MXPA99008741A - Electronic module for chip card - Google Patents

Abstract

The invention concerns an electronic module, in particular designed to be fixed in an electronic device in the form of a card, comprising a medium (40) including at least a surface (44) provided with contact pads (46;48;50) and a microcircuit (56) which is fixed on said medium (40) and which comprises exit hubs (60, 62) each connected to a medium contact pad. The invention is characterised in that the connections (66, 68) between the exit hubs and the contact pads consist of a cord made of an adhesive conductive substance matching the relief of the medium. Advantageously, the conductive substance is a conductive isotropic adhesive.

Description

ELECTRONIC MODULE FOR MAGNETIC CARD DESCRIPTION The present invention relates to electronic modules, in particular that are intended to be mounted on an electronic device in the form of a card, which comprises a support which comprises at least one face provided with contact tracks and a microcircuit that is on that support and comprising exit pins each connected to a contact track of the support. This type of devices in the form of a card, in particular, comprise the integrated circuit (s) cards, also known as magnetic cards, but also supports for electronic elements for television, VTRs, etc. A card The magnetic element is constituted by a card body and a module that comprises the magnetic part that is integrated in the body of the card.

A magnetic card module is constituted by a support, generally made of epoxy glass, which is metallized on one side so as to present contact tracks and a magnetic part that is glued on the other side of the support and which comprises exit pins on its surface. outer face. Connection wells are provided through the support for the passage of connection wires joining an output pin with a contact track.

The connection wires, made of stainless metal such as gold or aluminum, are welded using different technologies, such as welding by means of ultrasound or thermocompression, which require a subsequent "glob top" coating of the wires connection by means of a resin, to protect them. Sometimes, it is necessary to previously fix a retaining barrier of the resin, such as a metal or silicone ring, on the support. The resin mass is deposited in an uncontrollable manner and, when polymerized, forms a drop of great thickness that exceeds in height the specifications of the magnetic cards. Therefore, it is necessary to perform a milling operation to reduce the thickness of the module to the required value. This milling operation can damage the module, which is the main cause of manufacturing waste. In the body of the magnetic card, a cavity is provided that is intended to receive the module that must be relatively deep to receive a significant height module. As a result, the thickness of the card body at the level of the cavity is small, which causes, when the card is subjected to bending, a significant deformation of the card body that limits the reliability and life expectancy of the card. card In addition, the polymerization of this drop of resin causes a phenomenon of bulging of the module. This bulging can cause deterioration of the readers of the magnetic card. The problem with the base of the invention is that of providing an electronic module of reduced height, so as to eliminate the aforementioned drawbacks. The electronic module according to the invention is especially notable in that the connections between the output pins and the contact tracks are constituted by a string of adhesive conductive substance which takes the shape of the relief of the support. These connections do not need a protective coating, which makes it possible to significantly reduce the height of the module. As a result, manufacturing is simplified and, in particular, the milling operation is eliminated, which greatly reduces the rate of manufacturing waste.

Advantageously, the conductive substance is an isotropic conductive glue. Also, a metal deposited by screen printing can be used. In the case where the support comprises connecting wells, these are filled with a conductive substance.

The support can comprise two faces provided with contact tracks and the connections are made directly on two faces, without using connection wells. Advantageously, one of the faces of the support is covered by an activatable adhesive film. This constitutes an additional protection of the microcircuit and makes it possible to simplify the operation of fixing the module in the body of the card. Output pins of the microcircuit, can comprise bulky connection, so as to reduce the contact resistance. The subject of the invention is also a method of manufacturing an electronic module, characterized in that the bead is made by depositing a viscous conductive substance. This technique of deposit by means of a syringe or similar, is quick and easy to put on site.

The invention also has for its object, a magnetic card characterized in that it comprises at least one electronic module of the aforementioned type. Other features and advantages of the invention will become apparent upon reading the detailed description below for the understanding of which one will be reported to the accompanying drawings in which: Figure 1 is a diagram showing, in cross section, a module of known type; Figure 2 represents an electronic module in accordance with the present invention; Figure 3 is a top view of an embodiment of a module whose support comprises two faces provided with contact tracks; Figure 1 represents an electronic module of known type. It comprises a support 10, for example of epoxy glass. One of its faces 12 comprises contacting tracks 14 made by metallization The other face 16 comprises a layer of glue 18 which serves to fix the inner face of a microcircuit 20 comprising exit pins 22 on its free upper face. between the output pins 22 and the contact tracks 14, they are made by welding metal wires 24 which pass each one through a connecting hole 26 made in the support 10. After the welding operation of the wires 24, these are coated with a polymerizable resin which forms a drop 28 which is retained by a peripheral ring 30 of silicone.This drop 28 is applied in an uncontrolled manner and has a significant thickness which considerably increases the height of the module in such a way that it is necessary to shave its upper part with a machining operation, such as a milling, which is schematized with dashed line 32. As indicated above, the prese This drop 28 can reduce the mechanical resistance of the magnetic card to the level of the cavity receiving the module in such a way that the mechanical strength of the card at that level is insufficient and that, in addition, the card can present a bulge to that level. Figure 2 represents an electronic module in accordance with the present invention. The support 40 comprises connecting pits 42. The lower face 44 of the support 40 is metallized and comprises contact tracks 46, 48 and 50. The upper face 52 of the support 40 carries a layer 54 of glue which serves to fix a part magnet 56 comprising, on its upper face 58, outlet pins 60 and 62 that may be provided with bulges ("bumps") not shown. A coating 64 of adhesive is applied on the periphery of the magnetic part 56, on the face 52 of the support in the vicinity of the magnetic part and in the connecting wells 42. In accordance with the invention, the connections 66 and 68 between the output pins 60 and 62 and the contact sockets 46 and 50 are constituted by a string of adhesive conductive substance that takes the form of the support, more particularly that it is in contact with the adhesive coating 64 and whose ends are in contact with the pin output and the associated contact track. This substance is applied to the viscous state. The application of this substance, for example an isotropic conductive adhesive, is carried out by means of a deposition technique called "dispensing" according to which a liquid or low viscosity substance by means of a syringe or the like, of flow and opening controlled . This "dispensing" operation is carried out, for example, by means of an installation marketed under the name CAM / ALOT by the American company Camelot Systems Inc. and it is used for the realization of electronic circuits. The displacement and the opening of the syringe are controlled by a computer program.

You can also make these connections using a metal deposited by screen printing. To improve the electrical contact, the output pins may comprise contact bulges and the contact of the ends of the conductive cord, it is done with the latter. The invention also applies to the case where the support comprises two metallized faces comprising contact tracks. This is used in Figure 3 which is a partial top view of a module showing a magnetic part 70 with its output pins 72, 74, 76, 78 and 80. The pins 72, 74 and 76 are joined together. a contact track of the lower face of the support and the pins 78 and 80 are joined to a track 82 respectively 84, disposed on the upper face of the support, also by means of a bead of adhesive conductive substance 86, respectively 88. The The electronic module according to the invention can be coated with an activatable adhesive film, for example by heating or ultraviolet radiation, in order, on the one hand, to increase the protection of the magnetic part and, on the other hand, to simplify the fixing operation on the magnetic part. the body cavity of the card.The realization of direct connections according to the present invention, applies to the manufacture of any electronic device in the form of a card such as control boards of video devices or household appliances. It is seen that the invention makes it possible to suppress the lining of the connections and then reduce the thickness of the modules. On the other hand, the resins that are used as a conductive substance are very flexible, which increases the reliability of the module. The operations attached to the lining of the connections, namely the placement of a retention barrier such as a silicone ring, the deposit of the coating resin and the machining of the resin droplet, are suppressed. It results from this, a simplification of manufacturing and a reduction of manufacturing cost. The invention makes it possible to have a more important card body thickness at the module level and, consequently, to increase the mechanical strength of the board. Thanks to the invention, the dimensions of the modules can be reduced in the plane of the microcircuit, which makes it possible to manufacture the modules in a chain with two adjacent lines of modules. Finally, the invention allows to suppress the phenomenon of bulging and, as a consequence, to avoid the deterioration of the readers.

Claims (6)

1. CLAIMS 1.- Electronic module, especially intended to be mounted on an electronic device in the form of a card, comprising a support which comprises at least one face provided with contact tracks and a microcircuit that is fixed on that support and which comprises pins of output joined each to a contact track of the support, characterized in that the connections between the output pins and the contact tracks, are constituted by a string of adhesive conductive substance that takes the shape of the relief of the support.
2. 2. Process for manufacturing an electronic module, according to claim 1, characterized in that the bead is made by depositing a viscous conductive substance.
3. 3. Electronic module according to claim 1, characterized in that the conductive substance is an isotropic conductive adhesive.
4. 4. Electronic module according to any of claims 1 to 3, characterized in that the support comprises two faces provided with contact tracks.
5. 5. Electronic module according to any of claims 1 to 4, characterized in that one of the faces of the module is covered by an activatable adhesive film. 6. Electronic module according to any of claims 1 to 5, characterized in that the output pins of the microcircuit, comprise connection bulges. 7. Electronic card characterized in that it comprises at least one electronic module according to any of claims 1 to
6. 6.