EP1433128A1

EP1433128A1 - Chip card and method for producing a chip card of this type

Info

Publication number: EP1433128A1
Application number: EP02779136A
Authority: EP
Inventors: Stefan Dohse; Jörg Zander
Original assignee: Orga Kartensysteme GmbH
Current assignee: Idemia Germany GmbH
Priority date: 2001-10-01
Filing date: 2002-10-01
Publication date: 2004-06-30
Also published as: WO2003032245A1; DE10148525B4; DE10148525A1

Abstract

The invention relates to a chip card comprised of a chip card body with a conductor track provided in the form of a coil. The coil (1) that is produced using an injection molding method or an injection stamping method is comprised of an electrically conductive plastic or the coil (1) that is produced using a powder injection molding method is comprised of an electrically conductive metal powder. The invention also relates to a method for producing a chip card of the aforementioned type during which, inside an injection molding tool (10), which has a closing side (13) and an injection side (12) respectively provided with at least two mold cavities (A and B), a printed rear-side label (4) is placed inside the mold cavity (A) and is subsequently fixed inside the mold cavity (A) by means of vacuum or electrostatic charging in order to be able to inject the electrically conductive plastic after closing the injection molding tool (10). After cooling the coil (1), the front-side label (5) can be placed inside another mold cavity (B) in order to complete the chip card. Said front-side label can then be joined to the coil (1) by back injection molding a plastic.

Description

Chip card and a method for producing such a chip card

description

The invention relates to a chip card and a method for producing such a chip card.

Chip cards, which are also commonly referred to as data cards or frequently referred to as SmardCards, are used in a wide variety of applications. Passive chip cards, that is to say chip cards with a read memory (ROM, EPROM or similar memory) and also active chip cards in the form of a processor card which can process data internal to the card, for example, are known.

Chip cards are used as telephone cards and also as credit or bank cards or are used for access identification in companies or other secure areas. There are recognized chip card standards for the manufacture and compliance with uniform sizes of the chip card body and the incorporation of internal circuits.

It is known to provide such chip cards, for example, with optical and / or electrical switching elements, with displays, batteries and other electronic switching elements. A chip module can take over a possible interconnection or storage of data. In addition, laminatable carrier films with an internal circuit are known, which can be applied to the chip card body or embedded therein.

It is generally known in the prior art to produce the chip card body by means of an injection molding process. The coil or antenna applied to the chip card body or integrated in the chip card body So far, for example, it can be produced by first coating a plastic film with an electrically conductive material, which is preferably metal, over the entire surface. In a subsequent process step, the excess material is etched away, so that a coil with the connection surfaces required for contacting remains on the plastic film.

Furthermore, it is known to produce a coil by unwinding a metal wire or to print an electrically conductive layer onto the surface of the chip card body, for example using the screen printing method, using an electrically conductive adhesive. In addition, the coil can be punched out of a metal foil. Coils for chip cards, which are produced by means of a hot stamping process, are also known. The coil is embossed directly on or in the chip card surface.

All these processes have in common that they are complex in terms of production technology and therefore cost-intensive. The described etching process of the coil is also disadvantageous because of its health and environmental effects. Since a coil once applied to the plastic film should be part of a chip card, the plastic film normally has to be connected to the chip card body in a further process step. This can be done, for example, by lamination with other foils or also by back injection with plastic material in an injection molding machine. A number of successive operations are therefore required until the known chip cards are completed.

The invention is based on the object of developing a chip card which is simplified overall in terms of its manufacturing outlay and can thus be produced at low cost. In addition, a manufacturing method for providing such a chip card is to be made available. The invention solves this problem with the features of the independent claims.

Further embodiments of the invention are the subject of the dependent claims following the independent claims.

According to the presented solution according to the invention, a chip card is equipped with a coil, which consists of an electrically conductive material and is produced by injection molding or injection molding. Both plastics and metal powder can be used as electrically conductive materials. However, the materials must be processable by injection molding, i.e. they must meet the requirement to be able to be converted into a flowable state.

The present solution according to the invention represents a real alternative to all the production processes known chip cards in use to date. Overall, it enables more economical production and also allows the coil to have a low overall height. In addition, the contacting of the coil with a chip module or other switching elements of the chip card is considerably simplified. In comparison to the etching processes for the production of coils for chip cards, which have been frequently used up to now, the production process according to the invention for a coil is environmentally friendly and harmless to health.

If an electrically conductive plastic is used to produce the coil for a chip card according to the invention, a thermoplastic plastic is particularly suitable.

Since it is becoming increasingly possible to also process materials in the injection molding process which could not previously be brought out of a melt into a mold, as is the case, for example, with ceramics, it is now possible according to a further solution according to the invention to provide a chip card with a coil which is produced using the powder injection molding process or the powder injection molding process is. Metal powder can be used as the electrically conductive material.

According to one embodiment of this invention, the metal powder can consist of metal mixtures.

As such, metal mixtures of this type are often denied melt-metallurgical shapes because they cannot be mixed with one another in the molten state. This problem does not arise with metal powders, since the powders, which originally had a solid consistency, can be mixed very well.

A metal powder which has a globular structure is particularly suitable for the powder injection molding process using electrically conductive metal powder. This ensures a very good flow for injection molding processing.

A binder is preferably required for shaping the material by means of injection molding. To a certain extent, this fulfills the function of a lubricant in the powder, so that its overall flow behavior is favored.

In known sintering processes, the binder originally added to the metal powder mixture has so far been removed from the present molded part, which is also referred to as green body, after the material has been shaped by means of an increase in temperature. This step is necessary before a sintering process, which is also referred to as firing, so that the component to be manufactured becomes resistant to mechanical loads.

Since transponders are used for the chip cards according to the invention, the mechanical loads are less relevant than is the case with conventional sintered metal components. For the chip cards, the focus is rather on electrical properties. Thus, according to a development of the invention, it is proposed to add an electrically conductive, liquid and solvent-free binder to the metal powder. The otherwise subsequent and necessary removal of the binder can thus be dispensed with. According to this further embodiment of the invention, the binding agent thus forms a component of the transponder and, as such, even enables the bend and torsional fatigue strength of the coil to be positively influenced.

Accordingly, according to a further embodiment of the concept of the invention, it is further proposed that when selecting the electrically conductive, liquid and solvent-free binder, care should be taken to ensure that it has a low tendency to evaporation, otherwise the positive influence on the coil properties would not be achieved, as explained above can.

A temperature between 120 ° Celsius and 170 ° Celsius should be maintained for processing the metal powder using the powder injection molding process. The temperature of the injection mold should advantageously be between 40 ° and 50 ° Celsius. These temperature value ranges allow the metal powder to be processed together with plastics without destroying the more sensitive plastics.

Accordingly, according to the present invention, combined processing of metals and plastics can take place in one work step, or a metal can be applied to a plastics material or vice versa. The chip cards according to the invention, which have a coil, can thus be produced using so-called compound materials.

What is common to the solutions according to the invention is that the coil is applied to a plastic label or a plastic film. Depending on the requirements of the card, the coil can be integrated into the chip card body or applied to the chip card body. According to a further embodiment of the invention, the chip card consists of at least three layers, an intermediate label arranged between a rear label and a front label receiving the coil and having a cavity for receiving a chip module.

This three-layer arrangement of the chip card according to the invention is advantageous because in this way the module cavity can be molded into the label or labels at the same time as the chip card is manufactured by injection molding.

In order to simplify the production of a chip card according to the invention, the contacting of the coil or antenna with chip modules or switching elements that may be integrated into the card should also be taken into account. According to an advantageous development, this takes place in that the coil has at least one elevation. This increase in the coil should advantageously extend into the cavity arranged in a plane above the coil and thus form a connection contact for the chip module.

The completion of the chip card according to the invention has become extremely simple. After the end of the injection molding process, by means of which both the chip card and the coil are produced, it is only necessary to make contact with the protruding elevations with the chip module or switching element to be integrated into the chip card.

As can already be seen from the input statements, a chip card according to the invention is preferably produced in a multi-component injection molding process, but in particular in a two-component injection molding process, and the coil or antenna is also produced in the process.

The method according to the invention for producing a chip card with the above-mentioned features is of few manufacturing technology not very complex and therefore inexpensive manufacturing steps.

An injection molding tool is required, which preferably consists of at least one injection side and one closing side, each with at least two mold nests therein. The closing side of the injection molding tool should be rotatable at least in one plane.

A printed label on the back is first inserted into a first mold nest. This label is then fixed in the mold cavity, for example by means of vacuum or electrostatic charging. The formation of the specific coil shape is made possible by a negative shape of the later coil. After the injection mold has been closed, the electrically conductive plastic can be injected to produce the coil.

The intermediate product produced in this way from the plastic film and the coil can now be embedded in the chip card body, which in turn is preferably carried out by injection molding and can be implemented according to the invention with the same injection molding tool.

According to a further embodiment of this method according to the invention, the cavity is shaped during the back injection of the front label in such a way that the connection contacts for the subsequent contacting of a chip module or a switching element of the chip card according to the invention are exposed.

Another method for producing a chip card is to be seen in the fact that, using injection molding in an injection stamping tool with one injection side and one closing side and two mold nests on each side, a printed label on the back is inserted into the mold cavity and then by means of vacuum or electrostatic charging in the mold cavity is fixed in order to be able to inject the electrically conductive plastic or the liquefied metal powder after closing the injection molding tool. Within the injection molding tool is only after it Filling with the liquid casting compound by at least one displaceable tool cavity builds up a pressure.

The process of injection stamping places only a very small amount of mechanical stress on the coil during production, which is advantageous in terms of production technology and reduces the overall rejection rate, which is why the process is very economical.

Overall, the present invention provides both a newly produced chip card and a method for producing such a chip card which simplify the vertical range of manufacture to an extent not known to date. With only a few successive process steps, both the chip card as such and the coil arranged thereon or therein can be produced by means of injection molding processes. The invention also goes completely new ways in that it makes it possible for the first time to connect materials that previously required separate processing or a subsequent, very complex connection. In this way, a possibility is provided for connecting metals and plastics to one another for the production of a chip card, which likewise takes place as a whole using the injection molding process.

A chip card according to the invention and the process steps required for its production are described in simplified schematic form in the following drawings. Show it:

Figure 1 is a plan view of a plastic film with applied thereon

Kitchen sink.

FIG. 2 shows a section course II-II according to FIG. 1.

Figure 3 is a plan view of a completed, the coil integrating chip card according to the invention.

FIG. 4 shows the section IV-IV from FIG. 3. Figure 5 shows the closing side of an injection molding tool for producing a chip card according to the invention.

6 shows the injection side of an injection molding tool for producing a chip card according to the invention

7 shows the closing side of an injection molding tool with a coil located therein and a chip card body and

8 shows the closing side of an injection molding tool rotated by 180 ° in a horizontal plane in comparison to FIG. 7, but without a chip card body.

An intermediate product 2 of a chip card according to the invention is shown in simplified form in FIG. 1 and in section in FIG. This consists of a plastic film, which forms a lower label 4 and onto which a coil 1 made of electrically conductive, thermoplastic is applied by means of an injection molding process.

As can be seen in particular from the sectional view in FIG. 2, an elevation 9 can be formed during the injection molding of the coil 1 for later formation of a connection contact for contacting the coil with a chip module 8 or a similar switching element of the chip card. The intermediate product 2 with the coil 1 applied to it is completely integrated into the chip card body 3 in a further manufacturing step, as can be seen clearly from the illustration in FIG.

FIG. 4 also shows the possible structure of a chip card according to the invention. This consists of a lower label 4, which carries the coil 1 in the form of a plastic film, as well as an upper label 5 arranged above it and an intermediate label 6 inserted between the two. An opening is present in the front label 5 and there is an opening in the intermediate label 6 Cavity 7 introduced for later holding a chip module 8. This cavity 7 is during the injection molding of the chip card generated. The connection contacts 9 are designed in the form of an elevation on the coil. They extend into the cavity 7, that is, into a plane above the coil plane.

The manufacturing method according to the invention will be illustrated below with the aid of figures 5 to 8. A multi-component injection molding process is used to produce a chip card body, two materials being required in the present case. Each of these materials is processed in a separate cylinder of the injection molding machine. The chip card is manufactured in two injection molding process steps.

FIG. 5 shows the closing side 13, which can be rotated in a preferably horizontal plane, of an injection mold, generally designated 10, for a two-component injection molding process. A printed label 4, which later forms the rear label 4 of the chip card, is first inserted into the first mold cavity labeled A. This rear label 4 is subsequently fixed in the mold cavity A by means of a vacuum process or electrostatic charging. After closing the tool, it is now possible to inject an electrically conductive material into the mold cavity A. In the present case, this is an electrically conductive thermoplastic.

As can be seen from FIG. 6, the injection side 12 of the injection molding tool 10 has the negative shape 11 of the coil 1 for this purpose. This forms the coil 1 of the chip card later by injecting the liquefied plastic.

The illustration in FIG. 7 shows an intermediate product 2 in the mold nest A, consisting of the label 4 and the coil 1 sprayed thereon for further processing and an already completed chip card body 3 in the mold nest B. This image would result after opening the injection side 12, as shown in FIG Figure 6 is shown and the associated closing side 13, as shown in Figure 5. For further processing of the coil 1 in the mold cavity A, the closing side 13 of the injection molding tool 10 is rotated by 180 ° in a horizontal plane, as illustrated by the arrow in FIG. 7, so that the coil in the mold cavity A, as can be seen in FIG. 8, located on the opposite side of the injection mold.

The already finished chip card body 3, which is located in the second mold cavity designated by B in FIG. 7, is removed. Here, the next coil 1 can already be connected to a label 4 during the next injection molding cycle.

To insert the above-described coil 1 into the chip card body 3, the front label 5 is inserted into the mold cavity B on the injection side 12. After the injection molding tool has been closed, plastic injection molding takes place in the manner already described by means of an injection molding process.

The mold cavity A of the closing side 13 and the mold cavity B of the injection side 12 are arranged opposite one another when the injection molding tool is closed and thus form a space, the dimensions of which correspond to the later chip card.

This space is designed so that the chip card body can be fully molded. This means that the module cavity 7 is already formed during the injection molding process for producing the chip card body. Furthermore, the connections 9, which are used later for contacting a chip module 8 with the coil 1, are exposed. Subsequent milling or other mechanical processing of a chip card according to the invention can thus be omitted. The production is thus considerably simplified and the accuracy of the contacting is improved. LIST OF REFERENCE NUMBERS

1st coil

2. Intermediate

3. Chip card body

4. Back label

5. Front label

6. Intermediate label

7. Cavity

8. Chip module

10 9th increase (connection contact)

10. Injection mold

11. Negative form

12. Spray side

13. Closing side

15 A mold nest

B mold nest

Claims

claims

1. Chip card consisting of a chip card body with a conductor track in the form of a coil, characterized in that the coil (1) produced by injection molding or injection molding consists of an electrically conductive plastic.

2. Chip card according to claim 1, characterized in that the plastic is a thermoplastic.

3. Chip card consisting of a chip card body with a conductor track in the form of a coil, characterized in that the coil (1) produced in the powder injection molding process or in the powder injection molding process consists of an electrically conductive metal powder.

4. Chip card according to claim 3, characterized in that the metal powder is a metal mixture.

5. Chip card according to claim 3 or 4, characterized in that the metal powder has a globular structure.

6. Chip card according to one of claims 3 to 5, characterized in that a binder is added to the metal powder.

7. Chip card according to one of claims 3 to 5, characterized in that a liquid, solvent-free and electrically conductive binder is added to the metal powder.

8. Chip card according to claim 7, characterized in that the binder having a low evaporation tendency is part of a transponder of the chip card.

9. Chip card according to one of claims 3 to 8, characterized in that the processing temperature of the metal powder during powder injection molding between 120 ° C and 170 ° C and that of the injection mold (10) is between 40 ° C and 50 ° C.

10. Chip card according to one of the preceding claims, characterized in that the coil (1) is applied to a plastic label or a plastic film (2).

11. Chip card according to one of the preceding claims, characterized in that the coil (1) is integrated in the chip card body (3) of the chip card.

12. Chip card according to one of the preceding claims, characterized in that the chip card consists of at least three layers, an intermediate label (6) arranged between a rear label (4) and a front label (5) and receives the coil (1) has a cavity (7) for receiving a chip module (8).

13. Chip card according to one of the preceding claims, characterized in that the coil (1) has at least one elevation (9).

14. Chip card according to claim 13, characterized in that the elevation (9) of the coil (1) extends into a cavity (7) arranged in a plane above the coil and forms a connection contact for the chip module (8).

15. Chip card according to one of the preceding claims, characterized in that the chip card is produced in a multi-component injection molding process.

16. Chip card according to one of claims 1 to 14, characterized in that the chip card is produced in a two-component injection molding process.

17. A method for producing a chip card with features according to one of claims 1 to 16, in which in an injection molding tool (10) with an injection side (12) and a closing side (13) and with each side (12, 13) at least two mold nests ( A and B) a printed back label (4) is placed in the mold cavity (A) and then fixed in the mold cavity (A) by means of vacuum or electrostatic charging in order to be able to inject the electrically conductive plastic after closing the injection molding tool (10).

18. The method according to claim 17, characterized in that after cooling the coil (1) this after rotation of the closing side (13) of the injection molding tool (10) in a plane by 180 ° in such a way that now from the mold cavity (A) of the closing side ( 13) and the mold cavity (B) of the injection side (12) equipped with the front label (5) is arranged so that after the injection molding tool (10) has been closed, the chip card can be finished by injection molding with plastic, while in another space, consisting of the mold cavity (A) on the spray side (12) and the mold cavity (B) on the closing side (13), another coil can be sprayed.

19. The method according to claim 18, characterized in that when the front label (5) is injection-molded, the cavity (7) is so it is formed that the connection contacts (9) for the subsequent contacting of the chip module (8) are exposed.

20. The method according to any one of claims 17 to 19, characterized in that a negative form (11) of the coil is used to generate the coil (1).

21. A method for producing a chip card with features according to one of claims 1 to 16, in which in a spray-embossing tool (10) with a spray side (12) and a closing side (13) and with each side (12, 13) two mold cavities (A and B) a printed label (4) on the back is placed in the mold cavity (A) and then fixed in the mold cavity (A) by means of vacuum or electrostatic charging in order to be able to inject the electrically conductive plastic after the injection molding tool (10) has been closed.

22. The method according to claim 21, characterized in that a pressure within the injection molding tool (10) is built up within the injection molding tool (10) after it has been filled with the liquid casting compound by at least one displaceable tool cavity.