SIMPLIFIED ELECTRONIC MODULE FOR A SMARTCARD WITH A DUAL COMMUNICATION INTERFACE

Abstract

An electronic module for a smartcard has a dual, contact and contactless, communication interface. The module includes an electrically insulating substrate on which are produced electrical contact pads enabling operation via contact with corresponding contacts of a smartcard reader, and contact pads for connection to corresponding pads of an antenna located on the body of the smartcard and enabling a contactless operation with a remote smartcard reader. The substrate is coated with a single electrically conductive layer, especially one made of metal, located on the lower face of the electronic module, and the upper face of the electronic module, which face is intended to be flush with the external face of the smartcard, is produced by said electrically insulating substrate, the latter being provided with windows leaving exposed all or some of said electrical contact pads.

Claims

1. An electronic module for a chip card with a dual, contact and contactless, communication interface, said module comprising: an electrically insulating substrate on which are disposed a first set of electrical contact pads, allowing an operation by contact with corresponding contacts of a chip card reader, and a second set of contact pads for connection to corresponding pads of an antenna located on a body of the chip card and allowing the contactless operation thereof with a remote chip card reader, wherein said substrate is coated with a single electrically conductive layer located on a bottom face of the electronic module, and wherein a top face of the electronic module, which face is intended to be flush with an outer face of the chip card, is produced by said electrically insulating substrate, the substrate being provided with windows allowing all or part of said electrical contact pads to be visible.

2. The electronic module as claimed in claim 1, wherein said electrically insulating substrate is capable of receiving a graphical personalization, via printing or equivalent.

3. The electronic module as claimed in claim 1, wherein an electronic chip of the module is located in an encapsulation area protecting the chip, and wherein said contact pads for making the connection to an antenna are located outside said encapsulation area.

4. A chip card with a dual, contact and contactless, communication interface, comprising an electronic module as claimed in claim 1.

Description

[0025] Other features and advantages of the invention will become apparent upon reading the detailed description and the appended drawings in which:

[0026] FIGS. 1A and 1B illustrate, respectively, a plan view from above and from below of an electronic module for a chip card, conforming to the prior art;

[0027] FIG. 1C illustrates a cross-sectional view of the electronic module of FIG. 1B along a sectional plane CC;

[0028] FIGS. 2A and 2B illustrate, respectively, a plan view from above and from below of an electronic module according to the invention;

[0029] FIGS. 2C and 2D illustrate cross-sectional views of the module of FIGS. 2A, 2B along multiple sectional planes.

DETAILED DESCRIPTION

[0030] As indicated above, FIGS. 1A and 1B illustrate a known electronic module 1, including a chip 2 bonded, using a layer of adhesive 4 (FIG. 1C), to an electrically insulating substrate 3. The chip 2 is connected, on the one hand, to a terminal block with electrical contacts (5) located on the top face 11 of the module, which is opposite the bottom face 10 bearing the chip, these contacts 5 being intended to provide for operation in contact mode with a contact reader (not shown). The electrical connections between the ISO contacts 5 and the corresponding output pads of the chip 2 are made through commonly known vias 6, also called bonding holes, which allow the output pads 8 of the chip to be electrically connected, using bonding wires 7, to the ISO contacts 5 located on the opposite face of the module.

[0031] The chip 2 is connected, on the other hand, to an antenna located in a card body or directly on the module 1, via metallic pads 9 located on the bottom face 10 of the module, the connection to the antenna allowing radiofrequency communication with a contactless chip card reader (not shown).

[0032] The module 1 comprises, on its bottom face 10, a peripheral surface 12 intended for the bonding of the module in the cavity of the chip card body provided for this purpose, and the antenna pads 9 are typically located on this peripheral surface 12, outside an encapsulation area 13 formed by a resin that protects the chip and its connections 7 to the ISO contacts 5.

[0033] The electrical contacts 5 of the terminal block are located on a face of the substrate of the module, corresponding to the top face 11 of the module, and the chip is located on the opposite face of the substrate, corresponding to the bottom face 10 of the module.

[0034] It will therefore be seen that in this known structure of a module for a chip card, the substrate 3 of the module is of the type referred to as double-sided, i.e. it comprises two metalized faces, namely a first metalized face (the top face 11 in the example shown) that bears the metallic ISO contacts 5, and a second face that is partially metalized (the bottom face 10 in the example shown) which bears the metallic solder pads 9 for making the connection to the antenna, and vias 6 for making the connections between the chip and the ISO contacts. The vias 6 for making connections to the contacts 5 are located inside the encapsulation area delimited by the resin 13 protecting the chip. It is typically a blob of polymerizable resin, while the pads 9 for making connection to the antenna are located inside or outside the encapsulation area, depending on whether the antenna is produced directly on the electronic module or on the body of the chip card.

[0035] In any case, the embodiment shown that corresponds to the prior art requires the substrate of the module to be metalized (i.e. at least partially coated with a layer of metal) on both of its faces.

[0036] The face referred to as the upper face of the module is defined as that which remains visible when the module is implanted into a chip card body. Consequently, in the example shown that corresponds to the prior art, the ISO contacts 5 are on the top face 11 of the module, and the chip 2 is bonded to the bottom face 10 of the module.

[0037] This double metalization is problematic in certain cases of use, as it effectively doubles the unit cost of an electronic module for a chip card with respect to a module having only one metalized substrate face. In particular, as seen in FIG. 1C, the area 18 that surrounds the via 6 is metallic and leaves only a small space 19 with respect to the bonding wire 7 which is also metallic, thereby running the risk of a short circuit as mentioned above.

[0038] The present invention has therefore sought to design an electronic module referred to as a single-sided electronic module, having a single, preferably metalized, conductive face, in order to reduce the procurement costs of the substrate of the module, while avoiding the problems of low communication performance and low resistance to wear mentioned in relation to the module described in the aforementioned document DE 196 32 115 C1.

[0039] The solution obtained is that shown schematically in FIG. 2. One and the same functional element is denoted by the same numerical reference in each of FIGS. 1 and 2. The thickness of the module in cross-sectional view is exaggerated for the sake of clarity.

[0040] In the electronic module 21 according to the invention, the substrate 3 is indeed coated with a single metalized layer. However, in contrast to the aforementioned document, it is located on the bottom face 10 side of the module, the top face 11 of the module being composed of an electrically insulating layer (the substrate 3) made of a plastic material or of a dielectric material. This electrically insulating layer is provided with a series of apertures 15, also referred to as windows, which allow the ISO contacts 5 produced on the bottom face of the module to be at least partially visible. In this way, the ISO contacts 5 remain accessible to the corresponding contacts of a contact chip card reader.

[0041] Thus, as the top face 11 of the electronic module is essentially (i.e. apart from the area of the windows 15) composed of a plastic material, it is easily graphically personalized, by printing information or logos relating to the application of the chip card, or to its issuer (bank, etc.).

[0042] In order to allow the chip card to communicate via radiofrequency, an antenna is required. However, according to the invention, this antenna is not produced on the module itself as taught in document DE 196 32 115 C1. An antenna of larger size, typically in ID1 format, is used. In order to be able to connect it to the electronic module 21, the latter comprises, on its single metalized side 10, two antenna pads 9 produced outside the encapsulation area of the chip. Homologous pads (not shown) are then produced in a known manner in the cavity of the card body that is able to receive the electronic module, and the insertion of the module into the card body makes the electrical connection between the antenna pads of the card body and the antenna pads of the module.

Advantages of the Invention

[0043] Specifically, the invention proposes a design of electronic module, in particular for chip card with dual-mode, contact and contactless, communication chip, having a particularly innovative but simple design, employing a substrate which is very economical since it is provided with a single metallized conducting side, while maximizing radiofrequency communication performance by using an antenna of large format (ID1 format), and while leaving a plastic area of relatively large size, which lends itself readily to graphical personalization, free on the top face of the module. In this sense, the invention makes it possible to meet several constraints which go beyond those typically imposed on a chip card module.

[0044] The invention therefore allows the manufacture of an electronic module capable of optimizing the best compromise between cost and simplicity of manufacture, operational performance in radiofrequency mode, and the use of the visible surface of the module as communication support.

[0045] Moreover, the design of an electronic module having a single conducting face makes it possible to solve the problems of short-circuiting between antenna and ISO contacts, which exist for certain modules according to the prior art.

[0046] Furthermore, all the combinations of assembly which are known in the prior art (flipchip, wire deposition, transfer molding, etc.) remain possible with this design of module.