DE19637214A1 - Smart card with inductive antenna for contactless data transmission - Google Patents

Abstract

The smart card has a card carrier provided with a milled recess in one of its major surfaces. The recess is for reception of a semiconductor chip (25) with antenna contacts (31,32) for connection to the inductive antenna. The antenna is provided by an antenna coil layer (11) within the card carrier. The antenna coil layer has chip contacts (20,21) cooperating with the antenna contacts of the semiconductor chip. It has thickened sections (16,17) embedded in the card carrier and exposed during milling, to ensure good contact with the antenna contacts.

Description

The invention relates to a method for producing a electrical and mechanical connection one in a Ausneh tion of a card holder of a chip card used module using a hot or hot melt adhesive as well as a ver binders for performing this method.

Chip cards for contact-based but also contactless d. H. Inductive data transmission have one with the card body connected chip card module on one on an art Contains semiconductor chip located, which at contact cards with a galvanic contact field connected is. In a card reader, these contacts surfaces scanned electrically, so that the required commu nication becomes possible.  

In the case of contactless, inductive systems, the Da occurs transmission through alternating electromagnetic fields using at least one arranged in the chip card or in the card carrier neten induction coil.

In the case of so-called combination cards, both systems mentioned above are united in one card. The combination card therefore has both via a contact field for contact transfer as also via an inductively connectable contact. It is for that required, in addition to the electrically conductive connections from Semiconductor chip to the system for the contact-related data wearing connections to the system for inductive data to establish transmission.

To solve this problem, the electrically conductive connections between the connection points and the means for contactless data transmission by means of egg to produce an anisotropically conductive adhesive. This aniso tropically conductive adhesive has electrically conductive particles, which distributes the adhesive evenly during manufacture be added. The amount of conductive particles in the adhesive should be chosen so that between the connection points and the means for contactless data transmission z. B. one enough particles in front of the corresponding contact field of an antenna are available to ensure an adequate electrical connection to build speaking contact quality.

In the method described above, the comes electrically Conductive connection that the anisotropic lei tend adhesive at least in the area of the connection points and under the connection points of the agent for the contactless Data transfer applied and the adhesive at least in the loading range of the connection points is compressed so far under pressure, that an electrically conductive bridge d. H. a current path between rule the connection points and the means for contactless Da transmission is formed. In the case of the adhesive mentioned above material with electrically conductive particles, this leads to the fact that the particles in the area between the connection points and the agent  are quasi compressed for contactless data transmission, so that the individual particles with each other and the An touch terminal and connection points so that the conductive Connection results.

The module provided with a semiconductor chip is usually used implan in a recess made in the card carrier animals, using an adhesive method for this a hot or hot melt adhesive (hotmelt process) is gripped.

For the production of combination cards, the module mentioned is included another contact level provided with the connection provide for the means for contactless data transmission, for. B. to be electrically connected to a coil. This electrical Connection should, if possible, in one operation with the mechani connection of the module based on the recess in the card can be realized. The existing in the card carrier z. B. Copper wire coil leads to connection points, which during manufacture make the recess for the module z. B. part by milling be wisely exposed. With such an arrangement assembly and gluing of the module to the card carrier simultaneously with the manufacture of the electrically conductive Ver binding between the means for contactless data transmission supply and the connection points of the module, if the anisotropically conductive adhesive essentially over the entire surface of the card carrier recess is applied and ensure an appropriate temperature and pressure will be carried.

However, it is disadvantageous to use the anisotropically conductive adhesive to be applied over the entire contact area because the adhesive on the one hand is expensive, which results in cost increases, other optimal electrical connections are often not sufficient appropriate adhesive connection or adhesion between module and cards sluggish. It will also be used for compression higher the conductive components of the anisotropic adhesive Compressive forces needed to perform a safe per se Hot glue connections to the same extent are not necessary.

It is therefore an object of the invention to produce a method position of an electrical and mechanical connection of a inserted in a recess of a card carrier of a chip card specified module that allows using a hot or hot melt adhesive in a single operation with regard to long-term stability and contact quality optimized process parameters are both excellent electrical contact quality as well as a safe mechanical connection of the module in the card carrier guarantee. Furthermore, for the implementation of the A suitable lanyard can be specified.

The object of the invention is achieved with a method ren according to the features of claim 1 and with a Lanyard according to the features of claim 7.

The subclaims include at least appropriate configuration lines and developments of the invention.

The basic concept of the invention according to the method lies in for establishing an electrical and mechanical connection one in a recess of a card holder of a chip card used module on a be on a film-like carrier sensitive, non-conductive hot or hot melt adhesive layer fall back, this hot or hot melt adhesive layer in Area of electrical contacts to be trained between module and Card carrier with an additional conductive layer or is to be provided with conductive particles. This additional conductive layer or the conductive particles can by Punching the hot or hot melt adhesive layer with subsequent Filling trained using recourse to conductive material will.

The hot or hot melt adhesive layer prepared in this way with conductive sections is then on the module or in the recess of the Card holder pre-fixed. This fixing is done so that the with the additional conductive layer or the conductive Particles provided between the contact  surfaces of the module and the recess of the card carrier are located. Following this fixation will be in a single Pressure-temperature exposure step both mechanical Connection between module and card carrier as well electrical contact between the opposing Contact areas realized.

It is not necessary according to the invention that the rule based on the connection area mentioned only small contact surface sections make a significant contribution to the adhesive bond, rather, optimized electrical properties such as low line inductance or transition resistance can be achieved. By the usual hot or Hot melt adhesive connection is used for adequate pressing and Compaction of the conductive particles is taken care of so that the desired long-term contact stability results.

In the case when according to the invention for the conductive particles a solder paste or a solder ball can be used through the defined supply of thermal energy in the contact area after or during the gluing of the module in the card carrier Soldering is done, thereby further increasing the contact security is given. In this case, the solder joint is made by mechanical tensions, shear or other forces hold, because these are also in the ongoing use of the card by the Adhesive connection can be recorded over a large area.

According to a further basic idea of the invention, depending on Material of the card carrier or module a suitable before Assembled hot or hot melt adhesive selected and there Visible layer thickness and selection of the conductive particles for individually prepared the respective application and thus op be timed.

The conductive particles or the conductive layer are on the hot or hot melt adhesive film, for example by means of a Dispensers, a roller or a stamp can be applied locally, using a mask if necessary can, so that the reproducibility when applied  capable coatings increased. In the case of the surface side Application of a conductive layer or of conductive par In one embodiment of the invention, the particles are so applied layer briefly from a thermal treatment set so that a certain melting of the respective parts and thus sticking and connecting with the hot glue or the Hot melt adhesive is the result. This will make sure asked that the subsequent handling the conductive Layer or the conductive material before unwanted removal is protected.

In the case when the hot or hot melt adhesive layer Ausneh mung or perforations with conductive particles How to fill solder balls or solder paste can be done on usual and proven solder are used. The dosage the amount of particles to be introduced into the recesses or Punching is not critical as there is excess material during soldering and / or pressing and simultaneous gluing into the adhesive layer can be displaced into it without the contact overall security is impaired.

The connecting means according to the invention for performing the ge described method consists of a on a carrier film non-conductive hot or hot melt adhesive layer, which in the field of electrical contacts Ab cuts with conductive particles or a conductive Layer.

These sections can be made with solder paste or conductive adhesive filled recesses or perforations.

In one embodiment of the connecting means there are conductive sections inside a hot or melt adhesive overlay, this during assembly by means of pressure tempera impact is displaced and raised contact surfaces in Active connection with the inner conductive layer or inner conductive sections occur.  

All in all, the invention, a method and a connecting means for producing an electrical and mechanical connection of one in a recess of a card Specify carrier of a chip card used module, where egg on the other hand use known hot or hot melt adhesives can be and on the other hand both high quality electrical contacts or electrical connections realized can be and the required mechanical strength of the Mo duls is given in the card carrier, without that during operation adverse shear or other forces on the contact areas act.

The inventive method is particularly for contactless Suitable for smart cards or combination cards, both of which mechanically contactable contact surfaces as well as inductive Components are present. By using the Hot or hot melt adhesive films modified according to the invention card manufacturing costs can be reduced because it is not necessary to conduct expensive anisotropic conductive To resort to adhesives that are used to glue the rest Modules with the card carrier are only suitable to a limited extent.

Due to the only partial electrical connection to the respective electrical contact points there is enough space to carry out the integral adhesive connection to the Mo dul securely in the card carrier.

The invention is illustrated below with the aid of an embodiment be explained in more detail with the help of figures.

Here show:

FIG. 1 is a section through a hot-melt adhesive film;

Fig. 2 is a plan view of a prepared hot melt film;

Fig. 3 shows a section through a hot melt film with conductive particles and inside

Fig. 4 is a schematic sectional view of the Einbauposi tion of the module in the recess of a card carrier using the connecting means according to the exemplary embodiment.

The section shown in FIG. 1 through a hot melt film has a carrier film 1 which is coated with a hot or hot melt adhesive 2 . The layer thickness is between 20 and 80 µm, depending on the card material such as ABS, PVC, PC or PET, different adhesives are used.

The prepared hot or hot melt adhesive shown in FIG. 2 has perforations 3 for receiving the chip as well as laterally arranged sections 4 which consist of or contain a conductive layer or of conductive particles 16 .

These sections 4 can for example be perforations or recesses which have been filled with solder paste. As can be seen from FIG. 2, the hot or hot melt adhesive 2 located on a carrier film 1 is made up. On this blister-like film strip, the module 10 provided with a chip 11 ( FIG. 4) can be fastened, in order to then in a next operation the module 10 provided with carrier film 1 and hot or hot-melt adhesive 2 towards the recess 12 of a card carrier 13 position ( Fig. 4).

In a further embodiment, solder balls with egg a diameter of 25 µm on the hot or hot melt adhesive layer applied selectively, so that in a subsequent Pressure-temperature process both a solder joint between the opposing contact surfaces using the Solder ball as well as the adhesive connection between module and car can be realized.

In the hot or hot melt adhesive 2 shown in FIG. 3, this has an inside layer 5 made of conductive particles. In the case when the configuration according to FIG. 3 is used, raised contact surfaces on the module or on the card carrier are able to displace the hot or hot-melt adhesive which changes into the semi-liquid state during the pressure-temperature treatment step, so in Actively connect with the conductive particles of the inner layer, whereby the desired contact is formed.

Which comprises using the Fig. 4, which shows a schematic sectional view through a card carrier 13 has a recess 12, the method for producing compound will now he be explained.

The ver with the prepared hot or hot melt adhesive layer 2 module 10 , which comprises a chip 11 , z. B. positio ned by means of a suitable tool in the recess 12 .

Contact surfaces 14 , which are connected to an induction coil for contactless data transmission, are located on the inner surface side of the recess 12 . The hot or hot-melt adhesive in layer 2 heats up by exerting a compressive force in the direction of the arrow and by the action of temperature. At the same time, the conductive particles 16 , which are located in the sections 4 or in the layer 5 , establish an electrical connection between the contact surfaces 14 and the opposite contact surfaces 15 of the module. When the adhesive cools and hardens, there is both a secure mechanical connection of the module 10 in the recess 12 of the card carrier 13 and a corresponding electrical connection between the contact surfaces 14 and 15 . In the case when, for example, solder paste is introduced into recesses or holes in the hot or hot melt adhesive 1 , this is used to implement the electrical connection between the opposing contact surfaces 14 and 15 .

In a further embodiment, when using a solder ball in the adhesive film during or after the pressure-temperature action step, additional heat locally in the area of the contact surfaces 14 and / or 15 can be brought into effect, so that the desired soldering process is carried out.

The exemplary embodiments described above become clearly that the conductive particles or the conductive Layer both be inside the hot-melt film can, as well as can be applied to the surface. A fixation of a layer applied on the surface or of surface Particles arranged on the side can be caused by brief heat treatment take place, whereby the corresponding particles on Adhere glue. For example, for heat treatment to a heated roller that is guided over the film be resorted to, the roller also at the same time Applying the conductive particles is usable.

Reference list

1 carrier film
2 hot or hot melt adhesives
3 holes for chip
4 sections
5 inner layer
10 module
11 chip
12 recess
13 card carriers
14 contact surfaces card carrier
15 module contact surfaces
16 conductive particles

Claims (10)

1. A method for producing an electrical and mechanical rule's connection of a module inserted in a recess of a card carrier of a chip card using a hot or hot melt adhesive, characterized in that

• the non-conductive hot or hot-melt adhesive layer located on a film-like carrier is provided with an additional conductive layer or conductive particles in the area of electrical contacts to be formed between module and card carrier,
• - Then the hot or melt adhesive layer prepared in this way is fixed to the module or in the recess of the card carrier, the sections provided with the additional conductive layer or the conductive particles being located between the contact surfaces of the module and the recess of the card carrier and
• - Furthermore, both the mechanical connection between the module and the card carrier and the electrical contact are implemented in a single pressure-temperature action step.

2. The method according to claim 1, characterized in that depending on the given material of the card holder and the month duls suitable hot or hot melt adhesive selected and these with regard to their layer thickness and selection of conductive particles for the respective application indi be prepared vidually. 3. The method according to claim 1 or 2, characterized in that the conductive particles or the conductive layer given locally by means of a dispenser, roller or stamp if applied by means of a mask, whereby by simultaneous or subsequent brief heat treatment the particles or the layer components with the Adhesive layer can be adhesively bonded. 4. The method according to any one of the preceding claims, characterized in that solder balls are used as conductive particles. 5. The method according to any one of the preceding claims, characterized in that recesses or in the hot or hot melt adhesive layer Perforations are made, which with conductive par items are filled. 6. The method according to claim 5, characterized in that solder paste is used as the conductive particle.   7. Connection means for carrying out the method according to one of claims 1 to 6, characterized by a non-conductive hot or hot melt adhesive layer ( 2 ) located on a carrier film ( 1 ), which in the region of the electrical contacts to be produced sections ( 4 ) with conductive particles ( 16 ) or has a conductive layer. 8. Connection means according to claim 7, characterized in that the sections ( 4 ) consist of ver filled with solder paste or hot glue recesses or perforations of the hot or hot melt adhesive film. 9. Connecting means according to claim 7, characterized in that the conductive sections ( 4 ; 5 ) are located inside a hot or hot melt adhesive layer which can be displaced under the action of temperature and pressure. 10. Connection means according to claim 7, characterized in that the connection by means of pre-applied, rolled Solder wire is realized.