JP2014109843A - Module substrate for contact type ic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an IC module for a contact type IC card having: a plurality of partitioned conductor surfaces for contact on one surface; and on the other surface, a through-hole electrode making a through-hole connection with the conductor surfaces; a connection pad for connecting an IC chip connection terminal; a wiring pattern connecting the through-hole electrode and the connection pad; and the IC chip under flip-chip connection, and in which the through-hole electrode 12 and the connection pad are connected with a shortest wiring pattern.SOLUTION: In an IC module for a contact type IC card, an IC chip 7 is installed so that an alignment direction of conductor surfaces for contact C1, C2, C3 and an alignment direction of terminals 5 for connecting the IC chip 7 are at right angles to each other. An antenna coil 13 is provided surrounding the IC chip 7.

Description

  The present invention relates to an arrangement mode of an internal conductor pattern of an IC module incorporated in a contact IC card to exchange electrical signals with a read / write device side.

  An IC card with a built-in IC chip such as a central processing unit or semiconductor memory has higher security and higher storage capacity due to advanced encryption compared to conventional magnetic cards. Instead, it is popular and widely used.

  IC cards are roughly classified into two types: contact type and non-contact type. Contact type IC cards are small-sized cards with contact terminals that are exposed on the surface with IC chips built into the card body that is made of synthetic resin. The module board is inserted. An IC card is inserted into the card slot of the read / write device, and data is exchanged by bringing the contact terminal on the IC card side into contact with the contact terminal on the read / write device side. Contact-type IC cards are used in cash cards, credit cards, and the like, which are uses that require safety in communications such as exchange of large amounts of data and settlement operations.

  On the other hand, the non-contact type IC card has an IC chip and a communication antenna built in the card body. Since it transmits and receives wirelessly between the antenna of the IC card and the antenna of the read / write device, there is no need to insert and remove the card, so it is used for gate management such as clearing and settlement processing of railways and buses.

  Since any type of IC card is carried in a wallet / bag or the like, it is easy to receive external force, and the IC chip of the IC module part may be destroyed by bending deformation due to the external force. Therefore, means for preventing destruction of the IC chip has been applied to the IC card. When the IC chip is wire-bonded to the connection terminal, the entire chip including the wire is covered with a resin. As another example, there has been proposed an IC card structure in which a wavy groove is formed in a card base on the outer periphery of an IC module so that deformation due to an external force is concentrated in the groove and bending deformation of the IC module is reduced ( Patent Document 1).

  FIG. 7 shows an external view of the contact type IC card as viewed from above. The surface of the contact type IC card 2 that is in contact with the contact terminal on the side of the read / write device is exposed. An IC chip is mounted. However, the contact type IC card is different from the non-contact type because the connection method between the IC chip and the conductor surface has been changed from the wire bonding to the flip chip connection method, and it is necessary to put it in and out of the slot of the read / write device. The problem is occurring.

  In the contact type, it is necessary to insert an IC card into a read / write slot so that a contact terminal (partitioned conductor surface) on the IC card (module substrate) side and a contact terminal of the read / write device are in physical contact. Specifically, conduction is obtained by pressing a metal pin on the read / write device side against a conductor surface on the module substrate side. If various conductor patterns (conductive through-holes, solder connection parts with IC chips, wiring patterns, etc.) of the module board are laid within the area where the pins are pressed, they are damaged by receiving the pin pressure. There is.

  In the contact type, the wire bonding method is often applied to the conventional IC chip mounting form. In the wire bonding method, mounting is performed so that the contact conductor surface of the IC module and the connection terminal of the IC chip are back to back. This is because, in the back-to-back direction, the contact conductor surface and the connection terminal of the IC chip are more easily connected by the gold wire, and the arrangement of both terminals is determined as such (Patent Document 3).

Japanese Patent Application Laid-Open No. 11-296639 Japanese Patent Laid-Open No. 4-120744 JP 2002-133385 A

  However, in flip chip mounting, the mounting direction (back / front) of the IC chip is opposite to that of the wire bonding method. Therefore, the positional relationship between each terminal drawn from the contact conductor surface and the connecting terminal of the IC chip is the connection distance. In many cases, the wiring pattern for electrically connecting the two is greatly bypassed the IC chip. Redundant wiring patterns can cause defects such as disconnection failure due to bending when carrying or reading and reading, and malfunction due to mixing of noise.

  Therefore, the present invention has a plurality of conductor surfaces partitioned on one surface, and a through-hole electrode connected to the conductor surface via a through-hole and an IC chip are connected to the other surface by flip-chip connection. An object of the present invention is to provide a module substrate for a contact type IC card in which a through-hole electrode and a connection pad are connected by a shortest wiring pattern in a module substrate having pads.

In order to achieve the above object, the invention according to claim 1 is provided with a plurality of partitioned contact conductor surfaces C1, C2, C3, C5, C6, and C7 on one surface and the conductor surface on the other surface. Through-hole electrodes for connecting through holes, connection pads for connecting IC chip connection terminals, wiring patterns connecting through-hole electrodes and connection pads, and contact type in which the IC chip is flip-chip connected An IC module for an IC card,
The contact-type IC card IC module is characterized in that the direction in which the contact conductor surfaces C1, C2, C3 are arranged and the direction in which the connection terminals of the IC chip are arranged are perpendicular to each other.

  According to a second aspect of the present invention, a planar coil-shaped antenna pattern is provided on the other surface so as to surround the IC chip, and one end of the antenna pattern is connected to a predetermined connection pad via the first wiring pattern. The other end of the antenna pattern is connected to a conductor surface different from C1 to C7 provided on one surface via the first through-hole electrode and the first through-hole, and the conductor surface is further connected to the first through-hole electrode. 2. The contact IC card IC module according to claim 1, wherein the contact module is connected to a connection pad through a second through hole, a second through hole electrode, and a second wiring pattern.

  The invention according to claim 3 is characterized in that the IC chip, the through-hole electrode, the connection pad, and the wiring pattern are covered with a sealing resin. This is an IC module for a contact type IC card.

  The invention according to claim 4 is characterized in that the line width of the first and second wiring patterns connecting the antenna pattern and the connection pad is wider than the line width of the antenna pattern. The contact IC card IC module according to Item 3.

According to the first aspect of the present invention, it is possible to connect the wiring connecting the bump of the IC chip and the contact IC card terminal portion in the shortest time, and the failure risk due to disconnection of each wiring can be reduced.

  According to the invention of claim 2, an IC chip having a connection terminal to the antenna coil, one of the wirings connecting the bump of the IC chip and the antenna coil, the bump of the IC chip and the contact type IC card terminal portion It is possible to connect the wirings in the shortest direction even when a part of the wirings connecting the planes intersects in a planar manner, and the risk of failure due to disconnection of the wirings can be reduced.

  According to the invention of claim 3, it becomes possible to protect not only the IC chip but also the wiring connecting the bump of the IC chip and the contact type IC card terminal portion with resin, and the risk of failure due to disconnection of each wiring due to bending fatigue or the like can be prevented. Can be reduced.

  According to the fourth aspect of the present invention, it is possible to reduce a risk that the wiring connecting the bump of the IC chip and the antenna coil is disconnected due to bending fatigue or the like particularly in the outer portion of the resin molded portion.

It is a figure of the cross sectional view of an IC module. (A) In the case of flip chip connection, (b) In the case of wire bonding. (A) It is the figure of the upper surface view which looked at the conductor surface of the IC module surface from the surface (contact terminal surface). (B) The left figure is a top view when the IC chip is viewed from the connection terminal side. The right figure shows the left figure as seen from the back. (A) It is the figure of the top view seen through the contact conductor surface back surface wiring pattern of the IC module surface. (B) This is a case where an IC chip is mounted on (a). Both are flip chip connections. (A), (b) It is the perspective view from the surface which illustrates typically the example of the wiring pattern which becomes this invention. (B) is the one rotated 180 degrees of (a). It is a perspective view from the surface which shows an example of the wiring pattern which connects the terminal of a coiled antenna, and the terminal for connection of an IC chip. It is a perspective view from the surface explaining the coating range of resin for sealing. It is a perspective view from the surface for demonstrating the position and magnitude | size of an IC module on an IC card ticket surface.

  Hereinafter, an IC module according to the present invention will be specifically described with reference to the drawings.

  FIG. 7 is a diagram for explaining the approximate position and size of the IC module 10 (hereinafter simply referred to as a module substrate) in the non-contact IC card 20. The module substrate 10 is a square resin base with rounded corners of about 13 mm square, and the surfaces of the module substrate 10 are flush with the opening formed at a predetermined position of the main body of the IC card 20 made of a plastic base. It is inserted and fixed so as to become.

  On one surface of the module substrate 10, a plurality of metallic conductor surfaces 2 partitioned as shown in FIG. 7 are arranged substantially symmetrically, and these conductor surfaces 2 and contact terminals on the side of the read / write device are arranged. Electrical contact is made with a metal pin (not shown, for example, although not shown). A linear contact mark may remain on the surface of the conductor surface 2 by taking in and out of the slot for reading and writing.

  The module substrate 10 that is the subject of the present invention is a type of module substrate in which an IC chip is flip-chip mounted on the other surface (back surface) of a base substrate. Conventionally, the wire bonding method has been the mainstream as a method for mounting an IC chip, but it has gradually shifted to a flip chip mounting method. As shown in the left diagram of FIG. 2 (b), from the IC chip 7, when viewed from the connection terminal 5 side, the connection terminals AC0, C1, C2, C3 are on the right side, and the C5, C7, AC1 terminals are on the left side. Yes.

  On the other hand, the IC chip 7 is mounted on the back surface of the module substrate, and a plurality of contact terminals to be connected to the connection terminals 5 of the IC chip are formed as the conductor surface 2 on one surface (front surface) of the module substrate. However, the arrangement is as shown in FIG. 2A when viewed from the front side of the module substrate 2. The IC card reading device exchanges data by interpreting that the contact terminals (conductor surface 2) on the IC card side are arranged as shown in FIG.

  In the wire bonding method, since the connection terminals 5 of the IC chip 7 cannot be connected unless they are exposed on the surface, when viewed from the front surface side of the module substrate 10, the conductor surface arrangement of FIG. ) On the right side of the connection terminals is connected 1: 1. Accordingly, in the wire bonding, as shown in FIG. 1B, a part of the base substrate 1 on the back side of the conductor surface 2 is counterbored to form the opening 8 and the back surface of the conductor surface 2 is exposed. It is common to do it. A conductive through hole may be formed in the base substrate 1 on the back surface of the conductor surface 2 to form a through hole electrode, and the through hole electrode may be wire bonded to the connection terminal of the IC chip. In any case, the arrangement of the terminals is determined so that the wire distance is the shortest.

  On the other hand, in the flip chip connection, as shown in FIG. 1 (a), the connection terminal 5 faces the base substrate 1 side, and the IC chip 7 is mounted with the front and back reversed with respect to the wire bonding. . Accordingly, the connection terminal pattern of the IC chip 7 is as shown in the left diagram of FIG. 2B, and the connection pads 9 having the same pattern are formed on the back surface side of the base substrate 2. The surface of the connection pad 9 is subjected to surface treatment by gold plating or the like, and then the connection terminal 5 of the IC chip 7 is subjected to solder connection 6 or the like. The left diagram in FIG. 2 (b) shows a terminal arrangement in which the chip is reversed left and right, but it may be reversed up and down (same as rotating 180 degrees after left-right reversal).

  Accordingly, it is necessary to connect the corresponding portions of the conductor surface arrangement in FIG. 2A and the connection terminal 5 on the left side in FIG. This is clearly different from the shortest connection for wire bonding and requires routing. Although an example of the routing is shown in FIG. 3, the positional relationship of the connecting portions is opposite to each other, so that the IC chip 7 is largely bypassed. Redundant wiring as shown in FIG. 3 can cause defects such as disconnection failure due to bending or the like, or malfunction due to noise. Although it is conceivable to form the connection wiring 11 on the back surface of the base substrate 2 corresponding to the ground conductor surface of the center C5, it is difficult because the wirings 11 cross each other.

  The arrangement of the conductor surfaces 2 partitioned on the surface of the module substrate 10 is determined by the standard in relation to the read / write device side, and the wire bonding method and the flip chip connection method are the same. The arrangement of the connection terminals of the IC chips 7 to be used is the same with no difference depending on the method. The arrangement of the connection terminals 6 and the conductors 2 of the IC chip 7 is in a positional relationship that facilitates wire bonding. However, when the flip chip connection is used, the front and back of the IC chip 7 are reversed, so that special consideration is given to the wiring pattern 11. The present invention relates to this point.

<First embodiment>
As the base substrate 1 of the module substrate 10, a flexible material configured in a plate shape from a nonconductive material such as resin represented by FR-4, polyimide, PET, and PEN is used. The partitioned conductor surface 2 can be formed by applying a regular photolithographic method to a resin laminate having a thickness of about 200 μm made of the resin with a copper foil on one side.

The first embodiment is an IC in which the distance of the wiring pattern 11 to be routed becomes as short as possible.
The method of mounting the chip 7 is defined based on the arrangement of the conductor surfaces 2.

  As shown in FIG. 1 (a), the IC module 10 has a plurality of partitioned contact conductor surfaces C1, C2, C3, C5, and C7 on one surface for contacting the contact terminals on the read / write device side. At least. On the other surface, a through-hole electrode 12 connected to the conductor surface 2 through the conductive through-hole 4 and a connection pad 9 for connecting to a connection terminal of the IC chip are provided.

  The IC chip 7 is mounted by flip chip connection with the connection terminals 5 facing the base substrate 1 side. However, when the conductor surface 2 is fixed, the IC chips 7 are lined up with the connection terminals 5. There are two directions orthogonal to the direction. One is the direction shown in FIG. This direction is parallel to the direction of the arrow in FIG. Another one is the direction shown in FIG. 4 and perpendicular to the arrow. The present invention is an IC module on which the IC chip 7 is mounted so that the arrow direction in which the latter conductor surfaces C1, C2, C3 are arranged and the direction in which the connection terminals 5 of the IC chip are arranged are perpendicular to each other. This is because the IC chip 7 can be connected at the shortest distance without bypassing the IC chip 7 so that the wirings 11 do not intersect. This is clear from FIG. 3 and FIG. If they are parallel, the wirings 11 cross each other and eventually detour.

The conductive surface 2 has a conductive through hole 4 formed in a predetermined position of the base substrate 1 for each conductive surface 2, and the through hole 4 is connected to an electrode (through hole electrode 12) formed on the other surface. doing. The through hole 4 is formed by directly drilling the resin substrate 1 or by ablating the resin layer with a laser (CO ₂ , UV, excimer) until the lower copper foil is exposed if the laminate is provided with a copper foil. it can.

  The IC chip 7 is preferably mounted on the back surface side corresponding to the conductor surface 2a at the center of the partitioned conductor surfaces 2, and a connection pad 9 for this purpose is provided on the base substrate 1. The through-hole electrode 12 and the connection pad 9 are connected so as not to intersect with the patterned wiring 11. The central conductor surface 2a preferably has such a size that the IC chip 7 is contained in the top view. This is because the larger the bending resistance, the greater the deformation of the semiconductor chip 7 itself.

  The conductive through hole 4 can be filled by screen printing from the back side using a conductive paste, or can be filled by electrolytic plating using a copper foil as an electrode. In the through-hole plating, first, a predetermined pretreatment, that is, degreasing, sensitization, and activation treatment is performed, and then a predetermined electrolytic copper plating solution containing copper sulfate is used to form a copper plating layer. When electrolytic plating is employed, the through hole 4 is filled with copper and at the same time a copper foil is obtained. Therefore, the wiring pattern 11 connected to the through hole electrode 12 and the connection pad 9 are formed by a semi-additive method or a subtractive method. Can be applied simultaneously.

A predetermined surface treatment such as gold plating can be applied to the connection pad 9 used for connection by solder or the like and the conductor surface 2 on the surface of the base substrate 1. The surface treatment can be appropriately selected from Au / Ni, Au / Pd / Ni, and the like. After plating pretreatment, in a sulfamine nickel plating tank, electrolytic nickel plating is applied at a current density of 2 A / dm ² for about 2 minutes, and then a palladium plating layer is formed on the nickel plating layer, and a gold plating layer is further formed thereon. Form. The nickel plating layer preferably has a thickness of about 1.0 μm, the palladium plating layer has a thickness of about 0.10 μm, and the gold plating layer has a thickness of about 0.05 μm. Thereafter, a solder layer is printed or solder balls are mounted on the connection pads as necessary.

  Next, after the connection pads 9 and the terminals of the IC chip 7 are aligned, the terminals are flip-chip connected through a reflow furnace at a predetermined temperature. Since the flip-chip connected electrode portion 6 is vulnerable to external force, a gap of about several tens of μm formed on the back surface of the IC chip 7 and the base substrate 1 can be filled with an underfill resin (not shown). As a method for underfilling, a CUF (Capillary Under Fill) method in which a thermosetting sealing resin is filled from a dispenser can be applied.

  In this way, the module substrate 10 used for the contact type IC card 20 is obtained. Even when the IC card is subjected to a bending action when it is carried, a reinforcing plate (not shown) having the same size can be attached to the upper surface of the back of the IC chip so as to improve the bending resistance. Thereby, generation | occurrence | production of the conduction defect of IC chip 7 by repeated fatigue can be suppressed.

  The base material composing the contact-type IC card body is preferably a flat paper quality paper or plastic resin having a thickness of about 0.20 mm, and at least the surface layer is preferably PET-G made of a non-conductive substance. A contact-type IC card 20 can be obtained by providing a recess capable of accommodating the IC module 10 at a predetermined position and then fitting and bonding the IC module 10.

<Second Embodiment>
The second embodiment is a module substrate 10 having a planar coil antenna pattern 13 so as to surround the IC chip 7 as shown in FIG. Both ends of the antenna pattern 13 need to be connected to predetermined terminals AC0 and AC1 on the IC chip 7.
The present invention specifies the connection mode. The antenna pattern 13 itself is irrelevant to the conductor surface 2 on the module surface and does not need to be connected via the through hole 4.

However, the inner end of the antenna coil 13 can be wired to either AC0 or AC1 by the first wiring pattern 18a, but the outer end is not inside the antenna coil 13 unless it crosses the antenna coil 13. I can't guide.
Therefore, the present invention removes a part of two partitioned conductor surfaces 2 (for example, the top or the ground and C5 (ground)) provided on the surface of the module base 1 as shown in FIG. A conductor surface 17 is formed, and this conductor surface 17 is a jumper portion that passes through the back side of the antenna.

  Another end of the antenna coil 13 is connected to one end of the jumper conductor surface 17 via the first conductive through hole 4a, and the other end of the jumper conductor surface 17 is connected to the back surface via the second through hole 4b. Connected to through-hole electrode. Since the through-hole electrode protrudes inside the antenna coil 13, it is connected to the connection pad 9 for connection to AC1 or AC0 by the second wiring 18b.

<Third embodiment>
In the third embodiment, as shown in FIG. 6, an IC chip, a through-hole electrode, a connection pad, a wiring pattern, and the like provided on the back surface of the module substrate are covered with a sealing resin. It is preferable to bury a gap between the IC chip having the flip chip connecting portion and the resin substrate simultaneously with the coating. A special underfill resin may be infiltrated in advance. The sealing resin is preferably a thermosetting epoxy resin. When covering with resin, it is desirable not to cover the antenna part due to problems such as cost and workability. In that case, since the first and second wiring patterns that connect the pads for connection with the IC chip and the antenna body are exposed without being covered, there is a risk that stress is applied to the boundary portion where the wiring is exposed from the resin coating film. Therefore, it is preferable that the wiring line width of the part is larger than the line width of the antenna body.

The first and second wiring patterns do not have to be linear as shown in FIGS. 6A and 6B, and may be inclined obliquely as shown in FIG. 6C. This is intended to reduce the risk of disconnection of the wiring by making the wiring obliquely intersect with the outer portion of the portion protected by the resin and by increasing the wiring width in the outer portion.

DESCRIPTION OF SYMBOLS 1, Resin base material 2, Conductor 2a, 2b, 2c, 2d, Conductor piece 3, Wiring layer 4, Through hole 4a, 1st through hole 4b, 2nd through hole 5, Connection terminal (IC chip side)
6. Solder connection (or connection pads and terminals)
7, IC chip 8, opening 9, connection pad 10, IC module 11, wiring itself or pattern 12, through-hole electrode 13, antenna coil 14, central band 15, contact electrode (metal pin)
16, metal wire 17, conductor surface (for jump)
18, wiring 18a, first wiring 18b, second wiring 20, contact IC card

Claims (4)

A plurality of partitioned contact conductor surfaces C1, C2, C3, C5, C6, and C7 are provided on one surface, and through holes on the other surface are connected to the conductor surfaces, and IC chip connection terminals are provided. A contact-type IC card IC module having a connection pad for connection, a wiring pattern connecting the through-hole electrode and the connection pad, and the IC chip being flip-chip connected,
An IC module for a contact type IC card, wherein the direction in which the contact conductor surfaces C1, C2, C3 are arranged and the direction in which the connection terminals of the IC chip are arranged are perpendicular to each other.   A planar coil-shaped antenna pattern is provided on the other surface so as to surround the IC chip, and one end of the antenna pattern is connected to a predetermined connection pad via a first wiring pattern, and the other end of the antenna pattern is , A first through-hole electrode, and a conductor surface different from the C1 to C7 provided on one surface through the first through-hole, and the conductor surface further includes a second through-hole electrode and a second through-hole electrode. The IC module for a contact type IC card according to claim 1, wherein the IC module is connected to a connection pad through a second wiring pattern.   3. The contact IC card IC module according to claim 1, wherein the IC chip, the through-hole electrode, the connection pad, and the wiring pattern are covered with a sealing resin.   4. The contact IC card IC according to claim 2, wherein a line width of the first and second wiring patterns connecting the antenna pattern and the connection pad is wider than a line width of the antenna pattern. module.