JPH02208996A - Plastic wiring board and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a plastic wiring board which satisfies all requirements such as workability, cost, and performance by a method wherein an electric circuit and an adhesive agent are buried in a plastic molded piece, and the plastic molded piece and the electric circuit are combined in an integral structure through the intermediary of the adhesive agent. CONSTITUTION:A foil or a plate of copper or copper alloy 0.1-0.6mm in thickness is pasted on the surface of a plastic film 1 of a thickness of 15-100mum, an electric circuit 2 is formed thereon through a subtractive method, and furthermore an adhesive agent 3 is made to adhere to the upside of the circuit 2. The film l is placed in a molding die making its side on which the circuit 2 has been formed and the adhesive agent has been attached face upward, then a resin material which is to be a plastic molded piece after molding is filled from the upside to mold the circuit 2, the film 1, and the plastic molded piece 4 into one piece. Then, the film 1 is separated to obtain a plastic wiring board. By this setup, the circuit 2 can be fixed at a specific position in the molded piece 4 and strongly bonded, a useless space can be eliminated, components can be arranged small in wiring and a wiring board of this design can be formed in a simple process, so that a product can be made satisfactorily small, lightweight, and its production can be rationalized.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a plastic wiring board and a method for manufacturing the same.

(Prior art) In conventional plastic wiring boards used in industrial, office, and household electronic and electrical equipment, internal electrical wiring connections are made by assembling and placing electrode fittings on plastic molded products. After that, conductive wires were soldered and caulked, etc. Method 1 Individual electrode wiring parts were produced by punching out metal plates, rods, etc., three-dimensional processing (three-dimensional processing), and these were placed in a mold. A method of filling the resin material and integrating the metal electric circuit with the individual electrode wiring parts connected in the mold, filling the resin material and integrating, and press punching, etc. There is a way to cut off unnecessary metal connections.

(Problem to be solved by the invention) However, these methods require a large number of parts and a large number of processing steps, and also require a large amount of unnecessary space.
There is a problem in terms of weight reduction and rationalization.

Since there are many reinforcement connections, there are many processing steps.

This increases the cost and causes a decrease in electrical reliability.

Today, the demand for smaller, lighter, and more streamlined products has become even stronger, and conventional wiring connection methods are no longer able to meet these demands.

In order to solve the above problems, extensive research has been carried out and improvements have been made, but at present it is not possible to obtain a plastic wiring board that satisfies all aspects of workability, price, and performance.

The object of the present invention is to provide a plastic wiring board that solves these problems and a method for manufacturing the same.

(Means for Solving the Problems) The present invention is characterized in that a plastic molded product and an electrical circuit made of copper or a copper-based alloy are integrated via an adhesive, and that an electrical circuit made of copper or a copper-based alloy is integrated in the plastic molded product. Plastic wiring board with embedded circuit and adhesive and thickness of 15 μm to 1
0.00μm plastic film with a thickness of 0.0μm on the surface.
After pasting a foil or plate of 1 rtm~0.6aamO copper or copper-based alloy, an electric circuit is formed by a subtractive method, and an adhesive is attached to the top surface of the electric circuit, and then electricity is placed in the mold. The circuit is formed and the surface to which the adhesive is attached is positioned on the top surface, and then a resin material that will become a plastic molded product after molding is filled from the top surface to form an electric circuit, a plastic film, and a plastic molded product. This invention relates to a method of manufacturing a plastic wiring board, which involves peeling off a plastic backing film after integrally molding the product.

In the present invention, the thickness of the copper or copper-based alloy foil or plate used as the material for the electric circuit is 0.1 mm to 0.6 mm, preferably 0.1 mm to 0.6 mm, preferably 0.1 mm to 0.6 mm.
．． If the thickness is less than 0.1 m, the thickness of the electric circuit layer embedded in the plastic molded product will be thin, resulting in less anchoring effect, and the electric circuit and plastic molding will be less thick. The adhesion with the product decreases. Another disadvantage is that the electric circuit is easily moved and deformed due to the flow of the resin material that becomes the plastic molded product after molding.

On the other hand, if the thickness exceeds 0.6 mm, the accuracy of processing the electric circuit using the subtractive method will drop significantly, and voids (bubbles) will easily occur at the interface between the plastic molded product and the electric circuit, reducing the reliability of the electric circuit. .

There are no particular restrictions on the method of attaching the copper or copper-based alloy foil or plate to the surface of the plastic film, but it is preferable to use a polyester heat-sealing adhesive, for example.

The adhesive in the present invention includes a thermosetting resin, a heat-fusion resin,
Adhesives such as thermal adhesive resins can be used.9 For example, adhesives such as epoxy resins, phenolic resins, polyester resins, silicone resins, polyurethane resins, acrylic resins, polyvinyl acetal resins, and area resins can be used. .

It is preferable if the adhesive strength is stronger than that of the material used to attach copper or copper-based alloy foil or plate to the surface of the plastic film, since the plastic film can be easily peeled off in the final step.

Plastic films include heat-resistant polyester films and polyimide films.

Polyether sulfonate film, polyetheretherketone film, polyphenylene sulfide film, polymethylpentene film.

Polyethylene film, polypropylene film, etc. alone or laminated together can be used. The thickness of the plastic film is 15 μm ~ l
OOAm, preferably in the range of 50 μm to 75 μm; if the thickness is less than 15 μm, the plastic film will be flexible, making it difficult to stabilize the shape, and when integrally molded with a plastic molded product, it will become a plastic molded product after molding. There is a disadvantage that the plastic film and the electric circuit are deformed due to the flow resistance of the resin material.
If it exceeds 0 .mu.m, workability will be poor due to the rigidity of the plastic film, and when the plastic film is peeled off in the final step, the plastic film will leave a clear mark on the plastic molded product.

Resin materials that become plastic molded products after molding include phenolic resin, cresol resin, epoxy resin, unsaturated polyester resin, and melamine resin.

Fluorinated resin, polyimide, polybutadiene, polyamide,
Polyamideimide, polysulfone, polyphenylene oxide, polyphenylene sulfide, polybutylene terephthalate, polyethylene terephthalate, polyetherimide, polyether sulfone, polyether ether ketone.

Single resins or modified resins such as aromatic polyester, aromatic polyamide, polycarbonate, polypropylene, polystyrene, polyphenyl ether, nylon, acrylonitrile butadiene styrene copolymer, and mixtures thereof are used, and if necessary, glass fiber, Inorganic fillers such as carbon fiber, calcium carbonate, clay, Merck, pulp, aluminum hydroxide, wood flour, organic fillers 9
Those with added coloring agents etc. can be used.

Molding methods for integrating plastic molded products, electric circuits, and plastic films include injection molding,
Transfer molding, compression molding.

Cast molding etc. can be used, and the molding conditions depend on the molding method.

It varies depending on the plastic film, adhesive, and resin material of the plastic molded product used, so it should be selected appropriately.

Depending on the type of adhesive used, plastic molded products and electric circuits may be heat treated after integral molding to further improve adhesion, so it is preferable.

If the surface of the copper or copper-based alloy foil or plate is roughened in advance, the adhesion to the plastic molded product will be further improved and effective.

If it is necessary to three-dimensionally process the electrical circuit before integrally molding it with the plastic molded product, generally known press working, vacuum forming methods, etc. can be used.

In the present invention, it is preferable to make holes at the adhesive part between the plastic molded product and the electric circuit, so that the formation of voids (bubbles) can be prevented if the holes do not interfere with the electric circuit formed in the plastic film. The size and number of holes shall be selected as appropriate, and there is no limit to 2%.

If an electric circuit is embedded in a plastic molded product as in the present invention, it is effective because the plastic molded product and the electric circuit are tightly fixed.

In the present invention, after forming an electric circuit and adhering an adhesive to the upper surface thereof, it may be used after being three-dimensionally processed if necessary.

(Example) The present invention will be explained in detail below.

Example 1 As shown in Figure 1, a polyester heat-adhesive adhesive (manufactured by Toagosei Kagaku Kogyo Co., Ltd., manufactured by Toagosei Kagaku Kogyo Co., Ltd.,
Aronmel) PE8-120H815) was applied to a thickness of 15 μm, and then a phosphor bronze plate (manufactured by Nippon Mining Co., Ltd., trade name NK2O2) with a thickness of 0.25 μm was applied, and then the phosphor bronze plate was applied using a subtractive method. An electric circuit 2 with a residual balance of 70% was formed.

Furthermore, a contact having the composition shown in Table 1 was obtained on the upper surface of the electric circuit 2.

Table 1 (Main ingredient: Curing agent = 10:4) Next, the polyester film 1 on which the electric circuit 2 is formed and has the adhesive layer 3 is pressed into a predetermined shape, and the internal dimensions are 60 x 210 +++ m.

Place it in the center of the injection mold, which is the inside of the casing with a height of 18 scales and two ribs, and place the side of the polyester film l on which the electric circuit 2 is not formed on the bottom of the mold. The surface with the electric circuit 2 and the adhesive layer 3 is placed so as to be in contact with the surface that will become the plastic molded product after molding (the top surface of the mold), and then the metal plate in the center of the surface of the housing is placed. The molten I'BT resin (Higashi Shisaki, trade name PBTII 0IG30) is poured into i2 through the pin gate provided at the mold position.
The molded product shown in FIG. 1 was obtained by injection molding under the conditions shown in the table. After that, the surface layer polyester film 1 was peeled off, and heat treatment was performed for 2 hours in a constant temperature bath at 100°C.
A plastic wiring board as shown in the figure was obtained. In addition, in FIGS. 1 and 2, 4 is a plastic molded product.

Table 2 Example 2 Polyimide film with a thickness of 30 μm (manufactured by Toshi).

Apply a polyester heat-adhesive adhesive (manufactured by Takuya Gosei Kagaku Kogyo, Aronmelt PE) to one side of the product (product name Kapton Film).
S-120H815) was applied to a thickness of 15 μm, and then a thin bronze plate (made by Nippon Mining Co., Ltd., trade name: NK2O2) with a thickness of An electric circuit with a residual balance of 70 inches was formed. Furthermore, the adhesive shown in Table 1 of Example 1 was applied to the top surface of the electric circuit to a thickness of 20 μm, and the adhesive was placed in a thermostatic oven at 60°C for 2 hours.
The adhesive layer was heat-treated for a minute and was dry to the touch.

Next, the polyimide film on which an electric circuit is formed and has an adhesive layer is pressed into a predetermined shape.

It was placed in the center of an injection mold inside a casing with internal dimensions of 60 x 210 mm, height of 18 m, and thickness of 2++ m, and the side of the polyimide film on which no electrical circuit was formed was molded with gold. Arrange it so that it is in contact with the bottom of the mold, with the side that has the electric circuit and adhesive layer facing the side that will become the plastic molded product after molding (the top surface of the mold), and then place it in the center of the casing surface. Molten PES resin (manufactured by Mitsui Toatsu Chemical Co., Ltd., trade name: PE54101GL20) was injection molded under the conditions shown in Table 3 through a bin gate provided at the mold position to obtain a molded product. Thereafter, the polyimide film of the surface layer was peeled off, and heat treatment was performed in a constant temperature bath at 100° C. for 2 hours to obtain a plastic wiring board.

The third surface impact treatment condition was to cool at -55°C for 40 minutes and then to 150°C.
Heat for 40 minutes, then repeat the cooling and heating steps described above for 10 minutes.
Repeated 0 times.

Table 4 Comparative Example 1 A plastic wiring board was obtained through the same steps as in Example 1 except that no adhesive was applied to the upper surface of the electric circuit shown in Example 1.

Next, a comparative test was conducted on the appearance (including after thermal shock treatment) of the plastic wiring boards obtained in each Example and Comparative Example and the workability of the plastic wiring boards. The test results are shown in Table 4.

The appearance was visually observed for blistering, peeling, etc. at the bond between the phosphor bronze plate and the plastic molded product. As shown in Table 4, the plastic wiring board according to the present invention is as follows:
It can be seen that the workability and appearance at the initial stage and after thermal shock treatment are superior to the plastic wiring board of the comparative example. In addition, in the plastic wiring board of Comparative Example 1, the phosphor bronze partially peeled off from the plastic molded product.

(Effect of the invention) According to the present invention, the following excellent effects are achieved.

(1) Since an electric circuit with a plastic film is used, the electric circuit can be fixed in a fixed position on the plastic molded product without moving or deforming the wiring due to the flow of the resin material.

(2) The electric circuit firmly adheres to the plastic molded product, providing strong adhesive strength.

(3) It is possible to design and manufacture plastic wiring boards that can be shaped freely to conform to the shape of a three-dimensional object, and since the electric circuit is adhered to the surface of the plastic molded product, it does not take up wasted space.

(4) It can be manufactured using fewer parts and processing steps that require less electrical wiring with large capacity.

(5) The plastic wiring board and the method for manufacturing the same according to the present invention solve the conventional problems and make the product smaller.

This fully satisfies the requirements for weight reduction and rationalization.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the state before peeling off the polyester film during production of a plastic wiring board according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a plastic wiring board according to an embodiment of the present invention. . Explanation of symbols 1... Polyester film 2... Electric circuit 3
... Adhesive layer 4 ... Plastic molded product

Claims (2)

[Claims] 1. A plastic wiring board in which a plastic molded product and an electrical circuit made of copper or a copper-based alloy are integrated via an adhesive, and the electrical circuit made of copper or copper-based alloy and the adhesive are embedded in the plastic molded product. 2. After pasting a copper or copper-based alloy foil or plate with a thickness of 0.1 mm to 0.6 mm on the surface of a plastic film with a thickness of 15 μm to 100 μm, an electric circuit is formed by a subtractive method, and an electric circuit is formed. After applying adhesive to the top surface of the circuit, an electric circuit is formed in the mold, and the surface to which the adhesive is applied is placed on the top surface.Then, after molding from the top surface, plastic molding is performed. A method of manufacturing a plastic wiring board, which is characterized in that the electric circuit, the plastic film, and the plastic molded product are integrally molded by filling the product with a resin material, and then the plastic film is peeled off.