WO2022144508A1

WO2022144508A1 - Electronic module for a smart card

Info

Publication number: WO2022144508A1
Application number: PCT/FR2020/000286
Authority: WO
Inventors: Sebastien Marmugi; Didier LIVRATI; Bernard Calvas
Original assignee: Smart Packaging Solutions
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2022-07-07

Abstract

The invention relates to an electronic module (20) with a dual contact or contactless communication interface, comprising a dielectric substrate (13) having, on a first face, a terminal block of electrical contacts (C1, C2, C3, C5, C6, C7) which are standardised according to ISO 7816 and intended to function by contact with the corresponding contacts of a smart card reader, the substrate (13) having, on a second face, the coils of an antenna (6) located underneath the electrical contact area of the terminal block, and the antenna (6) comprising a distal end (8) located at the peripheral edge of the electronic module (20) and a proximal end (9) located inside the coils of the antenna (6), characterised in that it comprises two separate microelectronic chips (7a, 7b), i.e. a first chip (7a) provided with a contact communication interface connected to terminal block contacts, and a second chip (7b) provided with a contactless communication interface connected to the distal end (8) and the proximal end (9) of the antenna (6), the distal end (8) of the antenna (6) being connected to the second contactless communication interface by a metal pad incorporating a standard contact which is not connected to the first contact communication interface.

Description

DESCRIPTION

Title: Electronic module for smart card

The present invention relates to an electronic module for a smart card having a contact and contactless dual mode of operation, as well as a smart card integrating such an electronic module.

State of the art

Several types of chip cards already exist in the state of the art. Some are said to operate by contact. They have a terminal block of contacts intended to cooperate with the contacts of a smart card reader provided with corresponding contacts.

Others are said to operate without contact. They include an antenna that allows radio frequency communication with a remote reader.

Finally, there are also mixed-function contact and contactless smart cards. They comprise both a contact terminal block and at least one antenna. Some contacts of the terminal block are connected to the contact interface of a microelectronic chip of the module, and the ends of the antenna are connected to the contactless interface of the electronic module.

The electronic module may comprise a single chip comprising both a contact communication interface and a contactless communication interface. This is a so-called dual module. An example of such a module is described in document WO 2015/071086 Al. This module comprises connection bridges (“connection bridges”) configured to bring the ends of the antenna of the module inside the zone of encapsulation that protects the single chip. These connection bridges are either arranged between two neighboring standardized contacts, or encroach on part of the surface of a standardized contact. In any case, they remain visible as an element that interferes with the appearance of the standardized contacts and with the surface available for the realization of a possible logo in the area of the contacts.

But the module can also comprise two microelectronic chips, namely a so-called contact chip comprising a contact interface connected to certain contacts of the terminal block, and a separate so-called contactless chip, comprising a contactless interface intended to be connected to the terminals of an antenna. This is a so-called hybrid module. An example of such a two-chip module is described in document WO 2019/045642 A1. However, this module has under certain contacts large multi-contact pads. As a result, there is no longer any space available to position the coils of an antenna on the module itself. Consequently, the antenna is offset outside the module, so it cannot be an antenna module as targeted by the present invention.

However, in certain cases, the microelectronic module must itself include an antenna, located on the underside of the module, and not visible when the module is integrated into the body of a chip card.

The module contacts are standardized according to the ISO 7816 standard. They can be 6 or 8 in number, numbered from Cl to C8. Within the framework of the so-called 5-wire communication protocols, the contacts C6, C7 and C8 are not used and are not connected to the contact communication interface of the chip of the electronic module. The contacts Cl - C8 are included in the metal pads of the terminal block and located on the upper face of the module, which remains visible when the module is integrated into a smart card.

The antenna of the module comprises a so-called distal end which terminates the outer circumference of the antenna which extends along the periphery of the module, and a so-called proximal end, which is located in the vicinity of the microelectronic chip located in the center of the surface of the module.

In order to be able to connect the distal end of the antenna to the corresponding terminal of the contactless interface of the module, it is known in the state of the art to use an electrical connection passing above the turns of the antenna to bring its distal end towards the appropriate pad of the contactless interface of the microelectronic chip of the module. This electrical connection is made in the form of a bridge, generally called a “strap” in Anglo-Saxon terminology. It consists of an individualized and clearly visible track on the surface of the module, as is in particular the case in the aforementioned document WO 2015/071086 Al. It extends between the periphery of the module and the central metal pad located between the module contacts. This track is electrically insulated from the central metal pad by an engraving, which makes the bridging all the more visible.

However, this bridging used in the state of the art has several drawbacks. In addition to its unsightly appearance, it presents problems on a functional level, since it risks breaking during a bending of the smart card, which would render the antenna non-functional.

In addition, the bridging limits the space available on the central pad of the module to engrave a sign or a logo as is often required by suppliers of applications using smart cards, such as banks.

Furthermore, current technology presents difficulties in integrating a bridge into a module in the standard format of 11.8 mm×13 mm. Indeed, the location of the ends of the bridging leads to a reduction in the useful surface available for the active components of the module. In particular, because of the bridging, the turns of the antenna must have a recess towards the inside of the surface of the module, and this recess in turn encroaches on the surface available to accommodate the microelectronic chip(s) of the module, this which may limit the module to applications requiring only small size chips.

Purpose of the invention

The general object of the invention is to propose a new electronic module for smart card, devoid of the disadvantages of the state of the art.

The specific object of the invention is to provide an electronic module with mixed contact and contactless operation which is devoid of a bridge in the form of a clearly visible track on the upper surface of the module.

Object of the invention

According to the principle of the invention, the clearly visible bridging is replaced by a connection between the distal end of the antenna and the appropriate pad of the contactless interface of the module, and this connection is fully integrated into one of the standard contacts of the module which are not connected to the contact interface of the chip. The subject of the invention is therefore an electronic module with a double contact and contactless communication interface, comprising a dielectric substrate having on a first face a terminal block of electrical contacts (C1, C2, C3, C5, C6, C7) standardized according to the ISO 7816 standard intended for operation by contact with the corresponding contacts of a smart card reader, said substrate having on a second face the turns of an antenna located under the zone of the electrical contacts of the terminal block, and said antenna comprising a distal end located on the periphery of the electronic module and a proximal end located inside the turns of the antenna, characterized in that it comprises two distinct microelectronic chips, namely a first chip provided with a communication interface with contact connected to contacts of the terminal block, and a second chip provided with a so-called contactless communication interface connected to the distal and proximal ends of the antenna, and the distal end of the antenna being connected to said second contactless communication interface by a metal pad integrating a standardized contact not connected to said first contact communication interface.

Thanks to this arrangement, it becomes possible to bring the distal end of the antenna back to the zone located inside the turns, without using a specific visible bridge, the connection being integrated into a standardized contact, which leaves the central area of the module terminal block. According to an advantageous embodiment, the metal pad integrates the standardized contact C6 which is not connected to the contact communication interface of the microelectronic chip. In addition, the use of two chips then makes it possible not to polarize the contactless chip and avoids destroying it when inserting the card into a contact reader.

According to one embodiment, the distal end of the antenna is connected to contact C6 by a connection perpendicular to the plane of the module, for example a blind via.

According to one embodiment, the standardized contact C6 is connected to a terminal of the contactless communication interface by a second blind via connected to a conductive track and a connection wire. Advantageously, the electronic module according to the invention comprises, between the standardized electrical contacts (C1, C2, C3, C5, C6, C7), a metal pad devoid of visible bridging and entirely available, in particular for producing a logo.

The invention also relates to a chip card, characterized in that it comprises an electronic module according to any one of the preceding claims.

detailed description

The invention will be described in more detail in relation to the figures, in which:

Figures IA to IC represent a terminal block for the contacts of an electronic module for a smart card according to the state of the art;

FIG. 2 represents a partially transparent detailed view of the electronic module of FIG. 1;

FIG. 3 represents a diagram of the terminal block of the module of FIG. 2 and its equivalent electrical diagram;

FIG. 4A represents a partially transparent view of the upper face (contact side) of the printed circuit of an electronic module according to the invention;

FIG. 4B represents a view of the upper face (contact side) of the printed circuit of FIG. 4A;

FIG. 5A represents a partially transparent view of an electronic module in accordance with the invention, provided with the printed circuit of FIG. 4A and two distinct chips;

FIG. 5B represents a sectional view of the electronic module of FIG. 5A according to section planes AA and BB; FIG. 6 represents a more detailed view partially in transparency of the contact interface of the electronic module according to the invention;

FIG. 7 represents the upper face (contact side) of an electronic module according to the invention.

Figures IA to IC represent the upper face of a dual electronic module 1 according to the state of the art. It has a set of metal pads, namely contact pads 2 surrounding a central area 3. Depending on the module used, there are 6 or 8 contact pads, the model shown is a model with 6 contact pads. At the center of the contact pads are contact zones standardized according to the ISO 7816 standard, numbered from Cl to C6 and whose functions are as follows:

Cl = Power (Vdc)

C2 = Reset

C3 = Clock (Clk)

C5 = Ground (Gnd)

C6 = not connected

C7 = Inputs/Outputs (I/O)

These contact areas serve as a contact area for corresponding contacts of a contact chip card reader.

As shown, the electronic module comprises a conductive track 4 forming a bridge, or strap in Anglo-Saxon terminology, extending from the periphery of the module to the central area 3. This bridge 4 is well individualized and clearly visible on the known mods. It is used to connect the distal end of the antenna of the module, to the contact pad of the contactless interface of the microelectronic chip. As can be seen in FIG. 1C, chip card issuers may be asked to engrave a sign or logo 5 in the central area 3. The bridging 4 limits the space available for the production of this logo, and visually interferes with him.

The invention aims in particular to solve this problem.

In Figure 2 there is shown a view of an electronic module similar to that of Figure 1, observed from the side of the antenna and the microelectronic chip, with a reminder by transparency of the position of the contacts C1-C6 and the bridge 4. We see in particular the turns of the antenna 6, a microelectronic chip 7 placed in the center of the module, and 6 standardized contacts C1 to C6. The distal end 8 of the antenna is brought by the bridge 4 to the level of a metallized via or hole 9 located inside the turns of the antenna and connected by a conductive track 10 and a connection wire 11 to a connection terminal c of the contactless interface of the microelectronic chip 7. The proximal end 12 of the antenna 6 is connected to another connection terminal d of the contactless interface of the microelectronic chip.

As can be seen, the presence of the distal end 8 and of the bridge 4 implies a localized offset of the turns of the antenna 6 inwards, which leads to the via 9 being moved and the surface available for the implantation of a second chip or a larger chip.

Figure 3 shows in the left part the layout diagram of the ISO contacts C1-C6 and of the chip, and in the right part an equivalent electrical diagram of the electronic module of Figure 2. As can be seen, in the state of the technically, the connection pad C6 is not used, consequently it is connected neither to the contact communication interface nor to the contactless communication interface of the chip 7. The terminals of the antenna 6 are connected to the pads (c, d) of the contactless interface of chip 7.

As represented in FIGS. 4A and 4B, the invention proposes a dual electronic module with contact and contactless operation, devoid of a clearly visible and identifiable bridging like that known in the state of the art. The central area 3 of the terminal block is full, in one piece, without discontinuity. She lends herself to engraving of a large logo. The bridge 4 in accordance with the state of the art is replaced by a hidden or integrated electrical connection in an unused connection pad of the terminal block, for example the connection pad C6, as can be seen in more detail in FIGS. 5B and 6.

FIG. 5A represents a transparent view of an electronic module according to the invention, comprising two chips, namely a chip 7a connected to contacts C1, C2, C3, C5 and C7 of the terminal block and dedicated to contact communication, and a chip 7b connected to the terminals of antenna 6 via contact C6 and dedicated to contactless communication. Consequently, the contact C6 now acts as a bridge to bring the distal end 8 of the antenna back to the central zone of the module, without introducing any track or visible disturbance in this central zone.

Figure 5B is a sectional view along section lines A-A and B-B of Figure 5A. The distal end 8 of the antenna 6 is connected by an electrical connection, for example by a blind via 12, to the contact C6 of the terminal block, located opposite the antenna 6 on the other side of the substrate 13. The contact C6 provides the electrical connection with another via 14, a track 15 and a connection wire 16, to a terminal 17 of the contactless interface of the contactless chip 7b.

This arrangement advantageously makes it possible to bring the distal end 8 of the antenna 6 towards the contactless chip 7b, without having to use an individualized bridge in the central zone 3 of the module, as can be seen in FIG. to have the entire central zone 3 of the module for the production of a logo, in particular by engraving the metal.

It should be noted that in theory a module without bridging in accordance with the invention could also be obtained by using a single dual chip 7. However, this embodiment is liable to pose problems linked to the polarization of the contactless interface of the chip by the contact reader at the time of its use, risking the destruction of the contactless chip. The invention therefore provides a hybrid solution with 2 chips, one 7A with contact only and the other radio frequency 7b only. In this case, a module is obtained which is both robust in its use, and devoid of a visible bridge on the face of the contacts of the terminal block.

Advantages of the invention

The invention achieves the stated aims. In particular, it allows the elimination of the unsightly bridging on the contact side of the module, and the production of logos on the entire surface of the central zone 3 of the terminal block. In addition, it maximizes the useful space available for the implantation on the module of large chips, or of several chips in the case of hybrid modules.

In addition, the removal of the bridge, which can be broken, makes it possible to eliminate a source of module failure from the module.

Claims

CLAIMS Electronic module (20) with dual contact and contactless communication interface, comprising a dielectric substrate (13) having on a first face a terminal block of electrical contacts (C1, C2, C3, C5, C6, C7) standardized according to the ISO 7816 standard intended for operation by contact with the corresponding contacts of a smart card reader, said substrate (13) presenting on a second face the turns of an antenna (6) located under the zone of the electrical contacts of the terminal block , and said antenna (6) comprising a distal end (8) located on the periphery of the electronic module (20) and a proximal end (9) located inside the turns of the antenna (6), characterized in that it comprises two separate microelectronic chips (7a, 7b), namely a first chip (7a) provided with a contact communication interface connected to contacts of the terminal block, and a second chip (7b) provided with a communication interface so-called connected contactless at the distal (8) and proximal (9) ends of the antenna (6), and the distal end (8) of the antenna (6) being connected to said second contactless communication interface by a metal pad incorporating a standardized contact not connected to said first contact communication interface. Electronic module (20) according to Claim 1, characterized in that the said metal pad integrates the standardized contact (C6) not connected to the contact communication interface of the microelectronic chip (7; 7a, 7b). Electronic module (20) according to Claim 2, characterized in that the distal end (8) of the antenna (6) is connected to the contact (C6) by a connection perpendicular to the plane of the module, for example a via (12 ) non-opening. Electronic module (20) according to any one of the preceding claims, characterized in that the standardized contact (C6) is connected to the terminal (LA) of the contactless communication interface by a second blind via (14) connected to a conductive track (15) and a connection wire (16). Electronic module (20) according to any one of the preceding claims, characterized in that it comprises between the standardized electrical contacts (C1, C2, C3, C5, C6, C7) a metal pad (3) devoid of bridging and entirely available for the realization of a logo. Smart card, characterized in that it comprises an electronic module (20) according to any one of the preceding claims.