JP2000200331A - IC module and IC card using the same - Google Patents

Abstract

(57) [Problem] To improve reliability against bending and impact applied to an IC module from the outside of an IC chip mounting portion. In an IC module in which a circuit pattern is formed on a substrate and an IC chip is mounted on the circuit pattern, a bump (8) serving as a terminal portion formed on a surface of the IC chip (7) and a circuit on the substrate of the IC module. An IC module in which the pattern 4 is joined with a conductive elastic material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an IC card for communicating data with an external device such as a terminal device.
In particular, it relates to improvement of reliability against bending and impact applied to the IC module from the outside.

[0002]

2. Description of the Related Art Conventionally, ICs have been used for storing and processing important and large amounts of data such as cash cards and ID cards.
IC cards using chips have become widespread. in recent years,
Not only a contact type IC card that connects and uses the external terminal of the IC card and an external terminal, but also a built-in antenna and a non-contact type that exchanges data with external devices in a non-contact manner by radio waves or electrostatic coupling The use of IC cards is increasing, and the demand is increasing for reasons such as the necessity of taking out and inserting the card and the reduction of maintenance of external terminals.

FIG. 4 is a sectional view showing the structure of an IC module which is a component of a conventional IC card. IC
The module (2) is formed by mounting an IC chip (7) on a circuit pattern (4) of a substrate (3) made of glass epoxy or the like. The IC chip (7) and the circuit pattern (4) on the substrate are electrically connected by bonding wires (12). An IC chip (7) is adhered to the circuit pattern (4) side of the substrate (3) by an adhesive (11). Furthermore, in order to protect the mounted IC chip (7) and the bonding wires (12) in a bare state from a humid environment and to secure physical strength, heat curing,
It is common practice to seal with an ultraviolet curable epoxy or silicone resin.

In the sealing, an IC chip (7) is sealed by dropping a sealing resin on the upper surface of a printing metal plate having a hole of a predetermined shape, pouring the sealing resin into the hole with a squeegee, and printing. There are a screen printing method and a method of applying using a dispenser which is a pneumatically operated liquid application device.

[0005] IC module (2) having the above configuration
Is called COB (Chip On Board) because the IC chip (7) is mounted on a printed circuit board. The one mounted on the film substrate is COF (C
(Hip On Film). In particular, the case where the surface of the IC chip faces the opposite side of the printed circuit board as described above is called a face-up type IC module.

As shown in FIG. 5, an IC chip (7) whose surface faces the printed circuit board (3) is called a face-down system.
An anisotropic conductive film (hereinafter ACF:
Anisotropic Conductive Fi
lm). ACF is an adhesive material in the form of a film in which conductive particles such as plastic coated with nickel or metal are dispersed in an adhesive such as an epoxy resin. The adhesive is melted by heating, and the conductive particles are pressed by a bump on the chip. And on the wiring pattern of the substrate, the conductivity is obtained in the vertical direction and the insulating property is obtained because the particles exist alone in the horizontal direction.

[0007] Since the ACF also has a role of sealing between the IC chip and the substrate, the number of manufacturing steps can be reduced as compared with the face-up method. Also, a liquid anisotropic conductive paste (hereinafter referred to as ACP: Anisot)
(ropic conductive paste), an underfill agent that does not contain conductive particles, or the like.

[0008]

However, in the face-up method using wire bonding as shown in FIG. 4, the IC chip (7) and the printed circuit board (3) are connected by an extremely thin bonding wire (12). When a card is used, if a force is applied from outside the IC card due to bending or twisting of the card, there is a problem that the bonding wire (12) is broken.

Also, in the face-down type as shown in FIG. 5, for example, the one mounted by ACF and the like, when the card is used, when the card is bent or twisted, the bump (8) of the IC chip (7) is removed. In some cases, the IC module (2) is separated from the circuit pattern (4) of the substrate (3), and the conductive particles are no longer held, thereby making communication impossible. Also, regardless of the configuration of the IC module, if a force is applied to the IC chip portion from the outside, the IC chip is fixed, so there is no mechanism for releasing the force, the force is applied to the IC chip as it is, and the IC chip is broken. There was something.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to improve reliability against bending and impact applied to an IC module from outside of an IC chip mounting portion.

[0011]

In order to achieve the above object, according to the present invention, there is provided an IC module in which a circuit pattern is formed on a substrate and an IC chip is mounted on the circuit pattern. The bumps, which are terminal portions formed on the surface of the chip, and the circuit pattern of the substrate of the IC module were joined by a conductive elastic material. According to the second aspect, a spring material is used as the conductive elastic material. According to claim 3, in the IC module according to claim 1 or 2,
Resin sealing was performed so as to cover the C chip. According to a fourth aspect, in the IC module according to the first or second aspect, a frame is formed so as to surround the mounted IC chip, and resin sealing is performed in the frame to cover the IC chip. Claim 5
The present invention is an IC card in which the IC module according to any one of claims 1 to 4 is mounted on a card base material.

[0012]

Embodiments of the present invention will be described below. FIG. 1 is a sectional view of the IC card of the present invention,
It is a basic configuration of the present invention. That is, as shown in FIG. 1, an IC chip is formed by using an elastic material (5) and a solder (6) for a circuit pattern (4) of a substrate (3) of an IC module (2) in a card base (1). (7) is mounted and sealed with a sealing material (9), or a frame (1) is provided around the IC chip.
0) is formed, and the inside of the frame is sealed.

As the card base material (1) shown in FIG.
Resins such as vinyl chloride, ABS, and PET can be used. Examples of carding methods include an injection molding method, an adhesive-filled laminating method, a low-temperature laminating method, and a heat laminating method.

As a form of the IC module (2), an IC module (2) is mounted on a printed wiring board (3) made of glass epoxy or the like.
COB mounting C chip (7), 25
A CO that mounts an IC chip (7) on a film-like substrate (3) having a circuit pattern 4 formed of copper, aluminum, or the like on a film of polyimide, PET, or the like having a thickness of about μm.
It is possible to use an F type or the like.

The circuit pattern (4) of the substrate (3) can be formed by etching and printing. The substrate (3) may be of a contact type or a non-contact type.

The elastic material (5) is preferably a material having elasticity and good conductivity and having a spring shape as shown in FIGS. Regardless of the material of the spring-shaped elastic material, beryllium copper, phosphor bronze, or the like can be used as a metal, and a resin or the like coated with conductive particles may be used. Further, conductive rubber may be used.

The solder (6) is made of a commonly used Sn-Pb
A system having a mixing ratio of 6: 4 and a melting point of about 200 ° C. can be used. The shape may be lump-shaped, plate-shaped, spherical, or the like, but paste-like flux-added ones are easily used.

The IC chip (7) has a thickness of 100 μm to 300 μm obtained by cutting a planar silicon wafer.
It is desirable that an IC chip of about m is used, and the tip of the bump (8) is processed into a flat surface so as to be easily joined to the elastic material (5) by the solder (6).

As a method of mounting the circuit pattern (4) of the substrate (3) of the IC module (2) and the bumps (8) of the IC chip (7) with the elastic material (5) and the solder (6), for example, A paste-like solder (6) is applied to the upper and lower portions of the elastic material by a dispenser which is a pneumatically operated liquid application device, and is applied to the circuit pattern (4) of the substrate (3) of the IC module (2). Temporarily put the elastic material (5) to which the solder (6) has been applied,
The IC chip (7) is adsorbed on the head of a bonder, which is a device for mounting the IC chip by heating, and the head of the bonder adsorbing the IC chip (7) is placed above the temporarily placed elastic material (5). It is moved and the head is lowered until the bumps (8) of the IC chip (7) and the elastic material (5) are in contact with each other, then the bonder is heated, and the solder (6) applied by the heated heat is melted. By that, I
A C chip (7) can be mounted.

As the sealing material (9) shown in FIG. 1, it is preferable that the cured material becomes soft like a rubber, and a thermosetting resin or an ultraviolet curable resin can be used. In the case of forming, a thermosetting resin is preferable because ultraviolet rays are hardly irradiated between the bump (8) of the IC chip (7) and the circuit pattern (4) of the substrate (3). Examples of the thermosetting resin include an unsaturated polyester resin, a phenol resin, and an epoxy resin, and the epoxy resin is preferable because of its excellent chemical, electrical, and mechanical properties after curing. As the epoxy resin, a novolak type epoxy resin, an alicyclic epoxy resin or the like is used as a main material, an aliphatic or aromatic amine is used as a curing agent, and a curing accelerator, a plasticizer, and an inorganic filler are used. Various additives such as ingredients can be used.

As the ultraviolet curable resin, a resin obtained by mixing a reactive diluent and an additive with a base resin is used. As the base resin, a photopolymerizable oligomer having epoxy acrylate, polyester acrylate, polyurethane acrylate, and a plurality of acryloyl groups or mithacryloyl groups can be used.

For sealing, the IC chip (7) is sealed by dropping a sealing resin on the upper surface of a printing metal plate having a hole of a predetermined shape, flowing the sealing resin into the hole with a squeegee, and printing. There are a screen printing method and a method of applying using a dispenser which is a pneumatically actuated liquid application device. In the case of forming a frame (10), a dispenser is used because the frame (10) becomes an obstacle during screen printing. Is more preferred. As a method for curing the sealing material, thermal curing and ultraviolet curing are performed depending on the properties of the sealing material.

The frame (10) is not limited to a particular shape, but is preferably formed so as to surround the periphery of the mounted chip so that the sealing material sealed by the dispenser does not flow out.
Materials such as metal, resin, and ceramics can be used. This is fixed on the IC module using an adhesive. As the adhesive (11), an acrylic, silicone, epoxy, or cyanoacrylate adhesive can be used. However, if the frame (10) is made of a resin and the resin itself has an adhesive force, it is not necessary. .

[0024]

Embodiment 1 Hereinafter, the present invention will be described in detail with reference to embodiments. A paste-like Sn-Pb-based solder is applied to the upper and lower portions of a finely processed spring-shaped elastic material having a shape as shown in FIG. 2 by a dispenser, and a circuit pattern is formed by etching from a polyimide-copper substrate. Become IC
It is temporarily placed on the circuit pattern of the module substrate.

The bonder on which the IC chip is sucked is moved so as to be in contact with the temporarily placed elastic material having a spring shape, and heated to 200 ° C. to mount the IC chip. The IC chip used was 5 mm long × 5 mm wide, 270 μm thick, and had three bumps. Around the IC chip of the IC module,
SUS ring frame with epoxy resin polythiomir,
It is installed with an adhesive to which a tertiary amine is added. A thermosetting encapsulant using novolak type epoxy resin, moisture curable silicone rubber composition and polyether-modified organopolysiloxane as the main material is applied to this ring made around the IC chip by a dispenser. And 1
Place in a 30 ° C. oven for 1 hour to cure.

The thus obtained IC module was prepared by using the same substrate and IC chip, and performing wire bonding and dispersing nickel conductive particles in an epoxy resin adhesive.
For comparison with an IC module mounted by CF, a card was formed by a thermal lamination method using ABS as a card base material, and bending, twisting and point pressure tests were performed.

The bending test was carried out according to JIS X6305 (1995).
According to the test method specified in 6.1, the card was subjected to a bending of 22 mm in the long side direction and 11 mm in the short side direction. 350 on average for IC cards manufactured by wire bonding
0 times, the average number of IC cards manufactured by ACF is 4500
In contrast, the IC card according to the present invention became incapable of communication after an average of 6,000 times.

The torsion test is based on JIS X6305 (1995)
According to the test method specified in 6.2, the card was twisted by 30 degrees in the long side direction and 20 degrees in the short side direction. An average of 5000 IC cards manufactured by wire bonding
In contrast, the IC card manufactured by the ACF failed to communicate on average 6000 times, whereas the IC card of the present invention lost communication on average 8000 times.

In the point pressure test, the card was placed on silicon rubber, and a substance having a spherical tip was displaced at a constant rate per unit time over the entire surface of the IC module. The IC card manufactured by wire bonding has an average load of 6.0 Kgf on the tip, and the IC card manufactured by ACF has an average load of 8.0 Kgf on the other hand. The IC card became incapable of communication when the tip load became 10.0 kgf on average. Therefore, for the bending, torsion, and point pressure tests, the IC card in the present invention uses wire bonding, ACF
Good results were obtained as compared to the IC card manufactured by the company.

[0030]

Embodiment 2 A paste-like Sn-Pb solder is applied to the upper and lower portions of a spring-shaped elastic material finely processed into a shape as shown in FIG. Temporarily on the circuit pattern. Move the bonder on which the IC chip is sucked so as to be in contact with the top of the temporarily placed spring-shaped elastic material.
Heat to 00 ° C and mount the IC chip. An IC chip having a length of 4 mm × a width of 3 mm, a thickness of 180 μm, and four bumps was used.

Around the IC chip of the IC module, a ring frame made of ceramics is installed with an adhesive obtained by adding modified polyamide to epoxy resin. A thermosetting sealing material using an alicyclic epoxy resin, a moisture-curable silicone rubber composition and a polyether-modified organopolysiloxane as the main material is placed inside the ring made around the IC chip by a dispenser. Apply and cure in 130 ° C. oven for 1 hour.

The thus obtained IC module was prepared by using the same substrate and IC chip, and performing wire bonding and dispersing nickel conductive particles in an epoxy resin adhesive.
For comparison with an IC module mounted by CF, a card was formed by a heat lamination method using ABS as a card base material, and bending, twisting, and point pressure tests were performed in the same manner as in Example 1.

In the bending test, as in Example 1, the average number of IC cards manufactured by wire bonding was 3,500 times,
An IC card manufactured by CF became unable to communicate after an average of 4,500 times, whereas an IC card according to the present invention became unable to communicate after an average of 7000 times.

In the torsion test, as in Example 1, the average number of IC cards manufactured by wire bonding was 5,000 times.
The IC card manufactured by the ACF lost communication on average 6000 times, whereas the IC card of the present invention lost communication on average 8500 times.

In the point pressure test, as in Example 1, the tip load of the IC card manufactured by wire bonding was 6.0 Kgf on average, and the tip load of the IC card manufactured by ACF was 8.0 Kgf on average. While the communication was disabled, the IC card according to the present invention became unable to communicate when the tip load became 12.0 Kgf on average. Therefore, for the bending, torsion, and point pressure tests, the IC card in the present invention uses wire bonding, ACF
Good results were obtained as compared to the IC card manufactured by the company.

[0036]

The present invention has the following effects because of the following constitution. First, in the first and second aspects, an IC
Bumps and ICs that are terminal parts formed on the surface of the chip
The effect of absorbing the pressure applied to the IC chip part by joining the circuit pattern of the module substrate with the conductive elastic material, and the bump of the IC chip caused by bending and twisting of the card due to its flexibility. And IC
This has the effect of preventing separation of the module from the circuit pattern of the substrate.

According to a third aspect of the present invention, in the IC card according to the first aspect, moisture resistance is increased by encapsulating the resin so as to cover the mounted IC chip, and physical strength is enhanced. Can maintain adhesion.

According to the fourth aspect, there is an effect of reducing external stress applied to the IC chip itself and an effect of preventing a flow of a sealing material when sealing is performed by a dispenser. In the fifth aspect, since the IC module according to the first to fourth aspects is mounted on the card base material, the IC module having excellent reliability against external stress is provided.
You can get a C card.

[Brief description of the drawings]

FIG. 1 is a sectional view of an IC card according to the present invention.

FIG. 2 is an external view showing a spring-shaped elastic material according to the first embodiment of the present invention.

FIG. 3 is an external view showing a spring-shaped elastic material according to a second embodiment of the present invention.

FIG. 4 is a diagram showing an example of a conventional IC module on which an IC chip is mounted by wire bonding.

FIG. 5 is an IC in which an IC chip is mounted by a conventional ACF.
It is a figure showing the example of a module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Card base material 2 ... IC module 3 ... Substrate 4 ... Circuit pattern 5 ... Spring material 6 ... Solder 7 ... IC chip 8 ... IC chip bump 9 ... Sealant 10 ... Frame 11 ... Adhesive 12 ... Bonding wire 13 ... ACF (anisotropic conductive film) 14 ... ACF (anisotropic conductive film) conductive particles

Continuation of the front page F term (reference) 2C005 MA07 NA08 NA09 NB06 NB10 NB20 NB36 NB37 PA31 RA22 RA23 5B035 AA08 BB09 CA03 CA08 5F044 KK02 LL04 LL13

Claims (5)

[Claims] An IC module in which a circuit pattern is formed on a substrate and an IC chip is mounted on the circuit pattern, wherein a bump serving as a terminal portion formed on the surface of the IC chip and a circuit pattern on the substrate of the IC module are provided. Characterized by joining with a conductive elastic material
module. 2. The IC module according to claim 1, wherein the conductive elastic material is a spring material. 3. The IC module according to claim 1, wherein the IC module is sealed with a resin so as to cover the mounted IC chip. 4. The IC module according to claim 1, wherein a frame is formed so as to surround the mounted IC chip,
An IC module characterized by being sealed with resin so as to cover the IC chip in the frame. 5. An IC comprising the IC module according to claim 1 mounted on a card base material.
C card.