JP2000268152A - Manufacture of ic card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the movement of an adhesive material and a reinforcing plate at the heating and hardening of the adhesive material even without sur rounding the periphery of the adhesive material in the case of adhering the reinforcing plate to a semiconductor chip by the adhesive material composed of thermosetting plastic. SOLUTION: The adhesive material 17 composed of a thermosetting resin is applied to a semiconductor chip 16, a reinforcing plate 18 is mounted on the adhesive material 17 and then, heating is performed by radiation heat from an electric heater 22 of an infrared ray heating furnace 21 for the time until at least temporarily hardening the adhesive material 17. By heating and hardening the adhesive material 17 by the radiation heat in such a manner, the influence of a wind is not received differently from the case of heating and hardening the adhesive material 17 by a hot blast furnace 23 from the beginning.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an IC card having a structure in which a reinforcing member for preventing damage is attached to a semiconductor chip having functions such as a memory and a CPU.

[0002]

A cash card, a credit card, and the like, which are widely used at present, are obtained by applying a magnetic stripe to a plastic card and reading information recorded on the magnetic stripe. Such a magnetic recording method has problems such that information is easily read by a third party and the amount of recordable information is small.

Therefore, in recent years, an IC card in which a semiconductor chip having functions such as a memory and a CPU is mounted on a card-like base has been developed and has already been put to practical use. This IC card usually has a three-layer structure including a circuit sheet on which a semiconductor chip is mounted by forming a circuit pattern, an intermediate sheet adhered on the circuit sheet, and a cover sheet adhered on the intermediate sheet. Have been.

In an IC card having such a structure, there is a case where a semiconductor chip is weak against a bending force and is broken and becomes unusable. To solve this problem and improve the bending resistance of the semiconductor chip, for example, it has been considered to attach a reinforcing plate to the semiconductor chip.

In order to improve the bending resistance of the reinforcing plate, it is desirable to use a thermosetting plastic which is relatively hard in terms of strength as an adhesive. And when using a thermosetting plastic as an adhesive, it is necessary to heat and cure the adhesive, but when it is heated and cured using a commonly used hot blast furnace, hot air is strongly blown in the furnace. Therefore, as shown in FIG. 4, the adhesive 1 before curing is blown off by hot air (indicated by an arrow A), so that the dimensional stability in the height direction is impaired, or the reinforcing plate 2 is removed from the semiconductor chip 3. As a result, the intended purpose of reinforcing the semiconductor chip 3 cannot be achieved.

In order to solve such a problem, it is conceivable to bond a reinforcing plate in a procedure as shown in FIG.
That is, first, a semiconductor chip 4 is mounted on a circuit board 3 made of a plastic sheet (FIG. 5A), and then a plastic spacer 6 provided with a hollow 5 for accommodating the semiconductor chip 4 is mounted on a circuit board. It is adhered on the substrate 3 (FIG. 5B). Thereafter, an adhesive 7 made of thermosetting plastic is potted into the hollow 5 (FIG. 5).
(C)) A stainless steel plate 8 is placed on the adhesive 7 as a reinforcing member (FIG. 5D). Then, the adhesive 7 is heated and hardened by the hot air oven 9 (FIG. 5E).
A cover film (not shown) made of a plastic film is bonded onto the spacer 6.

If such a bonding method is adopted, the adhesive 7 and the reinforcing plate 8 are present in the hollow 5 and are surrounded, so that there is no possibility that the adhesive 7 and the reinforcing plate 8 are washed away by hot air. The problem can be solved. However, this configuration has a new problem that the number of steps increases, such as a process of forming the hollow 5 in the spacer 6.

The present invention has been made in view of the above circumstances, and an object thereof is that even when the adhesive is not surrounded, there is a possibility that the adhesive or the reinforcing member may move during the heating and curing of the adhesive. Another object of the present invention is to provide a method of manufacturing an IC card which can obtain a high reinforcing effect on a semiconductor chip.

[0009]

In order to achieve the above object, the present invention provides a semiconductor chip provided on a substrate provided with an adhesive made of a thermosetting resin, and the reinforcing member provided on the adhesive. In the arrangement state, the adhesive is heated by radiant heat for at least a temporary curing time, and then heated for main curing.

In this case, in order to reduce equipment costs, it is preferable that the adhesive is heated by radiant heat and then heated by a hot blast stove. Further, the time during which the adhesive is heated by radiant heat (the temporary curing time) is the time during which the adhesive is cured to such an extent that it is not flown by the hot air in the hot blast stove, or the time until the adhesive is gelled and begins to cure. Is preferred.

According to the above construction, the adhesive is heated by the radiant heat in a state where the adhesive has a fluidity. Therefore, unlike the case where the adhesive is heated and hardened in a hot blast stove, it is hardly affected by the wind, and the adhesive or the reinforcing agent is used. There is no possibility that the members are washed away.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First, as shown in FIGS. 2 and 3, the IC card 11 includes a circuit sheet 12 as a substrate, an intermediate sheet 13 as an intermediate adhesive layer, and a cover sheet 14.

The circuit sheet 12 is made of plastic, for example, polyester plastic, specifically, PET.
It consists of a sheet made of (polyethylene terephthalate) having a thickness of about 100 μm. On one side of the circuit sheet 12,
A coil-shaped circuit pattern 15 as a conductor circuit is formed, and a semiconductor chip 16 connected to the circuit pattern 15 is mounted. A reinforcing plate 18 as a reinforcing member is disposed on the semiconductor chip 16 with an adhesive 17 interposed therebetween. The circuit sheet 12
And the height from the upper surface of the reinforcing plate 18 is about 220 μm.

The reinforcing plate 18 is for reinforcing the semiconductor chip 16 and is formed of, for example, a stainless plate having a thickness of about 30 μm. The adhesive 17 has a function of bonding the reinforcing plate 18 to the semiconductor chip 16 and reinforcing the semiconductor chip 16 in cooperation with the reinforcing plate 18. For this purpose, the adhesive 17 is preferably a plastic that can be used as an adhesive, and a relatively hard plastic having an elastic modulus of about 3 to 10 GPa (gigapascal). In the example, an epoxy-based plastic is used.

In this embodiment, the coil-shaped circuit pattern 15 is formed by a screen printing means using a conductive paste, for example, a polyester-based silver paste, and the semiconductor chip 16 is formed by, for example, an anisotropic conductive adhesive. 19 is flip-chip mounted. This circuit pattern 15 is an element for transmitting / receiving a signal to / from an external device,
In this embodiment, the semiconductor chip 16 functions as an antenna for transmitting and receiving a radio signal.
, Etc., is configured to be obtained by a radio signal from an external device received by the circuit pattern 15.

The intermediate sheet 13 is made of a plastic material having a heat-melting property such that the intermediate sheet 13 becomes molten when heated and becomes fluid, for example, a sheet having a thickness of about 250 μm formed by a polyester-based hot melt adhesive. . The intermediate sheet 13 protects the circuit pattern 15, the semiconductor chip 16 and the like, and also includes the circuit sheet 1 itself.
2 and has a function of bonding the cover sheet 14 and covers the circuit pattern 15, the semiconductor chip 16 and the like without gaps. The cover sheet 14 has a function of protecting the relatively soft intermediate sheet 13, and is made of, for example, a PET sheet having a thickness of about 100 μm like the circuit sheet 12.

To manufacture such an IC card 11, first, as shown in FIG. 1A, a semiconductor chip 16 is mounted on a circuit sheet 12, and then, as shown in FIG. Then, an adhesive 17 made of an epoxy plastic is applied by printing means or potting. Then, as shown in FIG. 1C, the reinforcing plate 6 is placed on the adhesive 17.

After that, the circuit sheet 12 is carried into the infrared heating furnace 21 by the conveyor 20. This infrared heating furnace 21 serves as a heat source that radiates infrared rays to the upper surface of the furnace.
For example, an electric heater 22 such as a nichrome wire heater or a sheath heater is provided. The circuit sheet 12 carried into the infrared heating furnace 21 mainly includes the electric heater 22.
Heated by radiant heat from This infrared heating furnace 2
By heating at 1, the adhesive 17 starts to harden.

This curing is performed by the adhesive 17 being gelled, and the conveyor 20 takes a time until the adhesive 17 is at least temporarily cured, that is, until the adhesive 17 starts to be gelled and starts to be cured. The moving speed is set such that the circuit sheet 12 is in the infrared heating furnace 21 only for the time. Then, when the adhesive 17 gels and temporarily hardens, the circuit sheet 12 is carried out of the infrared heating furnace 21. Here, the tentatively cured state refers to a state in which the adhesive 17 has been cured to such an extent that the adhesive 17 is not blown off by the wind in the hot blast furnace 23 and the reinforcing plate 18 does not move.

Thereafter, the circuit sheet 12 is placed in a hot blast stove 23. In the hot blast stove 23, the adhesive 17 of the circuit sheet 12 is heated by receiving hot air and completely cured (finally cured).
I do. The complete curing of the adhesive 17 used in this example is 2
Since it takes 0 to 30 minutes, the circuit sheet 12 is kept in the hot blast stove 23 during that time. Then, when the adhesive 17 is completely cured, the circuit sheet 12 is taken out of the hot blast stove 23. The heating temperature in the infrared heating furnace 21 and the hot blast furnace 23 is 80 to 160 ° C.

Next, the intermediate sheet 1 is placed on the circuit sheet 12.
3 and the cover sheet 14 are sequentially stacked, and the whole is thermocompression-bonded by a hot press device (not shown). Then, the hot-melt adhesive constituting the intermediate sheet 13 is heated and melted and becomes fluid, so that the molten hot-melt adhesive covers the circuit pattern 15 and the adhesive 17 without gaps. At the same time, the intermediate sheet 13 is formed so as to have a uniform thickness by applying pressure from both upper and lower sides, and adheres the circuit sheet 12 and the cover sheet 14. And
By the subsequent cooling, the intermediate sheet 13 is hardened, and the circuit sheet 12, the intermediate sheet 13 and the cover sheet 1 are thus hardened.
4 is manufactured.

In such an IC card 11, the circuit sheet 12 and the cover sheet 14 are formed of PET, and the intermediate sheet 13 is formed of a polyester hot melt adhesive, and both have flexibility. Therefore, when a bending force is applied, the IC card 11 bends flexibly with elasticity. When the IC card 11 is bent, the semiconductor chip 16 is bent by the reinforcing plate 18 and the adhesive 17.
Is protected and the semiconductor chip 16 is prevented from being damaged.

As described above, according to the present embodiment, the circuit sheet 12 is placed in the infrared heating furnace 21 until the adhesive 17 made of the thermosetting plastic is temporarily cured, and then transferred to the hot blast furnace 23. Even when the hot air having a strong flow is received in the hot air furnace 23, there is no possibility that the adhesive 17 flows or the reinforcing plate 18 moves.

Incidentally, the circuit sheet 12 is transferred to the infrared heating furnace 21.
The reason why the adhesive 17 was completely cured by transferring to the hot blast stove 23 was that the adhesive 17 used in the present embodiment was used.
It takes a long time of 20 to 30 minutes to completely cure.
In the infrared heating furnace 21, if the circuit sheet 12 is not moved, there is a possibility that the circuit sheet 12 is locally heated to an abnormally high temperature. For this reason, the adhesive 17 is only provided by the infrared heating furnace 21.
In order to completely cure, the length of the infrared heating furnace 21 must be abnormally long, which is not practical.

On the other hand, in the hot blast stove 23, even if the circuit sheet 12 is stopped at a fixed position, there is no possibility that the heating is locally performed. Costs can be reduced.

The present invention is not limited to the embodiment described above and shown in the drawings, but can be extended or modified as follows. The adhesive 17 is not limited to the epoxy type, but may be a silicone type, a urethane type, or the like. The reinforcing plate 18 may be aluminum, glass cloth, or the like, and its shape is not limited to a flat plate. If an adhesive is used such that the time until complete curing is within 5 minutes, curing with only the infrared heating furnace 21 may be used.
The heat curing in 3 can be omitted.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of an IC card.

FIG. 3 is an exploded perspective view of the IC card.

FIG. 4 is a cross-sectional view for explaining a conventional problem.

FIG. 5 is a sectional view showing a conventional manufacturing process for solving the problem.

[Explanation of symbols]

In the figure, 12 is a circuit sheet (substrate), 13 is an intermediate sheet,
14 is a cover sheet, 16 is a semiconductor chip, 17 is an adhesive, 18 is a reinforcing plate, 21 is an infrared heating furnace, and 23 is a hot air furnace.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Kamiya 1-1-1, Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (reference) 4J040 EC001 EF001 EK031 JB02 JB10 LA06 NA20 NA21 PA18 PA20 PA30 PB05 5B035 AA08 BA03 BA05 BB09 BC00 CA01 CA03 CA23

Claims (4)

[Claims] 1. An IC card having a structure in which a reinforcing member is bonded to a semiconductor chip provided on a substrate, wherein an adhesive made of a thermosetting resin is provided on the semiconductor chip provided on the substrate, and the adhesive is provided on the adhesive. A method for manufacturing an IC card, wherein the adhesive is heated by radiant heat for at least a temporary curing time in a state where the reinforcing member is arranged, and then heated for main curing. 2. After heating the adhesive by radiant heat,
The method for manufacturing an IC card according to claim 1, wherein the heating is performed by a hot blast stove. 3. The method for manufacturing an IC card according to claim 1, wherein the temporary curing time is a time for curing the adhesive to such an extent that the adhesive is not washed away by hot air in a hot blast stove. 4. The method for manufacturing an IC card according to claim 1, wherein the temporary curing time is a time until the adhesive gels and starts to be cured.