WO2008142247A1

WO2008142247A1 - Electronic module with a dual communication interface, in particular for a chip card

Info

Publication number: WO2008142247A1
Application number: PCT/FR2008/000437
Authority: WO
Inventors: Philippe Patrice
Original assignee: Smart Packaging Solutions (Sps)
Priority date: 2007-04-16
Filing date: 2008-03-31
Publication date: 2008-11-27
Also published as: FR2915010A1; FR2915010B1

Abstract

The invention relates to a microelectronic module (7) with a dual contact and contactless communication interface, in particular for a chip card, including (i) a substrate (13) provided with a terminal block formed by a group of electric contacts (10) connected to a contact communication interface of a first electronic chip (21) and (ii) a main antenna (8) formed by at least one coil, the terminals of which are connected to the contactless communication interface of a second electronic chip (22). The microelectronic module is characterised in that it also includes a resonant circuit (9, 18) which can channel the electromagnetic flow received by the resonant circuit (9, 18) toward the main antenna (8) of the module. The invention is particularly suitable for the reliable, cost-effective production of chip cards having a dual contact and contactless communication interface.

Description

Electronic module with a dual communication interface, in particular for a smart card

The invention relates to a microelectronic module with a dual contact and non-contact communication interface, in particular for a smart card, comprising on the one hand a substrate provided with a terminal block formed by a set of electrical contacts connected to a communication interface. contacting an electronic chip and further comprising a main antenna composed of at least one turn and whose terminals are connected to the contactless communication interface of a second electronic chip.

The invention further relates to a dual-mode smart card contact and contactless communication, implementing a module according to the invention.

Already in the state of the art, smart cards with mixed operation with contact and without contact. Most have a microelectronic module provided with contacts, said module having a radio frequency communication interface connected to the terminals of an antenna which is itself made in the card body.

Thus, the dual communication interface cards according to the state of the art consist of:

- An electronic module having on the upper face the chip, the connection terminal block with contacts, and on the back of the chip and two contacts for connection to the antenna.

- A plastic card, having an antenna and a cavity adapted to receive the microelectronic module.

- An electrically conductive material for the electrical connection between the module and the antenna.

This structure generally provides a good range of radio frequency communication given the large size of the antenna, but poses a series of problems in achieving the mechanical connection between the antenna and the module, leading to loss of reliability or performance Manufacturing. Indeed, these cards are usually made in the following steps:

- manufacture of the card body comprising an antenna. These antennas can be fabricated using known methods using inlaid copper wires, or conductive ink printing or copper etching on the inner material of the card body.

- Manufacture of the electronic micromodule having on its first face a contact terminal block for contacting with counter contacts of a smart card reader contacts, and on its second side of the connection points for the antenna.

machining in the card body of the cavity allowing the housing of the electronic module, while exposing the connection pads of the antenna located inside the card body.

- Bonding of the electronic micromodule by establishing the electrical connection between it and the antenna connection pads exposed.

This connection can be obtained by known methods, such as the dispensing of conductive glue which will then be polymerized, the use of anisotropic adhesive or pastes anisotropically (in thickness), or the use of a polymer spring deposited on the module (conductive pad with extra thickness and compressible).

These methods of manufacturing such cards presently pose the following problems:

- Need to manufacture specific card bodies for cards dual contact communication mode and contactless (also called "dual interface" cards in English terminology) with an antenna and thus inducing complex manufacturing processes.

- Need to machine card bodies by exposing the antenna connection pads, a delicate operation that lowers the manufacturing yields. - Use of a specific method of bonding the electronic module in the card for electrical interconnection of the module and the antenna. These methods are often very slow compared to the methods generally used for standard contact smart cards, and they induce additional losses in manufacturing efficiency.

After manufacturing the module and the smart card, the interconnection methods between module and antenna used also strongly limit the reliability of the final card during its use.

Indeed, the mechanical and thermal stresses applied to the card during use, lead to connection failures, or large increases in the electrical resistance of this connection, resulting in a loss of performance of the card during its use.

Thus, this type of card can not be guaranteed over a very long period of use (> 5 years for example), which restricts the applications available for this type of card.

To overcome these manufacturing problems, it was thought to integrate the antenna directly on the microelectronic module, and then simply postpone the module in a smart card body, which is easy to achieve with a low cost and great reliability, with most inserting machines for the manufacture of contact smart cards.

Such an embodiment is described in EP 0 875 039 B1, in connection with FIG. 6A / 6B which is reproduced hereinafter (FIGS. 1A and 1B of the present patent application). As will be described in more detail later, this known embodiment simplifies and makes the manufacturing more reliable, but introduces a new problem compared to the previous technology with the antenna in the card body. Indeed, the module described in this document presents a problem of degraded operation in non-contact mode, because the antenna of the module is made on one face of the module, while the electrical contacts are made on the other side of the module. , directly next to the antenna. As a result, since the electrical contacts are metallic, they disturb the electromagnetic flux between the reader and the antenna, to the point of greatly degrading the contactless communication capability of the module. In addition, the antenna being of small size, the electromagnetic flux it recovers is therefore small and the contactless communication capability is degraded.

There is also in the state of the art, as represented in FIG. 1C, an embodiment as described in EP 031 939 B1, in which a resonant circuit located on all or part of the body has been incorporated in the card body. Map. This resonant circuit, which may in particular consist of a simple metal foil, has characteristics R, L, C capable of channeling the electromagnetic flux received by the smart card, towards the antenna, so as to improve the quality of the operation of the the smart card in contactless mode.

It should be noted that in this configuration there is no electrical interconnection between the electronic module and the antenna of the card body, which is positive for a reliable manufacture of the card. But the fact of adding an antenna in the body of the card greatly complicates its mode of realization.

Indeed, the fact of adding an antenna in a plastic card body modifies its structure and its physical characteristics including its resistance to delamination, which is a major factor for identity card bodies that must be non-delaminable.

In addition, these card bodies used for identity control type applications include extremely expensive physical security and the fact of incorporating with a low manufacturing efficiency an antenna significantly increases the unit cost of the card. An object of the invention is therefore to provide a new electronic module with a dual contact and non-contact communication interface, which does not have the aforementioned drawbacks.

Another object of the invention is to provide a dual-interface smart card, using an electronic module according to the invention, and having a good communication capacity in contactless mode, despite a large compactness of the module. Another object of the invention is to provide a microelectronic module with a dual communication interface, in particular for a smart card, and a smart card using such a module, having a very high reliability during use, order five to ten years, while allowing a high manufacturing efficiency and low cost, like simple contact-operated cards.

For this purpose, the invention relates to a microelectronic module with a dual contact and non-contact communication interface, in particular for a smart card, comprising on the one hand a substrate provided with a terminal block formed of a set of electrical contacts connected to a contact communication interface of a first electronic chip and further comprising a main antenna composed of at least one turn and whose terminals are connected to the contactless communication interface of a second electronic chip, characterized in that it furthermore comprises at least one resonant circuit able to channel the electromagnetic flux received by the resonant circuit towards the main antenna of the module.

This module structure allows both a high performance in terms of radio frequency communication due to the presence of the resonant circuit, and a simple fabrication due to the integration of the resonant circuit on the module itself, and finally an integration very simple and very reliable in the time of the module in a smart card body. In particular, thanks to this design of the module, it becomes unnecessary to provide the body of the chip card of a resonant circuit or an antenna.

According to a first embodiment, the module comprises two separate and independent chips, namely one for operation in contact mode and whose pads of the communication interface are connected to the corresponding contacts of the terminal block of the module, and one for the operation in contactless mode, the terminals of which are connected to the main antenna of the module. In this way, it is possible to provide on board the module operating systems and / or completely independent software applications and this at a reduced cost since the chips simple to Contact or contactless operation are the least expensive.

According to another embodiment, the module comprises a single chip with a dual communication interface, having its contact communication interface connected to the contacts of the terminal block of the module, and its contactless communication interface connected to the terminals of the main antenna.

Advantageously, the resonant circuit comprises a secondary antenna connected to a capacitor, and its resonant frequency is tuned so as to optimize radiofrequency communication with a contactless card reader. ,

In a simple embodiment, the capacitor comprises two armatures located on either side of the module substrate.

In addition, the electrical contacts of the module are ideally located on a first face of the substrate, and the turns of the main antenna and the resonant circuit are located on the opposite face.

In one embodiment allowing the electrical contacts of the terminal block to be arranged in accordance with the ISO 7816-2 standard, the main antenna of the module and the resonant circuit are arranged at the periphery of the module in a zone substantially outside the the area delimited by the electrical contacts. Thus, the electromagnetic flux captured by the turns of the antenna is maximum, which favorably influences the range of communication without contact with the reader.

But it is possible to provide the reverse arrangement, in which the main antenna and the resonant circuit are arranged in a central zone of the module, the electrical contacts of the terminal block then being located at the periphery of the module.

Of course, the invention extends to all smart cards comprising a card body and an innovative module as described above. Advantageously, the turns of the main antenna of the module and the resonant circuit are situated on the same side of the substrate as the chip microelectronics, and the electrical contacts of the terminal block are located on the opposite side of the substrate.

Other features and advantages of the invention will appear on reading the detailed description and the accompanying drawings in which: FIG. 1A illustrates a sectional view of an electronic module according to the state of the art according to EP 0 875,039 B1; Fig. 1B illustrates a plan view of the module of Fig. 1A; FIG. 1C illustrates a sectional view of a card according to the state of the art according to EP 01 031 939 B1. FIG. 2 illustrates a view from above of an electronic module according to the invention. that is to say on the side of the contacts of the terminal block of the module; Figure 3 illustrates a bottom view of the module of Figure 2, Figure 4 illustrates a sectional view A-A of the module of Figures 2 and 3; - Figure 5 illustrates a sectional view A-A of a variant of the invention describing a solution with two chips.

As indicated above, FIGS. 1A / 1B show an electronic module with a dual communication interface, according to the state of the art. It is clear that the chip (denoted 1) is connected to an antenna (denoted 2) whose turns (denoted 3) surround the chip. Moreover, as shown in FIG. 1A, the electrical contacts (denoted 4) overhang the antenna and are separated from it only by a thin substrate. Thus, the electromagnetic field that reaches the antenna is necessarily disturbed by the electrical contacts, which degrades the operation of this type of module in contactless mode.

Referring now to FIG. 1C, there is shown an embodiment such as that described in EP 01 031 939 B1, in which is incorporated in the card body 4, a resonant circuit 5 located on all or part of the body of map. This resonant circuit, which may notably consist of a simple metal sheet, has characteristics R, L, C capable of channeling the electromagnetic field received by the smart card from a contactless reader (not shown), to the antenna 6 of the module, to further improve the quality of operation of the smart card in contactless mode. This embodiment improves that of FIGS. 1A / 1B from the point of view of the electromagnetic operation of the card and in particular of the communication range, but degrades the reliability of the smart card from the mechanical point of view and the manufacturing efficiencies. given the need to integrate a large antenna in the card body.

Referring to FIGS. 2 and 3, there is shown in these figures an electronic module 7 according to the invention, in plan view (FIG. 2), that is to say a view of the contact side, and in FIG. bottom view (Figure 3), that is to say here a view of the side of the substrate not carrying the electrical contacts.

To remedy the electromagnetic interference problems between the contacts and the antenna as described above, the applicant's engineers found a new module structure 7, in which the turns of the main antenna 8 of the module and the circuit resonant 9 constituted by a second antenna and a capacitance are reported at the periphery of the module 7, in an area where they are located neither below nor above the electrical contacts 10, but substantially outside the zone delimited by contacts. Also shown are the wells or vias 11 which electrically connect the contacts of the chip (not shown) to the corresponding contacts 10 of the terminal block of the module 7. The location for gluing the chip is noted 12 in Figure 3 .

This new structure has the double advantage of minimizing or even eliminating the electromagnetic shielding effects of the contacts 10 with respect to the turns 8 of the main antenna of the module, as well as of producing on the module itself the resonant circuit 9 in combination with the main antenna 8, thereby eliminating the integration problems of the resonant circuit 9 in the card body.

In a simple embodiment of the invention, the resonant circuit 9 consists of a second antenna 18 and a capacitor 20 of which one of the armatures 20a is located on the side of the contact terminal block 10 and the second armature 20b is located on the opposite face, as can be seen in particular in FIG. 4.

The module 7 has been shown in this figure with its substrate 13, carrying the chip (not shown) on its downward facing side. The chip is hidden here because it is embedded in a drop of encapsulating resin 14. The antenna 8 and the resonant circuit 9 constituted by the secondary antenna 18 and the capacitor 20 are located at the periphery of the module 7 and extend around the chip. According to the invention, both the main antenna 8 and the secondary antenna 18 extend out of the central zone of the module 7, which is covered by the contacts 10 on the opposite face (here the upper face) of the module 7. .

Of course, the exact dimensioning of the turns of the main antenna 8, the antenna 18 and the capacitance 20 of the resonant circuit 9 as a function of the radiofrequency communication characteristics sought, and in particular of the range, will not pose any problem for the skilled person. During the assembly of the smart card, the module 7 is moved in front of a cavity 15 formed in the card body 16. The cavity 15 is provided with a zone coated with an adhesive 17. The module 7 is transferred into the cavity 15 as shown in FIG. 4, the turns of the antennas (8, 18) coming into contact with the adhesive 17. This then results in a pressing step on the upper face of the module 7, to ensure a good quality bonding of the module 7 in the cavity 15.

It is essential to note that the electronic module 7 of the invention does not require any electrical connection with the card body 16 as well as any additional antenna located in the card body itself, and the standard embedding methods used for simple contact modules can be used, which results in a significant gain in manufacturing rate, a significant increase in manufacturing yields and reliability.

Thus, it becomes possible to apply this module technology to obtain smart cards intended for very severe or very long-term field applications, for example the application to identity cards or electronic passports. , for which government offices generally require a guarantee of good behavior and good functioning for ten years.

Referring now to FIG. 5, which represents a variant of this invention, in which the module 7 contains two chips including a first chip 21 dedicated to contact applications and whose terminals are connected to the contact terminal block 10, and second chip 22 dedicated to non-contact type applications and whose terminals are connected to at least one turn of the main antenna 8.

This arrangement is particularly useful for certain applications, in that it replaces a single chip with a dual contact and contactless communication interface, by two specialized 21,22 chips, which are generally much less expensive and able to run applications completely. separate, such as for example a payment application using the chip 21 to contact operation and the contact terminal block 10, and an identification or access control application using the chip 22 to contactless operation connected to the antenna 8 and coupled to the resonant circuit

9.

Finally, the invention proposes a particular microelectronic module design that allows both optimum operation of the module designed to allow the electromagnetic flux to pass inside the main and secondary antennas without being disturbed by the metallizations of the terminal block contacts. , and reliable and inexpensive integration in a card body itself without antenna.

Claims

1. Microelectronic module (7) with a dual contact and non-contact communication interface, in particular for a smart card, comprising on the one hand a substrate (13) provided with a terminal block formed by a set of electrical contacts (10) connected to a contact communication interface of a first electronic chip (21) and further comprising a main antenna (8) composed of at least one turn and whose terminals are connected to the contactless communication interface a second electronic chip (22), characterized in that it further comprises a resonant circuit (9) capable of channeling the electromagnetic flux received by the resonant circuit (9) towards the main antenna (8) of the module .

2. Microelectronic module according to claim 1, characterized in that the first chip (21) and the second chip (22) are replaced by a single chip provided both with a contact communication interface connected to the electrical contacts (10). module, and a contactless communication interface connected to the main antenna (8).

3. Microelectronic module according to claim 1 or claim 2, characterized in that the resonant circuit (9) comprises a secondary antenna (18) connected to a capacitor (20).

4. Microelectronic module according to claim 3, characterized in that the capacitor (20) comprises two armatures (20a, 20b) located on either side of the substrate (13) of the module (7).

Microelectronic module according to one of the preceding claims, characterized in that the electrical contacts (10) are located on a first face of the substrate (13), and in that the turns of the main antenna (8) and the resonant circuit (9) are located on the opposite side.

Microelectronic module according to claim 5, characterized in that the main antenna (8) and the resonant circuit (9) are arranged at the periphery of the module (7), in a zone substantially outside the zone delimited by the electrical contacts (10).

7. Microelectronic module according to claim 6, characterized in that the electrical contacts (10) of the terminal block are arranged to comply with ISO 7816-2.

8. microelectronic module according to claim 5, characterized in that the main antenna (8) and the resonant circuit (9) are arranged in a central zone of the module, the electrical contacts (10) of the terminal block being located at the periphery of the module .

9. Smart card, characterized in that it comprises an electronic module (7) according to any one of the preceding claims.