DE10084996B4 - Solder-carrying body for use in soldering operations - Google Patents

Abstract

A solder-carrying body (100) for use in electrically connecting at least a first contact (140) of a first electronic device (150) to at least a second contact of a second electronic device (160), the body comprising:
a substrate having a first surface and an opposing second surface, wherein in the first surface at least one groove (115, 117) are formed together with at least one first through hole (110), the substrate being adapted to interpose between the first and second surfaces the second electronic devices (150, 160) being spatially arranged, each groove (115, 117) being different and spaced from the first through hole (110) such that the two are not in communication with each other and the first through hole (110) is so adapted to receive a first contact (140); and
at least one length section (130) made of solder material, which is arranged in the at least one groove (115, 117), so that the solder material (130) is separated from the first through-hole.

Description

FIELD OF THE INVENTION

The The present invention relates to the field of devices for Connecting connectors or other electrical components together and more particularly to a method and apparatus for facilitating of soldering first electronic devices, such as connectors, to second electronic Facilities, such as circuit boards.

GENERAL PRIOR ART

It is often necessary and desirable to electrically connect one component to another component. For example, often a component with multiple ports, such as such as a connector, electrically connected to a substrate, such as a PCB, connected, so that the connections the component for providing an electrical connection between contact islands formed on the substrate these are attached. A preferred technique for secure attachment the component connections At the contact islands is a solder material around a certain Use around area, such as a hole, which is usually receives a component port. The component connections can often in the form of conductive pins which are in the substrate trained holes be received. The solder material, z. As solder paste, is common applied around each contact hole and then heated after the conductive pin is received in the contact hole and penetrated this extends. By heating the solder paste is effected that these flows around the conductive pin and the contact hole. By cooling The solder paste is the conductive pin securely on one of the on the Attached substrate formed contact islands.

Although the use of solder paste is effective in some applications, So there are a number of applications where the use of Solder paste is undesirable because of a number of factors, including those the design of both the component terminals and the substrate itself counts. Furthermore is generally not sufficient by the use of solder paste Lot volume for the correct connection of the component connections and provided the contact islands.

An alternative approach when using solder paste is in your own U.S. Patent No. 5,875,546 which is incorporated herein by reference in its entirety. The apparatus set forth in this reference includes an array of release clips which are readily attached by hand or machine to a corresponding array of connector or other component terminals. The clips are typically formed by die-stamping, increasing the cost and complexity of the overall soldering process.

From the US 50 29 748 a solder-carrying body is known for connecting at least one first contact of a first electronic device to at least one second contact of a second electronic device, wherein the solder-carrying body comprises a substrate body that can be placed between the first and the second electronic device.

The US 50 46 957 discloses a substrate body having a first surface and an opposing second surface having at least one segment of solder material found in a solder opening formed in the substrate body.

From the US 46 41 426 Furthermore, a solder-carrying body is known, which has a substrate body having a first surface and an opposite second surface, wherein the substrate body formed by the substrate body openings for receiving electrical contacts of an electrical device.

It is desirable an alternative device and an alternative method to the Applying solder to connector or the like.

BRIEF SUMMARY OF THE INVENTION

A Such device and such a method are by those in the claims 1 and 10 described solder-carrying body as well as by in the claim 14 described method provided.

The solder-carrying body, or wafer, is designed to provide a solder material used in a soldering operation to electrically connect a first electronic device to a second electronic device. The solder-bearing wafer may be formed of a variety of materials, and preferably the solder-bearing wafer is formed of a non-conductive material. The solder-carrying wafer can be formed, for example, from a thermoplastic, a thermally fixing plastic, etc. The solder-bearing wafer has a plurality of through-holes formed therein to facilitate soldering electrical terminals or contacts of the first electronic device. In one embodiment, the electrical terminals or contacts consist of pins that differ from the first compo extend outward. The first electronic device preferably consists of an electronic connector, and the second electronic device consists of a printed circuit board.

The Contacts of the first electronic device usually exist from conductive pens. The pins of the first electronic device are common in a certain kind of pattern about the surface the first electronic device arranged away. So can for example, a conventional one first electronic device a number of rows and columns of pins designed to provide a method of electrical Connecting terminals the first electronic device with in the second electronic Device, z. B. a circuit board, arranged electrical Provide contacts. The wafer accordingly contains first through holes, or also pin holes whose place and distance the place and distance of the pins of the correspond to the first electronic device. This allows the Wafer so coupled to the first electronic device be that the Pins in the pin holes of the wafer and extend through it. Consequently the wafer is disposed between the first and second electronic devices.

Of the Contains wafers also a plurality of through holes formed therethrough (through holes). The Through holes are formed in rows on both sides of each pin hole. Of the Contains wafers continue grooves that over and under each row of pin holes parallel to this run. The length of each of the grooves is in evenly spaced Intervals cut through the through holes. Prefers and according to this an embodiment For example, the grooves are formed only on a single surface of the wafer.

A length of Lotmasse, which generally corresponds to the shape of a groove is in a secured the grooves. In other words, the lot length becomes the groove placed. Because there are several grooves, there are also several, above the surface the solder extending solder lengths. With a press or an embossing stamp then become the solder lengths cut through at each through hole. At this point, the wafer contains Pin holes, being over and a solder segment is arranged under each pin hole. The solder segments are preferred between the next adjacent through holes arranged.

The pin heads the first electronic device are then in the so pinholes of the wafer, that the Pens emerge on the side of the wafer carrying the solder segments. The the solder segments supporting side of the wafer is then attached to a circuit board placed, and the solder is heated and melts, causing the electronic device is secured to the circuit board. Of the Wafer stays between the securely mounted first electronic Device and the circuit board arranged. In this first application The present invention relates to the present solder-bearing wafer with through-hole devices such as those described above PCB, used. Through hole devices are devices with a series of holes formed through it for receiving another conductive member, such as conductive pins. It understands that the Wafers in addition to printed circuit boards with a number of other through-hole devices can be used.

BRIEF DESCRIPTION OF THE DRAWINGS

tasks and features of the present invention will be described below with reference to certain preferred embodiments described in more detail with reference to the accompanying drawings. Show it:

1 a top perspective view of a wafer according to the invention (solder-carrying body) arranged through it with pin holes (first through holes);

2 a perspective side view of the wafer of 1 ;

3 a plan view of the wafer of 1 on which additionally lothaltende grooves are formed;

4 a plan view of the wafer of 3 through which additional through holes (second through holes) are arranged;

5 a cross-sectional view of the wafer of 4 along the line 5-5;

6 a plan view of the wafer of 5 , wherein the lothaltenden lengths have been divided and

7 a side view of the wafer of 6 wherein the pins of an electronic device are inserted through the respective pin holes of the wafer.

DETAILED DESCRIPTION OF THE PREFERRED Embodiment

In one aspect, the present invention facilitates the process of soldering electrical terminals or contacts of an electronic device to a surface of a second electronic device using a lottra body (wafer). In one embodiment, the electrical contacts include conductive pins, and the second electronic device includes a printed circuit board. The 1 to 3 illustrate a method of forming a wafer according to a first embodiment of the present invention.

With reference to 1 becomes a wafer 100 provided and formed of any number of suitable materials and preferably of a non-conductive material. The wafer 100 may be formed, for example, of a thermoplastic material, a thermally fixed plastic, etc. Through the wafer 100 are pin holes 110 (first through holes 110 ) educated. It is understood that the pin hole 10 does not necessarily have to have a ring shape, and the pin hole 10 generally consists of in the wafer 10 trained small holes. The location and the general distance of the pin holes 110 are determined by the location and spacing of pins on a second electronic device, e.g. B. a circuit board ( 7 ) to be mounted first electronic device ( 7 ) certainly. It is therefore understood that the pin holes 110 depending on the number of pin holes 110 and their location according to any number of patterns. At the in 1 the embodiment shown are the pin holes 110 arranged in horizontal rows along a first axis and vertical columns along a second axis and spaced apart a predetermined distance. The first axis generally extends over a length L of the wafer 100 , and the second axis generally extends across a width W of the wafer 100 , The first axis is thus preferably longer than the second axis. The pin holes 110 for example, are spaced a predetermined center dimension along the first axis and a predetermined extent along the second axis to receive an electrical device having correspondingly spaced pins.

In addition, the length and width of the wafer correspond 100 generally the length and width of the first electronic device to be mounted on the second electronic device. The depth or thickness of the wafer 100 is preferably about 0.030 inches. This measure is only illustrative.

The pin holes 110 can be prepared by using any of the methods known in the art, including e.g. B. the use of a punch, through the wafer 100 be formed. The pin holes 110 but also in the production of the wafer 100 be formed or shaped.

With reference to 2 it will be a perspective side view of the wafer 100 shown in the two pairs of grooves 115 and 117 can be seen on both sides of each row of pin holes 110 along the first axis of the wafer 100 extend. Although the grooves 115 and 117 are shown with a semi-cylindrical shape, it is to be understood that the shape of the grooves 115 and 117 can have any shape. The shape of the grooves 115 and 117 preferably corresponds to the shape of a Lotlänge 130 ( 4 ), which are described in more detail below, into each of the grooves 115 and 117 is to insert.

The grooves 115 and 117 are prepared using any of the methods known in the art, including e.g. Example, the use of an etch or a punch, in the wafer 100 educated. The grooves 115 and 117 but also in the production of the wafer 100 be formed. So can the grooves 115 and 117 for example, during a molding process with which the wafer 100 is produced, be formed. The grooves 115 and 117 can before, during or after the placement of the pinholes 110 be formed.

With reference to 3 is there the wafer 100 illustrates its through holes passing through it 120 (second through holes 120 ) are arranged along the first axis, that at least one through hole 120 on both sides of each pin hole 110 lies. Every through hole 120 As shown, it extends sufficiently along the second axis to be one of the grooves 115 respectively. 117 includes. The through holes 120 Be using any of the above to form the pin holes 110 and the grooves 115 and 117 formed method described.

According to the present invention, solder segments 135 to the wafer 100 added to provide a brazing material with which the first and second electronic devices are securely fastened together, as described below. The 4 to 6 illustrate the method of adding solder segments 135 to the wafer 100 ,

With reference to the 4 and 5 it becomes the wafer 100 with those in the grooves 115 and 117 placed lot lengths 130 illustrated. The solder lengths 130 include any of the solder joints known in the art and are preferably shaped to be secure and conformed to the grooves 115 and 117 be inserted. In other words, the solder lengths include 130 prefers elongated strips of solder material complementary to the grooves 115 and 117 are shaped. In the present example, in particular in 5 shown and shown are the solder lengths 130 Accordingly, cylindrically shaped to be in the semi-cylindrical grooves 115 and 117 as in 2 sure to fit.

Further referring to 4 It is shown that each pair of solder lengths 130 over a series of through holes 120 lies. In this way, a press or a punch with corresponding to the shape and position of through holes 120 on the wafer 100 formed and spaced punches used to solder lengths 130 at each of the through holes 120 separate.

6 shows the wafer 100 after the solder lengths 130 as described above for forming a plurality of solder segments 135 have been separated. As shown, each pin hole points 110 a lot segment 135 on, on both sides of the pin hole 110 lies. As every lot segment 135 through the groove 115 or 117 is held securely, the wafer can 100 in any position required to correspond to a particular manufacturing process or machinery being used (eg, solder side facing up, pointing sideways, facing down, etc.).

7 shows an electronic device 150 in which there are pens 140 from a first surface 151 extend from it. The first electronic device 150 may include any number of suitable devices electrically connected to a second electronic device 160 to be connected. By way of example and in accordance with one embodiment, the first electronic device comprises 150 an electrical connector and the second electronic device 160 a printed circuit board (through-hole device). The pencils 140 comprise conductive pins which are for making an electrical connection between not shown terminals of the first electronic device 150 and corresponding electronic components of the second electronic device 160 serve. The pencils 140 are in respective pin holes 110 of the wafer 100 arranged. As in 7 shown is the wafer 100 positioned so that the solder segments 135 point down. The solder segments 135 be by their positive connection with the grooves 115 and 117 recorded.

After the first electronic device 150 and the pins 140 sufficiently far in the wafer 100 and the pin holes 110 may have been introduced, the side of the wafer 100 with the exposed solder segments 135 to the second electronic device 160 with pin holes 110 be placed according to the distance and the size of the pin holes 110 correspond. The solder segments 135 are then heated, which causes the solder segments 135 around the pins 140 and the pin holes 110 around with other surfaces of the second electronic device 160 melt again. While the solder segments 135 cool, the pins are 140 at the second electronic device 160 secured, resulting in a secure electrical connection between the first and second electronic device 150 . 160 leads. After reheating and cooling the solder segments 135 the wafer stays 100 between the first electronic device 150 and the second electronic device 160 soldered. It is understood that the solder segments 135 be heated after the first and second electronic device 150 . 160 have been brought together.

It will now be on the 1 to 7 directed. It is understood that the provision of through holes 120 for permitting the separation of solder lengths 130 also serves to each of the pens 140 to define a lot of solder material around. By providing two solder segments 135 next to each of the pin holes 110 in other words, a defined amount of solder material for soldering a pen 140 to a corresponding portion of the second electronic device 160 provided. The separation of the solder lengths 130 reduces the mass of solder material used in the soldering process, which reduces the likelihood that it will come to a large soldered mass during the heating process. The separation of the solder lengths 130 also prevents adjacent pads from becoming impoverished. In other words, the heating of contacts is often not uniform, and a contact (pin 140 ) is heated more and even draws solder material from one or more adjacent locations. This causes the solder material to be withdrawn from the one or more adjacent contacts, resulting in ineffective soldering of these contacts. By around every pin 140 Around a defined amount of solder material is arranged, the solder material is effectively divided into local segments, which are responsible for the soldering of a respective pin 140 be used. The heating process thus generates around the pins 140 soldered masses spaced apart from one another of large soldered mass, and solder withdrawal sites associated with conventional techniques are eliminated.

The solder-bearing wafer 100 The present invention overcomes many of the deficiencies associated with the prior art devices. First, the wafer points 100 a relatively simple yet effective design. Since the solder carrier medium is a thermoplastic material, the solder segments remain after melting 135 no conductive material on the contacts (pins 140 ) hang. Second, thermoplastic materials are generally cheaper than those for making other solder Auxiliary devices used metallic materials. Third, this leads to reduced manufacturing costs because the simplicity of the present invention allows an operator to use the wafer 100 easier and faster at the first electronic device 150 to install. Fourth, the wafer presents 100 also by forming the solder segments 135 in the grooves 115 and 117 around the respective pins 140 around enlarged solder volume ready. This larger solder volume provides more solder material for each between the devices 150 . 160 formed solder joint, whereby the quality of each of the solder joints is improved. Fifth, the present invention provides a narrower lead spacing since the contacts (pins 140 ) of the first electronic device 150 closer together than would have been possible if other remedies were used. Sixth, the solder-bearing wafer allows 100 in that irregular soldering patterns are formed on it. This allows the solder segments 135 at desired places on the wafer 100 be formed. Thus, the location of the solder segments 135 depending on the specific application and configuration of one or more of the first and second electronic devices 150 . 160 custom tailored.

Depending on the particular application, there are different variations of the solder-bearing wafer 100 possible. For example, for each row of pinholes (first through holes 110 ) only a single lot length 130 and a single groove can be provided. On the wafer 100 can also have fewer or more than two rows of pin holes 110 to be provided. In addition, the through holes are 120 may not be necessary if the solder lengths 130 be segmented so that the solder parts between the desired segments can be removed, for example via a cutting and Vakuumentfernprozeß. In addition, the pin holes, through holes and grooves may take any required form depending on the particular application.

It is understood that the wafer 100 can be distributed in a number of forms. For example, if the specifications of a given application are known, the wafer can 100 be cut so that it has a desired length and width, so that the wafer 100 between the first and second electronic devices 150 . 160 is arranged without the wafer 100 either via the first or second electronic device 150 . 160 extends beyond. The wafer 100 but can also be wound up on rolls and then supplied to a number of connector and electrical component manufacturers to retrofit their existing or future products. The design of the wafer 100 thus allowing for versatility because it can not only be customized for a specific application, but also allows the wafer 100 delivered in a basic form and then retrofitted by the buyer.

It is understood that the wafer 100 instead of integrating with the first electronic device 150 can be attached to the respective first electronic device by any number of techniques. For example, the wafer may include locking features that cooperate with complimentary locking features provided on the first electronic device to securely attach the wafer to the first electronic device. The first electronic device can be marketed and sold in this way, namely that the wafer is attached to the formation of an assembly on the first electronic device and preferably removably attached. The assembly is then sent to the second electronic device 160 coupled and then heated to cause the solder material melts and electrically connects the respective components.

Various embodiments The present invention thus provides a wafer which is designed for carrying solder material, wherein when heated and Placing the wafer relative to the first and second electronic Device the solder material acts to the effect that there is a first contact of the first electronic device securely on one second contact of the second electronic device attaches. The wafer may advantageously be in a variety of environments can be used, including electronic through hole devices and also surface mount applications. The wafer has a simple yet effective design with one increased application potential relative to conventional Connecting devices on.

Even though for illustrative purposes a preferred embodiment The expert understands that many Additions, modifications and substitutions possible without departing from the scope and spirit of the invention.

Claims (23)

Lot carrying body ( 100 ) for use in electrically connecting at least a first contact ( 140 ) of a first electronic device ( 150 ) with at least one second contact of a second electronic device ( 160 ), the body comprising: a substrate having a first surface and an opposing second surface, wherein the first surface at least one groove ( 115 . 117 ) together with at least one first through-hole ( 110 ), wherein the substrate is adapted to connect between the first and the second electronic devices ( 150 . 160 ) is spatially arranged, each groove ( 115 . 117 ) different and spaced from the first through hole ( 110 ), so that the two are not in communication with each other and the first through hole ( 110 ) is adapted to make a first contact ( 140 ); and at least one length section ( 130 ) made of solder material, in the at least one groove ( 115 . 117 ) is arranged so that the solder material ( 130 ) from the first through hole ( 110 ) is spaced. A solder-carrying body according to claim 1, characterized in that the substrate has a plurality of grooves ( 115 . 117 ) formed in the first surface and having a plurality of first through-holes axially aligned along a longitudinal axis (L) of the substrate (Fig. 110 ), with a pair of grooves ( 115 . 117 ) having a series of axially aligned first through holes (FIGS. 110 ) surrounds in the longitudinal direction. A solder-carrying body according to claim 2, characterized in that the series of axially aligned first through-holes (FIG. 110 ) between the pair of grooves ( 115 . 117 ), resulting in the solder material ( 130 ) axially at opposite points of each first through-hole ( 110 ) is aligned. A solder-carrying body according to claim 2, characterized in that the plurality of grooves ( 115 . 117 ) are arranged in parallel. A solder-carrying body according to claim 2, characterized by a plurality of second through-holes ( 120 ) formed in the substrate so that each of the second through holes (FIG. 120 ) with two grooves ( 115 . 117 ) which cuts the groove pair ( 115 . 117 ) define the first through holes ( 110 ), the second through holes ( 120 ) are formed so that one of the first through holes ( 110 ) between a pair of second through-holes ( 120 ) lies. A solder-carrying body according to claim 5, characterized in that the plurality of second through-holes ( 120 ) are arranged in parallel. A solder-carrying body according to claim 6, characterized in that the plurality of second through-holes ( 120 ) perpendicular to a longitudinal axis of each of the two grooves ( 115 . 117 ) defining the pair of grooves are formed. A solder-carrying body according to claim 5, characterized in that in each groove ( 115 . 117 ) arranged solder material is segmented so that a Lotmaterialsegment ( 135 ) axially in the groove ( 115 . 117 ) between a pair of second through-holes ( 120 ) lies. A solder-carrying body according to claim 5, characterized in that each length of solder material ( 130 ) via the second through holes ( 120 ), but from the axially aligned first through-holes (FIGS. 110 ) remains spaced. Lot carrying body ( 100 ) for electrically connecting an electronic device to a via device, comprising: a substrate having a first surface and an opposing second surface; a plurality of first through holes ( 110 ) formed by the substrate for receiving first electrical contacts ( 140 ) of a first electronic device ( 150 ); Grooves ( 115 . 117 ) formed in the first surface of the substrate such that each first through-hole (FIG. 110 ) at least one groove ( 115 . 117 ) formed on its first side and another groove ( 115 . 117 ) formed on the second side thereof; a plurality of second through holes ( 120 ), which are formed in the substrate, wherein the second through holes ( 120 ) are spaced so that every other through hole ( 120 ) a pair of grooves ( 115 . 117 ), wherein in each case one of the first through holes ( 110 ) between two adjacent second through-holes ( 120 ), wherein the second through holes ( 120 ) for dividing the groove ( 115 . 117 ) serve in Nutsegmente; and a plurality of solder material segments ( 135 ), each solder segment ( 135 ) within a groove segment ( 115 . 117 ) is arranged so that each first through hole ( 110 ) a solder segment ( 135 ) and spaced at the first side thereof and another solder segment ( 135 ) and spaced apart on the second side thereof, for providing a solder connection between the first electrical contacts ( 140 ) of the first electronic device ( 150 ) and the second electronic device ( 160 ) when the first electrical contacts ( 140 ) of the first electronic device ( 150 ) in contact openings of the second electronic device ( 160 ). A solder-carrying body according to claim 10, characterized in that the plurality of second through-holes ( 120 ) are arranged in parallel. A solder-carrying body according to claim 10, characterized in that the plurality of second through-holes ( 120 ) perpendicular to a longitudinal axis of each of the grooves ( 115 . 117 ) defining a pair are formed. Lot carrying body according to claim 5, characterized in that the substrate is made of a non-conductive Material is formed. Method for electrically connecting a first contact ( 140 ) of a first electronic device ( 150 ) with a second contact of a second electronic device ( 160 ), the method comprising: providing a substrate having a first surface and an opposing second surface; Forming a plurality of first through holes ( 110 ) in the substrate, wherein the first through holes ( 110 ) to record the first contact ( 140 ) be formed; Forming at least one groove ( 115 . 117 ) within the first surface, so that each groove ( 115 . 117 ) different and spaced from each first through hole ( 110 ), so that the groove ( 115 . 117 ) and the first through hole ( 110 ) are not related to each other; Arranging a length of solder material ( 130 ) within at least one groove ( 115 . 117 ), so that the length of solder material ( 130 ) within the at least one groove ( 115 . 117 ), so that the solder material ( 130 ) different and spaced from the first through hole ( 110 ); Positioning the first electronic device ( 150 ) relative to the substrate such that the length of solder material ( 130 ) adjacent to the first contact ( 140 ) is aligned; and positioning the second electronic device ( 160 ) relative to the substrate and the first electronic device ( 150 ), so that the first ( 140 ) and second contacts are aligned adjacent to the substrate positioned therebetween; so that when heating the length of solder material ( 130 ), between the first contact ( 140 ) and the second contact a secure solder connection and an electrical path are formed. Method according to claim 14, characterized by the further steps: forming at least one further groove ( 115 . 117 ) in the first surface; and arranging at least a second length of solder material ( 130 ) within the at least one further groove ( 115 . 117 ), each additional groove ( 115 . 117 ) different and spaced from each first through hole ( 110 ), so that the further groove ( 115 . 117 ) and the through hole ( 110 ) are not related to each other. Method according to claim 14, characterized in that a pair of grooves ( 115 . 117 ) is shaped such that it has a series of first through-holes aligned axially along a longitudinal axis (L) of the substrate (11) 110 ) surrounds in the longitudinal direction. A method according to claim 16, characterized by the step of forming the groove pair ( 115 . 117 ), so that the series of axially aligned first through holes ( 110 ) between the pair of grooves ( 115 . 117 ), which results in the solder material ( 130 ) at the opposite points of each first through-hole ( 110 ) is arranged axially. A method according to claim 16, characterized by the step of arranging said plurality of grooves in parallel ( 115 . 117 ). The method of claim 16, characterized by the step of forming a plurality of second through holes ( 120 ) in the substrate so that each of the second through holes ( 120 ) with the grooves ( 115 . 117 ) which cuts a pair of grooves ( 115 . 117 ) defining a first through hole ( 110 ), wherein the second through holes ( 120 ) are formed so that a first through hole ( 110 ) between a pair of second through-holes ( 120 ) lies. Method according to claim 19, characterized in that the second through-holes ( 120 ) are formed so that they are aligned parallel to each other. A method according to claim 20, characterized in that the second through holes ( 120 ) perpendicular to a longitudinal axis of each of the pair of grooves ( 115 . 117 ) forming grooves ( 115 . 117 ) be formed. A method according to claim 19, characterized by the step of segmenting the solder material ( 130 ), which in each groove ( 115 . 117 ) is arranged so that a Lotmaterialsegment ( 135 ) axially in a groove ( 115 . 117 ) between a pair of second through-holes ( 120 ) lies. Method according to claim 19, characterized in that the solder material ( 130 ) into the grooves ( 115 . 117 ) is placed over the second through holes ( 120 ), but from the axially aligned first through-holes (FIGS. 110 ) remains spaced.