JPH0641069U - Electronic device board connection structure - Google Patents

Abstract

(57) [Summary] [Structure] An anisotropic conductive film 3 containing conductive particles 6 is interposed between an aluminum wiring 1 of a relay printed circuit 4 and an aluminum wiring 11 of a substrate 5, and a contact portion between them is provided. Then, the peripheral portion is adhered and covered with the resinous adhesive 2, a heating tool is pressed between them to apply pressure to heat the connection portion, and the conductive particles 6 are bitten into both wiring surfaces to conduct and adhere. [Effect] The peel strength between the relay printed circuit and the substrate is 3 kg / cm, which is about 6 times that of the conventional resin adhesive, and the resin adhesive covers the wiring portion, so the corrosion resistance is increased.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a connection structure for an electronic device board.

[0002]

[Prior art]

 Conventionally, in the electronic equipment, the wiring on the board and the wiring on the relay printed circuit are connected by a method of connecting both of the above wirings by soldering, and at least the surface of both of the above wirings is made of Au. A general method is to face each other and to suppress them with the elastic pressure of this elastic member via an elastic member. There is also a method of connecting both of the above wirings by conducting adhesion.

[0003]

[Problems to be solved by the device]

 According to the above-mentioned conventional method, the electrical connection between the wirings is reliable, but the wirings need to be disassembled or the gold plating treatment is required, and any of these treatments increases the manufacturing cost of the electronic device circuit board. There is a problem. If the wiring on the board is to be made of inexpensive aluminum (hereinafter referred to as Al), electroless nickel plating treatment or the like must be performed for solder connection, and the wiring on the print circuit is also required. Depending on the wiring material, a local battery may be formed on the surface of Al even if the wiring is pressed face-to-face with the wiring, and the reliability in a humid environment is impaired. In the case of electronic equipment circuit boards, if a metal with a low line resistance is used as the wiring material, and if a cheap metal is used, and if it is attempted to avoid the cost increase due to surface treatment, etc. Cause problems. On the other hand, if the conductive bonding method is used, the problem as in the case of Al 2 is solved, but as shown in the cross-sectional view of the connection of the conventional electronic device substrate of FIG. If the wiring 11 of the substrate 5 is connected through the anisotropic conductive film 3, the adhesive strength is about 500 g / cm, which is very weak, and there is a problem that it peels off during assembly in a later step.

[0004]

Means for Solving the Problems In view of the above-mentioned problems, the present invention has an anisotropy in which a resin adhesive is applied on the wiring of an electronic device circuit board, and the adhesive resin and the wiring of a relay printed circuit board are formed. By electrically connecting the wirings with the conductive film facing each other and the adhesive resin interposed, an inexpensive metal is used as the wiring material, and steps such as surface treatment are not required. Even so, it is intended to reliably obtain the reliability of the electrical connection and the adhesive strength.

[0005]

[Action]

 In the step of curing the adhesive resin, the conductive particles of the anisotropic conductive film formed on the wiring of the printed circuit are transferred to the substrate by applying external pressure to the connection portion or contracting the resin during curing. Even if the wiring is made of a material that makes the wiring difficult to form and thus forms an oxide layer, the conductive particles destroy the oxide layer, so that stable electrical connection is realized. Further, since the resin flows into the contact portions between the wirings or into the groove between the wirings to cover the contact portions, the adhesive strength can be surely obtained, and the contact portions can form a local battery even in a humid environment. It does not form and has excellent corrosion resistance.

[0006]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a contact of an electronic device board according to an embodiment of the present invention. The wiring 11 made of Al is formed on the substrate 5 made of glass epoxy or the like. Signals and power feeds from the outside propagate through the Al wiring 1 on the relay printed circuit 4, and the anisotropic conductive film 3 sandwiched between the substrate 5 and the intermediate printed circuit 4 reinforces the adhesive strength. The particles are bonded with a resinous adhesive 2, and the conductive particles 6 in the anisotropic conductive film 3 penetrate into the surfaces of both wirings and are transferred to the wirings 11 provided on the substrate 5. The anisotropic conductive film 3 is coated on the wiring 1, and when the substrate 5 and the relay printed circuit 4 are connected and assembled, the resinous adhesive 2 is interposed and the anisotropic conductive film 3 is sandwiched between them. By covering the periphery of the relay printed circuit 4 and the substrate 5 which are being heated and pressing a heating tool (not shown) to apply pressure to heat the connecting portion, the conductive particles 6 can be surely caught in the wiring. On the other hand, the resin adhesive 2 fills the contact gap between the substrate 5 and the relay printed circuit board 4 and the peripheral portion, and the adhesive strength can be improved by about 6 times as compared with the conventional example.

Although Al is used as the wiring material in this embodiment, it goes without saying that a conductive metal such as Cu will not cause any problem as the wiring material.

[0008]

[Effect of device]

 In the above-described embodiment, first, the wiring 11 on the substrate 5 and the wiring 1 on the relay printed circuit 4 are formed by the resin adhesive 3 so that the anisotropic conductive film in which the adhesive and conductive particles are interposed Even if the wiring is made of a conductive material that is not suitable for contact connection because it is adhered, it is easy to form a surface oxide layer, and good electrical continuity can be obtained and connection with adhesive strength can be obtained.

Further, the wiring 11 on the substrate 5 and the wiring 1 on the relay printed circuit 4 are made of a combination of different metals such as Al and Au, which cause a corrosive action by contact. However, since the resinous adhesive, which serves as an adhesive, coats the contact area and the periphery, corrosion resistance increases. Furthermore, not only the connection part of the wiring but also the extension part of the wiring of the board can be protected from moisture and disturbance by extension-coating a curable adhesive on the part where other protective coating is not applied. .

As described above, according to the present invention, an inexpensive metal such as Al or Cu is used as a wiring material, and signal propagation and power supply can be reliably performed without performing costly surface treatment. Thus, it is possible to provide an electronic device having a peeling strength of 3 kg / cm or more and a wiring connection structure which is realized with reliability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a connection of an electronic device board according to the present invention.

FIG. 2 is a cross-sectional view of a connection of a conventional electronic device board.

[Explanation of symbols]

 1 Wiring 2 Resinous Adhesive 3 Anisotropic Conductive Film 4 Relay Printed Circuit 5 Substrate 6 Conductive Particles 11 Wiring

Claims (1)

[Scope of utility model registration request] 1. An electronic device comprising: a substrate having wiring for propagating an electric signal on a surface thereof; and a printed circuit which faces the substrate, overlaps with the substrate, and contacts with the printed circuit to relay the propagation of the signal. A resin adhesive is interposed in a contact portion between the anisotropic conductive film formed on the wiring of the printed circuit and the conductive adhesive, and the adhesive is heated and pressured to electrically connect the electronic device substrate. Construction.