JPH0435084A - Manufacture of plastic molded item - Google Patents

Abstract

PURPOSE:To form one and two or more layers of electric circuit patterns integrally with no electric short circuit nor disconnection by integrating a thin leaf member, in which an electric circuit pattern is formed by filling plastic molding material in a cavity, with the plastic molding material. CONSTITUTION:At first a thin leaf member, where electric circuits are formed on the opposite sides of a substrate, is prepared. An adhesive is then applied on a part of the patterned surface member which will become the inner face of a plastic mold item, and subjected to heat treatment. It is then folded along folding lines 4. A preform obtained from the patterned surface member 1 is then set on the inner face of a lower mold, by means of a guide hole 3 and a protrusion provided on the surface of the mold, thus bringing the preform into tight contact with the surface of the mold. A preform obtained from a patterned surface member 2 is similarly brought into tight contact with the inner face of an upper mold. The upper and lower molds are then closed and reinforcing molten resin is extrusion molded through a pin gate hole 5 made through the upper mold.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides one or two layers on the surface and/or back surface of a molded product.
This invention relates to a method of manufacturing a plastic molded product having an electrical circuit pattern of more than one layer.

(Conventional technology) Electrical and electronic equipment such as AV equipment 9 signals and measuring instruments are made smaller, lighter, and more compact by increasing the density of wiring boards.
Multilayering, the introduction of flexible wiring boards, and surface mounting of package parts are being promoted. Furthermore, electrical circuits are also formed on the inner surface of the casing of electrical and electronic equipment that incorporates these wiring boards, and various methods are known for creating electrical circuits inside the casing. ing. Part of this is Nikkei Mechanical Magazine (November 1, 1989)
3-Etch Process), Mold'n Add Process
s), Mold 7-Plate Technology (Mo1
d'n Plate Technology), PSP Process
, the resend tracking method (Reces
There are methods that use electroless plating such as sedTracking Method, and methods that thermally transfer electrical circuits printed on a film during molding.In addition to these methods, there are also methods such as screen printing, pad printing (cone printing), etc. on the surface of the molded product.

There are two methods: one is to print an electric circuit using a pyramid-shaped silicone rubber offset printing method, and the other is to form an electric circuit by irradiating it with a laser.

(Problem to be solved by the invention) Each of the above methods has its own unique features.

It is either impossible to form two or more layers of electrical circuit patterns on both sides or one side of the same molded product, or even if it is possible, it requires extremely complicated processes.

It is not practical in terms of cost, performance, productivity, reliability, etc.

An object of the present invention is to provide a method for manufacturing a plastic molded product with a circuit that does not cause the above-mentioned problems.

(Means for solving the problem) In view of the current situation, the present inventors have developed smaller and smaller
In order to respond to the trend of electrical and electronic equipment requiring light weight and multi-functionality, we have developed a housing for electrical and electronic equipment9.
It has been found that a plastic molded article can be obtained that easily integrates not one layer, but two or more layers of electrical circuit patterns on each of one or both sides of a component.

The present invention involves forming an electrical circuit pattern on one or both sides of an electrically insulating thin sheet, and then closely fixing the thin sheet with the electric circuit pattern formed on one or both mold surfaces of a pair of molds. Then, a pair of molds is set, and then the cavity is filled with plastic molding material to integrate the thin sheet material with an electric circuit pattern formed thereon and the plastic molding material.Manufacturing method of plastic molded product and electrical insulation properties An electrical circuit pattern is formed on one or both sides of a thin sheet material, and then an electrically insulating thin sheet material on which no electric circuit pattern is formed is layered on the thin sheet sheet on which the electric circuit pattern is formed. It is closely fixed to one or both of the mold surfaces of a pair of molds, and the pair of molds is set with the lever b.

After this, the cavity is filled with plastic molding material to form a thin sheet with an electric circuit pattern formed thereon, a thin sheet without an electric circuit pattern formed thereon, and the plastic molding material, which are then integrated into a single piece of plastic molding. Concerning the manufacturing method of the product.

In addition, in the present invention, the electrically insulating thin sheet material includes 5 paper, cloth, etc., as well as nonwoven fabrics such as glass fibers and organic fibers, woven fabrics, or mixtures thereof as base materials.

A mixture of thermoplastic resin, thermosetting resin, etc. is used in this base material.

Examples of the above thermoplastic resins include thermoplastic polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyhexamethylene terephthalate, polyethylene, polypropylene, polysulfon, polyether sulfon, polyphenylene sulfide, polyamide, polyamideimide, polyetherimide, and polyimide. In order to improve the performance of plastic molded products, these thermoplastic resins are blended with adhesion promoters, flame retardants, etc., as well as fillers and colorants to the extent that they do not impede the desired performance. You can.

On the other hand, phenolic resin is a thermosetting resin.

Unsaturated polyester resins, melamine resins, epoxy resins, silicones, polyimides, etc. and modified products thereof are used for these thermosetting resins.

Adhesive agents to improve the performance of plastic molded products,
In addition to flame retardants and the like, filler 1 colorants and the like may be added within a range that does not impede the desired performance.

The materials that form the electrical circuit pattern are silver and copper.

Aluminum or the like is used. Further, as a method for forming the electric circuit pattern, in addition to printing of screens, bands, etc., methods such as electroplating, electroless plating, vacuum deposition, and sputtering can be used.

Note that the printing ink vehicle such as a screen or a pad is appropriately selected depending on the material of the thin sheet-like object to which the ink is applied.

On the other hand, in electroplating, electroless plating, vacuum deposition, and sputtering, the surface of the thin sheet is subjected to appropriate treatment in order to impart adhesiveness between the conductive material and the thin sheet.

One method of creating a multilayer structure by overlapping a thin sheet material with an electrical circuit pattern on it and an electrically insulating thin sheet material without an electrical circuit pattern is 1. There is a method of stacking materials to form a multilayer, or applying an adhesive that improves adhesion between the layers to form a multilayer. The above self-adhesive materials and adhesives include rubber-based, thermoplastic resin-based, and thermosetting resin-based materials, depending on the usage conditions such as heat resistance, chemical resistance, and moisture resistance required for plastic molded products. It is used by selecting from etc.

Between the layers of the electric circuit pattern provided on both sides of the thin sheet 9 Between the layers of the electric circuit pattern of a multi-layered thin sheet with an electric circuit pattern provided on one or both sides, and the plastic molded product formed by including these. The connection between the layers of the predetermined electric circuit pattern is not particularly limited, and may be made by interstitial via holes, inner via holes, through holes, or the like.

Thermoplastic resin is used as a plastic molding material.

A material whose main component is a thermosetting resin is used.

Among these, polyethylene is a thermoplastic resin.

Polypropylene, ABS, polymethylpentene.

Thermoplastic polyester, borizulfon, polyphenylene sulfide, polyphenylene oxide, polyether sulfon, polyketone ketone, polyether ketone, polyether ether ketone, polyamides, polyamideimide, polyetherimide, polyimide, liquid crystal polymers, etc. are used for plastic molding. Depending on the usage conditions of the product, it may be used singly or in combination of two or more, and if necessary, modifiers, flame retardants, flexibilizers, adhesion promoters, fillers 9
It is used in combination with colorants, reinforcing materials, etc.

For example, as a filler, it has a heat resistance of 9 mechanical strength without interfering with the desired performance of the plastic molded product.

Electrical Properties 1. Anything that improves dimensional stability, thermal expansion coefficient, cost, etc. may be used, such as calcium carbonate, kaolin, clay, dolomite, silica, mica, barium sulfate, antimony oxides, aluminum hydroxide, magnesium hydroxide, β-eucryptite and the like may be used alone or in combination of two or more.

Any reinforcing material may be used as long as it does not impede the intended performance of the plastic molded product and improves heat resistance (1) mechanical strength, electrical properties (9) dimensional stability, thermal expansion coefficient, etc., such as bulbs, glass fibers, etc. , aromatic polyester fiber, aramid fiber, calcium sulfate whisker, potassium titanate whisker, etc., may be used alone or in combination of two or more.

Furthermore, the wettability of additives such as fillers and reinforcing materials with the matrix resin is important for thermoplastic resin molding materials.

Fluidity as a molding material, adhesion between thin sheets and molding material, and moisture resistance as a plastic molded product.

Additives 9 coloring agents to further improve the electrolytic corrosion resistance etc., micro hollow spheres (7 Ichromaphere) 9 foaming agents to reduce weight and lower dielectric constant, etc. may be added.

On the other hand, phenolic resin is a thermosetting resin.

Epoxy resins, unsaturated polyester resins, vinyl ester resins, polyurethanes, silicones, polyimides, etc. are used singly or in combination of two or more depending on the usage conditions of the plastic molded product, and if necessary, modifiers and flame retardants are used. , a flexibilizing agent, an adhesion promoter, a filler, a reinforcing material 9, a coloring agent, etc., and are used in combination.

For example, when it comes to fillers, they are heat resistant and difficult resistant without interfering with the desired performance of plastic molded products.

Mechanical strength, electrical properties, 2-dimensional stability, coefficient of thermal expansion.

Any material that improves cost etc. may be used, such as carbonic acid A, sium, kaolin, clay, silica, mica, [romite,
Calcium sulfate, barium sulfate, aluminum hydroxide,
Magnesium hydroxide, talc.

One type or a combination of two or more types of glass peas and the like can be used.

Any reinforcing material may be used as long as it does not impede the desired Q/performance of the plastic molded product and improves heat resistance, mechanical strength, electrical properties, dimensional stability, thermal expansion coefficient, etc. Pulp, glass, etc. One type or a combination of two or more types of fibers, aromatic polyester fibers, aramid fibers, calcium sulfate whiskers, potassium titanate whiskers, etc. can be used.

In addition, thermosetting plastic molding materials include wettability between additives such as fillers and reinforcing materials and matrix resin, fluidity as a molding material, adhesion between thin sheets and molding materials,
It is also possible to add additives such as a coloring agent to further improve moisture resistance and electrical corrosion resistance as a plastic molded product, and a foaming agent for micro hollow spheres to reduce weight and lower electrical conductivity.

When the thin laminate or multilayered material provided with the electrical circuit pattern is placed in close contact with one or both mold surfaces of a pair of molds, the electrical circuit pattern of the thin laminate or multilayered material provided with the electrical circuit pattern is In order to obtain precision in the relative position of the circuit pattern and the mold, the thin sheet and/or
Or, it is preferable to provide one or more guide holes in the multi-layered product, and to provide a protrusion on one side of the mold with a position, dimension, and shape that matches the guide hole. A method such as punching, drilling, etc. is used to provide the thin sheet material and/or the multilayered material at a predetermined position.

Further, the thin sheet material and/or the multilayered material provided with the electrical circuit pattern is preformed in advance so as to be in close contact with one or both mold surfaces of a pair of molding molds, and is then formed in a manner that fits into the guide hole. It is preferable to fix it to the mold surface of the mold with a protrusion inside the mold. Preforming may be performed by cold forming, hot forming, or the like, depending on the type of material constituting the thin sheet, the shape to be preformed, etc.

Further, vacuum suction, electrostatic adsorption, etc. may be used in combination to bring the preformed thin sheet material provided with the electric circuit pattern or its multilayered material into close contact with one or both mold surfaces of a pair of molds.

After the thin sheet material or multilayered material provided with the electric circuit pattern is closely fixed to one or both mold surfaces of a pair of molds, the molds are closed, and the molding material 1 [- As a method for obtaining a plastic molded product by filling, methods that are practically used as a closed molding method for plastics in boat fishing can be applied, and these methods include injection molding method and transfer molding method.

Reaction injection molding method (几IM), reinforced reaction injection molding method (H,
4IM), Structural Injection Molding Method (S-IM).

There are liquid resin injection molding method (R・TM), structural liquid resin injection molding method (S 4TM), etc. Compression molding and casting methods can also be applied depending on the intended use, shape, etc. of the plastic molded product. These molding methods include post-treatments such as after-cure performed as appropriate after demolding.

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

Example 1 Thickness is 0.1. mm glass paper base modified epoxy resin prepreg (manufactured by Hitachi Chemical Mold, product name 0N62
Copper foil with a thickness of 35 μm was placed on both sides of the NS) at a temperature of 170°C.
Two substrates were created by heating and pressurizing them for 120 minutes at a pressure of 0.29 MPa, and then an electric circuit (not shown in the figure below) based on the designed pattern was formed on both sides of each board using the subtract method. A thin leaf-like material (hereinafter referred to as a patterned surface material) was obtained.

Next, four guide holes 3 with a diameter of 5 mm were formed in each of the patterned surface materials obtained in the shape shown in FIGS. 1 and 2.
Furthermore, in addition to the guide hole 3, one pin gate hole 5 having a diameter of 2 mm was formed by punching in the patterned surface material shown in FIG. Note that the patterned surface materials 1 and 2 shown in FIGS. 1 and 2 are placed on the outside and inside of the plastic molded product, respectively.

After this, for patterned surface materials 1 and 2 shown in Figures 1 and 2, apply an epoxy resin adhesive (manufactured by ThreeBond, product Three Bond 1570) was applied to a thickness of 10 to 15 μm and heat-treated in a constant temperature bath at 100° C. for 10 minutes to make it dry to the touch (the surface was pressed with a fingertip and did not stick to the fingertip). Next, the patterned surface materials 1 and 2 were kept at 80°C and bent at 90 degrees with a radius of 1 mm along the bending line 4 shown in Figs. A preform was obtained which was folded and bent.

Of the two preforms, the preform obtained from the patterned surface material 1 shown in FIG. It was then placed in close contact with the mold surface by vacuum suction through a suction port provided on the mold surface.

On the other hand, a preform obtained from the patterned surface material 2 shown in FIG. 2 was brought into close contact with the inner surface of the upper mold of a pair of upper and lower molds in the same manner as described above.

Thereafter, the upper and lower molds were closed, and molten glass fiber reinforced polybutylene terephthalate (manufactured by Toshi, trade name: PBT1101G30) was injection molded through the bin gate hole 5 provided in the upper mold. For molding, an injection molding machine 15-758 manufactured by Toshiba Machine Co., Ltd. was used.

The molding conditions were a mold temperature of 65±5°C and a cylinder stiffness of 2.
35±10℃, injection pressure (gauge pressure) 7, 84 MP
a. The injection speed was 99%, the injection time was 3 seconds, and the cooling time was 6 seconds.

After molding, the molded product was kept in a constant temperature bath at 150° C. for 3 hours (heat treatment) to obtain a plastic molded product.

The obtained plastic molded product had a rectangular box shape (4-OX 30 x 15 mm) with an open bottom side.

Four layers of electrical circuit patterns were formed on each of the four sides. Parts of the electrical circuits on the bottom surface A on the outside of the plastic molded product and on the bottom surface A' on the inside of the plastic molded product are connected by DIP bottle insertion and soldering.

Example 2 In place of the glass vapor-based modified epoxy resin prepreg used in Example 1, polyimide with a thickness of 30 μm (manufactured by Toshi Co., Ltd.,
A plastic molded article was obtained through the same steps as in Example 1 except that Kapton Film (trade name) was used.

Table 1 shows the results of examining the performance of the plastic molded products obtained in Examples 1 and 2.

Table 1 Explanation of symbols 1...Patterned surface material 3...Guide hole 5...Bing gate hole 2...Patterned surface material 4...Folding line (effects of the invention) The present invention The plastic molded product obtained by the manufacturing method is capable of forming electrical circuit patterns in one layer or two or more layers while ensuring electrical insulation between the layers and necessary electrical connections between the layers. It can be molded into one piece without any short circuits or disconnections, and can greatly contribute to making electrical and electronic equipment smaller, lighter, and more compact.

[Brief explanation of drawings]

FIGS. 1 and 2 are plan views showing the state before bending of a patterned surface material used in a plastic molded product according to an embodiment of the present invention.

Claims (2)

[Claims] 1. After forming an electrical circuit pattern on one or both sides of an electrically insulating thin sheet, the thin sheet with the electric circuit pattern formed thereon is closely fixed to one or both mold surfaces of a pair of molds, and then 1. A method for manufacturing a plastic molded product, which comprises: setting a mold, and then filling a cavity with plastic molding material to integrate the thin sheet material with an electric circuit pattern formed thereon and the plastic molding material. 2. After forming an electrical circuit pattern on one or both sides of an electrically insulating thin sheet, an electrically insulating thin sheet without an electrical circuit pattern is layered on top of the thin sheet with the electric circuit pattern formed on it to form a multilayer structure. The molded material is closely fixed to one or both mold surfaces of a pair of molds, and then the pair of molds are set, and the cavity is then filled with plastic molding material to form a thin leaf-like material with an electric circuit pattern formed thereon. 1. A method for producing a plastic molded product, which is characterized by integrating a plastic molding material, a thin sheet material having no electrical circuit pattern formed thereon, and a plastic molding material.