DE19708325B4 - Adhesive bond of electrically conductive parts - Google Patents

Abstract

Method for connecting electrically conductive adherends (4, 5) to joining surfaces (1, 2) by means of gluing, wherein between the joining surfaces (1, 2) a thermoplastic or temperature hardening adhesive (3) is brought, characterized in that
The required melting or reaction temperature and time of the adhesive (3) correspond to the process regime of the subsequent laminating step,
- The joining surfaces (1, 2) are positioned to each other,
In a subsequent laminating step, the surfaces of insulating parts (10, 11) to be laminated press the joining parts (4, 5) against one another and at the same time heat the adhesive (3) to the required melting or reaction temperature, the joining parts (4, 5) are brought as a result of the melting adhesive (3) and the compression in the final position and
- The joining parts (4, 5) form a direct contact and by the likewise under the laminating pressure slightly flowing and the space around the parts to be joined (4, 5) filling material of the insulating parts (10, 11) fixed and hermetically wrapped ...

Description

The The invention relates to a method for connecting electrically conductive joining parts at joint surfaces by means of Gluing, wherein between the joining surfaces a thermoplastic or temperature grade hardenable Glue is brought.

method of this type are applied to coil wires with terminals of electronic components, especially in contactless smart cards or in plastic-coated Make smart cards with at least one second connection level.

contactless Smart cards use etched, wire-wound or printed as receiving antennas wire laid antennas.

in the Generally, the chip module and antennas are located between laminatable plastic films. By Lamination becomes an insoluble bond between the plastic sheets achieved, at the same time press Chip module and antenna in the thermoplastic when laminating viscous Slides.

there and also in the subsequent use of the card are mechanical pressures on antenna, chip module and the junction of chip module contact surface to antenna connection exerted. At the Junction act mechanical forces affecting both the antennas as well as on the chip module during lamination in position to move each other. On the other hand, one endeavors the connection point in terms of volume so small as possible to keep the influence on the optical quality of the card after lamination.

To US 5,237,130 For example, semiconductor chips can be provided with epoxy or polyimide contact stirrups and contacted directly onto printed conductors. However, there are relatively fragile, rigid connections that are exposed to the risk of destruction during subsequent lamination of the plastic card as a result of mechanical stress when using the card.

Farther The method of soldering the wire contacts is known to the chip module connections, as it is e.g. is practiced by the company Westinghouse, USA. adversely are the expenses in the preparation and realization of the solder joints and the size of the solder joints.

In DE 43 29 708 Armatech GmbH & Co KG announces a process for thermocompression welding of enamel-insulated wires on chip module contact surfaces. A disadvantage of this method is the high temperature load of the substrate or the chip module surfaces and the high apperative effort.

Furthermore, in DE 43 37 920 an arrangement for achieving a permanent electrical pressure contact described. However, this arrangement is only applicable for relatively large contact surfaces on non-softening at laminating temperature substrate surfaces.

Out DE 195 00 925 A1 a chip card for contactless data transmission is known in which a built-in the card body transmission module which aufeist a coil and pads for electrical connection to the chip module. In this case, the connection surfaces of the chip module and the connection surfaces of the transmission module are connected to one another via a conductive adhesive. In this arrangement, it is disadvantageous that the electrical contact is not produced by direct contact, but is produced by means of conductive particles or conductive adhesive, which causes a larger contact resistance.

Further describes DE 37 01 343 A1 a method for mounting an LSI or IC device on a wiring substrate, are connected in the electrically conductive joining parts with an anisotropic conductive paste. Again, no direct contact is generated. The contact is formed by curing a conductive paste, which requires an additional operation.

To DE 43 43 272 A1 is a method for producing an electrically conductive adhesive layer for connecting two electrically conductive surfaces is known in which at least one of the surfaces to be bonded is wetted with a low-viscosity, electrically non-conductive adhesive and then at contact pressure of a temperature, at least the curing temperature of the used Adhesive corresponds, as long as suspended until the bond has a negligible electrical resistance. This process requires an additional operation to cure the adhesive. Direct contact is regularly not achieved.

In DE 44 37 721 A1 is described an electrical module for installation in a data carrier with an arranged on a support of the module integrated circuit. The installation of the modules is carried out in laminating technology, wherein several card layers are joined together by heat and pressure, after the coil ends and the connection points of the integrated circuit have been connected to each other. The generation of a permanent pressure contact is thus not achieved.

The invention is based on the object Specify a method for producing an electrical connection between the chip module and a connector, which is carried out fully automatically by simple means and has a very high productivity. The connection point should have a minimized volume, no impermissible thermal loads from the substrate and chip module o. Ä cause. Furthermore, the connection point and the contact partners should take their final position to each other in the subsequent Plastumhüllen and at the same time give the intended connection quality.

According to the invention, the solution of the problem succeeds by the following procedure:
Between the wing surfaces of both electrically conductive parts to be joined is a thermoplastic or themperaturstufenweise curable, with a required melting or reaction temperature u. Adhesive, the joining surfaces of the joining parts are positioned to each other, which press in itself in the following lamination step to be laminated surfaces of the insulating parts or in the following Plashüllungsschritt the mold cavity-forming mold walls in the following plastic coating Clamping faces the joining parts against each other, heat the adhesive to melting or reaction temperature, bring the joining parts as a result of the melting adhesive of the compression in the final position and fix the joining parts by also under the laminating pressure slightly flowing and filling the space around the parts to be joined Material of the insulating parts or by the injected into the mold cavity during Plastumhüllungsschritte plastic and enclose them hermetically.

Advantageous it is the parts to be joined even at low temperature or less than the final melting point or prefix reaction temperature and time. This can be done in the Joining process advantages with respect to joining position to each other can be achieved.

Further it is advantageous as an adhesive adhesive electrically conductive to use. Thus, a high contact layer is achieved, provided the joining surfaces themselves Do not touch or only at a few points directly.

Also it is advantageous to apply the adhesive as a liquid adhesive on a joining part, to pre-harden or to dry and then under heating this joining part to carry out the prefixing on the other joining part.

So let yourself perform the Vorfixiervorgang as a pure placement step.

Further advantageous embodiments are specified in the subclaims.

The inventive method is characterized by a number of advantages:
The preparation of the joining surfaces (coating and predrying of the adhesive) can be done fully automatically and with relatively little expenditure on equipment, the prefixing can be carried out as a pure placement step, the junction is exactly after the surrounding insulating or molding surfaces ago and they, since they only is finally produced in the actual subsequent step, not burdened or destroyed by material displacements during lamination or when closing the mold cavity. Finally, the junction is hermetically enclosed by plastics at the time of their formation and fixed in their position. The adhesive connects the joining surfaces and at the same time prevents penetration of material of the insulating parts or plastic between the joining surfaces.

The The invention will be explained in more detail below with reference to two exemplary embodiments. In the associated Drawings show:

1 a section through two joining parts with intermediate adhesive layer in front of the Plastumhüllen,

2 a section through the in 1 shown joining parts Plastum sleeves,

3 a section through a thermoplastic insulating layer with inserted joining part and about prefixed further joining part and

4 a section through to be laminated thermoplastic insulating layers with intermediate finally electrically conductive joined parts at the end of the lamination process.

In 1 represents the joining part 4 a part of a silver-coated lead frame. On the joining surface 1 of the joining part 4 is in one after pre-drying the glue 3 resulting thickness of the largest or equal to 50 .mu.m at 180 ... 200 ° C optimally melting and wetting the joining surfaces thermoplastic adhesive 3 , eg the silver-filled adhesive .... 81 of the company AIT / applied by dispensing. On the glue 3 is the metallic, gilded adherend 5 , which is a contact piece, prefixed by briefly pressing at about 170 ° ... 180 ° C.

Of the lead frame should be covered with thermoset.

2 represents the situation after wrapping. Due to the closing pressure and the temperature of about 190 ° of the upper mold wall 8th and the bottom one mold wall 9 be the two parts to be joined 4 and 5 pressed against each other and they close flush with the respective mold walls 8th . 9 from. The viscous glue 3 is squeezed out until the mold is completely closed. Transfermolding turns liquid plastic 6 in the remaining mold space through the tool parts 14 . 15 is gebil det injected. The thermoset 6 Gels and cures and closes the parts to be joined 4 . 5 and the glue 3 firmly in itself. During the Traunsfermolding cycle the thermoplastic adhesive has 3 sufficient time and sufficiently high reaction temperature to the joining surfaces 1 and 2 sufficiently wet. As the plastic to be injected 6 has a lower viscosity than the melted thermoplastic adhesive 3 , a washing away of the adhesive occurs 3 not up.

After removal from the mold, a molded part is available, which is an extension of the horizontal part to be joined 4 a connection 12 and at the same time on the upper side of the molded part, a contact surface 13 having. Thus, contacts of a semiconductor chip in 2 Realize levels of a molded part.

3 shows impressed in a thermoplastic, flat insulating 10 a joining part 4 , which in the example represents a metallically bright, silvered piece of an antenna coil. adherend 5 represents a connection pin of a chip housing, the connection pins were already in the lead frame association before separating out the housing from the lead frame by means of Disponsen with silver-filled adhesive .... the Fa. AIT coated, the adhesive was pre-dried.

After removing the housing from the leadfram dressing, the terminal pins are briefly heated to 150 ° C and through the slightly melted adhesive 3 both on the insulating part 10 as well as on the joining part 4 be prefixed.

Subsequently, after placing a further thermoplastic sheet-like insulating member 11 and compressing the insulating parts 10 . 11 by parallel, flat and heated to about 150 ° C mold walls 8th . 9 the lamination of the insulating parts 10 . 11 ,

4 represents the situation at the conclusion of the lamination. Under the pressure of the viscous insulating parts 10 . 12 are the parts to be joined 4 and 5 pressed together and changed in their position to each other and something in the direction insulating part 10 been moved.

The desired direct contact also occurred 16 between the two parts to be joined 4 ; 5 on. To support this direct contact 16 It is advantageous eventual cutting burrs on the parts to be joined 4 . 5 so that they point in the direction of joint partner. The glue 3 is squeezed wide and wets relatively large areas of adherend 4 and 5 ,

1

Joining surface A

2

Joining surface B

3

Glue

4

Joining part A

5

Joining part B

6

electrical insulating plastic

8th

upper mold wall

9

lower mold wall

10

Insulation A

11

Insulation B

12

connection

13

contact area

14

Mold shell

15

Mold base

16

Direct contact point

Claims (9)

Method for connecting electrically conductive parts ( 4 . 5 ) at joining surfaces ( 1 . 2 ) by gluing, wherein between the joining surfaces ( 1 . 2 ) a thermoplastic or temperature grade curable adhesive ( 3 ), characterized in that - the required melting or reaction temperature and time of the adhesive ( 3 ) correspond to the process regime of the subsequent lamination step, - the joining surfaces ( 1 . 2 ) are positioned to one another, in a following laminating step, the surfaces of insulating parts to be laminated ( 10 . 11 ) as clamping surfaces the joining parts ( 4 . 5 ) against each other and at the same time the adhesive ( 3 ) to the required melting or reaction temperature, wherein the joining parts ( 4 . 5 ) as a result of the melting adhesive ( 3 ) and the compression are brought into the final position and - the joining parts ( 4 . 5 ) form a direct contact and through the also slightly under laminating pressure and the space around the Fügeteile ( 4 . 5 ) filling material of the insulating parts ( 10 . 11 ) are fixed and hermetically wrapped. Method for connecting electrically conductive parts ( 4 . 5 ) at joining surfaces ( 1 . 2 ) by gluing, wherein between the joining surfaces ( 1 . 2 ) a thermoplastic or temperature grade curable adhesive ( 3 ), characterized in that - the required melting or reaction temperature and time of the adhesive ( 3 ) correspond to the process regime of subsequent plastic cladding steps, - the joining surfaces ( 1 . 2 ) are positioned to one another, - in a subsequent plastic wrapping step, the mold walls forming a mold cavity ( 8th . 9 ) when Clamping surfaces the joining parts ( 4 . 5 ) against each other and at the same time the adhesive ( 3 ) to the required melting or reaction temperature, wherein the joining parts ( 4 . 5 ) as a result of the melting adhesive ( 3 ) and the compression are brought into the final position and - the joining parts ( 4 . 5 ) form a direct contact and through which in the mold space ( 7 ) plastic injected in the plastic wrapping process ( 6 ) are fixed and at least partially wrapped. Method according to claim 1 or 2, characterized in that the adhesive ( 3 ) is electrically conductive. Method according to one of the preceding claims, characterized in that the joining parts ( 4 . 5 ) by means of the adhesive ( 3 ) are prefixed to each other at a much lower time or temperature loads than the final melting or reaction temperature and / or time. Method according to one of claims 1, 3 or 4, characterized in that the viscosity of the adhesive ( 3 ) at laminating temperature is lower than that of the layered thermoplastic insulating parts ( 10 . 11 ). Method according to one of claims 2 to 4, characterized in that at Plastumhüllungstemperatur the viscosity of the adhesive ( 3 ) is greater than that of the inflowing electrically insulating plastic ( 6 ). Method according to one of the preceding claims, characterized in that the expansion coefficients of the adhesive ( 3 ) and the parts to be joined ( 4 . 5 ) are each smaller than the expansion coefficient of the insulating parts ( 10 . 11 ) and the electrically insulating plastic. Method according to one of the preceding claims, characterized in that the joining parts ( 4 . 5 ) are designed so that any protrusions, cutting burrs, edges are pressed against each other to between the joining parts ( 4 . 5 ) Direct contact ( 16 ) to achieve. Method according to one of the preceding claims, characterized in that as joining parts ( 4 . 5 ) metallic bare, surface-finished leadframes, contacts or antenna wires or conductors are used.