JPH0930170A - Ic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a physical fault from generating in an IC module part and thereby, reduce the fault rate by forming a first and a second recessed part in a card base and at the same time, providing a notch, in parallel with the outer periphery of a terminal substrate, on the extended line of the peripheral part of the second recessed part within the range of the first recessed part. SOLUTION: Recessed parts 1, 2 are formed on a card base and at the same time, a # shaped stress relaxation groove 3 is formed on the outer periphery of the recessed part 2. That is, a notch is formed by cutting, etc. Further, an IC module 7 including a resilient terminal substrate which shows a larger amount of deflection than the card substrate to a load, an outer connection terminal mounted on one of the surfaces of the terminal substrate 4 td an IC chip and a resin mold part 6 for sealing the IC chip, mounted on the other surface of the terminal substrate 4, is stored in the recessed part 2. In addition, the terminal substrate 4 is adhesively fixed in the recessed part 1. Thus, the IC card is deflected, and a stress is absorbed by the part of the stress relaxation groove 3, even if the stress is applied to the IC module 7. Consequently, the IC module is prevented from being broken down.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prevents a physical failure of an IC module, such as an IC chip crack, which is a main cause of a field failure, and aims to reduce the failure rate. Regarding

[0002]

2. Description of the Related Art Since an IC card having a built-in CPU has a high level of security, it can be expected to be used in various fields, and has attracted attention as a new information recording medium, especially as an information recording medium replacing a magnetic card. , Gradually becoming popular.

[0003] An IC card is generally a COB (Chip).
on-board) IC module is mounted, and each terminal of the IC module and the contact part of the R / W (reader / writer) are brought into contact and electrically connected to each other to connect the I / O line. After being formed, information is read and written through the I / O line.

However, in the IC card equipped with this IC module, the IC card itself is thin and is made of a base material such as polyvinyl chloride.
The bending of the card occurs, but this bending of the IC card causes a physical failure of the IC module, which has been a problem. In particular, the main cause of physical failure is IC
This is called chip crack, and when the IC card is bent, the IC module cannot cope with the external stress and breaks (cracks) at the boundaries between terminals.
Is generated. In addition, there are physical failures due to wire breakage and cracks in the sealing resin.

Some conventional COB type IC cards are also intended to prevent chip cracks when the card is bent, and a specific patent is JP-A-2-80299. (FIG. 5) In FIG. 5, when the IC card is bent, the stress concentration point A
Although the IC module is stressed at the portion, the bending stress is relaxed by providing the notch (stress relaxation groove) 36 in the card base material 30, and it is possible to prevent the stress from being concentrated on the IC chip (semiconductor element). On the other hand, as shown in FIG.
In the module (COT), since the terminal board is more flexible than the card base body against the load, the point of stress concentration when the card is bent is point B. Therefore, stress cannot be effectively relieved even if it is provided in the conventional notch (stress relaxation groove) 36 as shown in FIG.

[0006]

On the other hand, in recent years, an application system that uses an IC card for financial approval such as electronic money and electronic bill has been considered promising. High reliability is required for the IC card in the system. I
Investigating failures in the C card field shows that about 80% are physical failures such as IC chip cracks and wire breaks.

The IC module used for such an IC card has a conventional COB in order to support mass production.
As compared with the strip-shaped hard type printed circuit board as described above, a type capable of continuous processing using a reel-shaped flexible substrate such as COT (Chip On Tape) is advantageous. In the present invention, an IC module using such a flexible substrate excellent in mass productivity is used,
IC for card bending, which is the main cause of field failure
An object of the present invention is to provide a card structure capable of preventing a physical failure of an IC module part such as a chip crack and reducing a failure rate.

The present inventor has completed the present invention by paying attention to the following points. (1) An IC module (COT) using a reel-shaped flexible substrate can be continuously processed and is excellent in mass productivity. (2) Such a COT is a conventional hard type CO using a conventional BT resin and a glass epoxy two-layer substrate.
Unlike B, it is easy to bend because the board part is flexible.
As described above, in the conventional method of providing the stress relaxation groove on the outermost periphery, the effect of the groove is small because the stress concentration positions are different. (3) In addition, since the COT used in the present application is a single-layer board, no through hole is required, and there is no concern that the adhesive may stick out from the through hole when it is bonded to the card base. Is unnecessary, and it is not necessary to provide a groove on the outermost periphery. (4) Since the area of the terminal board is small in a COT having six external connection terminals, it is difficult to secure an effective bonding area between the terminal board and the card base concave portion when the stress relaxation groove is provided on the outermost circumference. . From the above points, in the present invention, the # -shaped stress relaxation groove is formed in parallel with the outer periphery of the terminal substrate on the outer periphery of the mold housing portion where the stress is concentrated by COT when the card is bent. The forming method is a method such as cutting such as routing, forming such as injection, pressing with a punching blade, and the like.
A notch of about 3 to 2 mm is formed. If the width is 0.3 mm or less, the stress relaxation effect is small and it is 2 mm.
If it becomes the above, the adhesive strength of COT will fall from the reduction of an adhesion area. The depth of the notch may be greater than or equal to the first concave portion and less than or equal to the second concave portion, but the test result is 0.45 to 0.55 m.
The depth of m is suitable for the effect and the appearance of the back surface of the card. 0.
When it is 45 mm or less, the stress relaxation effect is small and 0.55.
If it is not less than mm, cracks on the back surface are likely to occur, which is not suitable in terms of the appearance of the card.

[0009]

In order to achieve the above-mentioned object (problem), the highly reliable IC card of the present invention has the following four features.
It consists of two inventions. That is, (Claim 1) A flexible terminal board that exhibits a greater amount of deflection than a card base body with respect to a load, external connection terminals provided on one surface of the terminal board, and I provided on the other surface.
An IC module having a C chip and a resin mold portion for encapsulating the IC chip, and a card base having a recess for mounting the IC module are provided, and the recess of the card base is used for bonding and fixing the terminal board. A first recess having a shallow plane and a second recess which is provided inside the first recess and is deeper than the first recess which is housed so as not to contact the resin mold portion, and within the range of the first recess, An IC card, characterized in that a notch is provided in parallel with the outer periphery of the terminal board on an extension of the outer periphery of the two recesses. (Claim 2) The IC card according to claim 1, wherein the planar shape of the cutout portion is a # shape. (Claim 3) The IC card according to claim 1 or 2, wherein a planar shape of a tip end portion of the cutout portion in contact with the outer periphery of the first recess is an arc shape. (Claim 4) The resin mold part has a sealing frame, claim 1, claim 2 or claim 3 characterized in that
2. The IC card according to 1. It is.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Polyvinyl chloride, polystyrene, polycarbonate, polyester, ABS, alloys of these resins, and the like are used as the card substrate.

A flexible terminal board (base material) that exhibits a greater flexure than a card base with respect to a load is, for example, as shown in FIG.
In the above, as the base material (terminal substrate) 210, a flexible 100 μm thick glass epoxy was used. This is a flexible one having a larger amount of deflection than polyvinyl chloride which is a usual IC card substrate. Other than glass epoxy, polyimide, polyester, paper phenol, BT resin or the like may be used as a base material. The thickness of the base material (terminal board) 210 is preferably 30 to 120 μm including the plating in order to obtain a larger amount of deflection with respect to the load than the card base body. From the viewpoint of cushioning properties against the pressure from the terminal portion, it is preferable to make the thickness of the base material as large as possible.

Within the range of the first concave portion, the deeper second concave portion provided inside the first concave portion and accommodating the resin mold portion, and the first concave portion, on the extension line of the outer peripheral portion of the second concave portion, the terminal board is provided. A notch with a width of 0.3 to 2 mm can be formed by cutting such as routing, molding such as injection, pressing with a punching blade, and the like. Can be formed.

When the IC card is deflected and stress is applied to the IC module, the external terminal board, which is more flexible than the card base, is not stressed, and the portion where the outer periphery of the resin mold portion contacts the terminal board [FIG. Since the stress is concentrated on B) in (1), the IC module can be prevented from being broken by absorbing the stress in the stress relaxation groove portion provided at the stress concentration position of the adhesion portion with the card base. The decrease in the adhesive strength due to the provision of the stress relaxation groove can secure a sufficient adhesive strength in spite of the decrease in the adhesive area because the module outer periphery and the corner effective portion for adhesion can be secured. In addition, since the terminal board at the bonded portion is flexible and the stress relaxation groove is provided on the outer periphery of the mold housing, sufficient clearance can be secured. Therefore, the resin mold can be applied against the pressing force (point pressure) from the external terminal surface. Since the bottom surface of the portion easily contacts the bottom surface (second recess) of the storage portion, the resistance is strong and the durability is improved. (It is possible to prevent the drop of point pressure strength due to carding.)

[0014]

Embodiments will be described in detail with reference to the drawings. FIG. 1 is a schematic sectional view of a bent state of the IC card of the present invention. FIG. 2 is a diagram showing an IC module used in the present invention. 2B is a sectional view of an IC module for an IC card according to the first embodiment of the present invention, and FIG. 2A is a plan view thereof. Note that FIG. 2B shows A1-A of FIG.
It is sectional drawing in 2. In FIG. 2, 200 is an IC module, 210 is a base material (terminal substrate), 220 is an IC chip, 230 is a sealing resin, 240 is a sealing frame, 250 is a terminal portion, 251 is a terminal, 252 is an insulating groove, 280. Is a wire. FIG. 3 is a plan view of the card substrate of FIG. 1 seen from the recess side.

Example 1 Manufacture of IC Module In FIG. 2, as the base material (terminal substrate) 210, a flexible 100 μm thick glass epoxy was used. This is more flexible and flexible than polyvinyl chloride, which is an ordinary IC card substrate (substrate). Other than glass epoxy, polyimide, polyester, paper phenol, BT resin or the like may be used as a base material.
The thickness of the base material 210 is 30 to 120 μm including plating.
m is desirable. It is preferable that the thickness of the base material is as large as possible in terms of cushioning properties against the pressure from the terminal portion. When using polyimide as the base material, there is no choice but to use multiple layers from the viewpoint of increasing the thickness, but in this case, the copper foil is directly coated with polyimide without using an adhesive, or a thermoplastic resin is used for bonding between layers. There is one using a polyimide made in Japan. In any case, the peel strength between layers is required to be larger than the adhesive strength between the sealing resin and the substrate, and the strength is required to be 2 kg or more. Plate-making a copper foil laminated on the base material (terminal board) 210,
By etching, a wiring portion, a terminal portion, and the like are provided on the front and back of the flexible base material 210. As the copper foil, rolled copper foil,
It is also possible to use any of the electrolytic copper foils. Electrolytic copper foil is suitable in terms of adhesion to the substrate 210 and cost, but rolled copper foil is suitable in terms of flexibility. Terminal 25
Hard plating, soft gold plating, and silver plating can all be used for plating No. 1, but from the viewpoint of reliability, hard plating is suitable, and from the viewpoint of wear resistance, a thickness of 1 μm or more is preferable. The encapsulating resin 230 is preferably an encapsulating resin having higher strength and lower deformability than the IC chip (semiconductor element) 220 in terms of protecting the IC chip (semiconductor element) 220. In practice, the flexural modulus of JIS K6911 1
400 Kg / mm ² or more, bending fracture strength 11 Kg / mm
^As long as it has a high strength and low deformability of ² or more, it is effective from the viewpoint of preventing IC chip breakage, and it is preferable that the amount of deflection at break is 1.3 or less. Such a high-strength, low-deformability resin has a strength higher than that of a conventional transfer molding resin. However, in this embodiment, the crosslinking density of the epoxy resin is different from that of the epoxy sealing resin which is liquid at room temperature. Was improved and the shape of the filler (filler) was changed from spherical to flake, whereby a sealing resin 230 having a desired strength after resin sealing was obtained. As a method for sealing the epoxy sealing resin which is liquid at room temperature, in addition to the generally used potting method and printing method, an injection method of a liquid sealing resin can be used. IC card I
In the production of the C module, a liquid sealing resin injection method was used. As the sealing frame 240, the sealing resin 230
Of high strength and low deformation, the deformation of the IC card when mounted on the IC card and the IC
The sealing resin 230 can be protected against the case where stress is directly applied to the external terminal surface of the module. In the present invention, glass epoxy is used. The finer the diameter of the glass cloth, the better the strength, so the strength was adjusted with this. Specifically, as a sealing frame 240 made of glass epoxy, flexural modulus 1600 kg / mm ² of JIS K6911, bending fracture strength 13 kg / mm ²
The above high strength and low deformability was used. In the case of the present embodiment, the IC chip (semiconductor element) 220 is mounted on the surface of the base material 210 on which only one side of the terminal surface side is wired and not on the side of the terminal section 250, and the electrode pads (shown in the figure) No.) and the terminal 251 are directly electrically connected with the wire 280, and the sealing frame 240 for reinforcing the sealing resin 230 is provided. In the case of the present embodiment, it is apparent that the conventional IC module is different from the sealing frame 24.
Except for the fact that 0 is provided, the rest is almost the same, but chip cracks and sealing resin Cracks are less likely to occur.

Manufacture of Card Substrate A card substrate of a polyvinyl chloride sheet is provided with first and second recesses as shown in FIGS. 1 and 3. Next, a # -shaped stress relaxation groove is formed on the outer periphery of the mold storage portion of the card in parallel with the outer periphery of the terminal substrate. The forming method is a method such as cutting such as routing, forming such as injection, and pressing with a punching blade, and the width is 0.3 to 2 mm.
It forms a notch of a certain degree. If the width is 0.3 mm or less, the stress relaxation effect is small, and if the width is 2 mm or more, the effective bonding area is decreased and the COT bonding strength is reduced. The depth of the notch may be greater than or equal to the first concave portion and less than or equal to the second concave portion, but as a result of the test, a depth of 0.45 to 0.55 mm is effective and suitable from the viewpoint of the appearance of the back surface of the card. 0.45m
If it is m or less, the stress relaxation effect is small, and if it is 0.55 mm or more, surface cracking is likely to occur, which is also unsuitable from the viewpoint of card appearance.

An IC module made by the manufacture and evaluation of an IC card was mounted on a card base made of and used as an IC card.
The physical failure of the IC module caused by the bending of the IC card, which was observed in the card, could be reduced. In particular, it was confirmed that IC chip cracking was remarkably reduced in actual use. Separately, the IC card actually equipped with the IC module of Example 1 was bent to such an extent that the card was irreversibly deformed as shown in FIG. 1, but no physical failure of the IC module was observed. . Further, when the central portion of the external terminal was pressed by a hard ball having a diameter of 10 mm and the load at which the IC failed was measured, it was 20 kg or more for Example 1. On the other hand, Japanese Unexamined Patent Publication No. 2-8 described in the prior art
No. 0299, which corresponds to Example 1 (FIGS. 5 and 6), a “substrate 12, an IC chip 17 provided on this substrate, and I”.
An IC module 11 having a resin mold portion 19 for encapsulating the C chip 17 and a card base 30 having a recess 35 for mounting the IC module 11 are provided. The recess of the card base 30 covers the substrate 12. A relatively shallow plane to be bonded and fixed has a substantially rectangular first concave portion 35a, and a relatively shallow plane provided inside the first concave portion for receiving the resin mold portion 19 has a substantially rectangular second concave portion 35b,
An IC provided with a peripheral cutout 36 along the peripheral edge of the first recess, and a connecting cutout that connects the second recess and the peripheral cutout to the first recess and is parallel to the peripheral cutout. Card 10 ", that is, grooved CO
For the B type IC card, it was about 6 kg.

[0018]

According to the IC card of the present invention, the operation of the IC is good without causing any physical failure even if the IC card is subjected to a large deflection that causes irreversible deformation. IC is pressed by pressing the center of the external terminal with a steel ball with a diameter of 10 mm.
When the load leading to malfunction was measured, the card of the present invention showed a strength three times or more that of the conventional card (COB type). (The breaking strength of the card of the present invention is 20 kg or more, whereas that of the conventional card is 6 kg.)

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a bent state of an IC card of the present invention.

FIG. 2 is a diagram showing an IC module used in the present invention. FIG. 2B shows the I for IC card of the first embodiment of the present invention.
2A is a sectional view of the C module, and FIG. Note that FIG. 2B is a cross-sectional view taken along line A1-A2 of FIG.

FIG. 3 is a plan view of the card substrate of FIG. 1 viewed from the side of a recess. Flexible Single Layer Substrate COT of Card Base of the Present Invention
It is a top view which shows the groove cutting counterbore shape.

FIG. 4 is a plan view showing a grooved counterbore shape for a flexible single-layer substrate COT of a card substrate (telephone card type) of the present invention.

FIG. 5 is a side sectional view for explaining a conventional IC card.

FIG. 6 is a plan view showing a concave portion of a card substrate for explaining a conventional IC card.

[Explanation of symbols]

 1 1st recessed part (adhesion area) 2 2nd recessed part (mold part storage part) 3 Stress relaxation groove 4 External terminal board 5 Adhesive part 6 Resin mold 7 IC module (COT module) 10 IC card 11 IC module 12 Board 13 External terminal 13a Insulation groove 14 Through hole 15 Pattern layer 16 Protective resist layer 17 IC chip 18 Bonding wire 19 Resin mold part 20 Die bonding adhesive 30 Card base material 34 Adhesive 35 Recess 35a First recess 35b Second recess 36 Notch 200 IC module 210 Base Material (Terminal Substrate) 220 IC Chip 230 Sealing Resin 240 Sealing Frame 250 Terminal Part 251 Terminal 252 Insulation Groove 280 Wire

Claims (4)

[Claims] 1. A flexible terminal board that exhibits a greater amount of deflection than a card base body under load, external connection terminals provided on one surface of the terminal board, and I provided on the other surface.
An IC module having a C chip and a resin mold portion for encapsulating the IC chip, and a card base having a recess for mounting the IC module are provided, and the recess of the card base is used for bonding and fixing the terminal board. A first recess having a shallow plane and a second recess which is provided inside the first recess and is deeper than the first recess which is housed so as not to contact the resin mold portion, and within the range of the first recess, An IC card, characterized in that a notch is provided in parallel with the outer periphery of the terminal board on an extension of the outer periphery of the two recesses. 2. The IC card according to claim 1, wherein the notch portion has a planar shape of # shape. 3. The IC card according to claim 1, wherein a planar shape of a tip end portion of the cutout portion in contact with the outer periphery of the first recess is an arc shape. 4. The resin mold portion has a sealing frame, claim 1, claim 2 or claim 3.
2. The IC card according to 1.