EP1184942A1 - Manufacturing method of a microconnectic connector having a textile support with passing through conducting elements and such a connector - Google Patents

Abstract

The procedure for the manufacture of an interconnector for micro-connection entails forming at least one conductor pin (4) of an electrically conducting elastomer material across a thin base formed from a non-conducting textile substrate (1), the conductor being flush with the two faces of the substrate. The conductor pins are created by penetration under pressure of an elastomer polymerized afterwards, the penetration being carried out by a syringe or similar. An Independent claim is included for an interconnector produced by the said procedure.

Description

The present invention relates to microconnectics and more particularly to connection devices, more commonly called "interposers" by professionals, intended to interpose, for the purposes of connection, between two printed circuits, rigid or flexible, or between a component such as an integrated circuit with flush contacts beneath its surface bottom and a printed circuit with flush contact pads.

Different technologies exist to connect such elements.

By GB patent 1,587,416, there is known a connection device constituting an anisotropic conductive film formed of a film or sheet in elastomeric material in the mass of which, perpendicular to the plane of the film are arranged electrical conductors in the form of wires or fibers of preferably slightly longer than the thickness of said film.

The manufacturing process of such an "interpose" consists in dispensing in a liquid non-conductive elastomer matrix of the conductive wires magnetizable, to form a sheet and subject it to a field magnetic perpendicular to the tablecloth, while gathering in bundles the wires at determined points so as to obtain an electrically insulating film in X, Y i.e. in its plane, but conductive in Z through a plurality of transverse bundles of conductive fibers, said bundles being distributed according to a determined network, the ends of said beams protruding from the two opposite sides of the film.

Such a technique is sophisticated, delicate to implement and expensive. In addition, it can only be applied to substrates in elastomer and requires a special mold and conductors in the form of wires or fibers of material which is both electrically conductive and magnetizable.

In patent GB 2,269,061, the production of a film is described anisotropic conductor made from elastomeric strips trapping aligned conductive wires arranged in parallel along a plane parallel to the opposite faces of each strip.

One or more adjoining strips are flanked by more layers thick insulating elastomers to form a sandwich. The ends of the conductors slightly protrude from the edges opposite of said strips.

The production technique consists of cutting the wires to length desired and to drown them in an elastomer matrix constituting the substrate strips. The wires must of course be aligned properly with the right separation interval. This technique is neither simpler nor more practical, nor more economical than the previous technique.

US Patent 5,599,193 relates to an interconnection device electric consisting of an elastomer sheet pierced through and through in order to receive insulating elastomeric pads covered with a conductive layer, projecting on either side of the sheet so as to establish connections electrical through the sheet.

From US patent 5,681,647, we also know a conductive film anisotropic made from a polymer substrate pierced with through holes into which are inserted nail-shaped conductive elements the central part of which is made of hard material, while the two ends, projecting on either side of the film, are made of materials fuses.

The various techniques briefly described above have in common to be complex, expensive, which reduces their fields of application.

The present invention specifically aims to overcome the disadvantages of these techniques by proposing a manufacturing process simpler, more practical, faster interconnector and economical to implement.

To this end, the invention relates to a method of manufacturing a interconnector for the microconnectics, characterized in that it consists of constitute through a thin support formed of a textile support produced at from an electrically non-conductive material, at least one stud of a electrically conductive elastomeric material flush on both sides of said textile support.

By textile support is meant any woven or non-woven support including absorbent papers, filter papers or the like.

Advantageously, said conductive pads are produced by penetration under pressure of a polymerized elastomer then for example to ultraviolet.

Generally a multiplicity of such studs are formed in the textile support according to a regular distribution of determined pitch or irregular depending on the application.

Preferably, the textile support is a nonwoven, such support having the advantage of presenting a large perpendicular to its plane compressibility which, combined with the axial elasticity of the studs, gives the interconnector a cross compliance, that is to say an ability to deform elastically to adapt to the contact surfaces to be connected, quite interesting.

The subject of the invention is also the interconnects produced according to the above process.

This process has the characteristic advantages in comparison with the previous techniques mentioned above, to propose interconnectors particularly economical due to the low cost of the supports used, know textile supports, whether woven, non-woven or even mesh knitted fabrics, which are common industrial products offering great diversity of nature and texture.

• la figure 1 représente schématiquement en vue de dessus un support textile tissé muni de plots conducteurs selon l'invention, et
• la figure 2 est une vue en coupe suivant la ligne II- II du dispositif de la figure 1.

Other characteristics and advantages will emerge from the description which follows of modes of implementing the method of the invention, description given by way of example only and with reference to the appended drawing in which:

• FIG. 1 schematically represents a top view of a woven textile support provided with conductive studs according to the invention, and
• Figure 2 is a sectional view along line II-II of the device of Figure 1.

In the figures, there is shown schematically at 1 a woven support with its weft 2 threads and its 3 interwoven warp threads.

Perpendicular to the plane of the frame and throughout the thickness of the tissue are for example injected under pressure, in accordance with the invention, a plurality of pads 4 of elastomer whose ends are flush with the faces opposite of fabric 1.

The fabric 1 is made from a non-conductive material of the electricity and the nature of the material as well as the texture of the fabric may vary depending on the applications envisaged. For example, the fabric can be made to from polyamide or polybutylene terephthalate fibers.

The studs 4 are injected through the fabric 1 and creep between the wires of weft and chain.

The material of the pads 4 is an elastomer conducting electricity which, after injection, is polymerized for example under ultraviolet light by scrolling. The conductivity of the silicone is obtained for example using of a charge consisting of silver particles, however that in order to improve the temperature resistance of the silicone may advantageously be fluorinated.

The injection is made for example using a syringe brought to the contact of fabric 1 at the desired location and the piston of which is controlled to deliver the quantity of elastomer necessary for a pad 4, the operation being automatically repeated by moving the syringe next to the desired locations, in order to create a network of studs with determined pitch.

The length and diameter of the studs 4 depend on the type of fabric 1 and of its texture.

It should be noted that all of the studs can be made in one passes by means of an injection device with nozzles in number and with spacing in correspondence with the stud network to be obtained.

The thickness compliance of the interconnector thus produced is given by the texture of the fabric 1 and the elasticity of the studs 4.

Preferably, the textile support used for the manufacture of a interconnector according to the invention is a nonwoven.

The technique of manufacturing a nonwoven makes it possible to obtain a support of very variable characteristics which can be exactly adapted to the envisaged jobs of the interconnectors.

For example and according to a known technique, a substrate is produced with from fibers with a diameter of less than 25 micrometers and a length less than 10 cm in loose bales, roughly untangled by a carding operation, lengthened by spreading on a conveyor belt, applied in several layers and then interlaced by needling. The substrate is then finished by gluing by adding an adhesive or by heat sealing depending on the fibers used.

On such a substrate, the conductive pads, the like, are put in place. to pads 4 of Figures 1 and 2, by injection through the nonwoven, of a conductive elastomer, then polymerized for example with ultraviolet.

In this application, the injected elastomer resin does not fill a cavity but penetrates by diffusing into the thickness of the nonwoven, occupying thereby the interstices of the nonwoven continuously.

As a variant, it is possible to envisage an implantation of the pads 4 by a other technique for example by printing in the manner of screen printing on printed fabrics.

By varying the printing pressure and the wettability of the fibers of the non-woven support, it is possible to cross the support by diffusion of the elastomer in the thickness of the support.

The adjustment of the various manufacturing parameters of the support allows to adjust the nonwoven web to the specifications with regard to thickness, density, mechanical characteristics in Z, i.e. perpendicular to the plane of the tablecloth.

The substrate thus obtained has a very fine structure and statistically uniform.

Fibers of all kinds (cotton, polymer, polypropylene, polyester, polyamide, epoxy, glass fibers, "Kevlar", etc.) can be used.

The use of a non-woven support is also economical and allows high production rates.

Finally, the invention is obviously not limited to the modes of implementation work described above but on the contrary covers all variants. This is how the textile support could be knitted, or made up absorbent paper or filter paper.

Claims (7)

Method of manufacturing an interconnector for the microconnectors, characterized in that it consists in forming, through a thin support formed by a textile support (1) made from a material which is not electrically conductive, at at least one stud (4) of an elastomeric electrically conductive material flush with both sides of said textile support (1). Method according to claim 1, characterized in that said conductive pads (4) are produced by penetration under pressure of an elastomer which is subsequently polymerized. Method according to claim 2, characterized in that the penetration is carried out by injection under pressure using a syringe or the like. Method according to claim 2, characterized in that the penetration is carried out by printing analogous to printing by screen printing of printed fabrics. Method according to claim 1, characterized in that a multiplicity of conductive pads (4) is simultaneously formed in the textile support (1) according to a regular distribution, of determined pitch, of said pads (4), or not. Interconnector produced according to the method according to one any of claims 1 to 5. Interconnector according to claim 6, characterized in that the support is a textile support constituted by a nonwoven.

Images