DE20121235U1 - Contacting device for establishing an electrically conductive connection - Google Patents

Description

Herbert Amrhein Rainer Rothe

Weingartweg 6 Bergstr. 38

74321 Bietigheim-Bissingen 78234 Engen

Contacting device for establishing an electrically conductive connection

The invention relates to a contacting device for establishing an electrically conductive connection simultaneously on several conductors arranged next to one another with several contact elements arranged next to one another in an elastomeric elastic body in an electrically insulated manner and having contact points extending out of this body at both ends.

Such a contacting device is described in US 5,904,580 A. In this known contacting device, contact elements are embedded in an elastic molded body and have a trough-shaped

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bulge, which serves to secure the elastic molded body in a form-fitting manner. The contact elements protrude from the molded body with angled

Contact tabs protrude, which run slightly diagonally to the surface of the cuboid-shaped body, so that they are bent in a spring-elastic manner when contact is made. The free end section of the spring tabs is further

*5 the top of the molded body, so that an edge is created. If the contact tabs are pressed together so far (as shown in Fig. 3) that they rest on the corresponding surface of the body, further compression can occur, deforming the body and simultaneously bulging the entire clock element within the body. However, this poses the risk of shifting the contact point, so that precise contact cannot be guaranteed, particularly with small, closely spaced connections to be contacted on today's ICs.

Another contacting device is known from DE 196 52 271 A1, where the body with the contact elements is composed of several individual bodies and the tips are designed as clamping elements. This contacting device is particularly suitable for tapping or supplying signals to individual, closely spaced conductors in the form of IC connections and for fixing the contacting device to the connections of the component. Therefore, each individual contact element is also equipped with actuating mechanisms provided inside and outside the housing.

Further contacting devices, which are designed as test terminals or test probes, are described, for example, in DE-AS 1 266 385 and in McAllister, M.F.:

Marasch, M.R.: "Test probe with variable ground and constant impedance capabilities" in: IBM Technical Disclosure Bulletin, Vol. 18, No. 3, August 1975, pages 699 and 700. These contacting devices are relatively complex in design and are not designed, for example, to contact many adjacent conductors.

Furthermore, spring-loaded contact pins are known with diameters of up to 0.25 mm and lengths of a few millimeters. Due to the design of the contact tip, spiral spring and connection sleeve, the self-inductance, capacitance and frictional contact resistance are variable and not constant due to the length and temperature, humidity, pressure, etc., and their usability is limited, particularly for HF applications and for the transmission of analog signals and precise current and resistance measurements.

Silicone contact strips and mats are also known. This elastic carrier material is filled with conductive particles in narrow contact areas. When contact pressure is applied, these reduce their contact resistance and thus represent a variable resistance that depends on pressure, temperature and current. Their use is limited for measurements such as voltage, resistance, analog signals and HF applications.

The invention is based on the object of providing a contacting device of the type mentioned at the outset which, with a simple structure and easy handling, also enables reliable contacting of several adjacent conductors, in particular when the contact points and contact distances are on the order of tenths of a millimeter or even less.

This object is achieved with the features of claim 1. According to this, it is provided that the sections of the contact elements arranged in the body are designed to be spring-elastic in that they undergo at least one simple elastic bend in the body, which is shaped in such a way that the deflection of the contact points of the contact elements takes place essentially only parallel to the direction of a contact pressure applied during contacting, and that the

™ Body is made of elastic insulating material. The one made of elastomer (from

Bodies made of elastic insulating material (e.g. plastic, synthetic rubber, natural rubber or mixtures thereof) and the contact elements accommodated therein with an elastic bend result in an elastic body with contact element parts emerging from the insulating material, which are designed, for example, as tips or curves and are used for metallic contact. If these narrow contact surfaces are placed, for example, on a large number of conductor tracks lying close together for contacting with light pressure, the elasticity of the body and the contact elements reliably ensures that all contact points come into contact with the conductor tracks ^ and that, with small contact surfaces of the freely protruding contact element parts, a high surface pressure is achieved and contact contamination can be penetrated, so that a secure galvanic connection of all contact elements is achieved. In particular, the protruding contact element parts can be arranged next to one another in a row, with the formation of the springy, elastic bends also maintaining secure positioning in the contact area.

The elasticity of the contact elements is enhanced by the fact that the contact elements each have at least one in the elastic insulating material

existing, one-piece body have an opposite bend embedded in them and furthermore in that the bends are transition sections of a meandering arrangement. For example, the opposite bends can be U-shaped and arranged alternately opposite one another. A zigzag-shaped arrangement with round transitions is also conceivable.

™ Likewise, in accordance with the minimization of geometry sought according to the invention, a shape design with a semicircular or semi-oval bend is possible.

In order to safely maintain the contact points in the area of the contact points, it is also advantageous that the bends are aligned perpendicular to the direction of the contact elements arranged next to one another.

As in the previous embodiments, the contact elements are preferably arranged in parallel and spatially separated from one another by thin, highly elastic elastomer layers, whereby good insulation and good adhesion of the contact elements within the body are ensured.

In order to contact conductor tracks that are spatially adjacent to one another, an advantageous design is that the ends that are led out are also designed as tips.

The contacting device can be designed for receiving or supplying signals with connecting wires or the like in such a way that the
Ends as contact pin or as connector for connecting wires

are designed. To improve accessibility of the protruding ends, it can be provided that the body widens from the area of the protruding ends and that the protruding ends widen in a fan-like manner.

For handling and protection, it may also be advantageous to enclose the body in an outer housing, except for the exposed contact element parts.

An advantageous use consists in that the contacting device with contact element parts led out on both sides is used for contacting the conductor tracks of two circuit boards lying next to one another or of a circuit board with an adjacent liquid crystal display panel or the like.

Further advantageous uses include the contacting device being used to contact IC contacts, conductor tracks of printed circuit boards, contacts of adaptation devices or connectors with each other or in combination with each other.

The contacting device is essentially designed in a block-like manner and can be manufactured in practically any number of adjacent contact elements or contact element parts and cut to length parallel to the contact elements for the application. It is also possible to design the contacting device with contact rows adapted to a contacting task for contacting ICs, with circuit boards and adapters in order to achieve individual contacting.

contact arrangements and contact guides of ICs, adapters or similar contacting requirements.

In particular, it is possible to contact the connections of components such as resistors, capacitors, coils, connectors, etc., both printed components and surface-mounted SMD components, both loose and soldered on circuit boards, adapters and similar devices.

In addition to simply contacting the above-mentioned connections of these components, it is possible to carry out a 4-wire or Kelvin measurement due to the multiple parallel contacting of even the smallest connection surfaces. These measures can also be carried out on components, ultra-fine conductor tracks, vias, IC connections and minimal contact points of other possible devices.

The invention is explained in more detail below using exemplary embodiments with reference to the drawings.

Fig. 1 is a fragmentary perspective view of a contacting device with contact tips,

Fig. 2 a contacting device with contact tips arranged on opposite sides in perspective view,

ti* ·

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Fig. 3 a cutaway contacting device in the plane of a contact element,

Fig. 4 Possibilities for the execution of elastic bends of the contact element,

™ Fig. 5 Possibilities for the design of contact surfaces

guided contact element parts,

Fig. 6 an embodiment of the contacting device in which the outgoing ends are fanned out,

Fig. 7 a contacting device with an outer housing,

Fig. 8 a contacting device with another outer housing,

Fig. 9 the use of a contacting device for contacting an IC on a circuit board,

Fig. 10 a use of the contacting device for contacting

a circuit board with an adapter device,

Fig. 11 the use of several contacting devices for con

clocking two different ICs with a circuit board,

Fig. 12 the use of several contacting devices for con-

clocking an IC with an adapter and

Fig. 13 the use of several contacting devices for con

tactile switching of two circuit boards lying next to each other at a distance.

Fig. 1 shows a contacting device 10 with parallel embedded, narrow metallic contact elements 1, which are led out in a row with contact element parts 1.1 designed as tips from a cuboid-shaped body 2 made of highly elastic elastomer. The elastomer body is made of individual layers or is formed in one piece. The layers bring about a defined spatial separation, electrical insulation and sufficient adhesion of the contact elements 1 within the body. The tips 1.1 of the contact elements 1 protruding from the body 2 bring about a

contact surface cross-section a high surface pressure even at low pressure, so that contact contamination is penetrated and a secure galvanic connection with the conductors of a test object is ensured.

In the contacting device 10 shown in Fig. 2, tips are also formed on the side of the body 2 opposite the tips 1.1 at the protruding free ends 1.3. With such a contacting device 10 it is possible, for example, to connect the connection pins of an integrated electronic component (IC) with an adapter according to Fig. 9, a printed circuit board with an adapter according to Fig. 10, a
Circuit board 30 with ICs according to Fig. 11, an IC with an adapter according to Fig. 12

or to electrically connect two parallel-aligned circuit boards 30 lying next to each other as shown in Fig. 13.

In Fig. 3, a single contact element 1 is shown in a side sectional view. At both ends, the contact elements 1 are provided with triangular tips 1.1 in side view. In between, the contact element 1 is meandering

W -shaped with alternating U-shaped curves embedded in the body 2. This ensures a high level of elasticity together with the body made of elastomer material in the longitudinal direction of the contact element 1 and thus a secure contact of the tips 1.1 even in the event of any unevenness of the tips or the conductors to be contacted, even with low pressure.

Fig. 4 shows possible ways of designing the contact element, while retaining the principle according to the invention of allowing the elastic bending to take effect in a spring-elastic manner perpendicular to the contacting device, whereby the contacting positions are precisely maintained. Depending on the size or smallness and manufacturability, meandering, multiple, single, parallel, opposite or same direction bends are possible, which lead to an oval, half-oval, circular or semi-circular design. The contact pressure during contacting results in an effective, positionally accurate elastic deflection of the contact points of the contact element, e.g. through bending areas oriented essentially at right angles to the pressure direction.

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Fig. 5 shows in detail possible designs of the protruding contact element parts of the contact element 1. These are shown here, for example, pointed 1.1, rounded 1.1' or flat 1.1".

Detail 1.3" shows a connection option for a contact element 1, which has a hole at its free end to attach connecting wires to it.

Detail 1.3' shows a possibility of connecting one or more sockets to a contacting device 1. For this purpose, the free end 1.3' of each contact element 1 is shaped as a contact pin.

Fig. 6 shows a possible design of the housing shape of the contacting device 10. The housing of the contacting device 10 is formed by the elastomer body 2 itself. The housing shape is narrow and tapered in the longitudinal direction. Contact is made with the test object by means of the tips 1.1 protruding on the narrow side. The contact elements 1 are embedded in elastomer in the housing or body 2. The housing contour is provided with recesses, notches 5, depressions or elevations on the side or on the top or bottom so that, for example, an outer housing, a hood or the like can be secured in a form-fitting manner by snapping into place and/or by gluing. The housing 4 is widened on the exit side of the contact elements 1. The contact elements 1 extend apart in a fan-like manner and are freely accessible. At their ends they enable cables, wires or pins to be connected.

Fig. 7 shows a possibility of installing the contacting device 10 in an outer housing 6 with a rectangular basic shape. In this case, the positive and frictional connection between the body 2 or housing 4 and also the contact elements 1 with the outer housing 6 can be achieved by means of hardening adhesive 7.

In the outer housing 6, a socket unit for connecting external cables can additionally be provided.

Another possibility of installing the contacting device 10 in a housing 6' is shown in Fig. 8. The outer housing 6' has a round or oval cross-section. A round half-shell is shown, for example to form the front area of a probe. In the area of the body 2, the outer housing 6' is shaped in such a way that it engages in the lateral notches 5 of the contacting device 1 and thus offers a defined form fit. The adhesive 7 can further increase the position and shape retention.

Fig. 9 shows an embodiment for contacting an integrated component (IC) with a test device/adapter 40. In this case, the contact device 10 connects the connection pins of the IC on the one hand and the contacts/contact surfaces of the adapter 40 on the other hand.

Fig. 10 shows an embodiment of the contacting device 10, between fine and ultra-fine conductor tracks 30.1, a circuit board 30 and an adapter device 41. With very small dimensions of the contacting device 10, with a very short contact length of approx. 1 mm, excellent electrical and physical characteristics are obtained, such as minimal volume resistance, self-inductance, capacitance.

ity, attenuation, etc., which is particularly advantageous for use in the high and very high frequency range, for example to carry out comparative measurements with soldered components for test and inspection purposes. Contact can often be made here without thermally stressing pins or conductor tracks, as is the case with repeated desoldering and soldering.

Ws Fig. 11 shows an embodiment of several contact devices 10 to enable a connection of different IC connections and with the conductor tracks 30.1 of a circuit board 30. Here too, the advantages mentioned in Fig. 10 are to be mentioned.

Fig. 12 shows an embodiment of the contact device 10 for connecting an IC to a test adapter 42. Here, too, the advantages mentioned in Fig. 10 apply.

Fig. 13 shows an embodiment of the contact device 10 for connecting parallel ^5 circuit boards 30 arranged next to one another. Here too, the advantageous physical and electrical properties mentioned in the description of Fig. 10 with regard to HF applications are particularly worthy of mention.

The measures described enable contact spacing to be minimized to less than 0.1 mm. This takes account of the miniaturization of the geometric dimensions of electronic components that are operated at ever higher clock frequencies, such as microprocessors and microcontrollers. The design of the contacting device prevents crosstalk between neighboring conductors or contact elements 1, which can occur with increasing

Signal frequencies and the minimized geometric distances are largely avoided. The contact elements 1 in the present contacting device 10 are made of a single metallic, solid material, so that contact resistance in the contact elements 1 is avoided. As a result of the selected material hardness of the metallic contact elements 1, impurities between the contacting device 10 and the conductors Π5 of the test object are penetrated, so that a secure galvanic connection is guaranteed. The springy design of each individual contact element 1 and the body 2 from the highly elastic elastomer material creates a springiness that compensates for mechanical material unevenness when used on the test object and enables secure contact, for example, on IC connection pins or on thin conductor tracks.

The material used for the contact elements 1 is preferably non-oxidizing metal, which can be galvanically coated to improve contact.

The wedge-shaped design of the tips 1.1 pushes through dust and dirt, oil and grease films and slight surface corrosion and creates a secure galvanic contact. Any number of contacts is guaranteed. The bending of the contact elements 1 within the body 2 converts the axial contact forces into elastic bending forces, which allow the contact element to be shortened under spring tension. Since the bending takes place in the elastic range of the contacting material, the individual contact returns to its original position after the contact is released.

During production, the individual elements can be placed in a mold and then covered with the elastomer material for embedding. The shape of the embedding elastomer body 2 can be selected so that it is easy to handle and the contacting device 10 can be provided with a suitable outer housing 6, 6' in a form-fitting or force-fitting manner by gluing or clamping and electrical T5 cables can also be fixed. By embedding in the flexible elastomer material and the design of the contact elements 1, the tips 1.1 can move slightly relative to one another in order to compensate for unevenness. In order to enable the small distances between the contact elements 1 of less than 0.1 mm, the various material properties and physical limits of the metallic contact elements 1 and the insulating materials are coordinated and optimized. The bends and material cross-sections of the contact elements 1 are also coordinated according to the required spring travel of the contact elements 1 and the elastic body 2. In this way, for example,
a spring force at the tips 1.1 corresponding to a contact surface pressure of the *m wedge-shaped tips 1.1 of several Newton/mm ² can be achieved.

With regard to the limit values of the electrical breakdown voltage of the insulating materials used, in particular the elastomers, for example 20 KV/mm, an insulation distance of 0.03 to 0.05 mm, for example, results in a sufficient breakdown voltage to allow operating and test voltages of 50 V DC. With an insulation distance of, for example, 0.04 mm and a metal thickness of the contact elements 1 of 0.04 mm, the distance between the contact elements 1 is 0.08 mm.

The contact devices 10 accommodated in the outer housings 6, 6' and fixed therein, for example glued or cast, enable a large number of different shapes to be tailored to the respective application. A versatile range with different contact devices with different numbers of poles and dimensions can thus be provided.

T5 The contacting devices 10 can be used not only for contacting printed circuit boards, conductor tracks, through-holes and electrical and electronic components, but also in SMD design for contacting tissues, particles and the like in physical, chemical and biological technology, for example to connect measuring instruments.

Claims (8)

1. Contacting device for establishing an electrically conductive connection simultaneously on several conductors arranged next to one another with several contact elements ( 1 ) which are fixed next to one another in an elastomeric elastic body in an electrically insulated manner and which lead out of this at both ends ( 1.1 , 1.3 , 1.3 ', 1.3 "), characterized in that the sections of the contact elements ( 1 ) arranged in the one-piece body are designed to be spring-elastic in that they pass through at least one simple elastic bend ( 1.2 ) in the body, which is shaped such that the deflection of the contact points of the contact elements ( 1 ) only takes place parallel to the direction of an applied contact pressure. 2. Contacting device according to claim 1, characterized in that the contact elements ( 1 ) each have at least two opposing bends ( 1.2 ) embedded in the one-piece body consisting of elastic insulating material. 3. Contacting device according to claim 1 or 2, characterized in that the bends ( 1.2 ) are transition sections of a meandering arrangement. 4. Contacting device according to one of the preceding claims, characterized in that bends ( 1.2 ) are aligned perpendicular to the direction of the contact elements ( 1 ) arranged next to one another. 5. Contacting device according to one of the preceding claims, characterized in that the protruding ends are designed as tips ( 1.1 ), flat surfaces or curves. 6. Contacting device according to one of claims 1 to 4, characterized in that the protruding ends ( 1.3 ', 1.3 ") are designed as a contact pin or as a connecting piece for connecting wires. 7. Contacting device according to claim 6, characterized in
that the body expands from the area of the protruding ends and
that the protruding ends ( 1.3 ") expand like a fan. 8. Contacting device according to one of the preceding claims, characterized in that the body is fixed in an outer housing ( 6 ) except for the tips ( 1.1 ).