JPH03112691A - Ic card substrate - Google Patents

Abstract

PURPOSE:To eliminate the occurrence of the bend of a card and to prevent a fatigue failure accident through external stress by providing a recess on the side of a face, where a projecting bend is generated by heating of an IC card substrate body, and by injecting a sealing resin having a heat shrinkage factor larger than that of the IC card substrate body into the recess and curing the resin. CONSTITUTION:An IC chip-mounting recess 2 is provided on the side of one surface of an IC card substrate 1 and at least one recess 8 is formed on the side of the other surface, i.e. on the side of a surface, where a projecting bend is generated, to form the substrate. Further, an IC chip 3 is mounted in the recess 2, connected with the IC card substrate 1 by a bonding wire 4 and sealed by a sealing resin, which differs as little as possible from the substrate 1 in heat shrinkage factor, a row of external connection terminals 6 is formed on the other surface side in the manner of connecting with the chip 3, and a sealing resin 5 having a heat shrinkage factor larger than that of the substrate 1 is injected into the recesses 8 and cured the. The substrate 1 in the vicinity of the recesses 8 is pulled by the shrinkage of the sealing resin 5 on curing to bend in the direction opposite to that of the bend at the time without the shrinkage of the resin so that the occurrence of the bend of the IC card can be eliminated.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention forms a recess for mounting an IC chip on one side of an IC card substrate, the IC chip is mounted in the recess, and a recess is formed on the other side of the IC card substrate. This invention relates to an IC card board formed by connecting an IC chip with an external connection terminal row for exchanging and processing necessary information with an external terminal device, and can particularly prevent the occurrence of warping due to heating. The present invention relates to an IC card board having the above structure.

(Prior Art) Magnetic recording media such as floppy disks and cassette tapes have traditionally been widely used as external storage devices for computers and computer-based electronic equipment. In order to achieve this, RAM
, card-shaped or package-shaped recording media equipped with semiconductor memories such as ROM have been used. on the other hand,
In the fields of credit cards, ID cards, bank cards, etc., microprocessors and RAM are used in card-like components to replace magnetic cards.

The so-called IC card, which is equipped with electronic circuits including semiconductor memory such as ROM, has a very large information storage capacity.
It has been developed because of its high security properties. This IC card is designed to exchange and process necessary information with an external terminal device via a limited number of external connection terminals.

Incidentally, recently, as this type of IC card, an IC card that has rigidity and has improved reliability such as IC chips and bonding wires against external stress such as bending stress has been proposed. It has been used for

That is, as shown in FIG.
An IC chip is mounted on one side of the C card board, and an array of external connection terminals for exchanging and processing necessary information with an external terminal device is formed on the other side. It is electrically connected to the IC card board with a bonding wire and is connected to the IC chip, and a pattern-printed label is pasted on the IC chip mounting surface side and the external connection terminal row forming surface except for the external connection terminal row portion. It is made up of clothes. This IC card has a so-called IC module designed to be roughly card-sized, and the rigidity of the glass fiber-reinforced epoxy resin plate or glass fiber-reinforced BT resin resin plate used for the IC card substrate, which is the constituent material of the IC module, is improved. It takes advantage of the fact that it is larger than that of a laminate of vinyl chloride sheets, which is a common card material.

(Problem to be solved by the invention) However, in order to make the card thickness as thin as possible while maintaining the reliability of the card, such an IC card is forced to have an asymmetrical structure in the thickness direction. Also, considering the number of C memories of the actual device, etc., the sealed area is the I of the IC card.
It is set only in the recess for mounting the C chip. On the other hand, if the IC card is left in a car exposed to direct sunlight, or set in a card reader inside the car, the IC card becomes warm. As a result, the IC module, which is a card constituent material, warps due to the difference in expansion/contraction ratio due to the asymmetric material composition described above, resulting in
C card is warped.

In addition, during the IC card manufacturing stage, heat is applied to the IC module in order to harden the sealing resin that seals the IC chip in the IC module mounting process. In addition, IC
Due to the difference in thermal shrinkage rate between the card substrate and the sealing resin, warping occurs in that portion. This not only deteriorates the appearance of the IC card, but also adversely affects its suitability for card leagues (terminals). Furthermore, permanent bending stress is applied to the IC chip and the bonding wire, which may lead to accidents such as fatigue failure.

The present invention was made to solve the above-mentioned problems, and it is possible to eliminate the occurrence of card warpage and to reliably prevent fatigue failure accidents due to external stress on IC chips, bonding wires, etc. The purpose of the present invention is to provide an IC card board with a good appearance and extremely high reliability.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, a recess for mounting an IC chip is formed on one side of the IC card board body, and the IC chip is mounted in the recess. , in an IC card board in which a row of external connection terminals for exchanging and processing necessary information with an external terminal device is connected to an IC chip on the other side, heating of the IC card board body is performed. A recess is provided on the surface side where convex warping occurs, and a sealing resin having a thermal shrinkage rate higher than that of the IC card substrate body is injected into the recess and hardened.

(Function) Therefore, in the IC card substrate of the present invention, the concave portion provided on the surface side where a convex warpage occurs due to heating of the IC card substrate body has a heat shrinkage rate greater than that of the IC card substrate body. By injecting and curing a sealing resin with a certain ratio, the IC card substrate near the recess is pulled by the shrinkage of the sealing resin when it cures, causing the IC module (IC card substrate) to warp in the opposite direction to the warpage without it. By bending (warping) the card, it is possible to ultimately suppress the occurrence of warping of the card.

(Example) First, the concept of the present invention will be described.

Looking at the amount of warpage caused by conventional IC cards left at high temperatures,
It depends on the amount of warpage as a so-called IC module. This is because the temperature range in which the card can be used is limited by the glass transition temperature of the sealing resin, etc. (In an atmosphere above the glass transition temperature, large strains are applied to the IC chip and especially the bonding wires, resulting in a decrease in reliability. is significant).

However, conventionally, the amount of deformation was large even at lower temperatures. For this reason, when the encapsulation resin is cured as an IC module (due to the properties of the encapsulation resin and its reliability against moisture, for example, a room temperature curing method is not used, and curing is performed at a high temperature), the IC module is flat. It would be good if it could be finished.

The amount of warpage in the IC chip sealing part can be kept relatively small by setting the difference in thermal shrinkage rate between the sealing resin and the IC card substrate as small as possible, and the area of the sealing part can be kept relatively small. Since the target is small, the distortion it causes to the entire card can be generally ignored. Therefore, this problem can be solved by eliminating the distortion (warp) caused by the asymmetry seen in the thickness direction of the IC card substrate layer structure. For example, if a warp occurs as shown in Figure 3, when applying heat to harden the sealing resin, apply force that causes the warp in the opposite direction, and even after returning to room temperature. By continuously maintaining this force, it is possible to eliminate the occurrence of warpage.

Therefore, in the present invention, in order to apply and maintain such force,
A concave portion is provided on the side where convex warping occurs due to heating of the IC card substrate body, and a sealing resin having a thermal shrinkage rate higher than that of the IC card substrate body is injected into the concave portion. By applying heat during curing of the sealing resin or during curing of the sealing resin, the warping force of the card caused by the recessed portion in which the IC chip is mounted is neutralized.

Hereinafter, an embodiment of the present invention based on the above concept will be described in detail with reference to the drawings.

FIG. 1(a) is a sectional view showing an example of the structure of an IC card board according to the present invention, and FIG. 1(b) is a plan view showing an example of the structure of the IC card board. In FIG. 1, a recess 2 for mounting an IC chip is provided on one side of an IC card board 1.
At least one recess 8 is formed on the other side, that is, the side where convex warpage occurs, and an IC chip 3 is mounted in the recess 2 for IC chip mounting, and this IC chip 3 is bonded. It is electrically connected to the IC card board 1 through the wire 4, sealed with a sealing resin that has the smallest possible difference in heat shrinkage rate from the IC card board 1, and further communicates necessary information with an external terminal device (not shown). An external connection terminal row 6 for exchanging and processing the IC chip 3
The concave portion 8 is filled with a sealing resin (having a heat shrinkage rate higher than that of the IC card substrate 1).
For example, epoxy resin, etc.) 5 is injected and hardened.

FIG. 2 is a cross-sectional configuration diagram showing an example of an IC card using the IC card board 1 of FIG. 1. FIG. In Figure 2, IC
An IC card is constructed by pasting labels 7A and 7B with desired designs printed on both sides of the card board 1, excluding the external connection terminal row 6, as shown.

Here, the external connection terminal row 6 is a ground terminal (GND)
, clock supply terminal (CLK), input/output data transmission terminal (Ilo), reset signal supply terminal (R3T), operating voltage supply terminal (Vcc), and write voltage supply terminal (V
pp).

In the IC card configured as described above, the concave portion 8 provided on the surface side where convex warpage occurs due to heating of the IC card substrate 1 is made to have a thermal contraction rate higher than that of the IC card substrate 1. Since the sealing resin 5 with the sealing resin 5 is injected and hardened, the IC card board 1 near the recess 8 is pulled due to contraction when the sealing resin 5 hardens, causing the IC card board to warp in the opposite direction to the warpage without it. bend (warp) 1
It turns out. Therefore, it is possible to finally eliminate the warpage of the IC module and the warpage of the IC card as in the conventional case. Furthermore, there is no need to make the single-layer structure of the IC card board symmetrical in the thickness direction in consideration of warpage, and the thickness of the IC card can be reduced, resulting in an IC card that is highly portable and easy to store. . Furthermore, the card has greater rigidity (the area where the sealing resin 5 is present is wider than before, so a much more rigid body can be obtained), and reliability against external stress such as bending stress is improved.

One, IC chip 3. Constant bending stress applied to the bonding wire 4 is eliminated, improving reliability. Furthermore, when using a method of applying heat when pasting the labels 7A and 7B, there is no need to consider warping of the card due to the heat, and a special cooling process and equipment are not required, improving productivity. Furthermore, when using the IC card, there are no problems such as poor contact (inability to communicate) or inability to insert/remove the terminal due to warping, and the IC card can be used with peace of mind.

As described above, in this embodiment, a recess 2 for mounting an IC chip is formed on one side of the IC card board 1, an IC chip 3 is mounted in the recess 2, and an external terminal device is mounted on the other side. In the IC card board 1 formed by connecting the IC chip 3 with an external connection terminal row 6 for exchanging and processing necessary information between the IC card board 1 and the A recess 8 is provided on the side where the IC card is generated, and a sealing resin 5 having a thermal shrinkage rate higher than that of the IC card substrate 1 is injected into the recess 8 and hardened.

Therefore, the following various effects can be obtained.

(a) A sealing resin 5 having a thermal shrinkage rate higher than that of the IC card substrate 1 is injected and hardened into the recess 8 provided on the side where a convex warp occurs due to heating of the IC card substrate 1. Therefore, the IC card substrate 1 near the recess 8 is pulled by the shrinkage of the sealing resin 5 when it hardens, and the IC card substrate 1 is bent in the opposite direction to the warpage without it (
Therefore, it is possible to eliminate the occurrence of warping of the IC card.

(b) Since there is no need to make the single-layer structure of the IC card board symmetrical in the thickness direction in consideration of warpage, the thickness of the IC card can be reduced, and portability and storage properties can be significantly improved. It becomes possible.

(c) The rigidity of the card is large (the area where the sealing resin 5 exists is wider than before, so a more rigid body can be obtained), and the reliability against external stress such as bending stress is improved. It becomes possible to improve.

(d) IC chip 3. Since constant bending stress applied to the bonding wire 4 is eliminated, reliability can be improved.

(e) When using a method of applying heat when pasting labels 7A and 7B, there is no need to consider the warping of the card due to the heat (this eliminates the need for special cooling processes and equipment, improving productivity) It becomes possible to do so.

(f) When using an IC card, it is possible to use the IC card with peace of mind because troubles such as poor contact (inability to communicate) or inability to insert/remove the terminal due to warping when using the terminal are eliminated.

Incidentally, in the above embodiment, a case was described in which an epoxy resin was used as the sealing resin, but the present invention is not limited to this, and any sealing resin may be used as long as it has a thermal shrinkage rate higher than that of the IC card substrate 1. .

(Effects of the Invention) As explained above, according to the present invention, a concave portion is provided on the side where a convex warpage occurs due to heating of the IC card substrate body, and the concave portion has a thermal shrinkage rate higher than that of the IC card substrate. By injecting and curing a sealing resin that has a heat shrinkage rate, it is possible to eliminate the occurrence of card warping and to reliably prevent fatigue failure accidents due to external stress on IC chips and bonding wires. An IC card board with good appearance and extremely high reliability can be provided.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional configuration diagram showing one embodiment of an IC card board according to the present invention, and FIG.
FIG. 3 is a diagram for explaining the present invention in detail, and FIG. 4 is a cross-sectional diagram showing an example of a conventional IC card. 1... IC card board, 2... recess, 3... IC
Chip, 4... Bonding wire, 5... Sealing resin, 6... External connection terminal row, 7A, 7B... Label, 8... Recessed portion.

Claims (2)

[Claims] (1) A recess for mounting the IC chip is formed on one side of the IC card board body, the IC chip is mounted in the recess, and necessary information is exchanged with an external terminal device on the other side. and an IC card board in which a row of external connection terminals for processing is connected to the IC chip, a recess is provided on the side where a convex warpage occurs due to heating of the IC card board body, An IC card substrate characterized in that a sealing resin having a thermal contraction rate higher than that of the IC card substrate body is injected and hardened into the recessed portion. (2) The IC card board according to claim (1), wherein an epoxy resin is used as the sealing resin.