Anisotropic conductive adhesive electronic device.
The electronic device with anisotropic conductive adhesive simplifies enrollment and enhances functionality in biometric smart cards by using anisotropic conduction to connect pads and tracks, enabling efficient and secure transactions.
Patent Information
- Application Number
- FR2023010604
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-10-04
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2043-10-04
AI Technical Summary
Existing biometric smart cards require complex preliminary enrollment steps and hardware implementation, limiting their efficiency and applicability.
An electronic device with a multilayered support and anisotropic conductive adhesive that electrically connects first and second connection pads, allowing for secure and efficient transactions through anisotropic conduction perpendicular to the support plane, using conductive tracks and modules such as secure elements, sensors, and LEDs.
Facilitates secure and efficient transactions by simplifying the enrollment process and enhancing the functionality of biometric smart cards beyond biometrics, enabling applications in identity and banking transactions.
Smart Images
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Abstract
Description
Title of the invention: Electronic device with anisotropic conductive adhesive.
[0001] The present invention relates to the field of manufacturing electronic devices, in particular those enabling transactions.
[0002] By "transaction" we mean a preprogrammed interactive operation of "question-answer" form including the search, entry or modification of information in a file or in a database.
[0003] Typically such electronic devices are used for example in identity documents or smart cards, in particular passports for identity transactions, or in bank smart cards for banking transactions.
[0004] To secure transactions, it is known to implement various security measures, including biometrics. From a hardware perspective, biometrics requires an electronic sensor, and from a functional perspective, the implementation of biometrics requires a preliminary enrollment step, which can be complex.
[0005] In the field of biometric smart cards, document FR3128301 filed by the applicant is known.
[0006] The present invention aims to further improve the performance of the solution proposed in document FR3128301, while extending its application beyond biometrics.
[0007] More specifically, the invention relates, according to a first of its objects, to an electronic device (100), comprising a support (110), preferably multilayered, substantially flat, and an electronic circuit (120) disposed on the support (110) or in the support (110), the electronic circuit (120) comprising: • a first module (121), • comprising a set of first connection pads (122), integral with the first module (121), and • held in a first cavity of the support (110), by means of an anisotropic conductive adhesive (130) in contact with said first set of connection pads, the direction of anisotropic conduction being secant and preferably substantially perpendicular to the plane of the support (110), • a first set of conductive tracks (150), arranged on a substrate (170).
[0008] It is essentially characterized in that: • the electronic device (100) further comprises a set of second connection pads, arranged on the substrate (170), • each second connection block (140) being preferably positioned opposite a respective first connection block (122); • each second connection block (140) comprising: • a first face of the second connection pad (140) in contact with the anisotropic conductive adhesive (130), and a second face of the second connecting pad (140), opposite to the first face, in electrical contact with at least one respective conductive track of the first set of conductive tracks (150), • an assembly of at least one recess (143) which allows the finishing of a part of at least one layer of the multilayer support (110) or the finishing of the anisotropic conductive adhesive (130) during the manufacture of the electronic device (100), • so that at least one first connecting pad (122) is electrically connected to a respective track of the first set of conductive tracks (150) via the anisotropic adhesive (130) and a respective second connecting pad (140).
[0009]
[0010] The first set of conductive tracks (150) may be provided for by printing, for example by screen printing, on a conductive material, for example printed copper; or by etching at least one layer of aluminum or copper, including a printed circuit board (PCB), said first set of conductive tracks (150) being at least one of the following: • an antenna, and • a set of electrical connection tracks with a second module (200); the electronic circuit (120) may further include said second module (200).
[0011]
[0012] It can be foreseen that the first module (121) comprises one of the following: • a secure element, • a sensor, • an OTP display screen, • a dynamic cryptogram, • a sound device, • a set of at least one LED.
[0013]
[0014] It can be foreseen that the substrate (170) on which the first set of conductive tracks (150) is arranged is a material based on cellulose, synthetic paper, polymer or epoxy (PET, PVC, PC, PI); and that the second connection pads can have in cross-section parallel to the plane of the support (110), a structure in the form of fishbones, snowflakes, a spiral, a honeycomb, or centripetal shelving.
[0015]
[0016] We can predict that: The first set of conductive tracks (150) is arranged on a first face of the substrate (170), The electronic device (100) comprising a second set of conductive tracks (160), arranged on a second face of the substrate (170), opposite to the first face of the substrate (170), at least one of the tracks of the second set being arranged at the right of a second connection pad (140) and electrically connected to it by a via (180) passing through the substrate (170).
[0017]
[0018] It can be foreseen that at least one second connecting pad (140) includes a via (180), the via (180) including at least one recess (143); said second connecting pad (140) being able to be solid or to include at least one other recess (143).
[0019]
[0020] We can predict that:
[0021] The thickness of the second set of conductive tracks (160) is less than the thickness of the first set of conductive tracks (150), the thickness of the first set of conductive tracks (150) being less than or equal to the thickness of the second connection pad (140).
[0022]
[0023] A second module (200) may be provided, in which said second module (200) includes one of the following: • a secure element, • a sensor, • an OTP display screen, • a dynamic cryptogram, • a sound device, • a set of at least one LED.
[0024]
[0025] According to another of its objects, the invention relates to a passport comprising a electronic device (100) according to the invention.
[0026]
[0027] According to another of its objects, the invention relates to a smart card (125) comprising an electronic device (100) according to the invention, wherein said smart card (125) is a bank card or an identity card.
[0028]
[0029] The present invention therefore relates to any chip-enabled document.
[0030]
[0031] Other features and advantages of the present invention will become more apparent upon reading the following description, given by way of illustrative and non-limiting example and with reference to the accompanying figures. The figures are not necessarily to scale. Some details may have been omitted, others enlarged, to facilitate understanding.
[0032]
[0033] [Fig. 1A] illustrates an embodiment of an electronic device according to the invention,
[0034] [Fig.1B] illustrates an embodiment of an electronic device according to the invention,
[0035] [Fig.2A] illustrates an embodiment of a second connection pad according to the invention,
[0036] [Fig.2B] illustrates an embodiment of a second connection point according to the invention,
[0037] [Fig.2C] illustrates an embodiment of a second connection point according to the invention,
[0038] [Fig.2D] illustrates an embodiment of a second connection point according to the invention,
[0039] [Fig.2E] illustrates an embodiment of a second connection point according to the invention,
[0040] [Fig.2F] illustrates an embodiment of a second connection pad according to the invention in three-dimensional view
[0041] [Fig.3] illustrates one embodiment of the electrical connection between a second connection block according to the invention and a via,
[0042] [Fig.4A] illustrates, in cross-section, an electronic circuit according to the invention comprising a single antenna, with a polymer-based support,
[0043] [Fig.4B] illustrates the circuit of [Fig.4A] before lamination,
[0044] [Fig.4C] illustrates the circuit of the [Fig.4B] after lamination, with a machining plane A- A, and finage of the support,
[0045] [Fig.4D] illustrates the circuit of [Fig.4C] after machining according to machining plan AA,
[0046] [Fig.4E] illustrates the circuit of [Fig.4D] after inset,
[0047] [Fig. 5A] illustrates, in cross-section, an electronic circuit according to the invention comprising a single antenna, with a cellulose-based support,
[0048] [Fig.5B] illustrates the circuit of the [Fig.5A] before lamination,
[0049] [Fig.5C] illustrates the circuit of the [Fig.5B] after lamination, with a machining plane A- HAS,
[0050] [Fig.5D] illustrates the circuit of [Fig.5C] after machining according to machining plan AA,
[0051] [Fig.5E] illustrates the circuit of [Fig.5D] after insertion and finishing of the adhesive anisotropic conductor,
[0052] [Fig.6] illustrates, in top view, an embodiment of an electronic circuit according to the invention comprising two modules connected to each other by means of respective second connection pads,
[0053] [Fig.7]. Illustrates the diagram of [Fig.6] in which two second connecting pads comprise a respective via,
[0054] [Fig.8] illustrates the scheme of [Fig.1B] in which the thickness of the first conductive track is equal to the thickness of the second conductive track, and less than the thickness of a second connecting pad. Detailed description
[0055] [Fig.1A] illustrates an embodiment of an electronic device according to the invention, in which a first module is simplified, and [Fig.1B] illustrates the embodiment of [Fig.1A] in which the first module is more detailed.
[0056] In [Fig.IB], some of the main components of the first module have been illustrated more precisely, in particular a set of contact pads 126 of the module, accessible from outside the electronic device and typically allowing galvanic contact with the tips of a reader.
[0057] A chip 125 encapsulated in a drop of encapsulating resin 124 has also been illustrated. The chip 125 is electrically connected to the first connecting pads by a set of connecting wires 123.
[0058] The electronic device includes a substantially flat support 110. Preferably, the support 110 is a multilayer support. For example, for a smart card 125, the support 110 is the card body. For example, the support 110 is made of polymer, typically a plastic, and for example PVC.
[0059] Preferably, the support 110 includes a first cavity 111 (illustrated in [Fig.1A]) allowing the insertion of a first module described below.
[0060] The electronic device includes an electronic circuit disposed on the support 110 or in the support 110, for example between two adjacent layers of a multilayer support 110.
[0061] For example, the electronic circuit is a radio frequency circuit.
[0062] The electronic circuit comprises a first module.
[0063] It can be foreseen that the electronic circuit further comprises a second module 200, as illustrated in dotted lines on [Fig.6].
[0064] For example, any one of the first module and the second module 200 can be a secure element, in particular for banking or identity transactions.
[0065] The first module or the second module 200 can also be a sensor, for example a temperature, pressure, humidity sensor, a biomedical sensor, for example for measuring blood pressure, a biometric sensor, etc.
[0066] The first module or the second module 200 can also be a display screen, in particular for one-time passwords (OTP) or a dynamic code or dynamic cryptogram (DCVV).
[0067] The first module or the second module 200 can also be a sound device, for example a buzzer.
[0068] The first module or the second module 200 can also be a set of at least one LED.
[0069] The first module or the second module 200 comprises a set of at least one first connection pad 122, integral with the first module or the second module 200, respectively.
[0070] The first connection pads 122 allow, for example, the transfer of data or energy to or from the first module 121.
[0071] Similarly, when the electronic device includes a second module 200, the first connection pads allow, for example, the transfer of data or energy to or from the second module 200.
[0072] The first module 121 is disposed in a first cavity 111 of the support 110, and held therein by means of an anisotropic conductive adhesive 130 which is in contact with said first set of connection pads. For example, the anisotropic conductive adhesive is ACF or ACP, where ACF stands for Anistropic Conductive Film and ACP stands for Anistropic Conductive Paste.
[0073] The anisotropic conductive adhesive 130 is, for example, in the form of a film. It allows electrical conduction in a predetermined direction. In this case, the direction of anisotropic conduction is secant, and preferably substantially perpendicular, to the plane of the support 110.
[0074] The electronic circuit also includes a first set of conductive tracks 150, arranged on a substrate 170.
[0075] More specifically, the first set of conductive tracks 150 is arranged on a first face of the substrate 170.
[0076] For example, the first set of conductive tracks 150 includes an antenna.
[0077] The first set of conductive tracks 150 may also include a set of electrical connection tracks with a second module 200, in particular as illustrated in [Fig.6].
[0078] For example, substrate 170 is an antenna substrate.
[0079] For example, the substrate 170 comprises a polymer-based material, in particular plastic, or epoxy. For example, the substrate 170 comprises at least one of the following: PET, PVC, PC, PI.
[0080] It can also be foreseen that the substrate 170 comprises a cellulose-based material, for example cellulose paper, cardboard or wood, or a synthetic paper-based material.
[0081] The support 110 may also comprise a polymer-based material, in particular plastic, or epoxy. For example, the support 110 comprises at least one of the following: PET, PVC, PC, or PL
[0082] The support 110 may also include a cellulose-based material, for example cellulose paper, cardboard or wood, or a synthetic paper-based material.
[0083] As described later, part of the anisotropic conductive adhesive 130 can flow into the recesses 143 described later.
[0084] Or part of the support 110 itself can flow into the recesses 143 described later.
[0085] Preferably, the substrate 170 is at least locally planar and coplanar with the support 110. However, when viewed in cross-section, the substrate 170 may be in step(s).
[0086] For example, the first set of conductive tracks 150 is made by printing, for example by screen printing of a conductive material, for example printed copper, excluding wire copper.
[0087] The first set of conductive tracks can also be made by etching at least one layer of aluminium or copper, including a printed circuit board (PCB).
[0088] According to the invention, the electronic device further comprises a set of second connection pads 140, arranged on the substrate 170.
[0089] The second connecting pads 140 may have, in cross-section parallel to the plane of the support 110, a structure in the form of fishbones ([Fig. 2B]), snowflakes ([Fig. 2C]), a spiral ([Fig. 2E], [Fig. 3]), a honeycomb ([Fig. 2D]), or centripetal spokes ([Fig. 2A]), etc. In [Fig. 6], a second connecting pad 140, in this case in the form of fishbones, is illustrated by dashed lines. The structure The metallic shape of the second 140 connection pads may not be regular or symmetrical, when viewed from above in the XOY plane.
[0090] For simplification, "set of first connection pads" 122 and "first set of connection pads" are understood interchangeably; and "set of second connection pads" 140 and "second set of connection pads".
[0091] Each second connecting stud comprises a first face and a second face 142, opposite to the first face 141.
[0092] The first face 141 of a second connecting pad is in physical and electrical contact with the anisotropic conductive adhesive 130, and the second face 142 of a second connecting pad 140 is in physical and electrical contact with at least one respective conductive track 150 of the first set of conductive tracks, if necessary via a via 180.
[0093] Thus, in an orthonormal XYZ frame, illustrated in [Fig.1B], the anisotropic conductive adhesive 130 has an anisotropic conduction direction along the Z axis, in this case perpendicular to the XY plane of the support 110. Electrical conduction therefore occurs in this case along the Z axis.
[0094] Thus a first connection pad 122 is electrically connected to a second connection pad 140, in this case arranged opposite it, by means of the anisotropic conductive adhesive 130. As this is anisotropic, it can be arranged in the form of a film.
[0095] In this way, at least a first connecting pad 122 is electrically connected to a respective track 150 of the first set of conductive tracks via the anisotropic adhesive 130 and a second connecting pad 140.
[0096] Preferably, each second connection pad is positioned directly opposite a respective first connection pad. However, depending on the anisotropic conduction direction of the anisotropic conductive film 130, each second connection pad can be positioned offset from a vertical axis of a respective first connection pad.
[0097] Each second connecting pad includes a set of at least one recess 143, which is in the form of a through hole or a non-through hole.
[0098] As described below, the recess 143 allows the finishing of part of at least one layer of the multilayer support 110 or the finishing of the adhesive of the anisotropic conductive film 130 during the manufacture of the electronic device; in particular for a smart card during the lamination, inlay, or "inlay" thereof, i.e. the assembly of an insulating support, an antenna and an electronic chip 125 or an integrated circuit.
[0099] According to a first embodiment, the support 110 comprises a polymer-based material. The embodiment of an electronic device according to the invention is illustrated in Figures 4A to 4E.
[0100] In figures 4A to 4E, a second connection block 140 is shown in dotted lines, and includes purely illustrative two electrical conductor posts 144, 145, for example illustrated in [Fig.6].
[0101] Fig. 4A illustrates a set of second connection pads, which in this case are a single antenna, with a plastic support 110.
[0102] On [Fig.4B], a multilayer support 110 is placed on the set of second connection pads.
[0103] As illustrated in [Fig.4C], with heat and pressure, the thin multilayer support 110 in the interstices, including in the recesses 143.
[0104] Machining is then planned according to the machining plane AA, in this case parallel to the XY plane, the result of which is illustrated in [Fig.4D].
[0105] The inset with the first module is illustrated in [Fig.4E]. It has been shown that a first connection pad can be in contact with several conductive uprights (for example metallic) of the same second connection pad, for example in the form of fishbones, a top view of which, in the XY plane, is illustrated in [Fig.6].
[0106] According to a second embodiment, the support 110 comprises a cellulose-based material, for example a cellulose paper. The realization of an electronic device according to the invention is illustrated in Figures 5A to 5E.
[0107] In figures 5A to 5E, a second connection block 140 is shown in dotted lines, and includes purely illustrative two electrically conductive uprights 144, 145, for example illustrated in [Fig.6].
[0108] Fig. 5A illustrates a set of second connection pads, which in this case are a single antenna, on a substrate 170 made of plastic or cellulosic material.
[0109] On [Fig.5B], a support 110 made of cellulosic or synthetic paper is placed, or stacked, on all the second connection pads 140.
[0110] As illustrated in [Fig.5C], with heat and pressure, the fine cellulose-based support 110 in the interstices, including in the recesses 143, but less than with a plastic-based support 110, i.e. without completely filling said interstices.
[0111] Machining is then planned according to the machining plane AA, in this case parallel to the XY plane, the result of which is illustrated in [Fig.5D].
[0112] After machining the gaps do not include any plastic-based support 110 that would have flowed into them, the possible finishing remaining above the cutting line of the machining plane AA.
[0113] The inset with the first module is illustrated in [Fig.5E]. It has been shown that a first connection pad can be in contact with several conductive uprights (for example metallic) of the same second connection pad, for example in the form of fishbones, a top view of which, in the XY plane, is illustrated in [Fig.6].
[0114] During the inserting, due to temperature and pressure, the anisotropic conductive adhesive 130 thins particularly in the recesses 143 (see [Fig.5E]).
[0115] Comparing the two embodiments above, according to the first embodiment in which the support 110 comprises a polymer-based material, the support 110 finely fits into the recesses 143; whereas according to the second embodiment in which the support 110 comprises a cellulose-based material, the anisotropic conductive adhesive 130 finely fits into the recesses 143.
[0116] It can be foreseen that the electronic device comprises a second set of conductive tracks 160.
[0117] In this case, the tracks of the second set of conductive tracks 160 are arranged on a second face of the substrate 170, opposite to the first face of the substrate 170.
[0118] At least one of the tracks of the second set of conductive tracks 160 is disposed opposite a second connection pad 140 and electrically connected to it by a via 180, also known by the anglicism crimp, which passes through the substrate 170.
[0119] It can be foreseen, as illustrated for example in [Fig.6], that a via 180 is adjacent to a second connecting pad 140 and electrically connected to it by metal.
[0120] It is also possible, as illustrated for example in [Fig. 7], to integrate a via 180 into a second connection pad 140. In [Fig. 7], two second connection pads 140, each containing a via 180, are shown in dashed lines. This configuration advantageously reduces the surface area of a second connection pad 140 and its via 180, and limits the ghosting effect described below.
[0121] It can be predicted that the thickness of the tracks of the second set of conductive tracks 160 is less than the thickness of the tracks of the first set of conductive tracks 150.
[0122] Preferably, the tracks of the second set of conductive tracks 160 are made of aluminium.
[0123] If the thickness of the tracks of the second set of conductive tracks 160 is greater than a threshold value, during the manufacture of a smart card 125, a ghost image of these tracks may result after lamination with plastic layers.
[0124] To limit, or even eliminate, this effect, it can be provided that the thickness of the first set of conductive tracks 150 is less than the thickness of the second connection pad 140, and in this case equal to the thickness of the second set of conductive tracks 160, so that there is an excess of metal locally only at the level of the second connection pads 140, as illustrated in [Fig.8].
[0125] The electronic device can advantageously be implemented in a passport or other identity document, official (driving licence, etc.) or unofficial (company badge, secure access, etc.); as well as in a smart card 125, in particular a bank card, a subscription card, a transport card, an access card, etc.
[0126] Nomenclature 100 electronic devices 110 multilayer support 111 first cavity of the support 120 electronic circuit 121 first module 122 first connection point 123 connecting wire 124 coating resin (drop) 125 chip 126 contact points of the module 130 anisotropic conductive adhesive 140 second connection point 141 first face of the second connection block 142 second face of the second connection block 143 obviously 144 electrical conductor upright of a second connection block 145 electrical conductor upright of a second connection block (140) 150 first conductive track 160 second conductive track 170 substrate 180 via 200 second module
Claims
1. Demands Electronic device (100), comprising a substantially flat, multilayer substrate (110) and an electronic circuit (120) disposed on or in the substrate (110), the electronic circuit (120) comprising: • a first module (121), • comprising a set of first connection pads (122), integral with the first module (121), and • held in a first cavity of the support (110), by means of an anisotropic conductive adhesive (130) in contact with said first set of connection pads, the direction of anisotropic conduction being secant to the plane of the support (110), • a first set of conductive tracks (150), arranged on a substrate (170), characterized in that the electronic device (100) further comprises a set of second connection pads (140), arranged on the substrate (170), • each second connection block (140) being positioned opposite a respective first connection block (122); • each second connection block (140) comprising: • a first face of the second connecting pad (140) in contact with the anisotropic conductive adhesive (130), and a second face of the second connecting pad (140), opposite to the first face, in electrical contact with at least one respective conductive track of the first set of conductive tracks (150), • a set of at least one recess
2. (143) which allows the finishing of a part of at least one layer of the multilayer support (110) or the finishing of the anisotropic conductive adhesive (130) during the manufacture of the electronic device (100), • so that at least one first connecting pad (122) is electrically connected to a respective track of the first set of conductive tracks (150) via the anisotropic adhesive (130) and a respective second connecting pad (140). An electronic device (100) according to claim 1, wherein the first set of conductive tracks (150) is made by printing, for example by screen printing, on a conductive material, for example printed copper; or by etching at least one layer of aluminum or copper, including a printed circuit board (PCB), said first set of conductive tracks (150) being at least one of: • an antenna, and • a set of electrical connection tracks with a second module (200); the electronic circuit (120) may further include said second module (200).
3. Electronic device (100) according to any one of the preceding claims, wherein the first module (121) comprises one of: • a security element, • a sensor, • a display screen (OTP), • a dynamic cryptogram, • a sound device, • an assembly of at least one LED.
4. Electronic device (100) according to any one of the preceding claims, wherein the substrate (170) on which the first set of conductive tracks (150) is arranged is a material based on cellulose, synthetic paper, polymer or epoxy (PET, PVC, PC, PI); and wherein the second connection pads can have, in cross-section parallel to the plane of the support (110), a structure in the form of fishbones, snowflakes, a spiral, a honeycomb, or centripetal shelving.
5. Electronic device (100) according to any one of the preceding claims, wherein: • The first set of conductive tracks (150) is disposed on a first face of the substrate (170), • The electronic device (100) comprising a second set of conductive tracks (160), disposed on a second face of the substrate (170), opposite the first face of the substrate (170), at least one of the tracks of the second set being disposed at the right of a second connection pad (140) and electrically connected thereto by a via (180) passing through the substrate (170).
6. Electronic device (100) according to claim 5, wherein at least a second connection pad (140) comprises a via (180), the via (180) comprising at least one recess (143); said second connecting block (140) being able to be solid or comprising at least one other recess (143).
7. Electronic device (100) according to claim 5 or 6, wherein: The thickness of the second set of conductive tracks (160) is less than or equal to the thickness of the first set of conductive tracks (150), the thickness of the first set of conductive tracks (150) being less than or equal to the thickness of the second connection pad (140).
8. Electronic device (100) according to any one of claims 2 to 6, in its dependence on claim 2, comprising said second module (200), in which said second module (200) comprises one of: • a security element, • a sensor, • a display screen (OTP), • a dynamic cryptogram, • a sound device, • an assembly of at least one LED.
9. Passport comprising an electronic device (100) according to any one of the preceding claims.
10. Smart card (125) comprising an electronic device (100) according to any one of claims 1 to 8, wherein said smart card (125) is a bank card or an identity card.