JPH01165495A - Ic card and ic module for ic card - Google Patents

Abstract

PURPOSE: To enhance the reliability by forming a resist layer having a roughened surface on the surface of a circuit pattern layer at the boundary where the circuit pattern layer abuts on the resin molded part of an IC module board thereby preventing tailing or malfunction of the IC module. CONSTITUTION: Terminals 2 for external connection and a circuit pattern layer 3 are formed on the opposite sides of an IC module board 1 made of a material excellent in flexibility and strength. A resist layer 5 is formed on the surface of the circuit pattern layer 3 and subjected to surface roughening thus obtaining a mat-like surface. Consequently, moisture can be prevented from intruding from the boundary between a molded part and the circuit pattern layer 3 and adhesion to the basic material of the IC card can be enhanced even it the resist layer 5 contains silica, silicon oil, or the like. An IC chip 6 and the periphery of wiring part including the bonding part is then molded of a mold resin 7 to form an IC module 11 having a projecting 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, the IC modules used in the conventional IC cards described above usually have terminals for external connections formed on one side of the IC module substrate, and a circuit pattern layer with bonding pads on the other side. mounting an IC chip on the circuit pattern layer side of an IC module board formed by forming a terminal and a circuit pattern layer electrically connected to each other via a through hole, and molding the periphery of the IC chip portion with a resin. Consisted of.

In addition, in conventional IC modules, the purpose is to prevent moisture from penetrating through the adhesive interface between the circuit pattern layer and the resin molded portion formed on the surface of the circuit pattern layer and corroding the IC and wiring portions. In order to improve the moisture resistance, a layer of epoxy resin as a main component for protection is provided in advance on the entire surface of the circuit pattern layer.

However, in such IC modules, the resist layer is formed by silk screen printing, so inorganic fillers such as warping agents are added to the resist material to adjust the flow, or silicone is used as an antifoaming agent. It is necessary to add oil to make it suitable for screen printing. However, if a silica layer containing silica or silicone oil is formed on the surface of the circuit pattern layer, 1. °-, ゛, The contained components inhibit adhesion to the card base material, so when an IC module on which such a resist layer is formed is embedded and fixed in the card base material, sufficient adhesion is required. A new problem arises in that the IC module is more likely to fall off due to insufficient force.

[Summary of the invention]

The present invention has been 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 IC modules 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 at least the resin of the IC module substrate is formed on the surface of the circuit pattern layer. It is characterized in that a resist layer is formed at the boundary portion where the mold portion and the circuit pattern layer contact each other to heat the roughened surface.

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〕

The present invention will now be described in more detail with reference to the drawings.

First, the configuration of the IC module of the present invention 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 is made of, for example, glass epoxy resin, glass-BT resin, polyimide resin, polyester resin, etc. with a thickness of about 0.20 mm, and copper foil is laminated on both sides. First, prepare a through hole 4 (0,31111
1 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 circuit pattern layer 3 side, that is, on the surface of the circuit pattern layer 3 (excluding the bonding pad portion and the IC mounting portion). In this case, the material for the resist layer is preferably a solder resist (epoxy resin). The resist layer 5 can be formed by silk screen printing.

The present invention is characterized in that the surface of this resist layer 5 is roughened. This surface roughening treatment roughens the resist layer surface to 9. This is carried out by polishing to a depth (preferably 50 μm or less, more preferably 20 μm or less) that does not damage the underlying circuit pattern layer to make the surface of the resist layer matte (shiny). Specific methods for such surface roughening treatment include, for example, wrapping tape or sandpaper (about #400).
In addition to the polishing method, chemical polishing and other methods can be used.

Note that this resist layer may be provided on the entire surface of the circuit pattern layer as shown in the figure, but at least
It is sufficient if it is formed at the boundary portion where the resin molded portion of the module board and the circuit pattern layer are in contact with each other.

In this way, in the IC module of the present invention, since the resist layer with the roughened surface is formed, it is possible to effectively prevent moisture from entering from the boundary between the mold part and the circuit pattern layer. In addition, 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 IC module and the IC card base material in which the IC module is embedded. It is possible to increase the adhesive force between the two.

After configuring the IC module board as described above,
Necessary wiring is performed on the IC chip 6 using the die bond 1-.

In addition, as a wiring method between the IC chip and the printed circuit board, either the wire bond method or the lead bond method can be used, and the Guyang bond method may also be used. Figure 2 shows the lead bond method. This is a cross-sectional view when chips are mounted (7).The number of chips to be mounted is not limited to one chip, but it is also possible to mount multiple chips such as two chips. It is also possible to have a multilayer structure, for example, where 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 method of botting without a sealing frame is possible;
is preferred.

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

In the case of this figure, a roughened resist layer 5 is formed on almost the entire surface of the circuit pattern layer. In the case of the example shown in FIG. 4, the resin mold part 7 is molded using the transfer molding method.
This is a modification example of the case where the resist layer 5 is formed, and in this case, a vent path 40 for venting air during transfer molding is provided in the resist layer 5. Such a notch 40 is
This serves as a vent for air during transfer molding, and is advantageous in preventing voids and bubbles from forming in the mold part.

FIG. 5 shows another preferred embodiment of the IC module of the present invention. In this case, in order to reduce the thickness of the IC module, the IC chip mounting area is counter-bored using an end mill, router, etc. A concave portion is formed by processing and an IC chip is mounted in this concave portion.

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 four parts 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. When applied to the IC module through a material, the thickness of the extended part (flange part) of the IC module board is thinner than that of the molded part, so the flexibility of the collar part is higher than that of the molded part. It is absorbed by the flange portion and can reduce stress concentration on the IC chip and 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 explained.

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 explained.

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 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), sheets 21a and 21b having openings that fit into an IC module and a sheet 21c having no openings 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 recess. Further, 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 fourth part 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 fourth part when the IC module is buried in a later process, or if 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 of cutting the four parts for embedding the IC module into a predetermined shape using an end mill, drill, other engraving machine, etc. at predetermined positions.

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 four parts formed on the card base material are as follows:
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 surface of the first recess formed in the card base material 20 as shown in the figure, and the IC module 11 is inserted into the hot stand bar 31. By locally heat pressing only the surface of the terminal 2 (for example, 100 to 170°C, 5 to 15 kg/cj, 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, when a normal adhesive is used, room temperature suppression 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 space 32 formed in the card base material can be selected to an optimum value by considering the size of the IC module and the curvature of the card. It is preferable to provide a gap of about 50 to 100 μm. This gap provides play when the card is bent, so that the stress at the boundary between the IC module and the card base material can be reduced.

In the above example, the case where the space 32 is provided at the bottom of the second recess has been 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-rigid state, the stress applied to the IC module through the card base material when the card is bent is effectively reduced, and the IC The module may fall off or 134 (M
can be prevented.

In addition, in the above-mentioned example, the IC module can be buried by room temperature suppression 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, so that the card has good flexibility and followability against bending. Especially excellent.

Furthermore, since the IC module of the present invention is provided with a resist layer with a roughened surface, it prevents moisture from entering the IC chip part and also improves adhesiveness with the card base material in which it is embedded. It is excellent.

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, and problems such as folding or cracking at the boundary between the card base material and the IC module, which have conventionally been a problem due to warping, and falling of the IC module can be solved.

[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, and FIGS. 3 and 4 are plan views of IC modules of the present invention. 6 to 8 are cross-sectional views showing the manufacturing process of the IC card of the present invention. ]...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-Yuzu 100 engravings (No changes to the contents 7 Figure 2 Figure 3 d'l Figure 4 Figure 8 Figure 9 Figure 10 Procedural amendment document February G, 1985) 1 Indication of the case 1988 Patent Application No. 324496 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

Claims (4)

[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 a circuit pattern layer side of a module board and only the periphery of the IC chip is molded with resin, wherein at least the resin of the IC module board is on the surface of the circuit pattern layer. At the boundary part where the mold part and the circuit pattern layer contact,
An IC module for an IC card, characterized in that a resist layer having a roughened surface is formed. 2. I according to claim 1, wherein the surface of the resist layer is a fine matte surface with a surface roughness of 50 μm or less.
IC module for C card. 3. 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 a circuit pattern layer side of a module board and only the periphery of the IC chip is molded with resin, wherein at least the resin of the IC module board is on the surface of the circuit pattern layer. At the boundary part where the mold part and the circuit pattern layer contact,
An IC card characterized in that an IC module formed with a resist layer having a roughened surface is embedded in an IC card base material. 4. The IC card according to claim 3, 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.