DE10228373B4 - Method for producing an electrical connection between components of a chip card - Google Patents

Abstract

Method for producing an electrical connection between components of a chip card, which has a chip card body (1) made of thermoplastic material by injection molding, wherein at least one component (6) provided with contact surfaces (7) is cast into the chip card body (1) after the injection molding process, the exposed with the injection molding material contact surfaces (7) are exposed and these are then connected by means of an electrically conductive connection material (10) with contact surfaces of an additional inserted into the chip card body electronic component (11), characterized in that the exposure of the contact surfaces (7) by means of a heated over the melting temperature of the injection molding material plunger (8), which is so far pressed into the contact surfaces (7) covering the injection molding material until the plunger (8) on the hidden contact surfaces for Plant comes, wherein the overlapping injection molding material in the region of the contact surfaces (7) is melted and displaced.

Description

The The invention relates to a method for producing an electrical Connection between components of a chip card, which one by injection molding having produced, consisting of thermoplastic material chip card body, being in the chip card body at least one with contact surfaces provided electrical component is poured. In the process be according to the generic features of the claim 1 after the injection molding process covered with the injection molding material contact surfaces exposed the electrical component and then these contact surfaces by means an electrically conductive connecting material with corresponding contact surfaces one additional in the chip card body connected to another electronic component connected.

The described method is used in the production of smart cards used, which currently for one Variety of different applications, for example as means of identification or for the storage of other persons Data are used. The storage and partly processing The data is stored on a microchip, which is in a so-called Chip module is integrated, which in turn is often made of a thermoplastic Plastic existing chip card body is used. The chip module is used in the production of the chip card and during its later use the protection of the microchip on it.

In the DE 42 41 482 A1 a manufacturing method for the production of IC cards is described, in which initially introduced into the plastic card, a trough, whereupon in this trough an IC module is fixed with external contact surfaces. To shorten the cycle times, a blind hole is first introduced into the card for producing the depressions, and then the depression is formed with the aid of an embossing stamp, with the material displaced by the embossing die avoiding the blind hole. The production of the blind hole is preferably carried out by milling, while the molding of the trough is preferably carried out by hot stamping.

Next the chip module according to today Technology in a smart card often more electronic components such as batteries, rechargeable batteries or tracks Antenna coils for contactless communication of the chip card with external readers brought in. This extra Components serve to increase the functionality of the smart cards, in addition to the components mentioned, of course, additional further optical or electronic elements integrated in the card could be. To guarantee the function and the interaction of the individual components is their internal interconnection required. The individual components have this Contact surfaces, wherein in the production of such smart cards, the contact surfaces of individual Components, for example by means of soldering measures or by gluing with a so-called conductive adhesive electrically be connected to each other. Before such a connection of the contact surfaces take place can, must these are, however, freed from a plastic layer covering them, since the addressed electronic components, such as batteries, batteries, Antenna coils and the like after the manufacture of the chip card body in Injection molding process covered by a layer of the injection molding material are.

Conventionally done this exposure by a milling process, by nature, as a result of this Machining material is released, which is a clean working environment detrimental is.

In order to avoid the difficulties that arise in the production of smart cards with embedded components, in particular antennas, so in contactless smart cards, if you want to attach recesses in the card body such that contact surfaces of the antenna are accessible, is in the DE 197 20 226 C1 proposed during a Einsenkvorganges means of a Einsenkwerkzeuges (eg., a milling tool) then cancel the Einsenkvorgang when an electrical measurement shows that the Einsenkwerkzeug a contact portion of the antenna touches.

The DE 196 47 846 C1 describes a method for the production of chip cards, wherein a semiconductor chip located on a module is inserted in a recess of a card carrier and contacted with an inductive signal transmission device in the form of an antenna coil. According to the invention of this document, the antenna coil or the antenna coil ends at least in the region of electrical pads of the module or the semiconductor chip within the recess for receiving bending and torsional forces meandering or spiral. In a particularly preferred embodiment of the invention of this document, the formation of the antenna coil ends takes place in such a way that the meandering or spiral turns are provided with a profile which increases relative to the recess center to the card longitudinal or transverse section. By this measure, it is ensured that during the subsequent introduction of the recess in the card body, vorzugswese by milling, a sufficiently large contact point is given.

In the DE 198 31 565 C1 a method for the production of smart cards is described, which is suitable for exposing antenna pads of a substantially completely embedded in a card body of a smart card antenna. In the method, a cavity is incorporated into the card base body and, in the region of the cavity, the connecting surfaces are at least partially exposed by means of a laser. The exposure of the pads should be improved and security increased. For this purpose, the cavity is produced by removal of material while leaving a completely covering the pads protective layer and then exposed by destroying the protective layer by means of the laser, the pads.

task It is therefore the object of the present invention to provide a process for the preparation an electrical connection between components of a smart card in which the exposure of the contact surfaces to Connection of the components with each other quickly without machining and can be done easily.

These Task is inventively characterized solved, that the exposure of the contact surfaces by means one over the melting temperature of the injection molding of the chip card body heated plunger takes place, which in the contact surfaces covering injection molding material pressed so far, until the plunger on the hidden contact surfaces comes to the plant, with the overlapping Injection molding material is melted and displaced in the area of the contact surfaces.

With Help of the method described can be in the context of smart card production elaborate milling processes avoid, which is particularly advantageous that a complex metrological monitoring the milling process for Protection of sensitive contact surfaces from destruction in the Frame of the milling of the contact surfaces covering plastic material is no longer necessary. Furthermore does not fall any waste material in the method according to the invention on, which are removed by means of complex extraction devices would.

Special Embodiments of the method according to the invention arise additional to the technical teaching of claim 1 also from the features of Dependent claims.

Of the used plunger can, for example, according to an advantageous Embodiment cylindrical be formed or he may have a conical tip. at Formation of the plunger according to the latter variant the plunger continues after hitting the contact surface pressed on this until the top of the plunger pierced them. The hole formation in the contact surface can under certain conditions an improvement afterwards bring about the electrical connection to be made.

A Design variant of the electrical connection between the individual with the contact surfaces provided components can be done with the help of a conductive adhesive, with which the exposed contact surfaces are coated, wherein the recesses formed by the plunger above the contact surfaces Completely fill out. Subsequently For example, a chip module in existing recesses of Chip card body used so that the existing on him corresponding contact surfaces by the conductive adhesive with the previously exposed contact surfaces of in the chip card body already located component are connected.

in the The following is the method according to the invention in its individual steps with reference to the accompanying drawings explained in more detail.

It shows:

1 an injection-molded chip card body prior to starting the method steps according to the invention,

2A . 2 B . 2C . 2D an enlarged view of the detail D from

1 during different process steps of the process,

2E a sectional view similar to the 2A to 2D to explain a further particular sequence of the method according to the invention and

3 the chip card body after completion of the procedure with inserted electronic component in the form of a chip module.

In the presentation of the 1 is a partial area of a chip card body 1 represented, which is produced by injection molding. The chip card body 1 consists essentially of two located on the top and bottom film layers 2 and 3 and an injection-molded intermediate layer 4 , The Spritzgussherstellvorgang takes place in such a way that the film layers 2 and 3 be placed in an injection mold. The injection mold usually consists of two parts, in the unfolded state, the film layers 2 and 3 can be inserted easily. After closing the superimposed tool halves is in the inner cavity in which the at the film layers have been inserted, a liquid injection molding material, preferably pressed from thermoplastic material, which the film layers 2 and 3 presses against the outer walls of the injection mold and completely fills the gap between the layers. In the course of the injection molding process can in the smart card body 1 recesses 5 are introduced, which is provided for receiving, for example, a chip module. This is done by introducing appropriately designed additional elements in the mold.

From the 1 it can be seen that the film layer 3 at the top of the smart card body at its inner-facing surface conductor tracks 6 with contact surfaces thereon 7 having. The tracks 6 form on the foil layer 3 an antenna in the form of a coil, which is used for inductive contactless data transmission with suitable external data readers. These data are usually stored in a microchip, which is arranged on a chip module, which in turn into the recess 5 of the chip card body 1 is implanted. This chip module has in its in the recess 5 In reaching bottom contact surfaces, which in the context of the manufacturing process for the smart card with the contact surfaces 7 need to be connected.

Again 1 is removable, these contact surfaces 7 but after the injection molding process of the film layer 3 covered. To contact the contact surfaces 7 Consequently, the foil layer material, which has the contact surfaces, must be possible 7 covered, at least in a portion of the contact surfaces are removed.

This is done with the help of a printing stamp 8th , which from the top of the chip card body 1 into the recess 5 in the area of the contact surface 7 is retracted, as indicated by the pill P in the 2A is clarified. The printing stamp 8th is provided with a heating device, which is a heating of the plunger 8th allows to a temperature above the melting temperature of the plastic material of the film layer 3 lies. Since the melting temperature of the plastic materials used is very different, the temperature of the plunger can be controlled in a wide adjustment range. Due to the heating of the plunger 8th becomes the plastic material of the film layer 3 at the moment of impact of the plunger 8th on the top of the film layer 3 melted in the area of the pressure die tip, as shown in the 2 B is illustrated schematically.

The printing stamp 8th can thus easily into the plastic material of the film layer 3 penetrate until he, as in the 2C is clarified, at the contact surface 7 with the connected track 6 comes to the plant.

Will the plunger 8th then back up out of the recess 5 moved out, as remains in the 2D is shown in the film layer 3 above the contact surface 7 a cylindrical opening 9 ,

This breakthrough 9 is in a subsequent process step with a conductive adhesive 10 filled, with at the same time at the top of the film layer 3 a partial area is also covered with the conductive adhesive. After this process step can in the recess 5 of the chip card body 1 a chip module 11 be used. This chip module consists essentially of a carrier element 12 and a microchip disposed thereon 13 ,

The 3 makes it clear that the microchip on the inside of the chip card body directed bottom of the support element 12 is arranged, wherein the carrier element 12 a peripheral edge area 14 has, with it on a likewise encircling paragraph 15 the recess 5 comes to the plant. support element 12 and microchip 13 are designed so that in the area of the edge area 14 the carrier element 12 On its underside facing the interior of the chip card body contact surfaces 17 which, by not shown in the figure, printed conductors with the microchip 13 are connected.

Will the chip module 11 into the recess 5 used, so at the same time a connection between the on the support element 12 located contact surfaces and the conductive adhesive 10 produced. As the conductive adhesive 10 simultaneously with the contact surfaces 7 is thus simultaneously an electrical connection between the microchip 13 and the tracks 6 , which form the antenna for contactless data transmission, made so that a data transfer between microchip and external readers can take place.

Of course, instead of the tracks 6 at the contact surfaces 7 be connected to other electronic components such as a battery or a battery.

According to an advantageous embodiment of the method according to the invention, it may be useful for certain conditions when, according to the representation of 2E the plunger 8th is conical at its free end. The shape of the punch 8th with such a tip serves, not just an opening 9 in the film layer 3 of the chip card body 1 but beyond also in the contact area 7 a passage 16 to shape. This happens because of the pressure stamp 8th after hitting the surface of the contact surface 7 is moved further in the direction of the pill P, so that he under the action of a corresponding effort within the contact surface 7 the passage 16 ausformt. Because both the track 6 as well as the contact area 7 made of copper material, constitutes the production of the passage 16 with appropriate tip design of the punch 8th no difficulty. After the printing stamp 8th again from the recess 5 has been removed, the production of the electrical connection between the chip module 11 and the contact surfaces 7 analogous to the description of 3 ,

1

Smart card body

2

film layer

3

film layer

4

liner

5

recess

6

conductor path

7

contact area

8th

plunger

9

perforation

10

conductive adhesive

11

chip module

12

supporting member

13

microchip

14

border area

15

paragraph

16

passage

17

contact area

P

movement direction

Claims (3)

Method for producing an electrical connection between components of a chip card, which comprises an injection-molded, made of thermoplastic material chip card body ( 1 ), wherein in the chip card body ( 1 ) at least one with contact surfaces ( 7 ) provided component ( 6 ) is poured, wherein after the injection molding process, the covered with the injection molding material contact surfaces ( 7 ) are exposed and then by means of an electrically conductive connecting material ( 10 ) with contact surfaces of an additional electronic component to be inserted into the chip card body ( 11 ), characterized in that the exposure of the contact surfaces ( 7 ) by means of a heated over the melting temperature of the injection molding material plunger ( 8th ), in which the contact surfaces ( 7 ) overlapping injection molding material is pressed until the plunger ( 8th ) comes to rest on the concealed contact surfaces, wherein the covering injection molding material in the region of the contact surfaces ( 7 ) is melted and displaced. Method for producing an electrical connection between components of a chip card according to claim 1, characterized in that the plunger ( 8th ) after hitting the contact surface ( 7 ) continues through the exposed contact surface ( 7 ) is pushed through. Method for producing an electrical connection between components of a chip card according to claim 1 or 2, characterized in that the exposed contact surfaces ( 7 ) with a conductive adhesive ( 10 ) are coated, which by the plunger ( 8th ) recesses ( 9 ) are completed in full.