The notch may be formed by a single laser pulse, with each pulse about 0.2 milliseconds to about 20 milliseconds with a beam diameter of can take about 0.1 millimeters to about 0.3 millimeters. The notch may also be formed by multiple laser pulses, where each laser pulse may take from about 0.2 milliseconds to about 0.5 milliseconds (for each pulse) with a beam diameter of about 0.1 millimeter to about 0.3 millimeters. The typical working area may be about 1.0 millimeter long and about 0.5 millimeter wide.

Regardless of the particular design or manner in which the capacitor is formed, it may be connected to end portions as is well known in the art. For example, the anode and cathode end portions may be electrically connected to the one or more anode wires and the cathode, respectively. The particular configuration of the end portions may vary, as is well known in the art. Although not required, the cathode end part can 44 in an embodiment incorporated in the 2 and 12 - 13 shown, for example, a planar part 45 in electrical contact with a lower surface 39 the capacitor element and a towering part 46 which is substantially perpendicular to the planar part 45 and in electrical contact with a rear surface 38 of the capacitor element is positioned. To secure the capacitor element to the cathode end portion, a conductive adhesive may be employed as known in the art. The conductive adhesive may include, for example, conductive metal particles contained in a resin composition. The metal particles may be silver, copper, gold, platinum, nickel, zinc, bismuth, etc. The resin composition may comprise a thermosetting resin (eg, epoxy resin), curing agent (eg, acid anhydride) and coupling agent (eg, silane coupling agent). Suitable conductive adhesives are described in U.S. Patent Application Publication No. 2006/0038304 (Osako et al.), Which is hereby incorporated by reference for all purposes.

Again, we refer to the 2 and 12 - 13 , Although not required, the anode end portion may 35 also a planar part 41 and a towering part 42 contain. The towering part 42 may contain a region containing the anode lead wire 34 or the anode connection tape 84 of the present invention. As in 2 For example, the area may have a slot for receiving the anode terminal wire 34 have. The slot may have any desired shape, such as a U-shape, V-shape, circular, rectangular, square, stepped, etc., to provide surface contact and mechanical stability of the anode lead 34 in the notch area N further strengthen. For example, the geometry of the slot may be to the geometry of the notch 50 fit. Meanwhile, as in the 12 - 13 shown is the anode connection tape 84 also just on the towering part 42 rest. Furthermore, as in 12 is shown, the anode end part 35 also a second planar part 43 having, with the anode connection tape 84 comes in contact and supports this. After the at least one notch is formed in the anode lead wire, the anode lead wire may be formed 34 then electrically to the anode end portion 35 get connected.

Any technique can be used to Lead wire 34 or the anode connection tape 84 with the anode end part 35 Such as by laser welding, resistance welding or the use of conductive adhesives, etc. Regardless of the particular welding technique that is used to connect the anode lead wire 34 or the anode connection tape 84 with the anode end part 35 is the amount of energy required to form a sufficient weld because of the notch 50 reduced.

Because of the score 50 There are N in the notch area along the connecting wire 34 less material, so that welding in this area requires less energy than when welding at a point along the second part L of the anode terminal wire of thickness D. The smaller thickness D 'in the notch N, which is due to the formation of the notch 50 This means that less anode lead wire material must be heated to ensure adequate spot welding between the anode lead wire 34 and the anode end part 35 to accomplish. Likewise, there is the score 50 less material in the notch area N along the connection band 84 so that welding in this area requires less energy than welding at a point along the second part L of the anode lead strap with height / thickness H 'and width W'. The smaller thickness / height G and / or the smaller width E in the notch area N caused by the formation of the notch 50 This means that less anode lead tape material must be heated to ensure adequate spot welding between the anode lead tape 84 and the anode end part 35 to accomplish. Thus, by forming at least one notch 50 in an anode lead wire 34 or the anode connection tape 84 however, a relatively thick anode lead or a relatively thick anode lead can be used to provide improved contact with the porous anode body to reduce the ESR, and yet the welding process can result in reduced electrical connection to an anode end Thickness of the anode lead wire or ribbon at the notch can be performed efficiently and cost effectively. Although the anode lead wire 34 by any technique known to those skilled in the art, to the anode end portion 35 can be welded, show the 2 and 12 - 13 the anode connection wire 34 or the anode connection tape 84 how he or she through a laser 47 on a towering part 42 of the anode end part 35 to the anode end part 35 is welded.

Any laser welding technique may be used, such as the technique described in US Patent Application Publication No. 2010/0072179 (Dvorak et al.), Which is expressly incorporated by reference herein for all purposes. For example, laser welding an anode lead wire or ribbon to an anode end portion may include directing a laser beam through one or more refractive elements before contacting the lead wire or ribbon and the anode end portion. By selectively controlling the refractive index and the thickness of the refractive element, the angle at which the refracting element is positioned relative to the laser beam, etc., etc., the laser beam may aim for a precise weld such as at the notch 50 , which is located at a sufficient distance F from the porous anode body, to be directed without substantially coming into contact with other parts of the capacitor including the porous anode body and to damage them.

If a laser is also used, the notch 50 by removing material from the anode lead wire 34 or the anode connection tape 84 is the amount of energy required to form the notch 50 and then subsequently to provide the weld at the anode end portion 35 is used, different. In general, the energy required to form a notch is about 6 joules to about 16 joules, while the energy required to weld the anode lead to the anode end portion is about 6 joules to about 26 joules in the case of a single laser pulse.

Further, once the capacitor element is formed and attached to the end portions, as discussed above, it may be embedded in a resin housing which may then be filled with silicon oxide or any other known encapsulant material. The width and length of the case may vary depending on the purpose. However, the overall thickness of the housing is typically small so that the resulting assembly can be easily incorporated into low profile products (eg, smart cards). For example, the thickness of the housing may range from about 4.0 millimeters or less, in some embodiments, from about 0.1 to about 2.5 millimeters, and in some embodiments, from about 0.15 to about 2.0 millimeters. Suitable housings include, for example, housings "A", "B", "H" or "T" (AVX Corporation). After embedding, the exposed portions of the respective anode and cathode end portions may be aged, inspected, and trimmed. If desired, the exposed parts may optionally be bent twice along the outside of the housing (eg, at an angle of approximately 90 °).

We turn now to the 3 - 10 and 14 - 21 to. Various embodiments of possible notch geometries are discussed in more detail below. 3 shows a plan view of a capacitor element 300 containing an anode lead wire 34 having. A square notch 51 is formed in the notch area N. The score 51 is located on an X-axis facing surface 70 of the anode connection wire 34 , The notch is at a distance F from the porous anode body 33 along the second part L of the anode lead wire 34 away. Because of the removal of material from the anode lead wire 34 to the formation of the square notch 51 is the material density of the anode terminal wire 34 in the notch area N smaller than the material density of the anode terminal wire 34 along the remainder of the second part L of the anode lead wire 34 , In addition, the thickness D 'of the anode lead wire 34 at the notch 51 smaller than the thickness D of the remainder of the anode lead wire 34 ,

Another embodiment of a plan view of a capacitor element 400 is in 4 shown. Two rectangular notches 52 and 53 are formed in the notch area N. The score 52 is located on an X-axis facing surface 70 , and the score 53 is located on an X-axis facing surface 71 of the anode connection wire 34 such that the anode lead wire is in the notch region N is symmetrical. The notches are at a distance F from the porous anode body 33 along the second part L of the anode lead wire 34 away. Again, because of the removal of material from the anode lead wire 34 for the formation of rectangular notches 52 and 53 the material density of the anode lead wire 34 in the notch area N smaller than the material density of the anode terminal wire 34 along the remainder of the second part L of the anode lead wire 34 , In addition, the thickness D 'of the anode lead wire 34 at the notches 52 and 53 smaller than the thickness D of the remainder of the anode lead wire 34 ,

Yet another embodiment of a plan view of a capacitor element 500 is in 5 shown. Two triangular notches 54 and 55 are formed in the notch area N. The score 54 is located on an X-axis facing surface 70 , and the score 55 is located on an X-axis facing surface 71 of the anode connection wire 34 such that the anode terminal wire is symmetrical in the notch area N. The notches are at a distance F from the porous anode body 33 along the second part L of the anode lead wire 34 away. Again, because of the removal of material from the anode lead wire 34 for the formation of triangular notches 54 and 55 the material density of the anode lead wire 34 in the notch area N smaller than the material density of the anode terminal wire 34 along the remainder of the second part L of the anode lead wire 34 , Furthermore, the thickness D 'of the anode lead wire is 34 at the notches 54 and 55 smaller than the thickness D of the remainder of the anode lead wire 34 , In 5 lead the triangular notches 54 and 55 to an uneven thickness D 'in the notch region N, and thus D' refers to as in 5 to the smallest thickness of the anode lead wire 34 in the notch area N.

Yet another embodiment of a plan view of a capacitor element 600 is in 6 shown. A step-shaped notch 56 is formed in the notch area N. The score 56 is located on an X-axis facing surface 71 of the anode connection wire 34 , The notch is at a distance F from the porous anode body 33 along the second part L of the anode lead wire 34 away. Again, because of the removal of material from the anode lead wire 34 for the formation of the step-shaped notch 56 the material density of the anode lead wire 34 in the notch area N smaller than the material density of the anode terminal wire 34 along the remainder of the second part L of the anode lead wire 34 , Furthermore, the thickness D 'of the anode lead wire is 34 at the notch 56 smaller than the thickness D of the remainder of the anode lead wire 34 , In 6 leads the step-shaped notch 56 to an uneven thickness D 'in the notch region N, and thus D' refers to as in 6 to the smallest thickness of the anode lead wire 34 in the notch area N.

While the 3 - 6 show various embodiments of a capacitor element in which the notches on the X-axis facing surfaces of the anode lead wire are formed, show the 7 - 10 various embodiments of a capacitor element in which the notches on the Y-axis facing surfaces of the anode lead wire are formed. We first refer to 7 showing a side view of a capacitor element 700 shows that an anode lead wire 34 having. In the notch area N is a square notch 57 educated. The score 57 is located on a surface facing the Y-axis 72 of the anode connection wire 34 , The notch is at a distance F from the porous anode body 33 along the second part L of the anode lead wire 34 away. Because of the removal of material from the anode lead wire 34 to the formation of the square notch 57 is the material density of the anode terminal wire 34 in the notch area N smaller than the material density of the anode terminal wire 34 along the remainder of the second part L of the anode lead wire 34 , In addition, the thickness D 'of the anode lead wire 34 at the notch 57 smaller than the thickness D of the remainder of the anode lead wire 34 ,

Another embodiment of a side view of a capacitor element 800 is in 8th shown. Two rectangular notches 58 and 59 are formed in the notch area N. The score 58 is located on a surface facing the Y-axis 72 , and the score 59 is located on a surface facing the Y-axis 73 of the anode connection wire 34 such that the anode terminal wire is symmetrical in the notch area N. The notches are at a distance F from the porous anode body 33 along the second part L of the anode lead wire 34 away. Again, because of the removal of material from the anode lead wire 34 for the formation of rectangular notches 58 and 59 the material density of the anode lead wire 34 in the notch area N smaller than the material density of the anode terminal wire 34 along the remainder of the second part L of the anode lead wire 34 , In addition, the thickness D 'of the anode lead wire 34 at the notches 58 and 59 smaller than the thickness D of the remainder of the anode lead wire 34 ,

Yet another embodiment of a plan view of a capacitor element 900 is in 9 shown. Two triangular notches 60 and 61 are formed in the notch area N. The score 60 is located on a surface facing the Y-axis 72 , and the score 61 is located on a surface facing the Y-axis 73 of the anode connection wire 34 such that the anode terminal wire is symmetrical in the notch area N. The notches are at a distance F from the porous anode body 33 along the second part L of the anode lead wire 34 away. Again, because of the removal of material from the anode lead wire 34 for the formation of triangular notches 60 and 61 the material density of the anode lead wire 34 in the notch area N smaller than the material density along the remainder of the second part L of the anode lead wire 34 , Furthermore, the thickness D 'of the anode lead wire is 34 at the notches 60 and 61 smaller than the thickness D of the remainder of the anode lead wire 34 , In 9 lead the triangular notches 60 and 61 to an uneven thickness D 'in the notch region N, and thus D' refers to as in 9 to the smallest thickness of the anode lead wire 34 in the notch area N.

Yet another embodiment of a plan view of a capacitor element 1000 is in 10 shown. A step-shaped notch 62 is formed in the notch area N. The score 62 is located on a surface facing the Y-axis 72 of the anode connection wire 34 , The notch is at a distance F from the porous anode body 33 along the second part L removed. Again, because of the removal of material from the anode lead wire 34 for the formation of the step-shaped notch 62 the material density of the anode lead wire 34 in the notch area N smaller than the material density along the remainder of the second part L of the anode lead wire 34 , Furthermore, the thickness D 'of the anode lead wire is 34 at the notch 62 smaller than the thickness D of the remainder of the anode lead wire 34 , In 10 leads the step-shaped notch 62 to a nonuniform thickness D in the notch region N, and thus D 'refers as it does in FIG 10 to the smallest thickness of the anode lead wire 34 in the notch area N.

We turn now to the 14 - 21 to. Various embodiments of possible notch geometries will be discussed in more detail. 14 shows a plan view of a capacitor element 1400 , which is an anode connection tape 84 having. A square notch 51 is formed in the notch area N. The score 51 is located on an X-axis facing surface 70 of the anode connection tape 84 , The notch is at a distance F from the porous anode body 33 along the second part L of the anode terminal strip 84 away. Because of the removal of material from the anode connection tape 84 to the formation of the square notch 51 is the material density of the anode connection tape 84 in the notch area N smaller than the material density of the anode lead tape 84 along the remainder of the second part L of the anode terminal strip 84 , In addition, the width E of the anode connection tape 84 at the notch 51 smaller than the width W 'of the remainder of the anode lead tape 84 ,

Another embodiment of a plan view of a capacitor element 1500 is in 15 shown. Two rectangular notches 52 and 53 are formed in the notch area N. The score 52 is located on an X-axis facing surface 70 , and the score 53 is located on an X-axis facing surface 71 of the anode connection tape 84 . 50 the connecting band in the notch area N is symmetrical. The notches are at a distance F from the porous anode body 33 along the second part L of the anode terminal strip 84 away. Again, because of the removal of material from the anode connection tape 84 for the formation of rectangular notches 52 and 53 the material density of the anode connection tape 84 in the notch area N smaller than the material density of the anode lead tape 84 along the remainder of the second part L of the anode terminal strip 84 , In addition, the width E of the anode connection tape 84 at the notches 52 and 53 smaller than the width W 'of the remainder of the anode lead tape 84 ,

Yet another embodiment of a plan view of a capacitor element 1600 is in 16 shown. Two triangular notches 54 and 55 are formed in the notch area N. The score 54 is located on an X-axis facing surface 70 , and the score 55 is located on an X-axis facing surface 71 of the anode connection tape 84 such that the anode terminal strip in the notch area N is symmetrical. The notches are at a distance F from the porous anode body 33 along the second part L of the anode terminal strip 84 away. Again, because of the removal of material from the anode connector tape 84 for the formation of triangular notches 54 and 55 the material density of the anode connection tape 84 in the notch area N smaller than the material density of the anode lead tape 84 along the remainder of the second part L of the anode terminal strip 84 , Furthermore, the width E of the anode connection tape 84 at the notches 54 and 55 smaller than the width W 'of the remainder of the anode lead tape 84 , In 16 lead the triangular notches 54 and 55 to a non-uniform width E in the notch area N, and thus the width E, as in 16 described on the smallest width of the anode connection tape 84 in the notch area N along the length L '.

Yet another embodiment of a plan view of a capacitor element 1700 is in 17 shown. A step-shaped notch 56 is formed in the notch area N. The score 56 is located on an X-axis facing surface 71 of the anode connection tape 84 , The notch is at a distance F from the porous anode body 33 along the second part L of the anode terminal strip 84 away. Again, because of the removal of material from the anode connection tape 84 for the formation of the step-shaped notch 56 the material density of the anode connection tape 84 in the notch area N smaller than the material density of the anode lead tape 84 along the remainder of the second part L of the anode terminal strip 84 , Furthermore, the width E of the anode connection tape 84 at the notch 56 smaller than the width W 'of the remainder of the anode lead tape 84 , In 17 leads the step-shaped notch 56 to a non-uniform width E in the notch area N, and thus the width E, as in 17 described on the smallest width of the anode connection tape 84 in the notch area N.

While the 14 - 17 show various embodiments of a capacitor element in which the notches on the X-axis facing surfaces of the anode terminal strip are formed, which show 18 - 21 Various embodiments of a capacitor element, wherein the notches on the Y-axis facing surfaces of the anode terminal strip are formed. We first refer to 18 showing a side view of a capacitor element 800 shows that an anode connection tape 84 having. In the notch area N is a square notch 57 educated. The score 57 is located on a surface facing the Y-axis 72 of the anode connection tape 84 , The notch is at a distance F from the porous anode body 33 along the second part L of the anode terminal strip 84 away. Because of the removal of material from the anode connection tape 84 to the formation of the square notch 57 is the material density of the anode connection tape 84 in the notch area N smaller than the material density of the anode lead tape 84 along the remainder of the second part L of the anode terminal strip 84 , In addition, the thickness / height G of the anode connection tape 84 at the notch 57 smaller than the thickness / height H 'of the remainder of the anode lead tape 84 ,

Another embodiment of a side view of a capacitor element 1900 is in 19 shown. Two rectangular notches 58 and 59 are formed in the notch area N. The score 58 is located on a surface facing the Y-axis 72 , and the score 59 is located on a surface facing the Y-axis 73 of the anode lead tape, so that the anode lead tape in the notch region N is symmetrical. The notches are at a distance F from the porous anode body 33 along the second part L of the anode terminal strip 84 away. Again, because of the removal of material from the anode connection tape 84 for the formation of rectangular notches 58 and 59 the material density of the anode connection tape 84 in the notch area N smaller than the material density of the anode lead tape 84 along the remainder of the second part L of the anode terminal strip 84 , In addition, the thickness / height G of the anode connection tape 84 at the notches 58 and 59 smaller than the thickness / height H 'of the remainder of the anode lead tape 84 ,

Yet another embodiment of a plan view of a capacitor element 2000 is in 20 shown. Two triangular notches 60 and 61 are formed in the notch area N. The score 60 is located on a surface facing the Y-axis 72 , and the score 61 is located on a surface facing the Y-axis 73 of the anode connection tape 84 such that the anode terminal strip in the notch area N is symmetrical. The notches are at a distance F from the porous anode body 33 along the second part L of the anode terminal strip 84 away. Again, because of the removal of material from the anode connection tape 84 for the formation of triangular notches 60 and 61 the material density of the anode connection tape 84 in the notch area N smaller than the material density along the remainder of the second part L of the anode lead tape 84 , Furthermore, the thickness / height G of the anode connection tape is 84 at the notches 60 and 61 smaller than the thickness / height H 'of the remainder of the anode lead tape 84 , In 20 lead the triangular notches 60 and 61 to a nonuniform thickness / height G in the notch area N, and thus the thickness / height G as referred to in FIG 20 to the smallest thickness / height in the notch area N.

Yet another embodiment of a plan view of a capacitor element 2100 is in 21 shown. A step-shaped notch 62 is formed in the notch area N. The score 62 is located on a surface facing the Y-axis 71 of the anode connection tape 84 , The notch is at a distance F from the porous anode body 33 along the second part L removed. Again, because of the removal of material from the anode connection tape 84 for the formation of the step-shaped notch 62 the material density of the anode connection tape 84 in the notch area N smaller than the material density along the remainder of the second part L of the anode lead tape 84 , Furthermore, the thickness / height G of the anode connection tape is 84 at the notch 62 smaller than the thickness / height H 'of the remainder of the anode lead tape 84 , In 21 leads the step-shaped notch 62 to a nonuniform thickness / height G in the notch area N, and thus the thickness / height G as referred to in FIG 21 to the lowest thickness / height of the anode lead strap 84 in the notch area N.

We now turn to the separate components of the capacitor element. The porous anode body 33 is typically formed from a high specific charge valve metal composition such as 5000 μF x V / g or more, in some embodiments about 10,000 μF x V / g or more, in some embodiments about 20,000 μF x V / g or more , As noted, the terminal assembly of the present invention may be particularly well suited for "high specific charge" powders which shrink and often pull away from the leads frequently and to a greater extent than lower specific charge powders during sintering. Such powders typically have a specific charge of from about 20,000 to about 600,000 μF · V / g, in some embodiments from about 40,000 to about 500,000 μF · V / g, in some embodiments from about 70,000 to about 400,000 μF · V / g, about 100 in some embodiments 000 to about 350,000 μF * V / g, and in some embodiments, about 150,000 to about 300,000 μF * V / g. The valve metal composition includes a valve metal (ie, a metal capable of oxidation) or a valve metal-based compound such as tantalum, niobium, aluminum, hafnium, titanium, alloys thereof, oxides thereof, nitrides thereof, etc. For example the valve metal composition includes an electrically conductive oxide of niobium, such as a niobium oxide having an atomic ratio of niobium to oxygen of 1: 1.0 ± 1.0, in some embodiments 1: 1.0 ± 0.3, in some embodiments 1: 1 , 0 ± 0.1 and in some embodiments 1: 1.0 ± 0.05. The niobium oxide may be, for example, NbO _0.7 , NbO _1.0 , NbO _1.1 and NbO ₂ . In a preferred embodiment, the composition contains NbO _1.0 , a conductive niobium oxide which may remain chemically stable even after sintering at high temperatures. Examples of such valve metal oxides are in the U.S. Patent Nos. 6,322,912 (Fife), 6,391,275 (Fife et al.), 6,416,730 (Fife et al.), 6,527,937 (Fife), 6,576,099 (Kimmel et al.), 6,592,740 (Fife et al.) And 6,639,787 (Kimmel et al.) And 7,220,397 (Kimmel et al.) And U.S. Patent Application Publication Nos. 2005/0019581 (Schnitter), 2005/0103638 (Schnitter et al.), And 2005/0013765 (Thomas et al.), All of which are expressly incorporated herein for all purposes is taken.

To form the anode, a powder of the valve metal composition is generally employed. The powder may contain particles having a variety of shapes, such as spherulitic, angular, flake, etc., as well as mixtures thereof. Particularly suitable powders are tantalum powders available from Cabot Corp. (e.g., fluffy powder C255, fluffy / spherulitic powder TU4D, etc.) and H.C. Starck (eg, NH175 spherulitic powder). Although not required, the powder may be agglomerated using any method known in the art, such as by heat treatment. Also, before the powder is shaped into an anode, it may be mixed with a binder and / or lubricant to ensure that the particles sufficiently adhere to each other when pressed to form the anode body. Then, the resulting powder can be compacted by means of any conventional powder pressing apparatus to form a compact. For example, a mold can be used which is a single-station compacting press containing a die and one or more dies. Alternatively, anodising compacts of the anvil type using only a die and a single die can also be used. Single-station compacting dies are available in several basic types, such as cam, toggle and eccentric or crank presses with different capabilities, such as single acting, double acting, floating mantle die, moving platen, counter punch, auger, punch, hot press, stamping or calibrating.

Regardless of its particular composition, the powder thus becomes the anode lead wire 34 or the anode connection tape 84 that at least part of the assembly is compacted from the compacted body 33 extends away. In a particular embodiment, a die comprising a die having two or more parts (eg, top and bottom) may be used. During use, the parts of the die may be placed side by side so that their walls are substantially aligned to form a mold having the desired shape of the anode. Before, during and / or after the loading of the mold with a certain amount of powder, the connecting wire 34 or the connecting strap 84 be embedded in it. The die may define a single or multiple slots into which the wires or bands may be inserted. If more than one lead wire or ribbon is used, the lead wires or tapes may be placed in close proximity to each other to be connected by sintering, although this is not required. After filling the die with powder and embedding the lead wires and tapes therein, the die can then be closed and subjected to compressive forces by a punch. Typically, the compressive forces are applied in a direction that is either substantially parallel or substantially perpendicular to the length of the anode lead wire or the anode lead wire extending along a longitudinal axis. This forces the particles into close contact with the wires and creates a strong bond between wires and powder.

After pressing, any binder / lubricant present may be removed by heating the compact to a certain temperature (eg, about 150 ° C to about 500 ° C) in vacuo for several minutes. Alternatively, the binder / lubricant may also be removed by contacting the compact with an aqueous solution as described in U.S. Pat U.S. Patent No. 6,197,252 (Bishop et al.), Which is expressly incorporated by reference herein for all purposes. Thereafter, the porous anode body ( 33 ) sintered to form a porous integral mass. In particular, the compact is typically maintained at a temperature of from about 1200 ° C to about 2000 ° C, in some embodiments from about 1300 ° C to about 1900 ° C, and in some embodiments from about 1500 ° C to about 1800 ° C for a period of about 5 minutes to about 100 minutes and in some embodiments about 30 minutes to sintered for about 60 minutes. If desired, sintering may occur in an atmosphere that limits the transfer of oxygen atoms to the anode. For example, sintering may be done in a reducing atmosphere, such as in a vacuum, inert gas, hydrogen, etc. The reducing atmosphere may be under a pressure of about 10 Torr to about 2,000 Torr, in some embodiments about 100 Torr to about 1,000 Torr, and in some embodiments about 100 Torr to about 930 Torr. Mixtures of hydrogen and other gases (eg argon or nitrogen) can also be used.

Once built, a dielectric layer may be formed by anodizing ("anodizing") the sintered anode body. This results in the formation of a dielectric layer that forms over and / or within the pores of the body. For example, an anode of tantalum (Ta) can be anodized to tantalum pentoxide (Ta ₂ O ₅ ). Typically, the anodization is performed by first applying a solution to the anode, such as by immersing the anode in the electrolyte. In general, a solvent is used, such as water (eg, deionized water). In order to enhance the ionic conductivity, a compound which can dissociate in the solvent to form ions can be used. Examples of such compounds are, for example, acids, as described below in relation to the electrolyte. For example, an acid (eg, phosphoric acid) may be from about 0.01% to about 5% by weight, in some embodiments from about 0.05% to about 0.8% by weight, and in In some embodiments, from about 0.1% to about 0.5% by weight of the anodizing solution. If desired, mixtures of acids may also be used.

A current is passed through the anodization solution to form the dielectric layer. The value of the formation voltage corresponds to the thickness of the dielectric layer. For example, the power source may first be operated in the galvanostatic mode until the required voltage is reached. Thereafter, the power source may be switched to a potentiostatic mode to ensure that the desired thickness of the dielectric is formed over the entire surface of the anode. Of course, other known methods can be used, such as potentiostatic pulse or step method. The voltage at which the anodization occurs is typically in the range of about 4 volts to about 250 volts, in some embodiments about 9 volts to about 200 volts, and in some embodiments about 20 volts to about 150 volts. During the oxidation, the anodization solution may be maintained at an elevated temperature, such as 30 ° C or more, in some embodiments, from about 40 ° C to about 200 ° C, and in some embodiments, from about 50 ° C to about 100 ° C. The anodization may also be at ambient or below. The resulting dielectric layer may be formed on a surface of the anode and within its pores.

The capacitor element also contains a solid electrolyte, which acts as a cathode for the capacitor. For example, a solid electrolyte in the form of manganese dioxide can be formed by pyrolytic decomposition of manganese nitrate (Mn (NO ₃ ) ₂ ). Such techniques are for example in U.S. Patent No. 4,945,452 (Sturmer et al.), To which express reference is made for all purposes.

wobei
T = O oder S ist;
D ein gegebenenfalls substituierter C₁- bis C₅-Alkylenrest (z. B. Methylen, Ethylen, n-Propylen, n-Butylen, n-Pentylen usw.) ist;
R₇ Folgendes ist: ein linearer oder verzweigter, gegebenenfalls substituierter C₁ bis C₁₈-Alkylrest (z. B. Methyl, Ethyl, n-Propyl oder Isopropyl, n-, iso-, sek- oder tert-Butyl, n-Pentyl, 1-Methylbutyl, 2-Methylbutyl, 3-Methylbutyl, 1-Ethylpropyl, 1,1-Dimethylpropyl, 1,2-Dimethylpropyl, 2,2-Dimethylpropyl, n-Hexyl, n-Heptyl, n-Octyl, 2-Ethylhexyl, n-Nonyl, n-Decyl, n-Undecyl, n-Dodecyl, n-Tridecyl, n-Tetradecyl, n-Hexadecyl, n-Octadecyl usw.); ein gegebenenfalls substituierter C₅- bis C₁₂-Cycloalkylrest (z. B. Cyclopentyl, Cyclohexyl, Cycloheptyl, Cyclooctyl, Cyclononyl, Cyclodecyl usw.); ein gegebenenfalls substituierter C₆- bis C₁₄-Arylrest (z. B. Phenyl, Naphthyl usw.); ein gegebenenfalls substituierter C₇- bis C₁₈-Aralkylrest (z. B. Benzyl, o-, m-, p-Tolyl, 2,3-, 2,4-, 2,5-, 2,6, 3,4-, 3,5-Xylyl, Mesityl usw.); ein gegebenenfalls substituierter C₁- bis C₄-Hydroxyalkylrest oder ein Hydroxyrest; und
q eine ganze Zahl von 0 bis 8, in einigen Ausführungsformen 0 bis 2 und in einer Ausführungsform 0 ist; und
n = 2 bis 5000, in einigen Ausführungsformen 4 bis 2000 und in einigen Ausführungsformen 5 bis 1000 ist. Beispiele für Substituenten für die Reste ”D” oder ”R₇” sind zum Beispiel Alkyl, Cycloalkyl, Aryl, Aralkyl, Alkoxy, Halogen, Ether, Thioether, Disulfid, Sulfoxid, Sulfon, Sulfonat, Amino, Aldehyd, Keto, Carbonsäureester, Carbonsäure, Carbonat, Carboxylat, Cyano, Alkylsilan- und Alkoxysilangruppen, Carboxylamidgruppen usw.Alternatively, the solid electrolyte may also be formed from one or more conductive polymer layers. The conductive polymers used in such layers are typically π-conjugated and exhibit electrical conductivity after oxidation or reduction, such as electrical conductivity of at least about 1 μS · cm ^-1 after oxidation. Examples of such π-conjugated conductive polymers are, for example, polyheterocycles (eg, polypyrroles, polythiophenes, polyanilines, etc.), polyacetylenes, poly-p-phenylenes, polyphenolates, etc. Particularly suitable conductive polymers are substituted polythiophenes having the following general structure :

in which
T = O or S;
D is an optionally substituted C ₁ to C ₅ alkylene radical (eg, methylene, ethylene, n-propylene, n-butylene, n-pentylene, etc.);
R ₇ is: a linear or branched, optionally substituted C ₁ to C ₁₈ alkyl radical (for example methyl, ethyl, n-propyl or isopropyl, n-, iso-, sec- or tert-butyl, n-pentyl , 1-methylbutyl, 2-methylbutyl, 3 Methylbutyl, 1-ethylpropyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n- Undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, etc.); an optionally substituted C ₅ to C ₁₂ cycloalkyl group (e.g., cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, etc.); an optionally substituted C ₆ to C ₁₄ aryl radical (eg, phenyl, naphthyl, etc.); an optionally substituted C ₇ to C ₁₈ aralkyl radical (eg, benzyl, o-, m-, p-tolyl, 2,3-, 2,4-, 2,5-, 2,6, 3,4 -, 3,5-xylyl, mesityl, etc.); an optionally substituted C ₁ to C ₄ hydroxyalkyl radical or a hydroxy radical; and
q is an integer from 0 to 8, in some embodiments 0 to 2 and in one embodiment 0; and
n = 2 to 5,000, in some embodiments 4 to 2,000, and in some embodiments 5 to 1,000. Examples of substituents for the radicals "D" or "R ₇ " are, for example, alkyl, cycloalkyl, aryl, aralkyl, alkoxy, halogen, ether, thioether, disulfide, sulfoxide, sulfone, sulfonate, amino, aldehyde, keto, carboxylic acid ester, carboxylic acid , Carbonate, carboxylate, cyano, alkylsilane and alkoxysilane groups, carboxylamide groups, etc.

Particularly suitable thiophene polymers are those in which "D" is an optionally substituted C ₂ - to C ₃ -alkylene radical. For example, the polymer may optionally be substituted poly (3,4-ethylenedioxythiophene) having the general structure:

wobei
T, D, R₇ und q wie oben definiert sind. Besonders gut geeignete Thiophenmonomere sind solche, bei denen ”D” ein gegebenenfalls substituierter C₂- bis C₃-Alkylenrest ist. Zum Beispiel können gegebenenfalls substituierte 3,4-Alkylendioxythiophene eingesetzt werden, die die folgende allgemeine Struktur haben:

wobei R₇ und q wie oben definiert sind. In einer besonderen Ausführungsform ist ”q” = 0. Ein kommerziell geeignetes Beispiel für 3,4-Ethylendioxythiophen ist von der Heraeus Clevios unter der Bezeichnung Clevios M erhältlich. Weitere geeignete Monomere sind auch im US-Patent Nr. 5,111,327 (Blohm et al.) und 6,635,729 (Groenendahl et al.) beschrieben, auf die hier ausdrücklich für alle Zwecke Bezug genommen wird. Derivate dieser Monomere, die zum Beispiel Dimere oder Trimere der obigen Monomere sind, können ebenfalls eingesetzt werden. Höhermolekulare Derivate, d. h. Tetramere, Pentamere usw., der Monomere sind zur Verwendung in der vorliegenden Erfindung geeignet. Die Derivate können aus gleichen oder verschiedenen Monomereinheiten bestehen und können in reiner Form oder in einem Gemisch miteinander und/oder mit den Monomeren verwendet werden. Oxidierte oder reduzierte Formen dieser Vorläufer können ebenfalls eingesetzt werden.Methods of forming conductive polymers such as those described above are well known in the art. For example, that describes U.S. Patent No. 6,987,663 (Merker et al.), Which is hereby expressly incorporated by reference for all purposes, various techniques for forming substituted polythiophenes from a monomeric precursor. The monomeric precursor may, for example, have the following structure:

in which
T, D, R ₇ and q are as defined above. Particularly suitable thiophene monomers are those in which "D" is an optionally substituted C ₂ - to C ₃ -alkylene radical. For example, optionally substituted 3,4-alkylenedioxythiophenes having the general structure:

wherein R ₇ and q are as defined above. In a particular embodiment, "q" = 0. A commercially suitable example of 3,4-ethylenedioxythiophene is available from Heraeus Clevios under the name Clevios M. Other suitable monomers are also in U.S. Patent No. 5,111,327 (Blohm et al.) And 6,635,729 (Groenendahl et al.), Which are expressly incorporated by reference herein for all purposes. Derivatives of these monomers, which are, for example, dimers or trimers of the above monomers, can also be used. Higher molecular weight derivatives, ie, tetramers, pentamers, etc., of the monomers are suitable for use in the present invention. The derivatives may be the same or different Monomer units exist and may be used in pure form or in admixture with each other and / or with the monomers. Oxidized or reduced forms of these precursors can also be used.

The thiophene monomers are chemically polymerized in the presence of an oxidative catalyst. The oxidative catalyst typically comprises a transition metal cation such as iron (III), copper (II), chromium (VI), cerium (IV), manganese (IV), manganese (VII), ruthenium (III) Cation, etc. A dopant may also be employed to impart excess charge to the conductive polymer and to stabilize the conductivity of the polymer. The dopant typically comprises an inorganic or organic anion, such as an ion of a sulfonic acid. In certain embodiments, the oxidative catalyst employed in the precursor solution has both catalytic and doping functionality in that it contains a cation (eg, transition metal) and an anion (eg, sulfonic acid). The oxidative catalyst may be, for example, a transition metal salt containing iron (III) cations, such as ferric halides (eg, FeCl ₃ ) or iron (III) salts of other inorganic acids, such as Fe (ClO ₄ ) ₃ or Fe ₂ (SO ₄ ) ₃ , and the ferric salts of organic acids and inorganic acids comprising organic radicals. Examples of iron (III) salts of inorganic acids with organic radicals are, for example, iron (III) salts of sulfuric acid monoesters of C ₁ to C ₂₀ alkanols (for example the iron (III) salt of lauryl sulfate). Likewise, examples of iron (III) salts of organic acids are, for example, iron (III) salts of C ₁ to C ₂₀ alkanesulfonic acids (eg methane, ethane, propane, butane or dodecane sulfonic acid); Iron (III) salts of aliphatic perfluorosulfonic acids (eg trifluoromethanesulfonic acid, perfluorobutanesulfonic acid or perfluorooctanesulfonic acid); Iron (III) salts of aliphatic C ₁ to C ₂₀ carboxylic acids (eg 2-ethylhexylcarboxylic acid); Ferric salts of aliphatic perfluorocarboxylic acids (eg, trifluoroacetic acid or perfluorooctanoic acid); Ferric salts of aromatic sulfonic acids optionally substituted with C ₁ to C ₂₀ alkyl groups (for example, benzenesulfonic acid, o-toluenesulfonic acid, p-toluenesulfonic acid or dodecylbenzenesulfonic acid); Ferric salts of cycloalkanesulfonic acids (eg, camphorsulfonic acid); etc. Mixtures of these above-mentioned ferric salts may also be used. Iron (III) p-toluenesulfonate, iron (III) o-toluenesulfonate and mixtures thereof are particularly well suited. A commercially suitable example of iron (III) p-toluenesulfonate is available from Heraeus Clevios under the name Clevios ^™ C.

Various methods can be used to form a conductive polymer layer. In one embodiment, the oxidative catalyst and the monomer are applied either sequentially or together so that the polymerization reaction takes place in situ on the part. Suitable application techniques include screen printing, dip coating, electrophoretic coating and spray coating; they can be used to form a conductive polymer coating. As an example, the monomer may be first mixed with the oxidative catalyst to form a precursor solution. Once the mixture is formed, it can be applied and polymerized to form the conductive coating on the surface. Alternatively, the oxidative catalyst and the monomer may also be applied sequentially. For example, in one embodiment, the oxidative catalyst is dissolved in an organic solvent (eg, butanol) and then applied as a dipping solution. The part may then be dried to remove the solvent therefrom. Thereafter, the part may be immersed in a solution containing the monomer.

The polymerization is typically conducted at temperatures of about -10 ° C to about 250 ° C, and in some embodiments about 0 ° C to about 200 ° C, depending on the oxidant used and the desired reaction time. Suitable polymerization techniques, as described above, are more fully described in U.S. Pat U.S. Patent No. 7,515,396 (Biler) described. Still other methods of applying one or more of such conductive polymer coatings are described in U.S. Pat U.S. Pat. Nos. 5,457,862 (Sakata et al.), 5,473,503 (Sakata et al.), 5,729,428 (Sakata et al.) And 5,812,367 (Kudoh et al.), Which is hereby expressly incorporated by reference.

In addition to in situ application, a conductive polymer layer can also be applied in the form of a dispersion of conductive polymer particles. Although their size may vary, it is typically desirable for the particles to have a small diameter in order to increase the surface area available for attaching the anode part. For example, the particles may have a mean diameter of about 1 to about 500 nanometers, in some embodiments about 5 to about 400 nanometers, and in some embodiments, about 10 to about 300 nanometers. The D ₉₀ value of the particles (particles having a diameter less than or equal to D ₉₀ value constitute 90% of the total volume of all solid particles) may be about 15 micrometers or less, in some embodiments, about 10 microns or less, and in some embodiments from about 1 Nanometers to about 8 microns. The diameter of the particles can be determined by known techniques such as ultracentrifuge, laser diffraction, etc.

The processing of the conductive polymer into a particulate form can be enhanced by using a separate counterion to counteract the positive charge carried by the substituted polythiophene. In some cases, the polymer may have positive and negative charges in the structural unit, with the positive charge on the main chain and the negative charge optionally on the substituents of the radical "R", such as sulfonate or carboxylate groups. The positive charges of the main chain can be partially or completely saturated with the optionally present anionic groups on the radicals "R". Overall, the polythiophenes in these cases can be cationic, neutral or even anionic. Nevertheless, they are all considered cationic polythiophenes because the polythiophene backbone carries a positive charge.

The counterion may be a monomeric or polymeric anion. Polymeric anions may be, for example, anions of polymeric carboxylic acids (eg, polyacrylic acids, polymethacrylic acid, polymaleic acids, etc.), polymeric sulfonic acids (eg, polystyrenesulfonic acids ("PSS"), polyvinylsulfonic acids, etc.), etc. The acids may also be copolymers such as copolymers of vinylcarboxylic and vinylsulfonic acid with other polymerizable monomers such as acrylic esters and styrene. Likewise, suitable monomeric anions are, for example, anions of C ₁ to C ₂₀ alkanesulfonic acids (eg dodecanesulfonic acid); aliphatic perfluorosulfonic acids (eg trifluoromethanesulfonic acid, perfluorobutanesulfonic acid or perfluorooctanesulfonic acid); aliphatic C ₁ to C ₂₀ carboxylic acids (eg, 2-ethylhexylcarboxylic acid); aliphatic perfluorocarboxylic acids (eg, trifluoroacetic acid or perfluorooctanoic acid); aromatic sulfonic acids optionally substituted with C ₁ to C ₂₀ alkyl groups (for example, benzenesulfonic acid, o-toluenesulfonic acid, p-toluenesulfonic acid or dodecylbenzenesulfonic acid); Cycloalkanesulfonic acids (eg, camphorsulfonic acid or tetrafluoroborates, hexafluorophosphates, perchlorates, hexafluoroantimonates, hexafluoroarsenates or hexachloroantimonates); etc. Particularly suitable counterions are polymeric anions, such as a polymeric carboxylic or sulfonic acid (eg, polystyrene sulfonic acid ("PSS")). The molecular weight of such polymeric anions is typically in the range of about 1,000 to about 2,000,000, and in some embodiments, about 2,000 to about 500,000.

When employed, the weight ratio of such counterions to substituted polythiophenes in a given layer is typically from about 0.5: 1 to about 50: 1, in some embodiments from about 1: 1 to about 30: 1, and in some embodiments about 2: 1 until about 20: 1. The weight of the substituted polythiophene referred to in the above weight ratios refers to the weighed portion of the monomers used, assuming complete reaction takes place during the polymerization.

The dispersion may also contain one or more binders to further enhance the adhesive nature of the polymeric layer and also increase the stability of the particles within the dispersion. The binders may be of organic nature, such as polyvinyl alcohols, polyvinylpyrrolidones, polyvinyl chlorides, polyvinyl acetates, polyvinyl butyrates, polyacrylic acid esters, polyacrylic acid amides, polymethacrylic acid esters, polymethacrylic acid amides, polyacrylonitriles, styrene / acrylic acid esters, vinyl acetate / acrylic esters and ethylene / vinyl acetate copolymers, polybutadienes, polyisoprenes, polystyrenes, polyethers, Polyesters, polycarbonates, polyurethanes, polyamides, polyimides, polysulfones, melamine-formaldehyde resins, epoxy resins, silicone resins or celluloses. Crosslinking agents can also be used to increase the adhesiveness of the binders. Such crosslinking agents are, for example, melamine compounds, masked isocyanates or functional silanes, such as 3-glycidoxypropyltrialkoxysilane, tetraethoxysilane and tetraethoxysilane hydrolyzate or crosslinkable polymers, such as polyurethanes, polyacrylates or polyolefins, and subsequent crosslinking. There may also be other ingredients in the dispersion as known in the art, such as dispersants (eg, water), surfactants, etc.

If desired; For example, one or more of the application steps described above may be repeated until the desired thickness of the coating is achieved. In some embodiments, only a relatively thin layer of the coating is formed each time. The desired overall thickness of the coating may generally vary depending on the desired properties of the capacitor. Typically, the resulting conductive polymer coating has a thickness of from about 0.2 microns ("μm") to about 50 μm, in some embodiments from about 0.5 μm to about 20 μm, and in some embodiments from about 1 μm to about 5 μm. It should be understood that the thickness of the coating is not necessarily the same at all points in the anode part. Nevertheless, the average thickness of the coating on the substrate generally falls within the above ranges.

The conductive polymer layer may optionally be patched. The patching may be done after each application of a conductive polymer layer, or it may be done after the application of the entire coating. In some embodiments, the conductive polymer can be patched by placing the part in FIG immersing an electrolyte solution and then applying a constant voltage to the solution until the current is reduced to a preselected level. If desired, this patching can also be accomplished in several steps. For example, an electrolyte solution may be a dilute solution of the monomer, catalyst, and dopant in an alcohol solvent (eg, ethanol). Optionally, the coating may also be laundered to remove various by-products, excess reagents, etc.

If desired, the capacitor may also include other layers as known in the art. For example, a protective coating, such as a relatively insulating resinous material (natural or synthetic) may optionally be formed between the dielectric and the solid electrolyte. Such materials may have a resistivity of greater than about 10 ohm.cm, more than about 100 in some embodiments, more than about 1000 ohm.cm in some embodiments, more than about 1 x 10 ⁵ ohm.cm in some embodiments, and In some embodiments, more than about 1 × 10 ¹⁰ Ω · cm. Some resinous materials that can be used in the present invention include polyurethane, polystyrene, esters of unsaturated or saturated fatty acids (eg, glycerides), etc. Suitable esters of fatty acids include, for example, esters of lauric acid, Myristic acid, palmitic acid, stearic acid, eleostearic acid, oleic acid, linoleic acid, linolenic acid, aleuritic acid, schellolic acid, etc. These esters of fatty acids have been found to be particularly useful when used in relatively complex combinations to form a "drying oil" which makes up the resulting Film allows to polymerize quickly to a stable layer. These drying oils include, for example, mono-, di- and / or triglycerides which have a glycerol backbone with one, two or three fatty acyl residues which are esterified. Some suitable drying oils which may be used include, for example, olive oil, linseed oil, castor oil, tung oil, soybean oil and shellac. These and other protective coating materials are more detailed in the U.S. Patent No. 6,674,635 (Fife et al.), Which is expressly incorporated by reference herein for all purposes.

It is also possible to apply a carbon layer (eg graphite) or a silver layer to the anode part. For example, the silver coating may act as a solderable conductor, contact layer, and / or charge collector for the capacitor, and the carbon coating may limit the contact of the silver coating with the solid electrolyte. Such coatings may cover part or all of the solid electrolyte.

As a result of the present invention, a capacitor having excellent electrical characteristics can be formed. For example, the capacitor of the present invention may have an extremely low ESR, such as 300 milliohms (mΩ) or less, about 100 milliohms or less in some embodiments, about 0.01 to about 50 milliohms in some embodiments, and about 0 in some embodiments. 1 to about 20 mΩ, determined at a frequency of 100 kHz and a temperature of 23 ° C ± 2 ° C. In addition, a conductor flows through an insulator to an adjacent conductor, kept at relatively low levels. For example, in some embodiments, the numerical value of the normalized leakage current of a capacitor of the present invention is less than about 0.1 μA / μF * V, in some embodiments less than about 0.01 μA / μF * V, and less than about 0.001 in some embodiments μA / μF · V, where "μA" means microampere and "μF · V" is the product of the capacitance and the rated voltage.

test method

Equivalent series resistance ("ESR")

"ESR" generally refers to the extent to which the capacitor acts as a resistor when charged and discharged in an electronic circuit, and is usually expressed as a resistor connected in series with the capacitor. The ESR is typically used with a Keithley 3330 precision LCZ meter with Kelvin leads at 2.2 volts bias and a 0.5 volt sinusoidal signal between the peaks at an operating frequency of 100 kHz and a temperature of 23 ° C ± 2 ° C measured.

Capacity ("KAP")

The capacitance was measured on a Keithley 3330 precision LCZ meter with Kelvin leads at 2.2 volts bias and a 0.5 volt sinusoidal signal between the peaks. The operating frequency was 120 Hz and the temperature was 23 ° C ± 2 ° C.

leakage current

The leakage current ("DCL") was measured with a leakage current tester, which measures the leakage current at a temperature of 23 ° C ± 2 ° C and the rated voltage after at least 30 seconds.

laser welding

Laser welding was performed using a Trumpf Nd: YAG HAAS laser (which emitted in the near infrared at a wavelength of about 1064 nanometers). The energy for welding generally refers to the amount of laser energy required to connect the anode lead to the anode termination / lead frame. The energy for welding is given in Joule.

example 1

A 70,000 μFV / g tantalum powder was pressed into compacts to form porous bodies of 1.80 mm (length), 2.40 mm (width) and 1.20 mm (thickness). The tantalum powder was placed in the funnel of an automatic tantalum molding machine and automatically automatically molded together with a 0.40 mm width / diameter tantalum wire (Example 1) to make a porous body. The penetration depth of the wire was 70% of the anode length. This molded body was allowed to stand under reduced pressure at 1300 ° C to obtain a sintered body.

The porous sintered tantalum was welded to an auxiliary stainless steel strip when the anode lead was notched during loading by a punch in the particular area important for bonding the lead to the leadframe. The reduced area had a width / diameter of 0.22 mm.

The tantalum anode was anodized in a liquid electrolyte in the form of 0.1% phosphoric acid at 14 V to produce 150 μF capacitors at 120 Hz. Then, a conductive polymer coating was formed by immersing the tantalum anode in a butanol solution of ferric toluenesulfonate (Clevios ^™ C, HC Starck) for 5 minutes and then in 3,4-ethylenedioxythiophene (Clevios M, HC Starck) for 1 minute , After 45 minutes of polymerization, a thin layer of poly (3,4-ethylenedioxythiophene) formed on the surface of the dielectric. The parts were washed in methanol to remove by-products of the reaction, anodized in a liquid electrolyte and washed again in methanol. The polymerization cycle was repeated ten times. The finished parts were completed and measured by conventional assembly technology. A copper-based lead frame was used to complete the assembly process. The capacitor element was attached via a laser welding process so that the anode lead wire was bonded to the anode end portion. The energy used to score and weld the wire was set at 8.6 joules.

Then, the lead frame was sealed with epoxy embedding resin.

Comparative Examples 1A-1B Capacitors were formed in the manner described in Example 1 except that an additional punching device was used to score the wires. For the comparative examples, the tantalum powder was molded together with a tantalum wire of either 0.17 mm width / diameter (Example 1A) or 0.40 mm width / diameter (Example 1B). Many parts (1250) were made as described and then tested for electrical properties (ie ESR and capacitance). Table 1 summarizes the diameters of the tantalum wires, the laser welding settings, and the median capacitance and ESR values of finished capacitors from Example 1 and Comparative Examples 1A-1B. Ta wire, diameter [mm] Ta wire, notch area, diameter [mm] Laser welding energy [3] DCL [μA] Cape [μF] ESR [mΩ] example 1 0.40 0.22 8.6 2.63 138.3 36.8 Comparative Example 1A 0.17 0.17 6.0 1.47 145.2 45.1 Comparative Example 1B 0.40 0.40 26.0 deleted deleted deleted Table 1

Example 2

A 70,000 μFV / g tantalum powder was pressed into compacts to form porous bodies of 4.20 mm (length), 3.60 mm (width) and 0.95 mm (thickness). The tantalum powder was placed in the funnel of an automatic tantalum molding machine and automatically automatically molded together with a tantalum wire of 0.50 mm width / diameter (Example 2) to make a porous body. The penetration depth of the wire was 70% of the anode length. This molded body was allowed to stand under reduced pressure at 1300 ° C to obtain a sintered body.

The porous sintered tantalum was welded to an auxiliary stainless steel strip. Thereafter, the anode lead was notched by sawing with a diamond blade (Kulicke & Soffa Precision Saw). The thickness of the diamond blade was 1.0 millimeter, and the cut was made in the specific area important for bonding the lead wire to the lead frame. The reduced area had a width / diameter of 0.33 mm.

The tantalum anode was anodized in a liquid electrolyte in the form of 0.1% phosphoric acid at 13 V to produce 330 μF capacitors at 120 Hz. A conductive polymer coating was then formed by placing the tantalum anode in a butanol solution of ferric toluenesulfonate (Clevios ^™ C, HC Starck) for 5 minutes and then in 3,4-ethylenedioxythiophene (Clevios ^™ M, HC Starck) for 1 minute. dipped. After 45 minutes of polymerization, a thin layer of poly (3,4-ethylenedioxythiophene) formed on the surface of the dielectric. The parts were washed in methanol to remove by-products of the reaction, anodized in a liquid electrolyte and washed again in methanol. The polymerization cycle was repeated ten times. The finished parts were completed and measured by conventional assembly technology. A copper-based lead frame was used to complete the assembly process. The capacitor element was attached via a laser welding process so that the anode lead wire was bonded to the anode end portion. The energy used to score and weld the wire was set at 16.0 joules. Then, the lead frame was sealed with epoxy embedding resin.

Comparative Examples 2A-2B

Capacitors were formed in the manner described in Example 2, except that an additional sawing device was used to score the wires. For the comparative examples, the tantalum powder was molded together with a tantalum wire of 0.24 mm width (Example 2A) and 0.50 mm width (Example 2B). Many parts (900) were made in the manner described and then tested for electrical properties (i.e., ESR and capacitance).

Table 2 summarizes the diameters of the tantalum wires, the settings for laser welding, and the median values of capacitance and ESR of finished capacitors from Example 2 and Comparative Examples 2A-2B. Ta wire, diameter [mm] Ta wire, notch area, diameter [mm] Laser welding energy [J] DCL [μA] Cape [μF] ESR [mΩ] Example 2 0.50 0.33 16.0 17.2 301.4 18.1 Comparative Example 2A 0.24 0.24 10.5 14.8 321.2 29.2 Comparative Example 2B 0.50 0.50 32.0 deleted deleted deleted Table 2

Example 3

A 40,000 μFV / g tantalum powder was pressed into compacts to form porous bodies having a size of 5.20 mm (length), 3.70 mm (width) and 0.95 mm (thickness). The tantalum powder was placed in the funnel of an automatic tantalum molding machine and automatically automatically molded together with a tantalum wire of 0.50 mm width (Example 3) to make a porous body. The penetration depth of the wire was 70% of the anode length. This molded body was allowed to stand under reduced pressure at 1450 ° C to obtain a sintered body.

The porous sintered tantalum was welded to an auxiliary stainless steel strip. Thereafter, the anode lead was notched by a scanning laser (Trumpf TruMark Laser). The working range was 1.0 millimeter, each laser pulse was 0.2 milliseconds, and the power was set to 50 millijoules. The erosion occurred in the specific area that is important for bonding the lead wire to the lead frame. The reduced area had a width / diameter of 0.30 mm.

The tantalum anode was anodized in a liquid electrolyte in the form of 0.1% phosphoric acid at 18 V to produce 150 μF capacitors at 120 Hz. Then, a conductive polymer coating was formed by immersing the tantalum anode in a butanol solution of ferric toluenesulfonate (Clevios C, HC Starck) for 5 minutes and then in 3,4-ethylenedioxythiophene (Clevios ^™ M, HC Starck) for 1 minute , After 45 minutes of polymerization, a thin layer of poly (3,4-ethylenedioxythiophene) formed on the surface of the dielectric. The parts were washed in methanol to remove by-products of the reaction, anodized in a liquid electrolyte and washed again in methanol. The polymerization cycle was repeated ten times. The finished parts were completed and measured by conventional assembly technology. A copper-based lead frame was used to complete the assembly process. The capacitor element was attached via a laser welding process, which was necessary to bond the anode lead wire to the anode end part. The energy used to score and weld the wire was set at 15.0 joules. Then, the lead frame was sealed with epoxy embedding resin.

Comparative Examples 3A-3B

Capacitors were formed in the manner described in Example 3 except that an additional laser device was used to score the wires. For the comparative examples, the tantalum powder was molded together with a tantalum wire 0.19 mm wide (Example 3A) and 0.50 mm wide (Example 3B). Many parts (900) were made in the manner described and then tested for electrical properties (i.e., ESR and capacitance).

Table 3 summarizes the diameters of the tantalum wires, the laser welding settings, and the median capacitance and ESR values of finished capacitors from Example 3 and Comparative Examples 3A-3B. Ta wire, diameter [mm] Ta wire, notch area, diameter [mm] Laser welding energy [J] DCL [μA] Cape [μF] ESR [mΩ] Example 3 0.50 0.30 15.0 12.4 144.3 11.2 Comparative Example 3A 0.19 0.19 8.2 4.5 152.6 21.4 Comparative Example 3B 0.50 0.50 32.0 deleted deleted deleted Table 3

As shown in Tables 1, 2 and 3, the benefit of using a notched wire is in better ESR values and lower energy for welding as compared to the comparative examples which had the same total wire diameter. Electrical data for Comparative Examples B are not available because laser welding was not possible (there is not much material on the side of the leadframe to perform the welding operation, and all the capacitors had the circuit broken after the assembly process).

Example 4

A 40,000 μFV / g tantalum powder was pressed into compacts to form porous bodies of 5.20 mm (length), 3.70 mm (width), and 0.90 mm (height / thickness). The tantalum powder was placed in the funnel of an automatic tantalum molding machine and automatically automatically molded together with a tantalum ribbon of 1.50 mm (width) and 0.35 mm (height / thickness) to make a porous body. The penetration depth of the tape was 70% of the anode length. This molded body was allowed to stand under reduced pressure at 1450 ° C to obtain a sintered body.

The porous sintered tantalum body was welded to an auxiliary stainless steel strip as the anode terminal strip was scored during loading with a punch in the particular area important for bonding the terminal wire to the leadframe. The reduced area had a width of 1.00 mm.

The tantalum anode was not processed. A copper-based leadframe was used to simulate the assembly process. The capacitor element was fixed by a laser welding method so that the anode terminal tape was bonded to the anode end portion. Then, the ESR contribution was measured by a suitable method (two contacts on the positive end part of the lead frame and two contacts on the sintered but not formed anode body).

Comparative Examples 4A-4B

Capacitors were formed in the manner described in Example 4, except that an additional punching device was used to score the tapes. For the comparative examples, the tantalum powder was molded together with a tantalum wire of 0.24 mm width (Example 4A) and 0.50 mm width (Example 4B). Many parts ( 90 ) were prepared in the manner described and then also tested for their electrical properties. Table 4 summarizes the diameters of the tantalum wires / tapes and the median values of ESR of Example 4 compared to Comparative Examples 4A-4B. Ta Wire Diameter / Tape Height × Width [mm] Ta wire diameter / tape notch height × width [mm] ESR [mΩ] Example 4 0.35 x 1.50 0.35 × 1.00 3.3 Comparative Example 4A 0.24 0.24 9.8 Comparative Example 4B 0.50 0.50 4.8 Table 4

Example 5

A tantalum powder of 70,000 μFV / g was pressed into compacts to form porous bodies having a size of 1.80 mm (length), 2.40 mm (width) and 1.20 mm (height / thickness). The tantalum powder was placed in the funnel of an automatic tantalum molding machine and automatically automatically molded together with a tantalum ribbon of 1.50 mm (width) and 0.15 mm (height / thickness) to make a porous body. The penetration depth of the tape was 70% of the anode length. This molded body was allowed to stand under reduced pressure at 1300 ° C to obtain a sintered body.

The porous sintered tantalum body was welded to an auxiliary stainless steel strip as the anode terminal strip was scored during loading with a punch in the particular area important for bonding the terminal wire to the leadframe. The reduced area had a width of 1.00 mm.

The measurement of the ESR was carried out in the manner described in Example 4.

Comparative Examples 5A-5B

Capacitors were formed in the manner described in Example 5, except that an additional punching device was used to score the tapes. For the comparative examples, the tantalum powder was molded together with a tantalum wire 0.17 mm wide (Example 5A) and 0.50 mm wide (Example 5B). Many parts ( 90 ) were prepared in the manner described and then also tested for their ESR properties. Table 5 summarizes the diameters of the tantalum wires / tapes and the median values of ESR of Example 5 compared to Comparative Examples 5A-5B. Ta Wire Diameter / Tape Height × Width [mm] Ta wire diameter / tape notch height × width [mm] ESR [mΩ] Example 5 0.15 x 1.50 0.15 × 1.00 1.8 Comparative Example 5A 0.17 0.17 12.6 Comparative Example 5B 0.50 0.50 2.9 Table 5

Example 6

A tantalum powder of 150,000 μFV / g was pressed into compacts to form porous bodies having a size of 2.30 mm (length), 2.30 mm (width) and 0.55 mm (height / thickness). The tantalum powder was placed in the funnel of an automatic tantalum molding machine and automatically automatically molded together with a tantalum ribbon of 1.50 mm (width) and 0.15 mm (height / thickness) to make a porous body. The penetration depth of the tape was 70% of the anode length. This molded body was allowed to stand under reduced pressure at 1200 ° C to obtain a sintered body.

The porous sintered tantalum body was welded to an auxiliary stainless steel strip as the anode terminal strip was scored during loading with a punch in the particular area important for bonding the terminal wire to the leadframe. The reduced area had a width of 1.00 mm.

The measurement of the ESR was carried out in the manner described in Example 4.

Comparative Example 6A

Capacitors were formed in the manner described in Example 6, except that an additional punching device was used to score the tapes. For the comparative example, the tantalum powder was molded together with a tantalum wire 0.17 mm wide (Example 6A). Many parts ( 90 ) were prepared in the manner described and then also tested for their ESR properties. Table 6 summarizes the diameters of the tantalum wires / tapes and the median values of ESR from Example 6 compared to Comparative Example 6A. Ta Wire Diameter / Tape Height × Width [mm] Ta wire diameter / tape notch height × width [mm] ESR [mΩ] Example 6 0.15 x 1.50 0.15 × 1.00 8.2 Comparative Example 6A 0.17 0.17 17.6 Table 6

As shown in Tables 4, 5 and 6, the benefit of using a serrated lead or ribbon over an unnotched lead is in better ESR values compared to the comparative examples.

These and other modifications and variations of the present invention may be practiced by those skilled in the art without departing from the spirit and scope of the present invention. In addition, it should be understood that aspects of the various embodiments may be partially or completely interchanged. Furthermore, those skilled in the art will recognize that the above description is merely exemplary in nature and is not intended to limit the invention, which is further described in the appended claims.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

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Claims (19)

A solid electrolytic capacitor comprising a capacitor element, the capacitor element comprising: a sintered porous anode body having a width and a height; an anode terminal portion, the anode terminal portion having a first portion located within the anode body and a second portion extending longitudinally from a surface of the anode body, the second portion having a notched portion at least one notch is located; a dielectric layer covering the sintered porous anode body; and a cathode covering the dielectric layer and comprising a solid electrolyte. The solid electrolytic capacitor according to claim 1, wherein the notched portion is located at a distance from the surface of the anode body such that the ratio of the length of the second portion of the anode terminal to the distance from the surface of the anode body to the location of the notched portion is about 1 , 1 to about 20. The solid electrolytic capacitor according to claim 1 or 2, wherein the notch is rectangular, square, circular, elliptical, triangular, stepped, U-shaped or V-shaped. A solid electrolytic capacitor according to any preceding claim, wherein the anode body is formed of a powder having a specific charge of from about 10,000 μF · V / g to about 600,000 μF · V / g, the powder being a valve metal such as tantalum, niobium, aluminum , Hafnium, titanium, an electrically conductive oxide thereof or an electrically conductive nitride thereof. A solid electrolytic capacitor according to any one of the preceding claims, further comprising an anode end portion electrically connected to the anode terminal, a cathode end portion electrically connected to the cathode, and a molding material embedding the capacitor element and at least a part of Anoden-end portion and exposed at least a portion of the cathode end portion comprises. The solid electrolytic capacitor according to claim 5, wherein the anode terminal wire is welded in the notched area to the anode terminal portion. A method of forming a solid electrolytic capacitor comprising a sintered porous anode body having a width and a height, the method comprising: positioning a first portion of an anode fitting within a powder formed from a valve metal composition such that a second portion of the anode fitting extends longitudinally from a surface of the anode body; compacting the powder around the first part of the anode fitting; sintering the compacted powder and the first part of the anode terminal to form the porous anode body; anodizing the sintered porous anode body to form a dielectric layer; applying a solid electrolyte to the anodized anode sintered body to form a cathode; forming a notched portion in the second part of the anode terminal in which there is at least one notch; and welding the anode terminal to an anode end portion at the notched portion to form an electrical connection between the anode terminal and the anode end portion. The method of claim 7, wherein the notch is formed by a laser, by cutting, punching or sawing. A method according to claim 7 or 8, wherein the welding of the anode terminal part to the anode end part at the notched portion to form an electrical connection between the anode terminal part and the anode end part by laser welding. A method according to any one of claims 7-9, wherein the notch is formed by a laser, and wherein the anode termination is then laser welded to the anode end portion at the notched portion to form an electrical connection between the anode termination and the anode end portion is welded. The method of claim 10, wherein the laser is used at a first energy level to form the notch and then used at a second energy level to weld the anode termination to the anode termination by laser welding. The solid electrolytic capacitor according to claim 1 or the method according to claim 7, wherein the anode terminal is an anode terminal wire having a thickness that is at least about 10% of the height of the porous anode body. The capacitor or method of claim 12, wherein the thickness of the anode lead wire is from about 20 micrometers to about 3800 micrometers. The capacitor or method of claims 12-13, wherein the notched portion has a thickness that is from about 20% to about 90% of the thickness of the anode lead wire. The solid electrolytic capacitor according to claim 1 or the method of claim 7, wherein the anode terminal is an anode terminal tape having a thickness that is at least about 20% of the width of the porous anode body. The solid electrolytic capacitor or method of claim 15, wherein the width of the anode lead tape is about 80 micrometers to about 4500 micrometers and the thickness of the anode lead tape is about 10 micrometers to about 2800 micrometers. The solid electrolytic capacitor or method of claim 15-16, wherein the notched portion has a width that is from about 20% to about 90% of the width of the anode lead strap and a thickness that is from about 20% to about 90% of the thickness of the anode lead strap is, has. The solid electrolytic capacitor according to any one of claims 1-6 or the method according to any one of claims 7-11, wherein two notches are formed in the anode terminal part. A solid electrolytic capacitor or method according to claim 18, wherein the two notches are formed on opposite surfaces of the anode terminal, so that the notched portion is symmetrical.

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