Card body for a chip card, chip card and method for producing a card body

Description

[0001] The invention relates to a card body for a chip card, a chip card comprising a card body and a method for producing a card body for a chip card.

[0002] Card-shaped data storage devices, especially chip cards, are used in many areas, for example, for cashless payment transactions, as identification documents, or for verifying access authorizations. A chip card has a card body and an integrated circuit embedded in the card body, for example, in the form of a chip module with a chip. The chip module is usually inserted into a cavity or module opening in the card body.

[0003] Card bodies or chip cards with external metal layers, also called metal-face cards, are considered. The energy coupling of DI systems with a two-coil system (SPS) is achieved through metal structures with a slot, in which the magnetic / current flow is redirected in the metal surfaces. In this way, the slot prevents short-circuit currents. Such a slot must be provided in both external metal layers, which leads to reduced mechanical stability of the chip card or card body. Since the cut extends to the module opening, it can also cause damage to the module, for example, due to shear forces.

[0004] Card bodies for chip cards are known, for example, from US 2020 / 250506 A1 and US 2020 / 364527 A1.

[0005] The object of the present invention is therefore to improve the stability of the card body and the chip card in the area of ​​the slot.

[0006] This object is achieved by a card body for a chip card, a chip card comprising a card body, and a method for producing a card body for a chip card according to the independent patent claims. Embodiments and developments of the invention are specified in the dependent claims.

[0007] A card body according to the invention for a chip card comprises two metal layers between which a non-conductive middle layer is arranged, wherein in a metal layer and the middle layer a module opening for receiving a chip module has already been created or can still be created in a module opening zone, and two slots, one of which extends in a metal layer from a peripheral surface of the card body to the module opening or to the module opening zone and each cuts through the metal layer at a height, wherein the angle of entry of the two slots into the metal layer is each not equal to 90° to a surface of the metal layer, and wherein the two slots have an opposite inclination to a surface normal of the surface of the metal layer.

[0008] A basic idea of ​​the present invention is that the slots in the metal layers or metal bodies are no longer formed perpendicular to the surface, but at an angle other than 90°. In other words, the slot on the surface of the metal layer runs obliquely to the surface. This leads to an overlap of the metal layer regions separated by the slot in a direction perpendicular to the surface.

[0009] This overlap within a metal layer prevents shearing movement in one direction. Since both metal layers each have a slit, and the two slits are designed to be rotated relative to each other, shearing movements in both directions are suppressed.

[0010] The two slots have an opposite inclination to a surface normal of the surface of the metal layer, so that an intersection point of extensions of the two slots lies in the card body or in a plane or extension of the card body.

[0011] The card body is understood here to be a semi-finished product for a chip card into which no chip module has yet been inserted. Likewise, the module opening for the chip module may not yet be recessed in the card body. The chip module is inserted into the module opening on one side of the chip card. The module opening only extends partially into the middle layer of the chip card, so that the opposite metal layer may have a module opening into which no chip module is inserted. Thus, the recesses—i.e., the slot and the module opening—of both metal layers can be identical.

[0012] Alternatively, only the slot may be present in the opposite metal layer. In this case, the slot extends in length to a module opening zone corresponding to the opposite module opening. The slot may extend to a beginning, an end, or a middle region of this module opening zone. In particular, the slot may have a length equal to the opposite slot plus the module opening.

[0013] The slots proposed here stabilize the card body with respect to shear. Another advantage is that the angled entry of the slot significantly reduces the penetration depth into the metal layer compared to a vertical slot. This results in a more sophisticated visual appearance. Furthermore, the slot can now be filled with an adhesive or other material, since the angled slot prevents or at least significantly reduces the leakage of the adhesive or material.

[0014] The slots proposed here therefore have the advantage that the mechanical or structural stability of the card body is improved by the oppositely inclined design of the slots.

[0015] The entry angle of the slot into the metal layer is defined here as the angle of the slot to the surface of the metal layer. This angle can also be referred to as the exit angle, since this angle is not subject to any functionality with regard to entry or exit.

[0016] The module opening is formed as a through hole or a blind hole in the surface of the metal layer. When the slot is created, either the module opening or the corresponding module opening zone, in which the module opening will later be formed, is present.

[0017] The entrance angle may be less than or equal to 82°, preferably between 30° and 60°, and most preferably 45°. It has been shown that such angles, depending on the thickness or height of the metal layer and the slot width, provide good coverage of the metal layer regions separated by the slot. This means that the metal layer regions separated by the slot partially overlap each other when viewed perpendicular to the surface.

[0018] It can further be provided that the slot is formed by a serrated cut, which provides an overlap between two opposing walls of the slot. A serrated cut is understood here to be a cut in which there is an overlap along the length of the slot. This overlap prevents shearing or bending of the card body in one direction. The two main directions in which shearing or bending is to be prevented are the two normal vectors to the two surfaces of the card body, i.e., the two surfaces of the outer metal layers.

[0019] The two entrance angles can be configured as supplementary angles. For example, one entrance angle can be 45° and the second entrance angle can be 135° as a corresponding supplementary angle. The two entrance angles are then the same but rotated by 180°. Likewise, the two entrance angles can be different, especially if the thickness of the metal layers is different. In this case, the entrance angle can be adapted to the conditions such as the thickness and / or material of the metal layer.

[0020] It can also be provided that the two slots have an identical entry angle and that two metal layers are arranged on the middle layer, rotated 180° to each other. This enables simple manufacturing, allowing identical metal layers to be produced. The slots can be created, for example, by laser or water cutting from a sheet with a thickness between 50 µm and 300 µm.

[0021] The slot width can be less than or equal to 50 µm. The slot should be as thin as possible to achieve good mechanical stability. At the same time, the slot should not be too thin to avoid contact between the slot walls, as this could lead to a short circuit.

[0022] It can also be provided that the middle layer is made of plastic. For example, the middle layer can be a plastic layer or a core made of PVC, PE, PAL, PC, or a similar material. Since the structural rigidity is provided by the two outer metal layers, the middle layer does not need to meet any special requirements. Rigidity can be achieved despite the slots, as they are angled to each other.

[0023] It can be provided that the thickness of at least one metal layer is greater than or equal to 200 µm.

[0024] It can also be provided that the total thickness of the two metal layers is greater than the thickness of the middle layer. The slits, which are angled relative to each other, allow for thicker metal layers, i.e., a thinner plastic core, since this no longer needs to stabilize the chip.

[0025] It can be provided that the thickness of one metal layer is less than or equal to 50 µm and that one metal layer is provided with at least one embossing. Such thin metal layers can be embossed, for example, by embossing. This allows optical and / or tactile markings to be incorporated into the metal layer.

[0026] It can further be provided that the two slots are not arranged along a direction of a surface normal to the surface of the metal layer. The slots are thus arranged offset from one another. The slots are arranged in the region of an extension of the module opening or the module opening zone, so that at least one of the slots is connected to the module opening. If there is no module opening in a metal layer, the slot of this metal layer can also be located outside the extension of the module opening.

[0027] A chip card according to the invention comprises a card body as described above and a chip module at least partially embedded in the module opening of the card body. The same advantages and modifications apply as described above.

[0028] A method according to the invention for producing a card body for a chip card comprises the steps: Providing two metal layers, wherein a module opening for receiving a chip module has already been created in one metal layer or can still be created in a module opening zone, creating a slot in each of the two metal layers, which slots extend from a peripheral surface of the card body to the module opening or to the module opening zone and sever the metal layer at a height, and joining the two metal layers and a non-conductive middle layer, which is arranged between the two metal layers, wherein the entry angles of the slots into the metal layer are each not equal to 90° to a surface of the metal layer, and wherein the two slots have an opposite inclination to a surface normal of the surface of the metal layer.

[0029] The same advantages and modifications apply as previously described.

[0030] It can be provided that the joining takes place using an adhesive, with the slots being at least partially filled with the adhesive. The adhesive, which is still liquid or viscous during the joining process, then flows into the angled slot. Due to the angle of the slot, the adhesive remains in the slot and does not flow out. The then hardening adhesive holds the walls of the slot in position, thereby further hindering or preventing twisting or shearing of the card body and thus of the chip card. In addition, the risk of a short circuit can be further reduced because the adhesive prevents contact between the walls of the slot.

[0031] It can also be provided that the module opening is created only after the plastic layers have been applied. The slot creation proposed here can thus be used in various phases of the production of a card body or a chip card.

[0032] The present invention will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 : a plan view of a card body for a chip card; Fig. 2 : a view of an end face of a metal layer of the card body; Fig. 3 : a sectional view of a map body; Fig. 4 : a sectional view of a map body; and Fig. 5 : a schematic representation of a process for producing a card body.

[0033] Fig. 1 shows a chip card 20 with a card body 10. The card body 10 has a substantially rectangular basic shape with two opposite surfaces, of which one surface 11 is Fig. 1 The other, opposite surface 12 is in Fig. 2 The two surfaces 11, 12 run parallel to each other and are connected by a circumferential surface 13.

[0034] The card body 10 has a rectangular shape in an xy-plane, in which the peripheral surface 13 lies with two longitudinal surfaces running in the x-direction and two end surfaces running in the y-direction. The thickness or height of the card body 10 extends in the z-direction.

[0035] A module opening 14 for a chip module 21 is recessed in the surface 11 of the card body 10. The module opening 14 extends into the card body 10. The module opening 14 is created, for example, by a laser cutting or milling process. The chip module 21 is inserted into the module opening 14 and, for example, glued there.

[0036] The chip module 21 can comprise a contact surface structure supporting a coil. The chip module 21 can further comprise a chip, which is secured, for example, in a potting compound on an underside of the contact surface structure. The chip is supplied with energy and / or signals via the coil. An electromagnetic field can thus be coupled into the coil.

[0037] A slot 15 is provided in the card body 10, extending from the peripheral surface 13, or in other words, from an outer edge of the card body 10, to the module opening 14. Thus, the slot 15 connects the module opening 14 to the peripheral surface 13. The slot 15 serves to prevent short-circuit currents or eddy currents.

[0038] The slot 15 runs in the y-direction, i.e., parallel to the longitudinal surface. The slot 15 has, for example, a width between 30 µm and 100 µm, preferably between 50 µm and 80 µm. Fig. 1 The slot 15 is shown on a left side. The slot 15 can also be arranged on a right, upper, or lower side of the card body 10.

[0039] Fig. 2 shows a view of a front side of a metal layer 16 of the card body 10. The metal layer 16 is an outer metal layer or a metal plate. Accordingly, the chip card 20 is a so-called metal-face card.

[0040] It can be seen that the slot 15 completely cuts through the metal layer 16 in thickness or height, i.e., in the z-direction. The slot 15 thus connects the two surfaces 11 and 12. The slot 15 extends in the x-direction to the module opening 14.

[0041] An entry angle α of the slot 15 is not equal to 90° to the surface 11 and analogously to the surface 12.

[0042] In Fig. 2 The slot 15 is designed at a 45° angle throughout. The entry angle α can, for example, be less than or equal to 82° or between 30° and 60°. Depending on the selected side or wall of the slot 15, the entry angle α can be 45° or, as a corresponding supplementary angle, 135°.

[0043] The slot 15 is formed by a serration cut that provides an overlap or overlap between two opposing walls 15a and 15b of the slot 15. This overlap or overlap is in the direction of a surface normal to the surface 11, or in other words, in the direction of the thickness or height of the card body 10 or the metal layer 16. In the figures, this is the z-direction. The two walls 15a, 15b can run parallel.

[0044] The angles indicated above allow sufficient overlap or coverage for the usual thicknesses of the metal layer 16 of, for example, between less than 50 µm and about 200 µm and usual cutting widths between 40 µm and 80 µm.

[0045] In the Fig. 2 In the example shown, the thickness or height of the metal layer 16 is 200 µm. With an entrance angle α of 45°, a visible depth T is approximately 80 µm. The visible depth T is the distance of the wall 15b from the surface 11, viewed perpendicularly or in the direction of the surface normal of the surface 11 at the entrance point of the wall 15a. This visible depth T can be seen, for example, as a measure of an overlap or coverage.

[0046] The slot 15, with its walls 15a and 15b, divides the metal layer 16 into two regions 16a and 16b, with region 16a located on the side of wall 15a and bounded by it. Similarly, region 16b lies on the side of wall 15b and bounded by it.

[0047] In the area of ​​the slot 15, there is thus an overlap or covering of the two walls 15a and 15b and thus of the two regions 16a and 16b of the metal layer 16. This overlap or covering is in the direction of the surface normal of the surface 11. In a cut, even a virtual cut, in the direction of the surface normal through the metal layer 16, there is always an intersection point with both walls 15a and 15b and thus both regions 16a and 16b.

[0048] The overlap or overlap of the two walls 15a and 15b, or the two regions 16a and 16b, now blocks the displacement of region 16a over region 16b. This corresponds to a pressure movement on region 16b in the z-direction, i.e., a movement of the two walls 15a and 15b toward each other. Region 16b can only move a small distance, which roughly corresponds to the visible depth T. It then rests against region 16a and is stopped by it. Thus, the obliquely formed slot 15 can prevent undesired shearing movement of the card body 10 or the metal layer 16.

[0049] If, however, the area 16b is moved away from the area 16a, which in Fig. 2 corresponds to a downward movement in the negative z-direction, no blocking occurs.

[0050] The above considerations of the movement of area 16b apply analogously to area 16a, only with correspondingly reversed movement.

[0051] Fig. 3 shows a sectional view of a card body 10. The card body 10 comprises the above-described metal layer 16, a middle layer 17 made of a plastic such as PVC, and a further metal layer 18. The three layers have been joined together, for example, in a lamination process. The metal layer 18 shown below can correspond to the metal layer 16 arranged above. The above statements regarding the metal layer 16 also apply to the Fig. 3 example shown. These statements apply analogously to the further metal layer 18.

[0052] The total thickness or height of the card body 10 can be, for example, 750 µm. The thickness or height of each metal layer 16, 18 can be between 50 µm and 250 µm. The two metal layers 16 and 18 can have identical or different thicknesses. It can also be provided that the total thickness of the two metal layers 16, 18 is greater than the thickness of the middle layer 17.

[0053] The metal layer 16 comprises a slot 15c, which is arranged centrally in the area of ​​the module opening 14 or its extension. The module opening 14 for the chip module extends through the entire metal layer 16 and can be formed as a blind hole opening into the middle layer 17. It can also be created later. The module opening 14 is created, for example, by means of a laser or milling process.

[0054] In this example, the slot 15c of the metal layer 16 has an angle of 45° to a surface of the metal layer 16. This angle can be considered as +45°.

[0055] The metal layer 18 includes a slot 15d, which here is also arranged centrally in the area of ​​the module opening 14 or its extension. In this example, the slot 15d of the metal layer 18 has an angle of -45° to a surface of the metal layer 16. The slot 15d of the metal layer 18, in turn, has an angle of +45° to the surface of the metal layer 18. The two metal layers 16 and 18 can thus be identically formed and arranged on the middle layer 17 rotated by 180°.

[0056] The two slots 15c and 15d thus have an opposite inclination to a surface of the metal layer 16, so that an intersection point of extensions of the two slots 15c and 15d lies in the card body 10 or in a plane or extension of the card body 10.

[0057] In the area of ​​the slot 15c and 15d, there is thus an overlap or overlap of the two walls of the slots 15c, 15d and thus of the two regions of the metal layer 16 and 18 separated by the respective slot. This overlap or overlap is in the direction of the surface normal of the metal layer 16. In this example, even a virtual cut in the direction of the surface normal through the card body 10 always results in an intersection point with both walls of the slot 15c and with both walls of the slot 15d. Accordingly, shearing movement of the card body in both directions can be prevented.

[0058] Fig. 4 shows a sectional view of a card body 10. The structure of the card body 10 shown here essentially corresponds to the structure of the Fig. 3 shown card body. Here, too, there is a layer sequence of a middle layer 17 with two surrounding metal layers 16 and 18.

[0059] The angles of the slots 15c and 15d correspond to those of the slots in Fig. 3 However, the position of the two slots 15c and 15d is different here. Again, both slots 15c and 15d are located in the area of ​​the module opening 14. However, the two slots 15c and 15d are located outside a centerline of the module opening 14. This centerline of the module opening 14 can also correspond to the centerline of the card body 10.

[0060] According to Fig. 4 Slot 15c is arranged to the right of the center line and slot 15d to the left of the center line. This arrangement can also be reversed. The two slots 15c, 15d can be equally spaced from the center line or, in other words, from the edges of the module opening 14.

[0061] Even with this arrangement of the two slots 15c and 15d, shearing movements of the card body 10 in both directions can be effectively suppressed.

[0062] Fig. 5 shows a schematic representation of a method for producing a card body 10 for a chip card 20 as previously described.

[0063] In a first step 100, two metal layers 16, 18 are provided, wherein a module opening 14 for receiving a chip module 21 has already been created in one metal layer 16 or is still being created or can be created in a module opening zone. Only one module opening may be provided; in this case, only one of the two metal layers 16 or 18 is excluded from a module opening.

[0064] In a second step 110, a slot 15 is created in each of the two metal layers 16, 18, which extend from a peripheral surface of the card body 10 to the module opening 14 or to the module opening zone and completely sever the metal layer 16, 18 at a height.

[0065] If the module opening 14 is to be produced in a later manufacturing step, the slot is created up to the corresponding module opening zone where the module opening is to be formed later. If no module opening is provided in one of the metal layers, the slot is formed up to a module opening zone that is opposite the module opening in the other metal layer. The slot can also be formed through the module opening zone.

[0066] The tool for creating the slot 15 is directed towards the surface of the metal layer 16 or 18, obliquely at an entry angle α.

[0067] The slot 15 is formed such that the angle of entry α of the slot 15 into a surface is not equal to 90 degrees relative to the surface. The slot 15 is formed entirely through the thickness of the metal layer 16 or 18.

[0068] Furthermore, the two slots 15 are recessed in the two metal layers 16 and 18 such that the two slots 15 have an opposite inclination to a surface normal of the surface of the metal layer, so that an intersection point of extensions of the slots lies in the card body 10 or a plane or extension of the card body 10.

[0069] Optionally, for example, if slot 15 is cut with a laser, the focus of the tool or laser can be readjusted as the cutting depth increases. This allows material removal to always occur at an optimal operating point. Since the angled position of slot 15 increases its length, the readjustment ensures optimal cutting even with longer cuts.

[0070] In a third step 110, the two metal layers 16, 18 and a non-conductive middle layer 17, which is arranged between the two metal layers 16, 18, are joined together. This step can be carried out, for example, by lamination.

[0071] If an adhesive is used to bond the individual layers of the card body 10, the slot 15 can then be at least partially filled with the adhesive. The inner contour of the slot 15 at least partially prevents the adhesive from leaking out, so that it remains in the slot 15. The adhesive curing in the slot further stabilizes the card body 10 or the chip card 20.

[0072] If the module opening 14 in the card body 10 is only produced after lamination, the adhesive that has flowed into the slot 15 and dried or cured there prevents chips that arise during the creation of the module opening 14 from becoming lodged in the slot 15 and causing an electrical short circuit there.

Claims

1. Card body (10) for a chip card (20), having two metal layers (16, 18), between which a nonconductive central layer (17) is arranged, wherein a module opening (14) for receiving a chip module (21) is already created in one metal layer (16) and the central layer (17) or can still be created in a module opening zone, and two slits (15), one of which respectively extends in a metal layer (16, 17) from a peripheral face (13) of the card body (10) to the module opening (14) or to the module opening zone and respectively divides the metal layer (16, 17) at a height, characterized in that entry angles (α) of the two slits (15) into the metal layer (16) are respectively not equal to 90° with respect to a surface (11) of the metal layer (16), and wherein the two slits (15) have an opposite inclination with respect to a surface normal of the surface (11) of the metal layer (16).

2. Card body (10) according to Claim 1, characterized in that the entry angle (α) is less than or equal to 82°, preferably between 30° and 60°, and most preferably 45°.

3. Card body (10) according to Claim 1 or 2, characterized in that the slit (15) is formed by an interlock cut, which provides an overlap between two opposite walls (15a, 15b) of the slit (15).

4. Card body (10) according to one of Claims 1 to 3, characterized in that the two entry angles (α) are supplementary angles.

5. Card body (10) according to one of Claims 1 to 4, characterized in that the two slits (15) have an identical entry angle (α), and in that two metal layers (16, 18) are arranged rotated by 180° with respect to one another on the central layer (17).

6. Card body (10) according to one of Claims 1 to 5, characterized in that a width of the slit (15) is less than or equal to 50 µm.

7. Card body (10) according to one of Claims 1 to 6, characterized in that the central layer (17) consists of plastic.

8. Card body (10) according to one of Claims 1 to 7, characterized in that the thickness of at least one metal layer (16) is greater than or equal to 200 µm.

9. Card body (10) according to one of Claims 1 to 8, characterized in that a total thickness of the two metal layers (16, 18) is greater than a thickness of the central layer (17).

10. Card body (10) according to one of Claims 1 to 9, characterized in that the thickness of a metal layer (16) is less than or equal to 50 µm, and in that the one metal layer (16) is provided with at least one stamping.

11. Card body (10) according to one of Claims 1 to 10, characterized in that the two slits (15) are not arranged along a direction of a surface normal of the surface (11) of the metal layer (16).

12. Chip card (20) comprising a card body (10) according to one of Claims 1 to 11 and a chip module (21) at least partially embedded into the module opening (14) of the card body (10).

13. Method for producing a card body (10) for a chip card (20), having the steps: - providing two metal layers (16, 18), wherein a module opening (14) for receiving a chip module (21) is already created in one metal layer (16) or can still be created in a module opening zone, - respectively creating a slit (15) in the two metal layers (16, 18), which slits extend from a peripheral face (13) of the card body (10) to the module opening (14) or to the module opening zone and divide the metal layer (16) at a height, and - joining the two metal layers (16, 18) and a nonconductive central layer (17), which is arranged between the two metal layers (16, 18), characterized in that entry angles (α) of the slits (15) into the metal layer (16) are respectively not equal to 90° with respect to a surface (11) of the metal layer (16), and wherein the two slits (15) have an opposite inclination with respect to a surface normal of the surface (11) of the metal layer (16).

14. Method for producing a card body (10) according to Claim 13, characterized in that the joining is carried out by means of an adhesive, the slits (15, 15c, 15d) being at least partially filled with the adhesive.

15. Method for producing a card body (10) according to Claim 13 or 14, characterized in that the module opening (14) is not created until after the joining.