JPH0930169A - Ic card and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an IC card with excellent surface smoothness by mounting electronic parts on a circuit substrate, then providing a casing with a part slotted for electronic parts for insulative protection of the circuit substrate and the electronic parts, and packing an adhesive in a space between the slotted holes and the electronic parts. SOLUTION: A circuit substrate 1 to be used consists of a printed circuit formed in a transparent film of polyethylene terephthalate(PET) by a screen printing method, and also a semiconductor chip 2, a chip capacitor 3 and an antenna element 4 mounted on the substrate 1. In addition, the PET film 53 which is slotted and to the surface of which a polyester adhesive is applied is mounted on the circuit substrate 11, and both circuit substrate 11 and PET film(spacer layer) 53 are integrally stuck together. After that, an adhesive sheet 55 is laid on each part in a spacer layer 53 in order to fill a clearance 54 between the spacer layer 53 and the parts. Further, the parts are also held by the PET film from above and below, and are again thermally molded under pressure. Finally, the molding is punched out to the card size to obtain an IC card.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly reliable IC card having a smooth surface and a method for manufacturing the IC card.

[0002]

2. Description of the Related Art In recent years, there have been many needs for security, increase in the amount of recorded information, etc. Therefore, various types of cards such as conventional credit cards using magnetic fields are shifting to IC cards. Among them, the IC card is a general description of "Information Processing Handbook" (edited by Information Processing Society of Japan, edited by Ohmsha, 1st edition, May 30, 1989).
(Published daily) As described on pages 302-304,
"A circuit board having a conductor circuit, a semiconductor chip mounted on the circuit board, electronic components such as capacitors when necessary, an element for transmitting and receiving signals to the outside of the circuit board, and protecting the circuit board And a casing for doing so. " Furthermore, regarding the structure of the IC card, "IC card" (edited by Institute of Electronics, Information and Communication Engineers, published by Ohmsha, 1st edition, May 25, 1990)
Issued on page 33, the semiconductor chip is fixed to the card substrate with an adhesive as shown in FIGS. 5 and 6, and the connection terminals of the semiconductor chip and the connection terminals of the card substrate are connected by bonding wires. After that, the structure is such that the wire bonding portion is protected by the sealing resin.

The IC card is roughly classified into a contact type and a non-contact type. The most difference between the contact type and the non-contact type is that the method of transmitting / receiving a signal to / from the outside of the circuit board is performed through an electric contact. It is the point of whether or not.

The contact type IC card has an electric contact (wiring pattern plated with Au) on a substrate, and an electric contact of an external device makes contact with the electric contact to send and receive a signal, whereas a non-contact type IC card. The card incorporates an antenna element such as a winding coil or a sheet coil in the IC card, and thereby transmits and receives a signal to and from the outside wirelessly (by an electromagnetic wave or the like). In the case of a contact type card, the casing is preliminarily hollowed out, and the circuit board on which the semiconductor chips, etc. are mounted is mounted on the back surface of the circuit board with the semiconductor chip mounting surface facing down. The electrical contacts are exposed on the surface of the card.

In the non-contact type IC card, the circuit board and the antenna element are connected by soldering or the like. The circuit board, semiconductor chip, capacitor and antenna element are usually inserted into a pre-cut casing and then covered with a film or the like from above or from above and below. Has become.

Since the IC card is used in the same manner as a general magnetic credit card, it is susceptible to mechanical external force such as bending or twisting when carried. Therefore, in order to prevent stress from concentrating on the built-in components such as semiconductor chips mounted on the circuit board and cracking at the connection between the circuit board and the components, important points such as semiconductor chips should be made of glass fiber. There are two methods: a method of locally strengthening by using a high-rigidity base material such as a reinforced plastic and embedding the wire bonding portion with a sealing resin, and a method of thickening the casing to strengthen the entire body.

Currently, the thinnest IC card is 0.7
In the case of the contact type IC card, the former method of strengthening only the periphery of the semiconductor chip is predominant. In the case of a non-contact type IC card, the latter method is mainly used to increase the rigidity of the entire card by thickening the casing.

[0008]

In recent years, the need for thinning IC cards (1 mm or less, particularly 0.76 mm or less) has been increasing, and in order to reduce the thickness while maintaining thermal and mechanical strength. It is necessary to take measures such as making a casing with a high-rigidity material or integrating the entire card. As in the conventional case, if the structure has an air layer between the casing and the built-in parts and the casing, the internal bubbles cause expansion and contraction during heating, peeling the laminate adhesive part, swelling the card surface, Dimples, the workability of printing on the depressions is significantly deteriorated, and in some cases, print fading occurs. Also, even if there is no dent, if there is an air layer in the gap between the hollow part of the casing and the built-in parts,
When it is bent or twisted, it breaks at the weakest part of the air layer or wrinkles occur on the card surface.

It is an object of the present invention to provide an IC card having excellent surface smoothness and a method for manufacturing the IC card.

[0010]

The IC card according to the present invention comprises:
A circuit board having a conductor circuit, an antenna element for transmitting and receiving signals to and from the outside of the circuit board, a semiconductor chip having a memory for processing and storing received signals, and the power received by the antenna element A plastic film, sheet, or glass fiber reinforced plastic sheet, etc., in which electronic parts for driving a semiconductor chip are mounted, and parts of the electronic parts are hollowed out in order to insulate and protect the circuit board and the electronic parts, and further electronic parts It is characterized by comprising a casing laminated with a plastic film, a sheet, a glass fiber reinforced plastic sheet or the like for insulating protection of the above, and an adhesive filled between the hollowed hole and the electronic component.

To manufacture such an IC card, an electronic component is mounted on a circuit board, and a plastic film, sheet or glass fiber obtained by hollowing out a portion of the electronic component in order to insulate and protect the circuit board and the electronic component. A reinforced plastic sheet is laminated, an adhesive sheet of about the same size as the cutout hole is laminated on the cutout hole, and a plastic film, sheet, or glass fiber reinforced plastic for insulation protection of electronic parts It can be laminated with a sheet or the like.

Further, an electronic component is mounted on a circuit board, and a plastic film, a sheet, a glass fiber reinforced plastic sheet or the like obtained by hollowing out a portion of the electronic component in order to insulate and protect the circuit board and the electronic component is superposed on the electronic component. , Stack an adhesive sheet of about the same size as the cutout hole at the cutout hole, and then stack a plastic film, sheet, or glass fiber reinforced plastic sheet etc. for insulation protection of electronic parts, and laminate It can also be integrated.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION This adhesive is most preferably the same as the adhesive used for the casing in view of the coefficient of thermal expansion, compatibility with the casing and the like. For example, it is conceivable to put a liquid adhesive in the clearance between the hollowed-out part of the casing and the parts, and the viscosity of the liquid adhesive must be low in order not to leave air bubbles and to enter even a small gap. . However, the lower the viscosity of the adhesive is, the longer it takes to dry it, and it is necessary to allow the adhesive to stand still until the adhesive is dried, and it is also necessary to control the dosage. Therefore, handling work and quantitative management are easy,
In addition, as a method for enabling the work in a short time, it is preferable that the adhesive is formed into a sheet and the sheet is punched by a press or the like. This sheet adhesive can be prepared by coating the release film with the adhesive, drying it, and then covering the release film from above. When the thickness of the sheet adhesive does not reach the desired thickness, the upper release film is peeled off and the respective adhesive sheets are attached. When punching with a press or the like, the release film is held up and down. The workability is further improved by making the punched shape slightly larger so that the mounting position of the adhesive sheet may be slightly displaced.

[0014]

【Example】

Example 1 As shown in FIG. 1, a built-in component has a semiconductor chip of 4 mm.
× 3.8 mm × 0.25 mm, chip capacitor 1.6 mm
× 1.2mm × 0.25mm, antenna element diameter is 0.1mm
75 mm x 42 mm x 0.
A 4 mm winding coil was used. In addition, the circuit board is a film having a thickness of 0.1 mm and made of PET (polyethylene terephthalate) whose base material is transparent, and a printed circuit formed by a screen printing method using Ag-based conductive paste. For electrical connection between this circuit board and the mounted components, the semiconductor chip is anisotropic conductive film Anisolmu (Hitachi Chemical Co., Ltd., trade name), and the chip capacitor and winding coil are conductive adhesive. Were used to make electrical connections. After mounting these parts, press-punching the PET film coated with polyester adhesive that has been subjected to punching to one or both sides of the film and place it on a circuit board with a roll laminator at a temperature of 1
Molding is performed at 20 to 150 ° C. under a pressure of 5 to 40 kg / cm, and a circuit substrate and a hollowed PET film (referred to as a spacer layer) are integrated. Then, in order to fill the clearance of each part of the spacer layer, the PET
Put the same adhesive sheet as the adhesive used on the film, sandwich it with PET film of the same kind from the top and bottom, heat and press again with a roll laminator to mold, and finally
The card size of 5.6 mm x 54 mm was punched and completed. The adhesive sheet used here is an adhesive coated with a thickness of 0.05 mm and then punched into the same shape as the hollowed-out shape of the spacer layer by pressing. The PET film of the spacer layer is for insert parts. While the outer side punched with a die for hollowing out the hole was used, the adhesive sheet used the same die as the spacer layer PET punching die, and the punched inner side was used. The mounting area for the semiconductor chip and chip capacitor has a thickness of 0.25 mm.
Since the clearance was 0.5 mm or less, no adhesive sheet was used. The winding coil has a thickness of 0.4 mm
However, the size of the winding coil insertion spacer layer PET film and the volume of the winding coil were calculated because the clearance was 1.5 mm at maximum and the clearance was 0.5 mm at minimum. Then, it was decided to insert an adhesive sheet of which volume is reduced. This volume of the winding coil used was 0.26 cm ^3, the volume of the hollow portion provided in the spacer layer is 0.14 cm ^3, the area determined to be 6.3 cm ^2, as is this the insertion sheet weight, 0. 26 (cm ³ ) -0.14 (cm ³ ) = 0.12 (cm ³ ), 0.12 (cm ³ ) ÷ 6.3 (cm ² ) = 0.19 (cm), 0.019 (mm ) ÷ 0.05 (mm) = 4 (layers), and by inserting 4 layers of 50 μm thick sheets, the clearance between the hollowed-out part of the PET film of the spacer layer in the winding coil and the winding coil will be completely It has been found that it can be filled with an adhesive. The dents on the winding coil part on the surface of the card with or without the actual insertion of 4 layers were 90 to 150 μm indented, whereas the inserted one could be suppressed to a few μm indented. From the above, it was found that an IC card having a flat surface can be provided by inserting and laminating an adhesive sheet in the clearance between the built-in component and the spacer layer PET film cutout portion.

Example 2 Although the same structure and the same members are used as in Example 1, in Example 1 the adhesive sheet is mounted on the upper side of the built-in component and then laminated, as shown in FIG. Before inserting the built-in parts, it was decided to insert them all into the hollowed-out part of the casing in advance, and insert the parts later.

Example 3 The card structure and members described in Example 1 are used. In Examples 1 and 2, the adhesive sheets are all mounted on the upper side or the lower side of the built-in component, as shown in FIG. In order to insert the adhesive sheet, before mounting the component, some sheets were mounted in advance, then the component was mounted, and the rest of the adhesive sheet was mounted so that the built-in component was sandwiched.

Example 4 The card structure and members (other than the adhesive sheet) described in Example 1 are used, but in Examples 1 to 3, the clearance between the casing recess and the built-in component has the same shape as the cutout portion of the casing in advance or In contrast to the case in which an adhesive sheet formed a little larger than this is inserted, here, a work method and a structure in which a predetermined amount of the adhesive sheet is inserted only in a portion having a large clearance as shown in FIG.

[0018]

As described above, according to the present invention, an IC card which is excellent in connection reliability and is excellent in printability of various covers depending on the application to the surface of the card due to its flat surface. The manufacturing method can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing another embodiment of the present invention.

FIG. 3 is a sectional view showing still another embodiment of the present invention.

FIG. 4 is a sectional view showing still another embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a conventional example.

FIG. 6 is a sectional view showing another conventional example.

[Explanation of symbols]

1. Circuit board 2. Semiconductor chip 3. Electronic components (capacitors, etc.) 4. Element (antenna element) for transmitting and receiving signals to the outside of the circuit board 5. Casing 6. Bonding wire 7. Anisotropically conductive film (anisolum) 8. Integrated molding (by injection molding, etc.) casing 11. Circuit substrate (plastic film, etc.) 12. Conductor circuit (by conductive paste, etching, etc.) 51. Plastic film or sheet 52. Adhesive 53. Spacer layer 54. Clearance 55. Adhesive sheet 56. Cover layer 57. Cover printed by application

Claims (3)

[Claims] 1. A circuit board having a conductor circuit, an antenna element for transmitting and receiving signals to and from the outside of the circuit board, a semiconductor chip having a memory for processing and storing the received signal, and an antenna element. While mounting the electronic components for driving this semiconductor chip with the received power,
Plastic films, sheets, which are hollowed out parts of electronic parts in order to insulate and protect circuit boards and electronic parts.
Or a glass fiber reinforced plastic sheet, etc., and a plastic film for insulating and protecting electronic parts,
An IC card comprising a sheet or a casing laminated with a glass fiber reinforced plastic sheet or the like, and an adhesive filled between a hollowed hole and an electronic component. 2. A circuit board on which electronic parts are mounted, and a plastic film, a sheet, a glass fiber reinforced plastic sheet or the like obtained by hollowing out parts of the electronic parts to insulate and protect the circuit board and the electronic parts are laminated, An adhesive sheet of approximately the same size as the cutout hole is stacked on the cutout hole, and further laminated with a plastic film, sheet, or glass fiber reinforced plastic sheet for insulating and protecting electronic parts. IC card manufacturing method. 3. A circuit board on which electronic parts are mounted, and a plastic film, a sheet, a glass fiber reinforced plastic sheet or the like obtained by hollowing out parts of the electronic parts in order to insulate and protect the circuit board and the electronic parts are superposed on the electronic parts. , Stack an adhesive sheet of about the same size as the cutout hole at the cutout hole, and then stack a plastic film, sheet, or glass fiber reinforced plastic sheet etc. for insulation protection of electronic parts, and laminate A method of manufacturing an IC card, characterized by being integrated.