EP1126555A2 - Contact element - Google Patents

Abstract

The invention is concerned with the formation of aging-resistant contact elements 10 which, in the compressed state, produce a conductive connection between two opposing contacts. Contact elements 10 according to the prior art generally have a rectangular body, on the surface of which a plurality of contact tracks 15 are formed. Since the bodies 11 of such contact elements 10 are made of foamed or vulcanized plastics for the production of the elasticity, they are subject to aging and therefore cannot ensure permanent contact. Therefore, according to the invention, a contact element 10 is specified, the body 11 of which is only formed from a thin wall 12, which does not necessarily completely surround a hollow profile 13 enclosed by the body 11. Long-term stability is guaranteed here, especially if the wall 12 is formed from a metal or glass fiber material. The same results are achieved if the body 11 is provided with thin inserts 22 made of metal or glass fiber. <IMAGE>

Description

Technical field

The invention is concerned with the formation of age-resistant Contact elements that are conductive when compressed Establish connection between two opposite contacts.

State of the art

Contact elements according to the preamble of claim 1 are Known specialist and have been in large quantities for a long time Manufacture of conductive connections used.

These contact elements, which are also known as conductive rubbers are usually a rectangular body on the surface a plurality of contact tracks are formed. The body is complete formed from a foamed or vulcanized plastic ensure that the body deforms elastically under the influence of force can.

If a row of contacts formed on a circuit board, which has a plurality of mutually adjacent contacts, for example to be electrically conductively connected to a row of contacts of a component, the contact element is first placed on the row of contacts on the circuit board, the contact tracks of the contact element contacting the contacts on the circuit board . Then the component with its row of contacts is placed on the contact element such that its contacts come into physical connection with the contact tracks of the contact element. In order to ensure a certain durability of the contact made in this way, the overall height given in the unloaded state of the contact element is reduced. This can happen, for example, in such a way that the component, after it has been placed on the contact element, is easily pressed against the circuit board and fastened in this state. If this state is reached and the contact element clamped between the contact rows of the circuit board and the component, the restoring forces with which the contact element tries to resume its structural height or shape given in the unloaded state cause the contact paths of the contact element against the contact rows of the circuit board and component be pressed. In order to achieve the necessary elasticity or energy storage capacity, the known contact elements or the materials used for the body generally have very low elongation energy coefficients resulting from the multiplication of the tensile strength and the elongation at break. For example, when using silicone rubber as the body material, which has a tensile strength of about 0.49 N / mm ² and an elongation at break of 200%, this coefficient, which indicates the energy storage capacity, would be 98.

Even if this type of contacting is carried out very easily and quickly can be found, however, that such electrical Connections have limited long-term stability. In particular, was found that under changing climatic conditions or through Environmental influences using the contact elements described above established conductive connections no longer secure contact guarantee. Possible reasons for this are that the above Conditions and influences Material hardening and structural changes occur.

The invention is therefore based on the object of a contact element specify which one while maintaining a simple and quick Contacting rows of contacts also the necessary long-term stability owns.

Presentation of the invention

This object is achieved with the features according to claim 1. Beneficial Training and further developments of the invention are claims 2 to 5 removable. A method for producing a contact element is in Claim 6 specified. The features according to claim 7 have one independent - the problem-solving - embodiment to the object.

If the body is only formed by a thin wall, which does not necessarily completely surround a hollow profile enclosed by the body, it is ensured that the required elasticity of the body is essentially determined by the thickness of the wall and the spatial shape of the body. However, this does not mean that the properties of the material from which the body or the wall is made are completely immaterial. In contrast to the prior art, the materials from which the walls are made, in spite of the elasticity of the body set via the only small wall thickness, must have the ability to store a high amount of deformation energy per unit volume, in order to ensure that in view of what is necessary Deformation path a sufficient spring or contact pressure is provided
According to the applicant's knowledge, the "block-like" design of the contact elements, or the material quality associated therewith to produce the required elasticity, is responsible for the fact that the contact elements thus produced have only a limited long-term stability. In particular, the lack of long-term stability of the known contact elements is due in part to the fact that the materials used are subject to shrinkage. If, for example, a foamed material is used for the elastic body, gas bubbles trapped in the body diffuse into the environment after some time, which at the same time reduces the spatial dimensions of the contact element that were given previously. This shrinkage is responsible for reducing the force with which a contact element clamped, for example, between the circuit board and the component presses against the contact rows of the component and the circuit board or can lead to the former contacting being canceled.

However, according to the invention, the body of the contact element is only formed by a thin wall and the required elasticity is brought about by the spatial shape and the thickness of the wall, materials can be dispensed with that have an elasticity even in the case of a "block-like" design, which at the same time gives the given Shrinkage problem is minimized or completely eliminated.
If, for example, thin-walled glass fiber or glass fiber composite materials are used, whereby the overall elastic properties are essentially formed by the glass fiber, there are neither creeping reorientations of the material structure nor chemically induced material changes, since the glass material is resistant to this. In this context, it must also be regarded as surprising to use materials whose expansion energy coefficients are clearly above the values according to the prior art. In order to make this clear, it should be pointed out that the use of glass fiber material, which has a tensile strength of more than 2400 N / mm ² and an elongation at break of around 1.2%, results in coefficients of more than 2800.

As stated in claim 2, there are none for the formation of the walls Restrictions. In addition to the massive formation of the wall Use of braids is particularly advantageous if for example the bending elasticity that arises in the case of massive training should be increased further.

Also, as stated in claim 3, there are no major restrictions given the material selection, provided the materials used have a certain Have bending elasticity.

According to claim 4, an intermediate layer between the wall and Contact paths used, can possibly existing with this Irregularities on the surface of the wall or the contact tracks be balanced. In addition to the smoothing function, the intermediate layer can also be used as insulation if the wall does not have one conductive material.

A defined contact area and thus a defined contact resistance is given when on two opposite and for contacting the respective contact rows certain areas of the wall projections are formed, which compared to the directly adjacent areas of the Distance from the center of the body.

A particularly simple method of making one with a Intermediate layer provided contact element is when the Intermediate layer is formed as a tube profile and the wall of the The hollow profile enclosed by the body is not completely edged. In this case it is possible to put the compressed body in insert the hose profile. Does the body have its end position in Hose profile ingested and then the force no longer acts that has squeezed the body, the body lies on the inside of the Hose profile and tension it. It is irrelevant whether the hose profile before or after connecting to the body with the contact tracks is provided.

If the contact element according to the features of claim 7 formed, arise the same and already in connection with claim 1 explained advantages, because regardless of the material of the body alone Deposits a high amount due to their capabilities per unit volume Can store deformation energy and thus in terms of required deformation path, the required spring or contact pressure can provide permanently.

Brief presentation of the figures

Fig. 1

ein Kontaktelement in perspektivischer Darstellung;

Fig. 2

ein weiteres Kontaktelement in einer Darstellung gemäß Fig. 1;

Fig. 3

eine Einbausituation mit zwei Kontaktelementen in Seitenansicht;

Fig. 4

ein Kontaktelement im Seitenschnitt;

Fig. 5

ein Kontaktelement im Seitenansicht;

Fig. 6

ein weiteres Kontaktelement in einer Darstellung gemäß Fig. 5;

Fig. 7

ein weiteres Kontaktelement in einer Darstellung gemäß Fig. 4 und

Fig. 8a-e

fünf weitere Kontaktelemente im Seitenschnitt.

   Wege zum Ausführen der ErfindungShow it:

Fig. 1

a contact element in a perspective view;

Fig. 2

a further contact element in a representation according to FIG. 1;

Fig. 3

an installation situation with two contact elements in side view;

Fig. 4

a contact element in side section;

Fig. 5

a contact element in side view;

Fig. 6

a further contact element in a representation according to FIG. 5;

Fig. 7

a further contact element in a representation according to FIGS. 4 and

8a-e

five further contact elements in side section.

Ways of Carrying Out the Invention

The invention will now be explained in more detail with reference to the figures.

In Fig. 1, a contact element 10 is shown in perspective. The Body 11 of this contact element 10 is in the present case of a thin one Wall 12 formed, which is enclosed by the body 11 hollow section 13 completely rimmed. The outer surface 14 of this body 11 is with circumferential contact tracks 15 provided by the mutual distances 16 are electrically isolated from each other. These contact tracks 15 can for example by vapor deposition of a thin metal layer

The contact element 10 shown in FIG. 2 largely corresponds to that in FIG. 1 shown contact element 10. Also in Fig. 2, the body 11 of the Contact element 10 formed by a thin wall 12. In contrast to the wall 12 with a slot 17 Mistake. Since this slot 17, as can be clearly seen in FIG. 2, is above the extends the entire length of the contact element 10, edged out in FIG. 2 Wall 12 shown does not include the hollow profile 13 enclosed by the body 11 Completely.

In Fig. 3 an installation situation for contact elements 10 is shown, with on the right side a contact element 10 shown in FIG. 1 and on the left side Contact element 10 according to FIG. 2 is used. There are also another lower and an upper board 18u, 18o available, these two boards 18u, 18o are each provided with two rows of contacts 19. Just completeness For the sake of convenience, it should be pointed out that the term “row of contacts” includes a A plurality of individual contacts (not visible in FIG. 3) is understood, the mutually isolated and perpendicular to the paper plane (Fig.3) on the respective Circuit board 18u, 18o are arranged. The contacting of the two rows of contacts 19u of the lower board 18u with the contact rows 19o of the upper board 18o takes place in such a way that first each contact element 10 so on a Contact row 19u of the lower board 18u is placed. Simultaneously or then the contact elements 10 are aligned. It is essential that the contact tracks 15 (not shown in Fig. 3) of the left contact element 10 with the contacts (not visible in Fig. 3) of the left row of contacts 19u and that the contact tracks 15 (not shown in Fig. 3) of the right contact element 10 with the contacts (not visible in FIG. 3) of the right row of contacts 19u in come into physical contact. If this state is reached, the upper one Board 18o placed on the two contact elements 10. Here too is essential that the contacts (not shown in Fig. 3) of the left row of contacts 19o the contact tracks 15 (not visible in FIG. 3) of the left contact element 10 and the contacts (not shown in Fig. 3) of the right row of contacts 18 die Contact tracks 15 (not visible in FIG. 3) of the right contact element 10 touch physically. To a using the contact elements 10 sufficiently good electrical contact between the contact rows 19u, 19o the upper and lower board 180, 18u, it is necessary to two contact elements 10 used in FIG the boards 180, 18u - as shown in Figures 1 and 2 - a circular Cross section had to deform elastically. 3 in such a way that that -after the upper board 18o placed on the contact elements 10 was the upper board 18o in the direction of arrow P 1 against that of the Contact elements 10 exerted resistance is moved. Has the top one Board 18o reaches the distance from the lower board 18u shown in FIG. 3, the resulting assignment of the two boards 180, 18u becomes permanent fixed (not shown in Fig. 3). Because of the movement of the top board 180 in the direction of arrow P1 through the two previously circular contact elements 10 the onset of elastic deformation is an elliptical cross-section have received in the contact elements 10 against the direction of the arrow P1 acting restoring forces built up, which ensure that the Contact tracks 15 (not shown in FIG. 3) against the contacts (not shown in FIG. 3) visible) of the contact rows 19u, 19o.

Since it is essentially hollow according to the invention through the use of Contact elements 10 for the durability of such electrical Connections significant restoring forces less on the used Materials arrives, can form a contact elements 10 Many other materials not used for this purpose be resorted to. However, this does not mean that the material properties are completely irrelevant. Rather, the invention must also ensure be that the or used to form the hollow contact elements 10 Materials an elastic and explained in connection with Fig. 3 Allow deformation. However, in contrast to the prior art the required elasticity is brought about essentially via the hollow shape, aging-resistant materials can be used without any problems. So is for example, FIG. 4 (not shown to scale) is a contact element 10 shown, in which the wall 12 is formed from a metal. This Wall 12 is provided with an intermediate layer 20, which is the wall 12 completely covered. On the surface facing away from the wall 12 Intermediate layer 12, which in the present case is formed from an insulating material the circumferential contact tracks 15 have been applied.

Even if in the exemplary embodiment according to FIG. 4 the wall 12 is made of metal was not restricted to this material. Rather, in another embodiment (not shown further) the wall 12 also made of a natural rubber or a non-foamed polymer material. If the wall is 12 For example, made of PVC material, because of the insulating Effect of this material on the formation of an intermediate layer 20 Isolation purposes are waived.

Also, the wall 12 need not be solid. Quality Results were also achieved with walls 12 made from a braid Plastic, metal or a glass fiber material were formed. Will the Wall 12 formed as a braid, the intermediate layer 20 comes next to one possible insulating effect also a compensating effect to the one Braid naturally given irregularities in the Compensate surface structure.

The contact element 10 shown in FIG. 4 can be produced in this way, for example are that first the wall 12 is formed, then - if necessary - the Interlayer is applied and then the contact tracks 15th be formed. As can be easily seen, the sequence of steps in one corresponding system also run continuously, so that the formed contact elements only have to be assembled.

5 shows a contact element 10, which is essentially a has an octagonal cross-section. This contact element 10 can be anywhere there be used where it is necessary to make electrical connections, large Distances A1 between the rows of contacts to be contacted (not in FIG. 5 shown) with a limited width B to overcome.

This purpose explained in the last paragraph can also be shown in FIG. 6 and fulfill an contact element 10 having an elliptical cross section, if it is ensured that the large diameter of the elliptical Cross section with the respective contact rows (not shown in Fig. 6) in Contact comes.

In addition, two projections 21 are shown in Fig. 6, which compared to the the projections 21 directly adjacent areas of the wall 12 one have a greater distance from the center M of the body 11. These ledges 21 have the purpose of a good surface contact to the contacts of the Produce contact rows (not shown in Fig. 6).

For the sake of completeness, it is pointed out that the projections 21 are not limited to contact elements 10 with an elliptical cross section, but also for the contact elements according to FIGS. 1, 2, 4, 5 and 7 can be trained.

7 shows a contact element 10, in which, in contrast to the contact element 10 according to FIG. 2, the slot 17 only in the wall 12 and not in the intermediate layer 20 and the contact tracks 15 is. A contact element 10 designed in this way can be very useful, for example simply be formed in that the intermediate view 20 as Hose profile 20 'is produced and then in the direction of arrow P2 compressed wall 12 is inserted into the tube profile 20 '. Has the wall 12 in its end position in the tube profile 20 'and the force that is required for compressing the wall 12 was responsible, eliminated, the wall lies against the tube profile 20 ' and tense it. This purely mechanical connection excludes that because the material difference of wall and intermediate layer 12 and / or Contact tracks 15 complex connection techniques or restrictive Material combinations must be used. Just completeness for the sake of sake it should be added that it is irrelevant in this procedure whether the intermediate layer 20 or the tube profile 20 'before or only after the connection to the wall 12 is provided with the contact tracks 15.

8a to e show five exemplary embodiments of a contact element 10 according to claim 7 in a side section. Each of these contact elements 10 has a body 11 which is surrounded by a contact track 15. At least one insert 22 made of a metal and / or glass fiber material is integrated in the interior of each body 11.
In FIG. 8a, the insert 22 is formed by four elongated strips, two of these strips each having the same length. If the inserts 22 are designed as shown in FIG. 8a, it is essential for the operation of the inserts 22 that the boards (not shown in FIG. 8a) come into physical contact with the contact element 10 according to the arrows shown.

8b and c, the inserts 22 are circular, the Contact element 10 according to FIG. 8b with and the contact element 10 according to 8c is provided with two circular inserts 22. The insert 22 according to FIG. 8d has a spiral shape, while in FIG. 8e the insert 22 is arranged irregularly in the body 11. How easy it is to see it does not matter in the training according to FIGS. 8b to d like that respective contact elements 10 placed between two boards (not shown) as long as it is ensured that the boards are against each other opposite edges of the cube-shaped Contact elements 10 come into physical contact.

For the sake of completeness, it should be pointed out that the in FIGS to d shown contact elements 10 may also be round or oval can.

Claims (7)

Contact element with a body 11 and with a plurality of electrically conductive contact tracks 15, which are arranged isolated from one another on the outer surface 14 of the body 11, characterized,
that the body 11 is formed only from a thin wall 12 which does not necessarily completely surround a hollow profile 13 enclosed by the body 11. Contact element according to claim 1
characterized,
that the wall 12 is either solid or formed from a braid. Contact element according to claim 2
characterized,
that the wall 12 and / or the braid is formed from metal or a non-foamed plastic, in particular from a glass fiber material. Contact element according to claim 2 or claim 3
characterized,
that an intermediate layer 20 is arranged between the wall 12 and the contact tracks 15. Contact element according to one of claims 1 to 4
characterized,
that projections 21 are formed on two opposite regions of the wall 12, which have a greater distance from the center of the body 11 in comparison to the regions of the wall 12 which are directly adjacent to the projections 21. A method of manufacturing a contact element according to claim 4
characterized, that the intermediate layer 20 is formed as a tube profile 20 ', that the wall 12 of the body 11 does not completely surround the hollow profile 13 enclosed by it and that the wall 12 is compressed and inserted into the tube profile 20 'in this state. Contact element with a body 11 and with a plurality of electrically conductive contact tracks 15, which are arranged isolated from one another on the outer surface 14 of the body 11, characterized, that at least one thin insert 22 is arranged inside the body 11, that the respective insert 22 is either solid or as a braid and that the respective inserts 22 are formed either from a metal or a non-foamed plastic, in particular from a glass fiber material.

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