JPH05182709A - Heat seal connector - Google Patents

Abstract

PURPOSE:To provide a heat seal connector with which stable conductivity can be secured, at a low cost. CONSTITUTION:An anisotropic conductive adhesive film 3 is set at least on the connection part of a conductive pattern 2 formed on at least one surface of a flexible insulating sheet 1, and a cover film 4 is set thereon Moreover, a pressure sensitive adhesive film 6 is set under the cover film, and a separate sheet 5 is interposed between the anisotropic conductive adhesive film 3 which is placed on the connection part and the pressure sensitive adhesive film 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat seal connector for connecting circuit boards.

[0002]

2. Description of the Related Art Conventionally, a connector and a circuit board are heat-sealed to adhere only to one side, and a pressure-sensitive adhesive backup sheet is attached to the connector side or the circuit board side to increase strength and stabilize electrical continuity, if necessary. .. FIG. 6 shows a conventionally known heat connector, 1 is a flexible insulating sheet, 2 is a conductive pattern composed of parallel conductive lines, 3 is an anisotropic conductive adhesive film provided on the conductive pattern, and 4 is a cover film. The pressure-sensitive adhesive film 6 is provided between the one-way conductive adhesive film 3 and the one-side conductive adhesive film 3, and the release sheet 5 covers the film.

[0003]

However, in such a conventional connector, each film is peeled off due to the handling during operation or the vibration during use to cause poor conduction, and since both ends of the adhesive surface are exposed, moisture is not generated. There is a drawback that stable conduction cannot be obtained such as infiltration and insulation failure. In addition, since a backup sheet is used, the material cost and labor cost are high, and the cost is high.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and provides a connector capable of easily obtaining highly stable conduction at low cost. At least the connection portion of the conductive pattern formed on at least one surface of the sheet, an anisotropic conductive adhesive film, in a heat seal connector provided with a cover film on it, together with the pressure-sensitive adhesive film on the lower surface of the cover film, A heat-seal connector, characterized in that a release sheet is interposed between the anisotropic conductive adhesive film and the pressure-sensitive adhesive film in the connection portion.

The heat seal connector of the present invention will be described below with reference to the drawings. 1 (a), (b), and (c), a conductive pattern 2 composed of parallel conductive wire groups is arranged on a flexible insulating sheet 1, and an anisotropic conductive adhesive film 3 is bonded thereon. The cover film 4 is further adhered on the cover film via a pressure-sensitive adhesive film 6 provided on the lower surface of the cover film. This connector is a connecting portion, that is, an input / output electrode of a circuit board to be connected. By interposing the release sheet 5 between the portion of the anisotropic conductive adhesive film adhered to the pressure sensitive adhesive film 6 and the pressure sensitive adhesive film 6, the heat-sealing connector of the present invention with stable conduction can be obtained. FIG. 2 shows a type in which the cover film 4 having the pressure-sensitive adhesive film 6 is protruded from the conductive pattern 2. In this case, if the release sheet 5 is also protruded in accordance with this, it is easy to remove when used. There is.

The flexible insulating sheet used in the present invention may be a synthetic resin such as polyimide, polyester, aramid, polycarbonate, ethylene-vinyl acetate copolymer, polymethylmethacrylate or the like, or a laminate thereof. Considering flexibility and workability, the thickness is 5
Most preferred is 100 μm, preferably 10-50 μm polyester.

The conductive paste forming the conductive pattern is
One or more of metal particles such as stainless steel, copper, gold, silver, palladium, rhodium and carbon particles are dispersed in a binder resin, but the required price, low resistance and anti-migration property are required. It may be appropriately selected from such characteristics.

As the anisotropic conductive adhesive film, conductive particles 8 are dispersed in an insulating adhesive 7 as shown in FIG. 3 (a), or on the conductive pattern 2 as shown in (b). Alternatively, the conductive particles 8 may be fixed to and the insulating adhesive 7 may be applied.
The insulating adhesive 7 may be any one as long as it gives adhesiveness by heat activation, such as polyamide, polyester, ionomer,
Polyolefin (polyethylene, polypropylene, etc.),
Polyethylene copolymer, (ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-ethyl acrylate copolymer, etc.) and synthetic rubber thermoplastic resin, epoxy, Urethane, acrylic, silicone, and chloroprene-based thermosetting resins are considered, and if necessary, a curing agent, a deterioration preventing agent, a tackifier, etc. are added. The anisotropic conductive adhesive film may be provided on at least the connecting portion, and may be provided on the entire width as shown in FIGS. 1 and 2, or may be provided only on the connecting portion as shown in FIG. ..

Like the flexible insulating sheet, the cover film may be a synthetic resin such as polyimide, polyester, aramid, polycarbonate, ethylene-vinyl acetate copolymer, polymethylmethacrylate or the like, or a laminate thereof. Among these, polyester is most preferable in consideration of the properties and workability. The pressure-sensitive adhesive applied to the cover film is exemplified by natural rubber such as starch and glue, and synthetic resin such as silicone and acrylic. The cover film coated with these adhesives is purchased and used in advance. You may.

Since the release sheet is used in contact with the anisotropic conductive adhesive film and the pressure-sensitive adhesive film, any release sheet may be used as long as it has releasability to these, and this is also a commercially available product. Good. In addition, as shown in FIG. 4, a resist agent 9 may be applied to the conductive pattern on the conductive pattern for protection of the pattern on the portion where the anisotropic conductive adhesive film is not provided.

After a conductive pattern is formed on at least one side of the flexible insulating sheet by a method such as screen printing or gravure printing, as shown in FIG. 3 (a), an insulating material in which conductive particles are dispersed is formed. Conductive adhesive, or as shown in (b), conductive particles are fixed on the conductive pattern by an appropriate means, and the insulating adhesive is screen-printed,
The anisotropic conductive adhesive film is formed by coating with a coater or by spraying, and if necessary, a resist agent is applied and then cut and processed to form the flexible insulating sheet 1, the conductive pattern 2, and the anisotropic conductive film. A connector body having the basic configuration of the adhesive film 3 is obtained. Then, a release sheet cut to a desired length is attached to both ends of a cover film having a pressure-sensitive adhesive film applied to the lower surface, and the release sheet is attached to the surface of the conductive pattern of the connector body to form the heat-seal connector of the present invention. To get Before cutting the connector body, a release sheet may be placed and a cover film may be attached and cut.

[0012]

In order to connect a circuit board with the heat seal connector of the present invention, the release sheet 5 is pulled out, and then the circuit boards 10 and 11 to be connected have different input / output electrodes 12 and 13 as connectors. The one-sided conductive adhesive film 3 is pressure-contacted and heat-sealed to form a connection structure as shown in FIG. The contact interface between the conductive pattern 2 and the input / output electrodes 12 and 13 serves as a heat seal surface. Thus, by using the heat-sealing connector of the present invention, the cover film backs up the adhesion between the connector and the circuit board, and in addition to the adhesion of the heat-sealing surface when the circuit board is incorporated, the adhesion between the cover film and the board Since it is backed up from the backside, the adhesive strength of the connector itself increases, it becomes resistant to peeling due to vibration during handling or use, and poor conduction is less likely to occur. Further, since one end of the heat-sealing adhesive surface is covered with the cover film, it is more difficult for moisture to enter than the conventional product, insulation failure is prevented, and stable conduction is obtained.

[0013]

[Example] On one surface of an annealed sheet of polyethylene terephthalate (PET) having a thickness of 25 μm, a length of 34 mm with a silver paste ink and a pattern pitch of 0.3 m
A parallel conductive wire of m was screen-printed over a width of 72 mm and then irradiated with infrared rays at 140 ° C. to be cured to form a conductive pattern. Similarly, with respect to 100 parts by weight of the SBR thermoplastic resin, 50 parts by weight of a tackifier and 5 parts by weight of spherical carbon particles having an average particle diameter of 20 μm, and an anisotropic conductive adhesive film having a thickness of 30 μm is formed on a conductive pattern and a conductive wire. 5 from both ends of
After forming by screen-printing over a width of 78 mm in a range of mm, the connector body was obtained by cutting into a conductive wire direction of 35 mm and a width of 78 mm. Next, the cover film previously coated with the pressure-sensitive adhesive having pressure-sensitive adhesive property was cut into 38 mm in the conductive wire direction and 78 mm in width. In consideration of the thickness of the circuit board and the width of adhesion to the circuit board, a double-sided release sheet cut into a length of 6.5 mm and a width of 78 mm is attached to both ends of the cover film,
The conductive pattern side of the connector body and the pressure-sensitive adhesive side of the cover film were stuck together to obtain the connector of the present invention.

When a high temperature vibration test was carried out at 70 ° C. on a sample in which the connector of the present invention and the substrate were adhered, it was 300
No conduction failure was observed even with time, but the conventional sample produced a conduction failure within 24 hours. Further temperature 60
When left for 240 hours under conditions of ℃ and 95% humidity,
In the sample using the connector of the present invention, the insulation resistance was 200 MΩ or more in total, whereas in the sample of the conventional product, 20% of the insulation defective products having a dielectric breakdown resistance of 1 MΩ or less were generated. It was confirmed that stable conduction and insulating properties were obtained.

[0015]

According to the heat seal connector of the present invention,
Since the cover film acts as a backup sheet for adhesion to the circuit board, the adhesive strength of the connector is increased, peeling due to vibration during handling or use is reduced, and the cover film makes the contact surface between the connector and the circuit board. Since one end is hidden, moisture is prevented from entering, and as a result, stable conduction and high insulation are secured, and the environmental application range of the device using the heat seal connector of the present invention is expanded. Moreover, since the connector of the present invention can obtain a high-performance connector without separately providing a backup sheet, the effect of cost reduction obtained from the saving of man-hours and materials is remarkable. Also, in the case where the release sheet protrudes from the connector body, the cover film is easily peeled off, and the workability at the time of connection and assembly is improved.

[Brief description of drawings]

FIG. 1A is a plan view of a heat seal connector of the present invention, FIG. 1B is a longitudinal sectional view taken along line XX of FIG.
(C) is a vertical cross-sectional view taken along the line YY of (a).

FIG. 2 is a vertical cross-sectional view showing another example of the heat seal connector of the present invention.

3A is an explanatory view of an example of the anisotropic conductive adhesive film of the present invention, and FIG. 3B is an explanatory view of another example.

FIG. 4 is a vertical cross-sectional view showing another example of the heat seal connector of the present invention.

FIG. 5 is a vertical cross-sectional view showing another example of the heat seal connector of the present invention.

FIG. 6 is a vertical cross-sectional view of a conventional heat seal connector.

[Explanation of Codes] 1 flexible insulating sheet 6 pressure-sensitive adhesive film 2 conductive pattern 7 insulating adhesive 3 anisotropic conductive adhesive film 8 conductive particles 4 cover film 9 resist agent 5 release sheet 10, 11
Circuit board 12, 13 Input / output electrodes

Claims (1)

[Claims] 1. A heat-seal connector having an anisotropic conductive adhesive film on at least a connecting portion of a conductive pattern formed on at least one surface of a flexible insulating sheet, and a cover film formed on the anisotropic conductive adhesive film. A heat-seal connector, wherein a pressure-sensitive adhesive film is provided, and a release sheet is interposed between the anisotropic conductive adhesive film and the pressure-sensitive adhesive film in the connection portion.