JPH02202092A - Printed wiring plastic molded piece and manufacture thereof - Google Patents

Abstract

PURPOSE:To make a product lightweight and to enable the miniaturization and the rationalization of it by a method wherein a plastic molded piece is pasted on a plastic film in an integral structure through the intermediary of an adhesive agent, where an electric circuit of copper or copper alloy is formed on the surface of the film. CONSTITUTION:A plastic film 1, on whose surface of an electronic circuit 3 of copper or copper alloy is formed, is pasted on a plastic molded piece 4 into an integral structure through the intermediary of an adhesive agent 2 for the formation of a printed wiring plastic molded piece. A simple piece or a pasted piece (laminated) of a polyester film, a polyimide film, or the like excellent in heat resistance can be used as the above plastic film, and it is preferably that the thickness of the film is 50-100mum. By this setup, a product can be made lightweight, miniaturized, and rationalized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a printed wiring plastic molded product and a method for manufacturing the same.

(Prior art) Printed wiring boards conventionally used in the fields of industrial, office, and household electronic equipment include glass-based epoxy resin, paper-based epoxy resin, and paper-based phenol resin, etc. Copper foil is pasted on the surface of the electrically insulating board,
Subtractive method in which a circuit is formed by etching steel foil; Additive method in which a circuit is formed on a board by electroless plating or electrolytic plating; Screen printing method in which a circuit is formed on a board by screen printing using conductive ink. There are printed wiring boards manufactured by the above method, and flexible printed wiring boards in which multiple circuits are formed on the surface of polyester film, polyimide film, etc. by the same method as described above. These printed wiring boards, flexible printed wiring boards, and the like are attached at their ends to the inside of a housing made of a plastic molded product or the like by screwing, screwing, or the like.

(Problem to be solved by the invention) However, since conventional printed wiring boards are flat and hard, electrical circuits are limited to flat designs, and furthermore, they require relatively flat parts when attached to the casing etc. in which they are used. , the shape of the product was severely restricted and required unnecessary space. Furthermore, since the mounting to the housing is done by screwing, screwing, etc., the number of steps is large, and there are problems in terms of miniaturization, weight reduction, and rationalization. In addition, connections with switches, connectors, other circuit parts on the same plane, electrical components, etc. are made using jumper wires, wire bonding, soldering, or flexible circuit boards. However, the number of connection steps is large and the cost is high, and the number of electrical connections itself causes a decrease in reliability.

On the other hand, with flexible printed wiring boards, the board is lightweight and flexible, so the above-mentioned problems are somewhat improved, and restrictions on product shape are alleviated to some extent.

However, a flexible printed wiring board attached to a housing, etc. is set with its ends fixed and the middle part floating within the space of the housing, so the parts attached to the housing are flexible. It got caught on the printed wiring board and damaged the wiring.

Alternatively, a new problem arises in that the flexible printed wiring board is sandwiched between parts and bent.

In addition, even when using a flexible printed wiring board, the flexible printed wiring board must be fixed to the housing by screwing the ends, and there must be space to accommodate the flexible printed wiring board that is floating in the middle. Therefore, it required unnecessary space similar to when using a printed wiring board.

Nowadays, the demand for smaller and lighter products has become even greater, and conventional printed wiring boards and flexible printed wiring boards are no longer able to meet these demands.

Therefore, in order to solve the above problems,
As shown in Japanese Patent Application No. 91, a method has been proposed in which a heat-sealing resin layer or a sheet having an adhesive-treated electric circuit is adhered along the surface of a plastic molded product. However, in this method, since both the sheet (base film) and the plastic molded product are flat, adhesion is poor, and furthermore, the electric circuit formed by printing or vapor deposition has a problem in reliability. Furthermore, JP-A-62-158394 uses a transfer material for printed wiring boards in which electrical circuits are formed by screen printing conductive ink, and the circuits are thermally transferred onto the surface of the printed wiring board at the same time as the printed wiring board is formed. However, the adhesion between the circuit and the plastic molded product is poor.

Electrical circuits formed by screen printing, in which the molded special circuit is easily deformed, have low heat resistance and low circuit strength, resulting in reliability problems. Furthermore, metal foil and/or JP-A-62-7
As shown in Japanese Patent No. 7926, a method for manufacturing a molded product with a foil has been proposed in which the foil of a thin fibrous sheet and a resin material are integrated, but this method requires many circuit forming steps, and it is difficult to produce a three-dimensional shape. There are problems such as difficulty in forming an electric circuit.

An object of the present invention is to provide a printed wiring plastic molded product that solves these problems, and a method for manufacturing the same.

(Means for Solving the Problems) The present invention provides a printed wiring plastic molded product in which a plastic molded product and a plastic film on the surface of which an electric circuit is formed using copper or a copper-based alloy are integrated via an adhesive. After pasting a copper or copper-based alloy foil or plate with a thickness of 15 μm to 400 μm, an electric circuit is formed using a subtractive method.

Furthermore, after adhering an adhesive to the upper surface of the electric circuit and the upper surface of the plastic film on the side on which the electric circuit is formed, the adhesive is placed in the molding mold so that the surface to which the adhesive is applied is located at the upper surface, The present invention relates to a method for manufacturing a printed wiring plastic molded product, in which a plastic film and a plastic molded product are integrally formed by filling the top surface with a resin material that will become a plastic molded product after molding to form an electric circuit.

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 15 μm to 400 μm.

Preferably it is in the range of 35 μm to 250 μm.

If the thickness is less than 15 .mu.m, the electrical port embedded in the plastic molded product is too thin, resulting in the disadvantage of close contact with the glass molded product, plastic film, etc.

On the other hand, if the thickness exceeds 400 μm, voids are likely to occur at the interface between the plastic molded product, the electric circuit, and the plastic film, reducing the reliability of the electric circuit.

There are no particular restrictions on the method of forming the electric circuit.

For example, it is preferable to bond a plastic film and a copper or copper-based alloy foil or plate with an adhesive, and to form the film by a conventionally known subtractive method.

Adhesives such as thermosetting resins, heat-fusion resins, and thermoadhesive resins can be used.These resin adhesives include epoxy resins, phenolic resins, polyester resins, silicone resins, polyurethane resins, and acrylic resins. , polyvinyl acetal resin.

Adhesives such as area resin and melamine resin can be used without any particular restrictions.

The adhesive to be applied to the top surface of the electric circuit and the top surface of the plastic film on the side on which the electric circuit is formed is applied by coating, pasting, etc., and then heat-treated as necessary in step 3 to coat the adhesive surface. It is preferable to make it dry to the touch (no stickiness when touched) and then integrally mold it with the plastic molded product, since this will result in excellent adhesion between the plastic molded product and the plastic film on which the electric circuit is formed.

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 attached (laminated) can be used. The thickness of the film is 15 μm or more, preferably 50 μm or more.
The thickness is in the range of μm to 160 μm, and if the thickness is less than 15 μm, the plastic film is flexible and its shape is difficult to stabilize.

When integrally molded with a plastic molded product, the plastic film and electric circuit are deformed due to the flow resistance of the resin material that becomes the plastic molded product after molding.

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

Polyimide, polybutadiene, polyamide, polyamideimide, polysulfone, polyphenylene oxide,
Polyphenylene sulfide, polybutylene terephthalate, polyethylene terephthalate, polyetherimide, polyether sulfone, polyether ether ketone, aromatic polyester, aromatic polyamide, fluorinated resin, polycarbonate, polypropylene, polystyrene polyphenyl ether, nylon, acrylonitrile butadiene Single resins such as styrene copolymers, modified products, and mixtures thereof are used, and if necessary, inorganic fillers such as glass fibers, carbon fibers, calcium carbonate, clay, talc, pulp, aluminum hydroxide, and wood flour are used. , an organic filler, a coloring agent, etc. can be used.

Injection molding, transfer molding, compression molding, cast molding, etc. can be used to integrate the plastic molded product and the plastic film forming the electric circuit.The molding conditions depend on the molding method and the plastic used. Made of film, adhesive.

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

Depending on the type of adhesive used, the plastic film on which the plastic molded product and the electric circuit are formed may be heat-treated after integral molding to further improve adhesion.

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

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

If a plastic film with an electric circuit formed thereon needs to be three-dimensionally processed before being integrally molded with a plastic molded product, commonly known press processing is used.

Vacuum forming method etc. can be used.

When installing electrical contacts on an electrical circuit, before or after bonding the plastic film and copper or copper-based alloy foil or plate, or before integrally molding the plastic film, the part of the plastic film that will be the electrical contact is pre-filled with the necessary electrical contacts. A hole of the same size can be drilled and an electrical contact can be provided after integral molding. Note that when forming an electrical circuit using the subtractive method, the metal parts exposed through the holes drilled in the plastic film must be covered with a material that will not be eroded by the etching solution.

In addition, in the present invention, voids can be eliminated by making holes in the bonded area between the plastic molded product and the plastic film on which the electric circuit is formed, if necessary, in a part that does not interfere with the electric circuit formed in the glass film. This is preferable because it can prevent the generation of (air bubbles). The size and number of holes shall be selected as appropriate, and there are no particular restrictions.

If a plastic film with an electrical circuit formed is partially embedded in a plastic molded product.

This is preferable because it provides excellent adhesion and fixation between the plastic molded product and the plastic film on which the electric circuit is formed.Also, if the plastic film on which the electric circuit is formed is prevented from partially adhering to the plastic molded product, the plastic molded product can be easily fixed. This is preferable because the application can be relaxed at the adhesive interface.

If you use a glass film that has been heat-treated in advance as the plastic film.

This is preferable because it is excellent in improving the thermal shock resistance of the printed wiring plastic molded product after body molding.

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

Example 1 As shown in Figure 1, a 20 μm thick adhesive agent having the composition shown in Table 1 was applied to one side of a polyester film (manufactured by Toshi, trade name: Lumirror Film) 1 with a thickness of 30 μm. Then, a copper foil having a thickness of 35 μm was pasted, and then the surface of the copper foil was subjected to a subtractive method to form an electric circuit 3 with a residual copper ratio of 70%.

Furthermore, the same adhesive as above is applied to the upper surface of the electric circuit 3 and the upper surface of the polyester film 1 to a thickness of 20 μm,
Heat treated for 2 minutes in a constant temperature bath at 60°C.

An adhesive layer 2 that was dry to the touch was obtained.

Table 1 (Main ingredient: Curing agent = 100:4) Next, after forming the copper electric circuit 3 and punching out the polyester film 1 having the adhesive layer 2 into a size of 60 x 200 m, the internal dimensions are 60 x 210 m, and the height is 60 x 200 m. is 18g1
The polyester film 1 was placed in the center of the injection molding metal inside the casing with a thickness of 21 m, and the side of the polyester film 1 on which the copper electric circuit 3 was not formed was in contact with the mold surface. Then, after molding the side that has the copper electric circuit 3 and adhesive layer 2, the side that will become the plastic molded product (the top surface of the mold)
After that, molten PBT resin (manufactured by Toshi, trade name PBT1101G30) was injection molded under the conditions shown in the second light through a bin gate provided at the mold position in the center of the front side of the housing. After molding, heat treatment was performed for 2 hours in a constant temperature bath at 100° C. to obtain a printed wiring glass molded product as shown in FIG. In addition, in FIG. 1, 4 is a plastic molded product.

Table 2 Example 2 In place of the 30 μm thick polyester film and 35 μm thick copper foil used in Example 1, a 50 μm thick polyester film (Toshiten Co., Ltd.) was used.

A printed wiring plastic molded product was obtained through the same steps as in Example 1 except that a copper foil (trade name: Lumirror Film) and a thickness of 70 μm were used.

Example 3 Instead of the 30 μm thick polyester film and 35 μm thick copper foil used in Example 1, a 75 μm thick polyester film (manufactured by Toshi) was used.

A printed wiring plastic molded product was obtained through the same steps as in Example 1, except that a steel foil having a thickness of 70 μm (trade name: Lumirror Film) was used.

Example 4 In place of the 30 μm thick polyester film and 35 μm thick copper foil used in Example 1, a 30 μm thick polyimide film (manufactured by Toshi, trade name Kapton Film) and a 35 μm thick polyimide film were used. Example 1 except that copper foil was used
A printed wiring plastic molded product was obtained through the same process.

Example 5 Polyimide film with a thickness of 30 μm (manufactured by Toshi).

An adhesive similar to that used in Example 1 was applied to one side of the product (trade name: Kapton Film) to a thickness of 20 μm, and then a steel foil with a thickness of 35 μm was pasted.

After this, the remaining proportion is 70% by subtractive method on the steel foil surface.
An electric circuit was formed. Furthermore, an example is applied to the top surface of the electric circuit and the top surface of the polyimide film! An adhesive similar to that used in was applied to a thickness of 20 μm and heat treated in a constant temperature bath at 60° C. for 2 minutes to obtain an adhesive layer that was dry to the touch.

Next, after forming a copper electric circuit and punching out a polyimide film with an adhesive layer to dimensions of 60 x 20 Offll+, the internal dimensions are 60 x 210 mm and the height is 18!
The polyimide film is placed in the center of the injection mold inside the casing with a thickness of 2 am, and the copper is The side with the electric circuit and adhesive layer is placed facing the side that will become the plastic molded product after molding (the top surface of the mold), and then the bin gate is placed at the mold position in the center of the front side of the housing. A molten PES resin (Mitsui Toatsu Chemical Co., Ltd., trade name: PE54101GL20) was injection molded under the conditions shown in Table 3. After molding, heat treatment was performed for 2 hours in a constant temperature bath at 100° C. to obtain a printed wiring plastic molded product as shown in FIG.

Table 3 Example 6 As shown in Figure 2, one side of a polyester film 1 with a thickness of 30 μm (manufactured by Toshi, trade name: Lumirror Film) 1, with parts that will become electrical contacts of an electric circuit and gas vent parts punched out. Add 20μ of the same adhesive as that used in Example 1 to
Copper foil with a thickness of 35 μm was applied, and then steel foil was coated with a subtractive method until the residual ratio was 7.
A 0-chi electric circuit 3 was formed. Furthermore, the same adhesive as above was applied to the top surface of the electric circuit 3 and the top surface of the polyester film 1 to a thickness of 20 μm, and heat treated in a constant temperature bath at 60° C. for 2 minutes to form an adhesive layer 2 that was dry to the touch. Obtained.

Thereafter, a printed wiring plastic molded product was obtained through the same steps as in Example 1.

In Figure 2, 4 is a plastic molded product.

5 is an electrical contact and 6 is a gas vent hole.

Comparative Example 1 A polyester film having a thickness of 35 μm as in Example 1 was coated on one side of the polyester film with a thickness of 35 μm in the same manner as in Example 1.
formed a copper electrical circuit.

Next, the polyester film on which the electric circuit was formed was 60X
After punching to a size of 200ml11, place it in the center of an injection mold that will be the inside of the casing as in Example 1, and place the side of the polyester film on which the copper electric circuit is not formed into the mold. After molding the side that is in contact with the copper electrical circuit and the side that will become the plastic molded product (
The upper surface of the mold was placed facing K), and the same steps as in Example 1 were followed to obtain a printed wiring plastic molded product.

Comparative Example 2 In place of the 30 μm thick polyester film and 35 μm thick copper foil used in Example 1, a 10 μm thick polyester film (manufactured by Toshi) was used.

A printed wiring plastic molded product was obtained through the same steps as in Example 1 except that a copper foil (trade name: Lumirror Film) and a thickness of 10 μm were used.

Next, the appearance of the printed wiring plastic molded products obtained in each example and each comparative example, and the
A comparative test was conducted on the peel strength of copper after time heat treatment.

The test results are shown in Table 4.

The peel strength is determined according to JIS C6481 (90' peel, peel rate 59 oo/min), and the appearance is determined.

Air bubbles in the bond between plastic molded products and copper foil, polyester 74hm, or polyimide film.

Visual observation was made for blistering, damage to the adhesive layer, etc.

◎Excellent, △Good, X: Defective test count: 5 each It can be seen that the appearance and peel strength are excellent.

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

(1) The plastic film on which the electric circuit (conducting IT layer) is formed can be fixed at a fixed position on the surface of the plastic molded product without being moved or deformed by the flow of the resin material.

The plastic film formed with a sudden circuit (2) firmly adheres to the plastic molded product, resulting in a strong adhesive strength.

(3) Because the plastic film with the electric circuit is flexible, it can be attached to three-dimensional objects in a shape that follows the shape.However, since the plastic film with the electric circuit is adhered to the surface of the plastic molded product, there is no wasted space. It becomes possible to design and manufacture printed wiring plastic molded products that do not take up much space.

(4) The printed wiring plastic molded product of the present invention and its manufacturing method solve the conventional problems, miniaturize the product,
This fully satisfies the requirements for weight reduction and rationalization.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a printed wiring plastic molded product according to one embodiment of the present invention, and FIG. 2 is a sectional view of a printed wiring plastic molded product according to another embodiment of the present invention. Explanation of symbols 1... Polyester film 2... Adhesive layer 3.
...Electrical circuit 4...Plastic molded product 5...Electrical contact 6...Gas vent agent Patent attorney Kunihiko Wakabayashi

Claims (2)

[Claims] 1. A printed wiring plastic molded product in which a plastic molded product and a plastic film on which an electric circuit is formed using copper or a copper-based alloy are integrated via an adhesive. 2. After pasting a copper or copper-based alloy foil or plate with a thickness of 15 μm to 400 μm on the surface of a plastic film with a thickness of 15 μm or more, an electric circuit is formed by a subtractive method, and the upper surface of the electric circuit and the electric After applying adhesive to the top surface of the plastic film on the side on which the circuit is formed, place the adhesive in the mold so that the surface with the adhesive is at the top, and then insert the plastic film from the top surface after molding. A method for manufacturing a printed wiring plastic molded product, which is characterized by integrally molding a plastic film filled with a resin material to form an electric circuit and a plastic molded product.