Method for manufacturing an electronic chip card and an electronic chip card obtained by the method

Abstract

A method for manufacturing an electronic chip card, wherein: - metal is cut into strips to form a plurality of groups of contact areas (1), the plurality of groups of contact areas (1) being connected to at least one carrier strip by at least one tab (27), the plurality of groups of contact areas (1) being regularly arranged at predetermined intervals along the carrier strip, a group of contact areas (1) corresponding to a card connector intended to establish an electrical connection with a card reader; - an electronic chip (30) is fixed to the back of the connector and the electronic chip is connected to the contact areas; - and an electrically insulating plastic material is injection-molded to cover the chip (30) and the conductors (31). The invention also relates to a chip card produced by the method.

Description

[0001] The invention relates to a method for manufacturing an electronic chip card and to a chip card manufactured using the method.

[0002] In the field of chip card manufacturing, there are two main methods. One of the methods uses a dielectric substrate on which the contacts are produced (for example, the contacts are made by etching a conductive sheet laminated on the dielectric substrate). The other method uses a contact grid cut from a sheet of conductive material (this corresponds to lead frame technology). In both methods, it is necessary to provide an electronic chip and to connect it electrically to the contacts.

[0003] The method according to the invention belongs to the second class of the above-mentioned methods, ie methods in which contact grids are produced and used, which are produced from cut metal sheets.

[0004] The patent application published by US Patent Publication No. US 2015 / 0076240 A1 describes such a method, wherein the following steps are performed:

[0005] - Step A of cutting the metal material into strips to form groups of contact areas. These groups of contact areas are connected to at least one carrier strip by at least one tab. These groups of contact areas are regularly arranged along the carrier strip at a determined pitch; a group of contact areas corresponds to a SIM card connector (SIM is the abbreviation for Subscriber Identification Module). This connector has a front side and a back side, the front side being used to establish an electrical connection with a card reader.

[0006] - In a step C following step A, an electrically insulating plastic material is injection moulded around at least one set of contact areas to cover simultaneously at least a section of the rear face of the connector and a section of the carrier strip and thereby form a joint between the two.

[0007] In the step C of injection molding of the plastic material, a cavity and a connection well are formed in the plastic material. Thus, an electronic chip can be accommodated in the cavity and connected to the contact area via the connection well.

[0008] A method for manufacturing a chip card is also known from US Pat. No. 5,157,475 A, in which a plastic material is injection molded onto an integrated circuit connected to a lead frame. However, in this method, the integrated circuit cannot be tested before the card is singulated and the metal tabs connecting the contacts to the carrier strip are severed.

[0009] The inventors expect to find a method to replace the prior art. To this end, a method as claimed in claim 1 is provided. Therefore, the method according to the present invention further comprises a step B between step A and step C, in which an electronic chip is fixed to the back of the connector and the electronic chip is connected to at least some of the contact areas of the connector. The electronic chip is fixed to the portion of the back of the connector, which in step C will be covered by the first plastic material.

[0010] The method according to the invention, in particular the step of unwinding the metal material strip and the step of injection molding of one or more plastic materials, can be performed continuously, reel-to-reel or roll-to-roll, until the step of singulating the chip card equipped with its chip.

[0011] The method according to the invention also comprises one of the features mentioned in claims 2 to 9 , considered individually and independently of one another or in combination with one or more other features.

[0012] - the first plastic material is selected from one of the following product groups: hot melt materials, polypropylene, liquid crystal polymers (LCPs), polycarbonate; the second plastic material is selected from one of the following product groups: polypropylene, liquid crystal polymers, polycarbonate.

[0013] According to another aspect, the invention relates to a chip card produced using the method according to the invention. The chip card thus comprises in particular an electronic chip which is fixed directly to the contact area.

[0014] Other features and advantages of the present invention will become apparent from a reading of the detailed description of examples of embodiments of the present invention taken in conjunction with the accompanying drawings.

[0015] In the attached picture:

[0016] Figure 1 schematically shows a chronological sequence of the main steps selected to illustrate an example of the method of the invention;

[0017] Figure 2A and Figure 2B A perspective view and a top view, respectively, of a length of a strip of conductive material at the end of the cutting and molding steps are schematically shown.

[0018] Figure 3 A rear view of a section of a strip of conductive material is schematically shown after a chip has been secured to the rear side and the chip has been connected to the contact areas.

[0019] Figure 4A and Figure 4BA rear view and a front view, respectively, of a section of strip-shaped conductive material at the end of the injection molding step of a first plastic material are schematically shown.

[0020] Figure 5A and Figure 5B Rear and front views, respectively, of a section of strip-shaped conductive material are schematically shown after the step of cutting off the metal tabs supporting the groups of contact areas to the lateral strips, the central strip and the transverse strips.

[0021] Fig. 6A and Figure 6B A rear view and a front view, respectively, are shown of a section of strip-shaped conductive material at the end of the injection molding step of the second plastic material.

[0022] Figure 7 schematically shows a section of a strip-shaped electrically conductive material at the end of the injection-moulding step of the second plastic material in a perspective view and a semi-perspective view; both areas are enlarged to more clearly show how the chip card is anchored to the lateral carrier strips and the central carrier strip;

[0023] Fig. 8A , Figure 8B and Figure 8C A chip card produced using an exemplary method, which has been chosen to illustrate the invention, is schematically shown in a rear view, a perspective view and a front semi-perspective view, respectively. DETAILED DESCRIPTION

[0024] The present invention is described below by way of example based on a method for manufacturing a SIM card. However, the present invention can be applied to the manufacture of other types of chip cards.

[0025] This method example is performed reel-to-reel continuously. Figure 1 As shown, it includes:

[0026] - a step A of cutting the metal material into strips and a step A' of deforming the metal material so as to form contact zones connected to the carrier strip by tabs or tabs formed of the metal material,

[0027] - Step B of fixing the electronic chip,

[0028] - a step C of injection moulding of a first plastic material,

[0029] - a step D of severing the joint holding the contact area to the carrier strip,

[0030] - a step E of injection moulding of a second plastic material, and

[0031] - Step F of separating the chip cards from the carrier strip to which they are respectively connected.

[0032] Step A and step A' are techniques known to those skilled in the art. They are not necessarily performed in chronological order, with step A first and then step A'. Step A' may be performed before step A, or step A' may be performed only partially before step A, or even before or after some sub-steps of step A. Sub-steps of step A and step A' may be interspersed with each other.

[0033] Step A and step A' are performed on a roll of strip-shaped metal material. The metal material may be a copper alloy, steel, aluminum alloy, etc. Step A and step A' may be performed before or after a step comprising depositing (such as by electrodeposition) one or more layers of material intended to protect the metal material and / or improve the quality of its bonding or its contacts. These layers may be deposited locally (such as using a selective masking technique) or may be deposited entirely on one, each or both main faces of the metal strip.

[0034] The width of the metal strip is, for example, 70 mm, thus allowing two strips of 35 mm width to be pre-cut. Each of these two 35 mm wide strips allows two sets of contact areas to be produced across its width. Shown in the figure are multiple sections of this 35 mm wide strip.

[0035] In the example shown in the figures, each group of contact areas corresponds to a connector of five contact pads which are intended to be electrically isolated from one another.

[0036] like Figure 2A and Figure 2B As shown, at the end of step A and step A', a group 10 of five contact areas 1 is obtained ( Figure 2B Eight groups are shown). Each of these groups 10 is connected to a carrier strip 20, a carrier strip 21, a carrier strip 22, a carrier strip 23. For example, these carrier strips 20, carrier strips 21, carrier strips 22, carrier strips 23 include two lateral carrier strips 20 and lateral carrier strips 21 with drive openings 25, a central carrier strip 22, and a transverse carrier strip 23 on each side of each group 10 of contact areas 1. The lateral carrier strips 20, lateral carrier strips 21 and central carrier strip 22 extend longitudinally in the unwinding direction and the advancing direction of the conductive material roll. The transverse carrier strips 23 extend longitudinally substantially over the entire width of the metal material strip 24 and extend perpendicularly to the unwinding direction and the advancing direction of the conductive material roll.

[0037] The anchoring structure 26 is manufactured by molding (see Figure 2A ). These anchoring structures 26 are in the form of tongues which extend substantially out of the plane of the contact area 1 (such as perpendicular to this plane). These anchoring structures 26 are distributed around the peripheral edge of each contact area 1, as well as around the edges of the lateral carrier strips 20 and the central carrier strip 22.

[0038] like Figure 3 As shown, at the end of step B, an electronic chip 30 is fixed to the back of one contact area 1. In the example shown in the figure, the electronic chip 30 is fixed to the central contact area 1. The latter (central contact area 1) has a larger area than the other parts. In addition, the contact pads of each electronic chip are electrically connected to each of the five contact areas 1 by wires 31 (such as wires with a diameter less than or equal to 25 microns). The technology for attaching and bonding the wires 31 to the contact pads and contact areas 1 is selected from those known to those skilled in the art (thermocompression bonding, ultrasonic bonding, etc., that is, any wire bonding technology).

[0039] like Figure 4A and Figure 4B As shown, at the end of step C, pre-molding is performed by injecting a first plastic material 40 into a suitable mold, thereby encapsulating and protecting the electronic chip 30 and the connecting wires 31. This pre-molding step is performed using a first plastic material 40 selected from:

[0040] - hot melt materials, such as those based on polyolefins, copolyesters, or copolyamides,

[0041] -Polypropylene

[0042] -Ultra-tech materials such as liquid crystal polymers or polycarbonates.

[0043] The plastic material 40 is injected into a suitable mold, under conditions such as:

[0044]

[0045] Reference may also be made to the usage conditions provided by the material supplier selected for the first plastic material.

[0046] Thus, a viscosity of the injected plastic material 40 is obtained that allows the plastic material 40 to be injected without damaging the electronic chip 30 and the connecting wires 31, while maintaining an injection rate compatible with a continuous industrial process. Examples of injection rates are given in the table above, where "very fast" corresponds to an injection rate "injection Q" of about 80 to 85 cubic centimeters per second, and "medium" corresponds to an injection rate "injection Q" of about 30 to 50 cubic centimeters per second.

[0047] The pre-molding of step C allows a portion of the back side of the connector and a section of the lateral carrier strips 20, 21 and the central carrier strip 22 to be covered. Thus, on the one hand, plastic joints 41 can be formed between each group 10 of contact areas 1 and, on the other hand, between the lateral carrier strips 20, 21 and the central carrier strip 22. For example, the number of these joints 41 is four: two joints connecting each card 100 to the lateral carrier strips 20 or 21, and two joints connecting each card 100 to the central carrier strip 22. Between each card 100 and the lateral carrier strips 20, 21, and between each card 100 and the central carrier strip 22, the joints 41 comprise a section without metal material 24, in which there is only plastic material 40.

[0048] Since each card 100 is held to one of the lateral carrier strips 20 or 21 and to the central carrier strip 22, it is possible to cut the tabs 27 of all the metal material 24 between each card 100 and the lateral carrier strips 20, 21, central carrier strip 22 and transverse carrier strips 23. Therefore, the injection step C is followed by a step of cutting off the tabs 27 of all the metal material 24. This cutting step is also referred to as a deshorting step. Therefore, each contact 1 is electrically isolated from each other after the deshorting step.

[0049] like Figure 5A and Figure 5B As shown, at the end of step C and the deshorting step, each card 100 comprises a set 10 of contact areas 1 forming a connector, to which an electronic chip 30 is connected by wires 31, which are encapsulated and therefore protected in a first plastic material.

[0050] like Figure 7 As shown, the card 100 is now attached to the lateral strips 20, 21 and the central strip 22 only by means of the joints 41 made of the first plastic material, which surround the anchoring structure 26. Thus, the attachment of the plastic material to the carrier strips 20, 21, 22 is strengthened.

[0051] like Fig. 6A and Figure 6B As shown, at the end of step D, the entire back side of the card 100 is covered with a second plastic material 42. The second plastic material 42 is injected into a mold of a suitable shape. The second plastic material 42 is selected from:

[0052] -Polypropylene

[0053] - Liquid crystal polymers,

[0054] -Polycarbonate.

[0055] It can be seen that the second plastic material 42 can be selected from a family similar to the first plastic material 10. Alternatively, the above table can also be referred to regarding its use conditions. The use conditions provided by the material supplier selected for the second plastic material can also be referred to.

[0056] The second plastic material 42 is injected into the mold. This injection molding leaves a section of the connector 41 exposed. Therefore, only this section of the connector 41 connects the card 100 to the lateral carrier strips 20, the lateral carrier strips 21 and the central carrier strip 22 (hence the importance of the anchoring structure 26). Since this section of the connector only includes the first plastic material 40, its subsequent cutting is relatively easy. At the end of this step D, the card 100 has completed material processing, and the remaining work is to program and singulate it. Through the connection with the contact 1 of each card, the programming operation of the card 100 can be performed continuously roll-to-roll. After this step, the card 100 is singulated by cutting the connector 41 and separating it from the lateral carrier strips 20, the lateral carrier strips 21 and the central carrier strip 22. Fig. 8A and Figure 8C The two sides of the card 100 thus singulated are shown. Fig. 8A ) is completely covered by the second plastic material 42. The front side of the card ( Figure 8C ) is partially covered by the first plastic material 40 and the second plastic material 42, but the connector and its contact area 1 are not covered.

[0057] like Figure 8B As shown, a card 100 with an electronic chip 30 fixed directly to the contact area 1 is connected to the contact area 1 by means of wires 31. In this context, the expression "fixed directly" should be understood to mean that the contact area itself forms the carrier of the chip; on the contrary, an adhesive or other material is optionally inserted between the chip and the contact area supporting it. A first plastic material 40 covers the electronic chip 30, the wires 31 and most of the back of the contact area. A second plastic material 42 allows the final form factor of the card 100 to be obtained while making the group 10 of contact areas 1 forming the connector of the SIM card 100 flush.

Claims

1. A method for manufacturing an electronic chip card, wherein the method performs the following steps: - Step A, cutting the metal material into strips to form a plurality of groups of contact areas, the plurality of groups of contact areas being connected to at least one carrier strip by at least one tab, the plurality of groups of contact areas being regularly arranged along the carrier strip at predetermined intervals, a group of contact areas corresponding to a connector, the connector having a front face and a back face, the front face being intended to establish an electrical connection with a card reader, - in a step C after step A, injection molding a first electrically insulating plastic material around at least one set of contact areas, thereby simultaneously covering at least a section of the back side of the connector and a section of the carrier strip to form at least one joint therebetween, It is characterized in that A step B is also included between step A and step C, in which an electronic chip is fixed to the back of the connector and the electronic chip is connected to at least some of the contact areas of the connector, the electronic chip is fixed to the segment of the back of the connector, and the segment is covered by the first plastic material in step C, The method further comprises performing, after step C, a step D of cutting off each tab of the metal strip connecting at least one set of contact areas to the carrier strip so that the chip card is attached to the carrier strip only via the at least one connector made of the first plastic material. 2 . The method according to claim 1 , wherein a step E of injection molding a second plastic material is further performed to at least partially cover the first plastic material.

3. Method according to any one of the preceding claims, wherein a step A' is also carried out of deforming the metal material of which the strip is made so as to form a structure for anchoring the first injected plastic material.

4. The method of claim 1, wherein the first plastic material is selected from one of the following product families: hot melt materials, polypropylene, crystalline polymers, and polycarbonate.

5. The method of claim 2, wherein the second plastic material is selected from one of the following product families: polypropylene, liquid crystal polymer, and polycarbonate.

6. The method according to claim 1, wherein in step B, the electrical connections between the electronic chip and at least some of the contact areas are made using conductive metal wires.

7. The method according to claim 1, wherein a step F is also performed, in which the card comprising at least one set of contact areas and the electronic chip encapsulated by the first plastic material are separated from the carrier strip to which they are connected by cutting the at least one joint formed by the first plastic material.

8. The method of claim 7, wherein the electronic chip is programmed before performing step F.

9. A chip card manufactured using the method of claim 1, comprising an electronic chip attached directly to the contact area.

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