EP1394825A1 - Micromechanical contact arrangement and microrelay having the same - Google Patents

Abstract

The micro-electromechanical (MEMS) contact and micro-relay (1) may be used for switching electric and electronic equipment on and off. It has a flexible membrane (12) held at its edges. It is moved by drive actuators (4) between contact (B) and non-contact (A) positions. The membrane may carry a flexible contact region (11) on one side, which may touch fixed contacts (2,3).

Description

Technical field

The invention relates to the field of micro-electromechanical Systems (MEMS), in particular according to a MEMS contact arrangement according to the preamble of claim 1 and to a MEMS switching device the preamble of claim 16.

State of the art

Such a micro-electromechanical (MEMS) contact arrangement and a Such MEMS switching device is for example from the published patent application DE 10040867 A1 known. There is a substrate parallel, i.e. laterally working Microswitch disclosed, which by means of ion deep etching (DRIE, deep reactive ion etching) is made of a silicon substrate and three contact pieces includes. Two of the three contact pieces are fixed on the substrate (Fixkontakte). The other, movable contact piece is part of one part movable contact carrier. This contact carrier is parallel to the substrate bendable and fixed at its two ends on the substrate. The two Fixed contacts are with respect to the two ends of the movable contact carrier arranged asymmetrically so that the movable contact carrier two has stable positions (switching states). Has turned off the movable contact carrier in the form of a symmetrical antinode, when switched on the shape of an asymmetrical Antinode. When switched on, the movable contacts Contact piece the two fixed contacts. At least one electrostatic The drive is the movable contact carrier from a switching state switchable to the other switching state.

The fixed contacts are solid and rigid. They are finger-shaped and in Rounded direction of the movable contact piece. The mobile Contact piece is, even when switched on, despite the flexibility of the Contact carrier rigid. Because that at its two ends on the substrate Fixed contact carrier must be able to withstand high pressure forces to exercise the fixed contacts. When creating the contacts between the movable Contact piece and the fixed contacts therefore come the three contact pieces immediately to rest, and there is a point-like contact for each fixed contact or linear contact with the movable line perpendicular to the substrate Contact piece, namely at the points of the first touch of the movable contact piece with the fixed contacts.

Such a point-like or line-like perpendicular to the substrate Contact has a large electrical and thermal resistance, because the contact area or the number of contact points is very small. In addition, soiling of the contacting surfaces Increase contact resistance further, especially when switching small currents contamination, where there is no arc from the contact surfaces.

In addition to the bistable switch structure described, DE 10040867 A1 a monostable structure is also disclosed, in which only one fixed contact is shown which of the two ends of the movable contact carrier is located equally far away. The contacting problems are in in this case the same as in the bistable case.

From US 6,057,520 a MEMS switch is known, the one vertically, that is Has contact carrier movable perpendicular to the substrate. This contact carrier is tongue-shaped and at one end on the substrate set. At the free end of the contact carrier there are several massive, rigid contact pieces attached, which after switching the switch a corresponding number on the substrate in the switched-on state Contact fixed rigid contact pieces. The above mentioned also occur here Contact problems between the rigid contact pieces.

Presentation of the invention

The object of the invention is a micro-mechanical or micro-electromechanical (MEMS) contact arrangement and a micro-mechanical or micro-electromechanical (MEMS) switching device of the input to create the type mentioned, which does not have the disadvantages mentioned above exhibit. In particular, improved and reliable contacting is to be achieved become.

This problem is solved by a MEMS contact arrangement with the features of Claim 1 and a MEMS switching device with the features of the claim 16th

The MEMS contact arrangement according to the invention has at least a first one Contact piece and a second contact piece, at least one of the two contact pieces can be driven, and wherein the MEMS contact arrangement by means of the drivable contact piece between one first switching state and at least one second switching state switchable is, the two contact pieces in the first switching state of each other are separated and contacting each other in the second switching state are. It is characterized in that at least the first contact piece at least one flexible contact segment and a contact segment carrier has, and that the at least one flexible contact segment by means of at least the second contact piece during a switching operation of the first switching state in the second switching state and / or from the second switching state is elastically deformable in the first switching state.

This ensures reliable contacting. contacting problems due to manufacturing tolerances are reduced because of manufacturing tolerances Inaccuracies are compensated for. Any deformation are compensable. The influence of possible soiling on the The quality of the contact can be significantly reduced.

In particular, the at least one flexible contact segment is by means of at least one of the second contact piece in a switching process elastically deformable that the at least one flexible contact segment with the second contact piece in the second switching state at least one flat Touch area or a predeterminable plurality of touch points having. This makes contacting better and safer. The effective one Size of contact areas and / or the number of contact points is increased, so that the electrical and / or thermal resistance the contact point is reduced or one provided with the contact arrangement Micro valve closes more tightly.

The flexible contact segment in the second switching state is advantageous molded second contact piece. That means that in the second switching state the shape of the flexible contact segment in areas where the first and touch the second contact piece to the shape of the second contact piece is adjusted. Due to the elastic deformation that the flexible Contact segment experienced through the switching process is the shape of the flexible Contact segments in the first switching state differ from the shape of the flexible Contact segments in the second switching state. This ensures a safe, because large contact areas and / or many contact points Contact reached.

In an advantageous embodiment of the subject matter of the invention the flexible contact segment and the second contact piece in the second switching state at least one area of contact, in the second Switching state of the second contact piece in the contact area of the first contact piece is enclosed. This will make because large-scale contact is achieved.

In a particularly advantageous embodiment of the subject matter of the invention is the second contact piece opposite the flexible contact segment smoothly movable during a switching operation. This is advantageous both for switching operations from the first to the second as well as for switching operations from the second to the first switching state. When manufacturing and / or releasing a contact move the flexible contact segment and the second contact piece relative to each other while they are doing so touch. Due to the mutual friction of the two contact pieces Soiling of the contact pieces can be removed. This cleanses itself the contact arrangement automatically by switching operations. Clean contacts mean safe contacts. The reliability of contacting is thereby very high. This embodiment is particularly advantageous with electrical Applications and especially when currents are switched that do not generate an arc that has a contact cleaning effect could.

In particularly advantageous embodiments, the flexible contact segment due to its thin walls, flexible and elastic deformable. The flexible contact segment has at least one flexible section, the is so thin or narrow that it has flexibility. In particular, one of the flexible contact segment can be advantageous flexible section with a wall thickness between 1 µm and 60 µm, preferably between 5 µm and 25 µm. typically, The materials used then have a suitable flexibility and deformability on, but there is still sufficient breaking strength. The elastic deformations that a flexible section of a flexible Contact segments typically through the second contact piece at one Switching process experienced is advantageous at least on the order of magnitude the wall thickness of the flexible section of the flexible contact segment and / or in the range of 0.1 to 20 times, in particular 1 to 5 times the wall thickness of the flexible section of the flexible contact segment.

At least the first contact piece is advantageously formed in one piece. This improves the producibility of the first contact piece, and the The stability and reliability of the first contact piece is particularly great.

In a further advantageous embodiment of the subject matter of the invention has the flexible contact segment in addition to at least one flexible Section another base facing the contact segment carrier on. This base advantageously has a greater wall thickness than the at least one a flexible section of the flexible contact segment. This points the basis of less flexibility. For a base deformation requires more energy than to deform the at least one flexible one Section. The base is more stable than the flexible section. The base points greater electrical and / or thermal conductivity. For example heat can be dissipated better, and for short periods For large thermal loads, an increased heat capacity is an advantage. Improved contacting is realized.

A further advantageous embodiment is characterized in that for the elastic deformation of the at least one flexible contact segment by means of at least the second contact piece at one Switching process from the first switching state to the second switching state or from the second switching state to the first switching state an insertion energy or an execution energy is to be applied, and that in the second switching state of the flexible contact segment a restraining force is exerted on the second contact piece, by what retention force a switching operation from the second switching state is difficult in the first switching state. To carry out a Switching process, a potential mountain must be overcome. The for Switching required energy is generally applied by a drive, by means of which the drivable contact piece is driven. In The second switching state is a safe and good contact that supports the flexible contact piece due to the in it the deformation during the transition from the first to the second switching state stored deformation energy a compressive force on the second Contact piece. This pressure force can also be referred to as a retention force become. In the second switching state there can be a jamming connection exist between the two contact pieces.

In a further advantageous embodiment, the flexible contact segment acts and the second contact piece in the manner of the push button principle together that the contact segment carrier has at least one additional has a stable position. If the contact segment carrier is a monostable Is a switching element, it can be a bistable switching element (and a bistable contact arrangement) or a tristable switching element become. And from a bistable switchable contact segment carrier can become a tristably switchable switching element.

In further advantageous embodiments, the flexible contact segment and the second contact piece in the manner of a plug-socket pair ineinanderfügbar.

In a particularly advantageous embodiment, the flexible contact segment has at least two, advantageously four, six or more elastic deformable contact fingers. These advantageously elongated and thin, advantageous cane-like curved segments are such shaped and arranged that each (or at least most) of the sub-segments touches the second contact piece in the second switching state. Thereby result in at least one (approximately) the number of sub-segments corresponding predeterminable number of contact points or a corresponding one Majority of contact surfaces. This ensures a safe contact achieved with low contact resistance.

In a further particularly advantageous embodiment, this has at least a flexible contact segment in the second switching state at least an area of contact with the second contact piece, and the direction of relative movement from the flexible contact segment and the second Kontaktstückm in a switching operation closes with the flat contact area essentially an angle α with α = 45 ° ± 30 °, in particular α = 45 ° ± 15 °. The angle α lies in one plane, which is perpendicular to the plane of the area of contact. And those surfaces of the flexible contact segment and the second contact piece, those in the second switching state essentially parallel to one another are aligned and touch each other in the area of contact, are essentially up to an angle ε in the first switching state 0 ° ≤ ε ≤ 30 °, in particular 0 ° ≤ ε ≤ 10 °, aligned parallel to each other. In particular, the angle ε can advantageously additionally be at least 1 ° large, at least 2 ° large or at least 4 ° large. at a switching process from the first to the second and / or from the second in the surfaces mentioned rub against the first switching state, whereby contact deteriorating impurities can be removed. On In this way, a safe, large-area and self-cleaning contact is made achieved.

In a further particularly advantageous embodiment, this includes flexible contact segment a membrane-like section, which at a Switching process is deformed elastically. Such a membrane fits flat on the shape of the second contact piece and equalizes manufacturing tolerances out. Low contact resistance and reliable contacting can be achieved.

In a further particularly advantageous embodiment of the flexible contact segment or shared by the flexible contact segment a volume is enclosed with the first contact piece, which essentially with an electrically and thermally conductive, elastically deformable Filling is filled. This will make the electrical and / or thermal Conductivity of the flexible contact segment increased.

A MEMS switching device, for example a micro relay, which is an inventive Contact arrangement includes, has the above advantages.

Further preferred embodiments and advantages result from the dependent ones Claims and the figures.

Brief description of the drawings

Fig. 1

ein erfindungsgemässes MEMS-Relais mit membranförmigem flexiblen Kontaktsegment und elektrostatischen Antrieben;

Fig.2a

eine erfindungsgemässe MEMS-Kontaktanordnung mit zwei Kontaktstücken und mit membranförmigem flexiblen Kontaktsegment, geöffnet;

Fig. 2b

wie Fig. 2a, geschlossen;

Fig. 3a

eine erfindungsgemässe MEMS-Kontaktanordnung mit drei Kontaktstücken, mit membranförmigem flexiblen Kontaktsegment, geöffnet;

Fig. 3b

wie Fig. 3a, geschlossen;

Fig.4a

eine erfindungsgemässe MEMS-Kontaktanordnung mit zwei Kontaktstücken und mit asymmetrischem membranförmigem flexiblen Kontaktsegment, geöffnet;

Fig. 4b,4c

wie Fig. 4a, geschlossen;

Fig. 5

eine erfindungsgemässe MEMS-Kontaktanordnung mit drei Kontaktstücken und mit membranförmigem flexiblen Kontaktsegment auf einer Basis, geöffnet;

Fig. 6

wie Fig. 5, zusätzlich noch mit Federmechanismus;

Fig. 7a

eine erfindungsgemässe MEMS-Kontaktanordnung mit zwei Kontaktstücken nach Art eines Stecker-Steckdosenpaares und mit zwei Kontaktfingern, geöffnet;

Fig. 7b

wie Fig. 7a, geschlossen;

Fig. 8a

eine erfindungsgemässe MEMS-Kontaktanordnung mit zwei Kontaktstücken nach Art eines Stecker-Steckdosenpaares und mit zwei Kontaktfingern, geöffnet;

Fig. 8b

wie Fig. 8a, geschlossen;

Fig. 9a

wie Fig. 8a, zusätzlich noch mit Basis;

Fig. 9b

wie Fig. 9a, geschlossen;

Fig. 10a

eine erfindungsgemässe MEMS-Kontaktanordnung mit zwei Kontaktstücken und mit einer Mehrzahl von spiegelsymmetrisch angeordneten Kontaktfingern, geöffnet;

Fig. 10b

wie Fig. 10a, geschlossen;

Fig. 11a

eine erfindungsgemässe MEMS-Kontaktanordnung mit drei Kontaktstücken und mit gewinkelten, reibungserzeugenden Berührungsflächen, geöffnet;

Fig. 11b

wie Fig. 11a, geschlossen;

Fig. 12a

ein erfindungsgemässes MEMS mit zwei Kontaktstücken, wobei mittels des Druckknopf-Prinzips eine bistabile Schaltbarkeit erreicht wird, geöffnet;

Fig. 12b

wie Fig. 12a, geschlossen;

The subject matter of the invention is explained in more detail below on the basis of preferred exemplary embodiments which are illustrated in the accompanying drawings. They show schematically and under supervision:

Fig. 1

a MEMS relay according to the invention with a membrane-shaped flexible contact segment and electrostatic drives;

2a

an MEMS contact arrangement according to the invention with two contact pieces and with a membrane-shaped flexible contact segment, opened;

Fig. 2b

as Fig. 2a, closed;

Fig. 3a

a MEMS contact arrangement according to the invention with three contact pieces, with a membrane-shaped flexible contact segment, opened;

Fig. 3b

as Fig. 3a, closed;

4a

a MEMS contact arrangement according to the invention with two contact pieces and with an asymmetrical membrane-shaped flexible contact segment, opened;

4b, 4c

like Fig. 4a, closed;

Fig. 5

a MEMS contact arrangement according to the invention with three contact pieces and with a membrane-shaped flexible contact segment on a base, opened;

Fig. 6

like FIG. 5, additionally with spring mechanism;

Fig. 7a

an inventive MEMS contact arrangement with two contact pieces in the manner of a plug-socket pair and with two contact fingers, opened;

Fig. 7b

as Fig. 7a, closed;

Fig. 8a

an inventive MEMS contact arrangement with two contact pieces in the manner of a plug-socket pair and with two contact fingers, opened;

Fig. 8b

like Fig. 8a, closed;

Fig. 9a

like FIG. 8a, additionally with base;

Fig. 9b

like Fig. 9a, closed;

Fig. 10a

an inventive MEMS contact arrangement with two contact pieces and with a plurality of mirror-symmetrically arranged contact fingers, opened;

Fig. 10b

like FIG. 10a, closed;

Fig. 11a

opened a MEMS contact arrangement according to the invention with three contact pieces and with angled, friction-generating contact surfaces;

Fig. 11b

as Fig. 11a, closed;

Fig. 12a

opened a MEMS according to the invention with two contact pieces, wherein a bistable switchability is achieved by means of the push button principle;

Fig. 12b

like Fig. 12a, closed;

The reference symbols used in the drawings and their meaning are summarized in the list of reference symbols. in principle are the same or at least equivalent parts with the same in the figures Provide reference numerals. The exemplary embodiments described are available exemplary of the subject matter of the invention and have no restrictive Effect.

Ways of Carrying Out the Invention

Fig. 1 shows schematically an inventive micro-electromechanical Relays (MEMS relays, micro relays) under supervision. The structure this MEMS switching device largely corresponds to that described at the beginning MEMS relays, as described in the published patent application DE 10040867 A1 is described. Such a MEMS relay is ion-etched (DRIE) made of a semiconductor material, preferably single crystal Silicon can be produced. The linear dimension of such a MEMS switching device is typically of the order of 0.4 mm to 5 mm. The structures created using DRIE are mostly prismatic, with the Prism side faces are perpendicular to the surface of the substrate extend from which they are etched and optionally sacrificial layer technology were formed. The height of the prisms is typically from of the order of 50 µm to 500 µm. In the mentioned document DE 10040867 A1 are further details on such and similar microswitches described. In order not to repeat this here, the disclosure content this text hereby expressly in the present description accepted.

The MEMS relay shown in FIG. 1 has a first contact piece 1 second contact piece 2 and a third contact piece 3. The first contact 1 comprises a flexible contact segment 11 and one with the flexible Contact segment connected contact segment carrier 12. The contact segment carrier 12 is horizontal, that is perpendicular to the substrate normal bendable and has two stable positions. At both ends is the contact segment carrier 12 is fixed on the substrate. In the first, position of the contact segment carrier represented by solid lines the relay is in a first switching state A, in which the relay is open: the contact pieces 2 and 3 are not conductive with each other connected. By means of the electrostatic indicated at the top right in FIG. 1 The contact segment carrier 12 can be driven into its second bistable Position in which the relay is in a second, closed position B: by means of the flexible contact segment 11, which has a metallic coating, they are also metallically coated contact pieces 2 and 3 conductive with each other connected. By means of the drive 4 shown at the bottom right in FIG. 1 the relay can be switched back to the open switching state 2.

Details on the flexible contact segment 11 essential to the invention will be given discussed in connection with the other figures. In the other figures is usually only the contact arrangement and not a complete one Switching device shown.

In the as yet unpublished European patent application with the file number 02405334.0 are different micro-electromechanical systems, In particular, switches and relays described with an inventive Contact arrangement can be equipped. It's going on at this point on the performance of this unpublished European Details mentioned patent application waived. Instead it will hereby expressly expresses this unpublished European patent application with their entire disclosure content in the description.

2a, b, a contact arrangement is shown schematically, which is similar that is shown in Fig. 1. However, it only has a first contact piece 1 and a second contact piece 2. In the first switching state A (Fig. 2a) the two contact pieces 1 and 2 are separated from each other, in the second Switching status B touch (contact) the two contact pieces 1 and 2 (Fig. 2b). The first contact piece 1 is formed in one piece and has a flexible contact segment 11 and a contact segment carrier 12 on. The latter can be designed, for example, as in FIG. 1. The flexible Contact segment 11 is membrane-like. It represents a thin wall represents that with the contact segment carrier 12 encloses a volume 114. Because the flexible contact segment 11 and the contact segment carrier 12 like practically all micro-elements produced by DRIE prism-like are, the prism side walls perpendicular to the substrate plane extend, the enclosed volume 114 is prism-like and is enclosed laterally, while it is not in the direction parallel to the substrate is enclosed. This volume not enclosed but enclosed 114 can be filled completely or partially with a conductive filling. Surface effects help fill the volume 114 remains. Depending on the application, the filling, for example, can be more likely have good electrical and / or good thermal conductivity. As Filling is suitable, inter alia, for liquid metals, for example mercury, Indium, gallium or alloys of these metals, or also (electrical) conductive polymers, for example conjugated polymers. By means of such a Filled contact resistance can be achieved. Advantageous the unfilled contact pieces already have good conductivity on, for example in the case of semiconducting materials by appropriate Doping.

In the first switching state A, the flexible contact segment 11 (in supervision) about the shape of a letter "U", which is concavely bent at the bottom. At a Switching to the second switching state B becomes flexible Contact segment 11 through the front finger-shaped second Contact piece 2 elastically deformed. The flexible contact segment 11 is flexible and elastic deformable because it is thin-walled. in the In the case of silicon, the wall surfaces then typically have a thickness d from 1 µm to 60 µm; best results were obtained in the thickness range from 5 µm to 25 µm. In the second switching state 8, the two have Contact pieces 1,2 a flat contact area 5 on. In the contact area 5, the shape of the flexible contact segment 1 1 of the shape of the second contact piece 2. The The shape of the flexible contact segment 11 is different in the second switching state B. than in the first switching state A. In the contact area 5 is the second Contact piece 2 of the flexible contact segment 11 and thus of the first contact piece 1 enclosed flat. The shape of the two Contact pieces 1,2 a centering effect is still achieved, whereby Manufacturing tolerances can be compensated. When changing the Switching states there is a slight sliding friction between the flexible Contact segment 11 and the second contact piece 2. This can a cleaning effect of the contact pieces 1,2 can be achieved.

In the places where thin-walled sections of the flexible contact segment 11 are attached or pass into a wider section, such as for example in Figures 2a and b at the transitions from the flexible contact segment 11 to the contact segment carrier 12, advantageously gradual, For example, roughly parabolic transitions were chosen (see Fig. 2a, b). This improves stability and durability.

3a and 3b show a contact arrangement similar to that from FIG. 1 and Fig. 2a, b. The contact arrangement corresponds to that of FIG. 2, only that instead a second contact segment 2 has two contact pieces 2 and 3 become. Each of the two contact pieces 2 and 3 has the shape of a rounded Half of a split lengthwise, shown in Fig. 2a, b, finger-shaped contact piece. The above-mentioned sliding friction Self-cleaning effect is even stronger in this embodiment than in the embodiment of Fig. 2. Because for each of the contact pieces 2 and 3 results in a switch-on process (A to B) a clearly asymmetrical, laterally (not frontally) first point of contact with the flexible contact segment 1 1. Until then an end position of the contact pieces 1,2,3 is reached, there is a rubbing relative movement of the contact pieces 2 and 3 compared to the flexible contact segment 11.

Generally, in most electrical applications, the design is rounded preferred the contact pieces without tips, because this makes electrical Field stress and peak effects can be avoided.

4a, b and c is a further advantageous embodiment of the subject matter of the invention shown. It largely corresponds to that in Fig. 2a, b illustrated embodiment and is described based thereon. The 4 is not membrane-like flexible contact segment 11 as in FIG. 2 shaped essentially symmetrically, but has an asymmetrical shape Shape in relation to the direction of mutual movement of the flexible Contact segment 11 and the second contact piece 2. This results as described in connection with Fig. 3, an intense friction of the second contact piece 2 with the flexible contact segment 11, which lead to the removal of any impurities in the contact area 5 can.

Fig. 4a outlines the first switching state A. Fig. 4b shows a switching state during a switching process from A to B. The first contact piece 1 already contacts the second contact piece 2. You can use the contact arrangement so that the switching state shown in Fig. 4b ultimately reached switching state B corresponds. However, the contact arrangement can be advantageous be dimensioned so that only the position shown in Fig. 4c is the end position, i.e. the switching state B. Then the flexible Contact segment 11 not only one contact point at the two ends of the membrane with the contact segment carrier 12, but additionally a further contact point that is not present in the first switching state A. 6 (or a touch pad 6). This results in a lower one Contact resistance. Possible contacting problems due to manufacturing tolerances can at least be reduced, among other things, that the contact piece that is driven is always one Residual mobility, usually due to a spring-like suspension. If one transfers the structure from FIG. 4 to the switching device from FIG. 1, then the first contact piece 1 the driven contact piece.

Fig. 5 shows a further contact arrangement according to the invention, which the 3 and is described on the basis thereof. The flexible Contact segment 11 has in Fig. 5 except a membrane-like flexible Section another base 113. And the flexible contact segment 11 has approximately the shape of an isosceles triangle, with the Base side of the triangle from the second contact piece 2 and the third Contact piece 3 faces away and is formed by the base 113. It's the first switching state A shown. That of the flexible contact segment 11th enclosed volume 114 can be used as needed, as related to Fig. 2 described to be filled with a filling.

Preferably, the flexible contact segment 11, in particular on the Contact pieces 2 and 3 facing side (tip of the triangle), rounded (not shown). The flexible section of the flexible contact segment 11 elastically deformed, and there is a sliding motion between the flexible contact segment 11 and Contact pieces 2 and 3.

The base 113 of the flexible contact segment 11 increases the conductivity the contact arrangement. Electrical and / or thermal resistances will be thereby reduced. And a larger heat capacity is realized.

FIG. 6 shows a contact arrangement which largely corresponds to that from FIG. 5. There is also a means for suspension 13 between the flexible Contact segment 11 and the contact segment carrier 12 arranged. This creates contacting problems due to manufacturing tolerances reduced. The contact segment 11 can optimally contact the contact pieces Nestle 2 and 3

In Fig. 7 is a contact arrangement with a first contact piece 1 and shown second contact piece 2, in which the two contact pieces 1.2 interact in the manner of a plug-socket pair. The second Contact piece 2 has a nose that is approximately the shape of a rounded one Rectangle, which also has a small waist.

The first contact piece 1 contains the contact segment carrier 12 another flexible contact segment 11, the two flexible contact fingers 111,112. The contact fingers 111, 112 are each at one end connected to the contact segment carrier 12 and at another end free, and facing the second contact segment 2. The elongated contact fingers 111, 112 are essentially parallel to one another and perpendicular aligned to the contact segment carrier 12. They are slightly S-shaped, with the free ends bent away from each other.

In the second switching state B (Fig. 7b) is the plug-like second contact piece 2 arranged with his nose between the two contact fingers 111, 112. The contact piece points with each of the two contact fingers 111, 112 2 a flat contact area 5. In addition, the contact piece 2 advantageously also has a flat contact area 5 ' the contact segment carrier 12. In the second switching state B they are Contact fingers 111, 112 except for those attached to the contact segment carrier 12 End further apart than in the first switching state A.

When switching from A to B, the contact fingers 111, 112 elastically deformed, and there is a sliding movement between the second contact piece 2 and the flexible contact segment 11 instead. To introducing energy or contact finder deformation energy must be applied become. This insertion energy is generally from one Drive supplied. In the second switching state B, the contact fingers practice 111, 112 a retaining force on the second contact piece 2. You press the second contact piece 2 laterally together and thereby hold it firmly in the contacting position. This is a minimum for separation the contact pieces 1 and 2 required force can be specified. At a Switching process B to A must have an execution energy applied, to separate the contacts. The contact arrangement is in the Self-cleaning method already described above.

The shapes of the contact pieces 1, 2 are chosen such that the flexible Contact segment 11 in the second switching state to the first contact piece 1 is molded.

In Fig. 8a, b a contact arrangement is shown, which is similar to that of Fig. 7a, b and is described on the basis of this. Instead of the second contact piece 2 in the second switching state B between the two contact fingers 111, 112 is arranged (FIG. 7b), it contacts the two in FIG. 8b Contact fingers 111, 112 from the outside, ie from those sides of the contact fingers 111, 112 facing away from the other contact finger 112, 111 are. For this purpose, the second contact piece 2 has an approximately U-shaped, the first contact piece facing recess.

Fig. 9a, b shows a contact arrangement which is similar to that of Fig. 8a, b and starting from this is described. Instead of a second contact piece 2 in the second switching state B, the first contact piece 1 is replaced by a second one Contact piece 2 and another contact piece 3 contacted. Each of the two contact pieces 2 and 3 have the shape of a rounded half of a the length of the contact piece shown in Fig. 8a, b. In addition, the flexible contact segment 11 also has a base 113 equipped, which has the same effect as the bases 113 in Fig. 5 and Fig. 6. Im second switching state B (Fig. 9b) are contact surfaces 5 of the contact pieces 2 and 3 with the flexible section of the flexible contact segment 11 and also contact surfaces 5 'of the contact pieces 2 and 3 with the Base 113 demonstrated. The free ends of the contact fingers can be advantageous 111, 112 may also be bent further toward one another than in FIGS. 9a, b shown. As a result, the influence of Field stress and peak effects reduced.

10a, b shows a contact arrangement with a first contact piece 1 and a second contact piece 2. The first contact piece 1 has flexible contact segment 11, which a plurality side by side arranged flexible contact finger 111.112 comprises. The in Fig. 10a, b The six contact fingers 111, 112 shown are (in half) in two groups divided three contact fingers 111 or 112, preferably are arranged essentially mirror images. But 2, 3, 4, 5, 7, 8, 9, 10 or more, for example 12, 14, 16 or 18 contact fingers 111,112 are shown. The contact fingers 111, 112 are elongated trained and walking stick-shaped or in the manner of a curved finger bent. The ratio of length to wall thickness of the contact fingers 111, 112 is advantageously in the range from 5: 1 1 to 100: 1, particularly advantageously in the range from 12: 1 to 40: 1 or advantageously also in the range from 20: 1 to 30: 1. These length-to-wall thickness ratios are also for that other contact fingers shown in this description (see Figs. 7, 8, 9, 12). At one end are the contact fingers 111, 112 with the contact segment carrier 12 connected. At its other end (according to the handle of the walking stick or the tip of the finger) they are free. The direction of the Curvature of the contact fingers 111 (at their free end) is advantageous Curvature of the contact fingers 112 opposite. 10a is the first Switching status A (open) shown. The length of each contact finger 111, 112 is advantageously chosen such that an envelope of its free Ends essentially of the surface facing the contact fingers 111, 112 of the second contact piece 2 corresponds. At least that has Envelope in the second switching state (FIG. 10b) advantageously has such a shape, so that the contact fingers 111, 112 then contact the second contact piece 2 nestle.

In the second switching state B (Fig. 10b, closed) have the first contact piece 1 and the second contact piece 2 a plurality of contact points 5 on. It can also be a plurality of contact areas 5. The individual contact fingers 111, 112 of the flexible contact segment 11 are elastically deformed by the second contact piece 2. The flexible contact segment 11 is formed on the second contact piece 2. At a Switching process, the contact fingers 111, 112 of the flexible contact segment move 11 sliding against the second contact piece 2, so that the self-cleaning effect mentioned above occurs.

A contact arrangement according to Fig. 10a, b has the advantage that a minimum number of contact points 5 or contact areas 5 can be predetermined, so that a safe contact with low contact resistance can always be achieved is.

11a, b illustrate a further advantageous embodiment. In Fig. 11a shows the first switching state A, in Fig. 11b the second Switching state B. The contact arrangement has three contact pieces 1, 2, 3. The first contact piece 1 comprises a flexible contact segment 11 and one Contact segment carrier 12. The third contact piece 3 comprises a flexible Contact segment 31 and a contact segment carrier 32. The third Contact piece 3 is preferably mirror-symmetrical to the first contact piece 1 trained and arranged. The second contact piece 2 comprises one rigid section and one connected to the rigid section Contact carrier 22.

11a, b, the second contact piece 2 is the driven contact piece. The direction of the relative movement of the second contact piece 2 opposite the contact pieces 2 and 3 is shown by a dashed line. The rigid section of the second contact piece 2 has two essentially flat surfaces with the direction of the relative movement of the second Contact piece 2 relative to the contact pieces 1 and 3 an angle α ' lock in. In the second switching state B (Fig. 11b), the first and the third contact piece 1,3 on their flexible contact segments 11,31 contact surfaces 5 with the second contact piece 2. These touch surfaces 5 in the second switching state B close with the direction of the relative Movement of the second contact piece 2 relative to the contact pieces 1 and 3 an angle α. This angle α is preferably in the range of about 45 ° ± 30 °, especially in the range of 45 ° ± 15 °. Because of the rigidity of the rigid section of the second contact piece 2 becomes the rigid section essentially not elastically deformed during switching operations. Therefore the angles α and α 'are essentially the same.

In the first switching state A (FIG. 11a) those surfaces of the second are Contact piece 2 and the first and third contact piece 1, 3, which form the two-dimensional contact area 5 in the second switching state, in arranged at an angle ε to one another. The following applies preferably for this angle ε 0 ° ≤ ε ≤ 30 ° and in particular 0 ° ≤ ε ≤ 10 °. Are particularly advantageous even small angles ε with 0 ° ≤ ε ≤ 5 °. By the arrangement described and With the specified angles, a safe, large-area contact with pronounced friction and correspondingly good cleaning effect realized become.

Contact arrangements are preferred, at least for electrical applications used, which have more rounded corners and edges than shown in Fig. 11.

In Fig. 12a, b a contact arrangement is shown, which is similar to that in Fig. 7a, b is shown. It is described on the basis of this. In Fig. 12 that second contact piece 2 has a clear taper, in particular a waist on. The contact fingers 111, 112 of the flexible contact segment 11 are clear S-shaped, so that the contact segment carrier 12 further away bellies of the two "S" in the second switching state B (Fig. 12b) engage in the mentioned taper. The one to turn on (A to B) introductory energy to be applied and also to the Execution energy to be applied (B to A) is large. The Execution energy is so great that a monostable switchable contact segment carrier 12, like that shown in Fig. 12a, b, thereby bistable is switchable. The first stable position is the natural, manufacturing-related stable position of the monostable bendable contact segment carrier 12 (Fig. 12a, switching state A). The second stable position (Fig. 12b, second switching state) is the inherently unstable, bent position of the bendable contact segment carrier 12, in which the contact arrangement however, the execution energy remains until appropriately is applied. Due to the flexible contact segment 11 Contact arrangement thus held in the second stable switching position B. By means of the push button principle, a bistable switchable contact arrangement is created realized. The number of stable positions for the contact segment carrier can be increased by at least one. A not shown An example of a two stable position increase is one at one end clamped beam, which is flexible at its free end on each side Contact segments of the type of the flexible contact segment shown in Fig. 12a, b has, each of these flexible contact segments with one each another contact piece cooperates in the manner of the push button principle. This results in three stable positions of the contact segment carrier instead of just one.

In the presented embodiments, this improves, safer Contact arrangements created that due to its thin walls flexible contact segment 11 during a switching operation by means of mostly rigid second contact segment 2 is elastically deformed. In general the flexible contact segment 11 is different from the drive 4 and is not directly deformed by the drive 4. In general will the flexible contact segment both when switching from the first in the second also when switching from elastically deform the second to the first switching state. It is also conceivable that one of these (re) deformations only (shortly) after the switching process (and before another switching operation) takes place, such (Re) deformation can also be induced, i.e. not by itself, but stimulated, for example by electrostatic forces.

The alternative or additional listed above and below Features are optional and among themselves as well as with those in the description The exemplary embodiments shown can be combined as desired.

The contact arrangements can be made using one or more structuring methods, such as DRIE, 3D UV depth lithography, LIGA technology or other structuring processes from semiconductor manufacturing (Coating, etching).

As materials from which the contact arrangements or MEMS are made there are other materials besides silicon (Si), especially Semiconductor materials in question. Silicon carbide is particularly suitable (SiC), germanium (Ge), gallium arsenide (GaAs), gallium nitride (GaN), InSb (indium antimonide), InP (indium phosphide), quartz and diamond. One is important high tensile strength, high abrasion resistance and low mechanical Fatigue.

Materials with a tensile strength of at least 40 N / m ² , more preferably at least 50 N / m ² or even better at least 60 N / m ² are preferably used. Silicon has a tensile strength of 69 N / m ² , while steel typically has 21 N / m ² , maximum 42 N / m ² . Tungsten (W): 40 N / m ² , aluminum (AI): 1.7 N / m ² .

To increase the tensile strength, coatings can also be applied to the contact pieces, in particular to the flexible contact segment. Carbides, nitrides and oxides are particularly suitable for this. SiC has a tensile strength of 210 N / m ² , Si ₃ N ₄ one of 140 N / m ² and SiO ₂ one of 84 N / m ² .

Hardness is an important factor in terms of abrasion resistance. Silicon has a Knoop hardness of 850 kg / mm ² , while stainless steel has 660 kg / mm ² , tungsten 400 kg / mm ² and aluminum only 130 kg / mm ² . Coatings can also be advantageous for achieving improved abrasion resistance, for example with SiC (Knoop hardness 2480 kg / mm ² ) or Si ₃ N ₄ (3486 kg / mm ² ).

In the event that the contact arrangement switches electrical currents metallic coatings to reduce contact resistance (electrical, but also thermally) is an advantage. The contact pieces 1,2 then point metallic surfaces, which in the second switching state B touch. Semiconducting materials are advantageously doped, so that they are a have good electrical conductivity.

It is also advantageous to use material that has a low mechanical Exhibits fatigue. Fatigue fractures are almost exclusive Initiated surfaces. A material with a rough surface is very tiring much faster than a material with a smooth (polished) surface. Essential for the material fatigue is the defect density on the surface. For this reason, single-crystalline or highly crystalline material is advantageously used. And it is advantageous to produce smooth surfaces, for example middle etching process is easy to achieve.

Monocrystalline silicon is extremely small due to its manufacture Defect density. In addition, the generation of smooth surfaces with single-crystal Silicon is simple. So one can, with ordinary metals like compared to polycrystalline steel or aluminum, extremely low material fatigue be achieved.

The contact arrangements can advantageously be two, three, four, five, six or include more contact pieces. One, two or more of them can be driven or be agile. One, two or more each have one or several flexible contact segments 11, which are driven (movable) or non-driven (non-movable) contact pieces can act, and wherein one or more driven (movable) while one or more others are not driven (not movable). Advantageously touch in second switching state B, a first one provided with a flexible contact segment Contact piece and a second, essentially non-deformable Contact piece. Instead of a rigid second contact piece can also such a second contact piece can be used, which is a flexible contact segment or has an elastically deformable section. Preferably are the contact pieces with a flexible contact segment each formed in one piece.

A contact arrangement according to the invention can also have several first switching states A and / or have a plurality of second switching states B. For example in the case of a two-way switching relay with one open and two closed States, see for example also the unpublished mentioned European patent application with the file number 02405334.0.

The drive 4 and any other drives 4 can be electrostatic, for example, but also electromagnetic, piezoelectric or thermal work.

The contact arrangement or the MEMS can be one act lateral structure, in which movements essentially parallel to the substrate (horizontal) run. But it can also be a vertical structure be in which movements are substantially perpendicular to the substrate.

The contact arrangements can advantageously be used in switching devices, which are able to generate a high contact pressure, as is the case for example the case with the bendable contact segment carriers mentioned is.

Electrical micro-switches and micro-relays with one according to the invention can advantageously be used Contact arrangement can be equipped. With such Switches can advantageously automated test devices (ATE, automated test equipment). It is also possible to use mechanical Switches or interrupters or micro-valves with an inventive To provide contact arrangement.

The features mentioned can be common or individually or in any Combination can be advantageous.

1

erstes Kontaktstück

11

flexibles Kontaktsegment

1 11,112

Kontaktfinger des flexiblen Kontaktsegments

113

Basis des flexiblen Kontaktsegments

114

Volumen

12

Kontaktsegment-Träger

13

Mittel zur Federung

2

zweites Kontaktstück

22

Kontakt-Träger des zweiten Kontaktstücks

3

drittes Kontaktstück

31

flexibles Kontaktsegment des dritten Kontaktstücks

32

Kontaktsegment-Träger des dritten Kontaktstücks

4

Antrieb

5,5'

Berührungsbereich, Berührungsfläche, Berührungspunkt zwischen erstem Kontaktstück und zweitem Kontaktstück

6

zusätzlicher Berührungspunkt im zweiten Schaltzustand zwischen flexiblem Kontaktsegment und Kontaktsegment-Träger oder Basis

A

erster Schaltzustand (geöffnet)

B

zweiter Schaltzustand (geschlossen)

d

Wanddicke (des flexiblen Abschnitts) des flexiblen Kontaktsegments

α

Winkel

ε

Winkel

LIST OF REFERENCE NUMBERS

1

first contact piece

11

flexible contact segment

1 11.112

Contact finger of the flexible contact segment

113

Basis of the flexible contact segment

114

volume

12

Contact segment carrier

13

Suspension means

2

second contact piece

22

Contact carrier of the second contact piece

3

third contact piece

31

flexible contact segment of the third contact piece

32

Contact segment carrier of the third contact piece

4

drive

5.5 '

Contact area, contact surface, point of contact between the first contact piece and the second contact piece

6

additional point of contact in the second switching state between the flexible contact segment and the contact segment carrier or base

A

first switching state (open)

B

second switching state (closed)

d

Wall thickness (of the flexible section) of the flexible contact segment

α

angle

ε

angle

Claims (17)

MEMS contact arrangement, with at least a first contact piece (1) and a second contact piece (2), at least one of the two contact pieces (1; 2) being drivable, and wherein the MEMS contact arrangement by means of the drivable contact piece (1; 2) a switching process can be switched between a first switching state (A) and at least a second switching state (B), the two contact pieces (1, 2) being separated from one another in the first switching state (A) and making contact with one another in the second switching state (B) .
characterized in that at least the first contact piece (1) has at least one flexible contact segment (11) and a contact segment carrier (12), and
that the at least one flexible contact segment (11) can be elastically deformed during the switching process by means of at least the second contact piece (2). MEMS contact arrangement according to claim 1, characterized in that the at least one flexible contact segment (11) by means of at least the second contact piece (2) during a switching process from the first switching state (A) to the second switching state (B) is elastically deformable such that the at least one flexible contact segment (1 1) with the second contact piece (2) in the second switching state (B) has at least one flat contact area (5) or a predeterminable plurality of contact points (5,5 '). MEMS contact arrangement according to one of the preceding claims,
characterized in that in the first switching state (A) the shape of the flexible contact segment (11) is different from the shape of the flexible contact segment (11) in the second switching state (B), and
that in the second switching state (B) the flexible contact segment (11) is molded onto the second contact piece (2). MEMS contact arrangement according to one of the preceding claims,
characterized in that in the first switching state (A) the shape of the flexible contact segment (11) is different from the shape of the flexible contact segment (11) in the second switching state (B),
that the at least one flexible contact segment (11) with the second contact piece (2) in the second switching state (B) has at least one flat contact area (5),
that in the second switching state (B) the flexible contact segment (11) in the contact area (5) is formed on the second contact piece (2), and
that in the second switching state (B) the second contact piece (2) in the contact area (5) is enclosed by the first contact piece (1). MEMS contact arrangement according to one of the preceding claims,
characterized in that during the switching process the second contact piece (2) is slidably movable relative to the flexible contact segment (11). MEMS contact arrangement according to one of the preceding claims,
characterized in that the flexible contact segment (11) is flexible and elastically deformable due to its thin walls,
in particular that the flexible contact segment (11) has a flexible section with a wall thickness between 1 µm and 60 µm, preferably with a wall thickness between 5 µm and 25 µm, and
in particular that the elastic deformations are at least of the order of magnitude of the wall thickness of the flexible section of the flexible contact segment (11) and / or in the range from 0.5 to 20 times, in particular from 1 to 5 times the wall thickness of a flexible section of the flexible contact segment (11) lie. MEMS contact arrangement according to one of the preceding claims,
characterized in that the first contact piece (1) is formed in one piece. MEMS contact arrangement according to one of the preceding claims,
characterized in that the flexible contact segment (11) contains, in addition to at least one flexible section, a base (113) facing the contact segment carrier (12), which base (113) has a greater wall thickness than the at least one flexible section. MEMS contact arrangement according to one of the preceding claims,
characterized in that for the elastic deformation of the at least one flexible contact segment (11) by means of at least the second contact piece (2) during an switching process from the first switching state (A) to the second switching state (B) an introduction energy is to be applied,
that for the elastic deformation of the at least one flexible contact segment (11) by means of at least the second contact piece (2) during a switching operation from the second switching state (B) to the first switching state (A), an execution energy is to be applied, and
that in the second switching state (B) a retaining force can be exerted by the flexible contact segment (11) on the second contact piece (2), by means of which retaining force a switching operation from the second switching state (B) to the first switching state (A) is made more difficult. MEMS contact arrangement according to one of the preceding claims,
characterized in that the contact segment carrier (12) is a switching element with at least one stable position, and
that the flexible contact segment (11) and the second contact piece (2) interact in the manner of the push-button principle in such a way that the contact segment carrier (12) has at least one further stable position. MEMS contact arrangement according to one of the preceding claims,
characterized in that the flexible contact segment (11) and the second contact piece (2) can be inserted into one another in the manner of a plug-socket pair. MEMS contact arrangement according to one of the preceding claims,
characterized in that the flexible contact segment (11) has a plurality of elastically deformable contact fingers (111, 112). MEMS contact arrangement according to one of the preceding claims,
characterized in that the at least one flexible contact segment (11) in the second switching state (B) has at least one flat contact area (5) with the second contact piece (2),
that the direction of the relative movement of the flexible contact segment (11) and the second contact piece (2) during the switching process with the flat contact area (5) essentially has an angle α = 45 ° ± 30 °, in particular α = 45 ° ± 15 °, includes, and
that those surfaces of the flexible contact segment (11) and of the second contact piece (2) which are aligned essentially parallel to one another in the second switching state (B) and touch each other in the flat contact area (5) in the first switching state (A) essentially to are aligned parallel to one another at an angle ε with 0 ° ε 30 30 °, in particular 0 ° ε 10 10 °. MEMS contact arrangement according to one of the preceding claims,
characterized in that the flexible contact segment (11) includes a membrane-like section which is elastically deformable during the switching process. MEMS contact arrangement according to one of the preceding claims,
characterized in that the flexible contact segment (11) or the flexible contact segment (11) together with the first contact piece (1) encloses a volume (114) which is essentially filled with an electrically and thermally conductive, elastically deformable filling , MEMS switching device characterized in that the MEMS switching device includes a MEMS contact arrangement according to one of the preceding claims. MEMS switching device according to claim 16, characterized in that the MEMS switching device is a micro-relay with a drive (4), and in particular that the drive (4) is an electrostatic drive (4).

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