JPH01114494A - Ic card and ic module for ic card - Google Patents

Abstract

PURPOSE: To prevent falling off or malfunction of IC module by mounting an IC chip on the face of a circuit pattern layer on IC module substrate which has connected terminals and the circuit pattern layer via through-holes and by resin-molding only the periphery of the IC chip. CONSTITUTION: Formed on a substrate 1 are terminals 2 on the front face and a circuit pattern layer 3 on the back, respectively. Then at a prescribed portion on the circuit pattern layer 3, namely at the boundary portion where a resin mold part 7 and the circuit pattern layer 3 come into contact, a resist layer 5 is formed only at the periphery of the resin mold part 7. This effectively prevents water from infiltrating from the boundary of the mold part 7 and the circuit pattern layer 3. After mounting an IC chip 6 on this IC module substrate, resin molding is conducted at the periphery of wired region containing the IC chip 6 and bonding portion. Accordingly, this IC module 11 is superior in flexibility and obedience against bending of card because only the resin- molded portion forms rigid area and the whole has convex cross section.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an IC card and an IC module to be installed or built into the IC card.

[Background of the invention]

In recent years, cards called chip cards, memory cards, microcomputer cards, or electronic cards (hereinafter referred to simply as IC chips) equipped with IC chips such as microcomputers and memories have become popular.
A variety of research is underway regarding cards.

Compared to conventional magnetic cards, such IC cards have
Because of their large storage capacity, banks are considering using them to store the history of deposits and savings in place of passbooks, and credit cards are considering storing the history of transactions such as shopping.

Such an IC card usually includes a card-shaped center core in which an IC module is embedded, and an oversheet laminated on both or one side of the center core to increase the mechanical strength of the card.

As a conventional general IC card, there is also known one obtained by modularizing all electrical elements including an IC chip and a circuit pattern, and embedding this IC module in a card base material. For example, the conventional IC
The method for embedding the module in the card base material is to create a recess the size of an IC module in the card base material, place the IC module in the recess, and then pressurize it under heat to embed the IC module in the card base material. The most common method is adhesive fixation.

However, in the conventional IC cards as described above, the buried IC module is usually made of a material with low elasticity, so when the card is bent, it may break at the boundary between the IC module and the card base material. There are problems that cracks may occur or the IC module may fall off from the card.

Incidentally, the IC module used in the conventional IC card described above usually has terminals for external connection formed on one side of the IC module substrate, and a circuit pattern layer having bonding pads on the other side. Mounting an IC chip on the circuit pattern layer side of an IC module board formed by forming an IC module board in which the terminal and the circuit pattern layer are electrically connected via a through hole, and molding the periphery of the IC chip part with a resin. Consisted of.

In addition, in conventional IC modules, the above-mentioned method is used to prevent moisture from penetrating through the adhesive interface between the circuit pattern layer and the resin molded portion formed on the surface thereof and corroding the IC and the wiring portion. A protective resist layer containing epoxy resin as a main component is previously provided on the entire surface of the circuit pattern layer to improve moisture resistance. However, in such an IC module, since the resist layer is formed by silk screen printing,
It is necessary to add an inorganic filler such as silica to the resist material to adjust the flow, or to add silicone oil as an antifoaming agent to impart suitability for screen printing. However, if a resist layer containing such silica or silicone oil is formed on the surface of the circuit pattern layer, these components will inhibit the adhesion with the card base material. When a formed IC module is embedded and fixed in a card base material, sufficient adhesive force cannot be obtained, which causes a new problem that the IC module is more likely to fall off.

[Summary of the invention]

The present invention was made in view of the above-mentioned problems, and provides an IC card with improved reliability by preventing the IC module from falling off or malfunctioning, and an IC module to be embedded in the IC card. is intended to provide.

In order to achieve the above-mentioned object, an IC module according to the present invention has terminals for external connection formed on one side of an IC module substrate, and a circuit pattern layer having bonding pads formed on the other side. The terminal and the circuit pattern layer are an IC module having a convex cross section in which an IC chip is mounted and only the periphery of the IC chip is molded with resin, and the portion where the resin molded portion of the IC module substrate contacts the circuit pattern layer. It is characterized in that a resist layer is formed only on the peripheral edge of the resin molded part.

Further, the IC card according to the present invention is characterized in that the above-mentioned IC module is embedded in an IC card base material.

In addition, in a preferred embodiment of the IC card of the present invention,
At least a portion of the IC module may be embedded in the IC card base material such that it is not fixed to the IC card base material.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

First, the structure of the IC module will be explained based on the manufacturing method.

As shown in the cross-sectional view of FIG. 1, an IC module substrate 1 made of a material with excellent flexibility and strength is prepared with external connection terminals 2 and circuit pattern layers 3 formed on both sides. In this case, the IC module substrate 1 has a thickness of, for example, 0. A glass epoxy resin, glass-BT resin, polyimide resin, polyester resin, etc. of about 2On+Ia is used, and copper foil is laminated on both sides of the resin. Through hole 4 (0.3m
(about m diameter). Next, this through hole 4 is made conductive by applying electroless copper plating, electrolytic copper plating, or the like. Next, resist films corresponding to the desired external terminal pattern and circuit pattern are pasted on both sides of the substrate 1, exposed to light in a predetermined pattern, developed, etched to form the desired pattern, and then the resist is removed. A terminal 2 is formed on the front side of the substrate 1, and a circuit pattern layer 3 is formed on the back side.

Next, Ni plating is applied to both sides of the IC module board obtained as described above, if necessary, and further, hard gold plating is applied to the terminal side and soft gold plating is applied to the circuit pattern layer side (not shown). .

Next, a resist layer 5 is formed at a predetermined position on the side of the circuit pattern layer 3, that is, only at a boundary portion where a resin mold portion and a circuit pattern layer, which will be described later, are in contact with each other, and only at the peripheral edge of the resin mold portion. In this case, the material for the resist layer is
A solder resist (epoxy resin type) is used, and an epoxy type thermosetting resin, an ultraviolet curable resin such as an acrylic modified epoxy type resin, etc. are used, and the resist layer 5 can be formed by silk screen printing. In this way, in the IC module of the present invention, since the resist layer is formed only on the peripheral edge of the resin molded part, it is possible to effectively prevent moisture from entering from the boundary between the molded part and the circuit pattern layer. In addition, since there is no resist layer formed in areas other than the boundary, it is compatible with the IC card base material in which the IC module is embedded even if the resist layer contains components that inhibit adhesion such as silica or silicone oil. There is no need to worry about reducing the adhesion between the two.

After configuring the IC module board as described above,
The IC chip 6 is mounted on the bonding pad and die-bonded to perform necessary wiring. Note that as a method for mounting the IC chip, either a wire bonding method or a lead bonding method may be employed, and furthermore, a Guyang bonding method may be used.

FIG. 2 is a cross-sectional view of the chip mounted by the lead bond method. Note that the number of chips to be mounted is not limited to one chip, but it is also possible to mount a plurality of chips such as two chips. Further, the layer structure of the IC module board can also be a multilayer structure if, for example, three-dimensional wiring is required.

Next, after mounting the IC chip as described above,
An IC module 11 having a convex cross section is formed by resin-molding the C chip 6 and the wiring section including the bonding section with a molding resin 7. In this case, the molding method includes (1) a transfer molding method, (2) a sealing frame 90 in the mold part as shown in FIG.
(in this case, the sealing frame 90 may be left as is), and
As shown in FIG. 10, any of the methods of potting without a sealing frame is possible, but method (2) is preferable in terms of the hardness, reliability, and dimensional and shape stability of the mold part.

FIG. 3 is a plan view of the IC module obtained as described above, viewed from the circuit pattern layer side.

As described above, in the IC module of the present invention, the resist layer 5 for protection is formed only on the peripheral edge of the resin mold section 7. FIG. 4 shows a modification in which the resin molded portion 7 is formed by the transfer molding method, and in this case, a notch 40 is provided in the resist layer 5 for venting air during transfer molding. Such a cutout 40 serves as a passageway for air during transfer molding, and is advantageous in preventing voids and bubbles from forming in the mold portion.

FIG. 5 shows another preferred embodiment of the IC module of the present invention. In the second case, an end mill, router, etc. is used in the mounting part of the IC chip in order to reduce the thickness of the IC module. A recess is formed by counterboring, and an IC chip is mounted in the recess.

The IC module of the present invention obtained as described above is
Since its cross section has a convex shape, when it is inserted and fixed into the recess of the IC card base material, a sufficient adhesive area between the IC card and the card base material can be secured, and the bending stress is reduced to the card base material. When applied to an IC module through a It is possible to reduce stress concentration on the IC chip and the wiring portion. Generally, the larger the area of the flange (the smaller the area ratio of the molded part), the higher the flexibility of the flange, which makes it possible to prevent stress concentration on the IC chip.

Further, in the IC module of the present invention, the resin mold portion may be formed so as to be unevenly distributed in a specific direction with respect to the IC module substrate. With this configuration, the resin mold part can be placed in a direction away from the stress concentration point (card center) when bending the card,
The stress applied to the mold part can be further reduced.

Note that the thickness of the resin molded portion needs to be equal to or smaller than the depth of the second and fourth portions of the card base material, which will be described later. Note that, in order to further improve the flexibility and bending followability of the IC module, it is preferable that the IC module substrate be as thin as possible.

Next, a method for obtaining an IC card by embedding the above-mentioned IC module in a card base material will be described.

The method for manufacturing the IC card of the present invention includes: (1) embedding the IC module and forming the card base material at the same time using a press lamination method; A method of cutting the recess with a carving machine, etc., and burying and fixing the IC module in the formed recess. ■ A dummy module with the same shape as the IC module is buried at the same time using the press lamination method, and this is removed to form a recess for embedding. A method for embedding and fixing an IC module in a card base material, and ■
There is a method in which a card base material and four embedding parts are simultaneously formed by an injection method, and an IC module is embedded and fixed therein.

In the present invention, any of the above methods can be adopted. Hereinafter, an example of manufacturing by the method (2) above will be described.

The IC card of the present invention is characterized in that at least a portion of the above-mentioned IC module is embedded in an IC card base material such that it is not fixed to the IC card base material. In the present invention, the non-adhesive state includes not only the case where the IC module and the IC card base material are in contact with each other in a non-adhesive state, but also the case where a gap or space is formed between the IC module and the IC card base material.

First, as shown in FIG. 6(a), a sheet 21 a s 21 having an opening that fits into an IC module is prepared.
b s and a sheet 21c without an opening are prepared. In this case, the opening in the sheet 21a constitutes the first recess, while the opening in the sheet 21b constitutes the second fourth part. In this case, the sheet 21C becomes an oversheet on the back side of the card. Therefore, by constructing the sheet 21c from an opaque material, it is possible to prevent the IC module from appearing on the back side of the card, which is also excellent in that the design value of the card can be improved. Moreover, printing etc. can be freely applied to this sheet 21c.

Next, a dummy module 22 having the same shape as the IC module to be buried is laminated together with the sheet and press laminated (FIG. 6(b)).

The dummy module 22 is removed to obtain a card base material 20 in which a first recess 23a and a second recess 23b for embedding an IC module are formed, as shown in FIG. 6(C).

In this case, the depth of the second recess 23b is determined by whether a space will be created between the resin molded part of the IC module and the second recess when the IC module is buried in a later process, or whether there will be a contact state or non-contact state. It is important that the depth is such that it will fit properly.

As another processing method for obtaining such a card base material, for example, as shown in FIG. Then, as shown in FIG. 8(b), there is a method in which a recess for embedding the IC module is cut into a predetermined shape at a predetermined position using an end mill, drill, other engraving machine, or the like.

Furthermore, in addition to this, an injection method may also be used as appropriate. When using the injection method, ABS resin, polyester, polypropylene, styrene resin, polycarbonate, and mixtures thereof may be preferably used as the resin for forming the card base material. In addition, when a processing method other than the injection method is employed, vinyl chloride, acrylic, polycarbonate, polyester, vinyl chloride/vinyl acetate copolymer, etc. can be preferably used.

Note that the first and second recesses formed in the card base material are
In order to facilitate insertion of the IC module to be buried, it is desirable that it be equal to or slightly larger than the IC module (approximately 0.05 to 0.1 mm).

Further, in the above example, the card base material 20 is constituted by a laminate of a plurality of sheets, but of course, the card base material 20 can also be constituted by two base materials.

Next, as shown in FIG. 7(a), an adhesive layer 30 is provided on the bottom of the first recess formed in the card base material 20 as shown in the figure, the IC module 11 is inserted, and the hot stamper 31 is inserted. By locally hot pressing only the surface of the terminal 2 (for example, 100 to 170°C, 5 to 15 kg/aj, 5 seconds is sufficient), the IC module 11 is fixed in the card base material 20 and the IC Obtain a card (Figure 7(b)
)). In this case, the adhesive layer 30 can be formed of, for example, a double-sided adhesive tape with an acrylic adhesive coated on both sides of a nonwoven fabric, a room temperature curable urethane adhesive, an epoxy adhesive, or a cyanoacrylate adhesive.

In addition, in order to obtain a stronger adhesion force, for example, a polyester-based thermal adhesive sheet is preferably used.The above-mentioned thermal pressing with a hot stamper is necessary when such a thermal adhesive sheet is used. However, if a normal adhesive is used, room temperature pressing is also possible.

Furthermore, by adjusting the thickness of the adhesive layer,
Space 32 formed between the resin mold part and the second recessed part
The width can be adjusted as appropriate.

The optimum value for the space 32 formed in the card base material can be selected by considering the size of the IC module and the curvature of the card, but usually, in order to obtain a good stress canceling effect, it is necessary to It is preferable to provide a gap of about 100 μm. This gap allows for play when the card is bent, so that stress applied to the boundary between the IC module and the card base material can be reduced.

In the example described above, the case where the space 32 is provided at the bottom of the second recess is described, but the present invention is not limited to this embodiment, and the space 32 is provided at the bottom of the second recess. It is only necessary that at least a part of the side surface of the plate be in a non-fixed state. By keeping at least a portion of the space between the IC module and the IC card base material in such a non-adhesive state, the stress applied to the IC module through the card base material when the card is bent is effectively reduced, and the IC module is This can prevent falling off and damage.

Furthermore, in the above-mentioned example, the IC module can be embedded by room temperature pressing or local (terminal area only) and short-term thermal pressing, so damage to the IC module and thermal deformation of the entire card base material can be avoided. This can be prevented as much as possible.

〔Effect of the invention〕

In the IC module of the present invention, only the central part of the IC module is resin-molded, and only that part forms a rigid body part, and the whole has a convex cross section. It is excellent.

Furthermore, in the IC module of the present invention, since the resist layer is provided only on the peripheral edge of the resin molded part, the
It prevents moisture etc. from entering the C-chip part, and also has excellent adhesiveness to the card base material in which it is embedded.

Furthermore, in the IC card of the present invention, at least a portion of the space between the resin molded portion of the IC module and the card base material can be made non-adhesive, so that when the card is bent, the resin molded portion of the IC module may Such stress can be effectively reduced, thereby solving the conventional problems such as bending and cracking at the boundary between the card base material and the IC module, as well as the IC module falling off.

[Brief explanation of the drawing]

1, 2, 5, 9, and 10 are cross-sectional views of IC modules according to embodiments of the present invention. FIGS. 3 and 4 are plan views of the IC module of the present invention, and FIGS. 6 to 8 are cross-sectional views showing the manufacturing process of the IC card of the present invention, respectively. 1...IC module board, 2...terminal, 3...
Circuit pattern layer, 4... Through hole, 5... Resist layer, 6... IC chip, 7... Resin mold part. Applicant's agent: Sato - Yu figure 100, +, z - 2 "knees" 4 points 1 figure 2 figure 3 figure 4 figure 5 figure 7 figure 9 figure 1o figure Procedural amendment book form) % form % 1. Indication of the case Patent Application No. 271650 of 1988 2. Name of the invention IC card and IC module for IC card 3. Person making the amendment Relationship to the case Patent applicant (289) Dai Nippon Printing Co., Ltd. 4. Agent (zip code 100) December 24, 1980 (shipped on January 26, 1988) 6. Drawings subject to amendment 7. Contents of amendment Engraving of drawings (contents) (no change)

Claims (3)

[Claims] 1. Terminals for external connection are formed on one side of the IC module board, and a circuit pattern layer having bonding pads is formed on the other side, and the terminals and the circuit pattern layer are electrically connected via through holes. IC
An IC module having a convex cross section in which an IC chip is mounted on the circuit pattern layer side of a module substrate and only the periphery of the IC chip is molded with resin, the boundary where the resin molded part of the IC module substrate contacts the circuit pattern layer. 1. An IC module for an IC card, characterized in that a resist layer is formed only on the peripheral edge of the resin molded portion. 2. Terminals for external connection are formed on one side of the IC module board, and a circuit pattern layer having bonding pads is formed on the other side, and the terminals and the circuit pattern layer are electrically connected via through holes. IC
An IC module having a convex cross section in which an IC chip is mounted on the circuit pattern layer side of a module substrate and only the periphery of the IC chip is molded with resin, the boundary where the resin molded part of the IC module substrate contacts the circuit pattern layer. 1. An IC card, characterized in that an IC module is embedded in an IC card base material, and a resist layer is formed only on the peripheral edge of the resin molded part. 3. The IC card according to claim 2, wherein the IC module is embedded in an IC card base material such that at least a portion of the IC module is not fixed to the IC card base material.