JPS62163388A - Manufacture of plastic molded printed wiring board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a heat-resistant thermoplastic resin molded article having a large number of small holes for conduction between the front and back sides, which is manufactured using a hard resin mold that is a -firf of a simple mold. This is a method of manufacturing a plastic molded printed wiring board in which a wiring network is formed by a method known in the art, and is suitable for small-lot, high-mix production.

[Conventional methods and their problems]

The molds used in the method of manufacturing heat-resistant plastic molded products with small holes are ordinary metal molds or simple molds made of low-melting point metals, but the molds are complex and expensive. Therefore, there was a drawback that the heat-resistant plastic molded product was expensive.

The present invention solves the above problems and provides a method for manufacturing a heat-resistant plastic molded printed wiring board at a lower cost by easily manufacturing a mold capable of forming a wide variety of complicated small holes at a low cost and in a short time. This was completed after careful consideration.

[Failure to solve the problem]

That is, the present invention provides a front-back conductive printed wiring board in which a molded body for a plastic molded printed wiring board is formed with a large number of small holes for front-back conduction, and a conductor layer is formed on the molded body to create a wiring network. In the method for producing the molded article, the composition before curing has a property of being fluidized at a temperature of 100°C or less, and the glass transition temperature of the cured resin is 15°C.
A resin mold made of a heat-resistant addition-polymerizable thermosetting resin composition containing 70% by weight or more of metal ``5''J bodies or metal fibers at 0°C or higher, with hard pins embedded in the small holes. This is a method for producing a plastic molded printed wiring board characterized by using a molded body produced by molding a heat-resistant thermoplastic resin using the above method.

The present invention will be explained below.

The plastic molded printed wiring board of the present invention is made of solderable heat-resistant plastic and is molded by compression molding or injection molding. Molded objects in the shape of flat plates, curved surfaces, bent shapes, etc. are subjected to surface swelling, oxidation, and other surface treatments using solvents as necessary, and are then subjected to known activation methods including Pd, Ag, Cu, etc. After activation with a chemical agent, a Cu or Ni layer is formed on the surface by electroless plating, electrolytic plating is applied, a resist is applied as appropriate, and Bakun is baked and etched; after surface treatment, a known photoactive catalyst is applied. This is a printed wiring board in which a wiring network is formed by a method known in the art, in which a wiring network is formed by a method known in the art, in which a method is applied, selectively activated by irradiation with light, and electroless plating is applied only to the activated portions.

Heat-resistant plastics that can be soldered include heat-resistant thermoplastic resins such as polysulfone, polyetherimide, polyether sulfone, polyphenylene sulfide, and polyphenylene ether, and thermoplastic resins such as polycarbonate, polyphenylene ether, and polyacetal. and cyanate ester compounds 30/7
Ink network polymer prepared by mixing in a ratio of 0 to 70/30 and adding a catalyst (Japanese Patent Application Laid-Open No. 54-142
No. 297 Publication), and compositions made by adding glass fiber, wollastonite, calcium carbonate, mica, other reinforcing materials, fillers, etc. to these resins as appropriate, or as they are or heat-cured. The heat resistance after is 26
Soldering at 0°C is enough to withstand the process.

The mold of the present invention used for molding the above molded article has a property that the composition before curing becomes fluid at a temperature of 100°C or lower, and a glass transition temperature of the cured resin of 150°C.
The resin mold is made of a heat-resistant addition polymerizable thermosetting resin composition containing 70% by weight or more of metal powder, and has hard bottles embedded in the small holes.

First, the composition before curing has the property of being fluidized at a temperature of 100°C or lower, and the glass transition temperature of the cured resin is 150°C.
Heat resistance above °C] As a polymerized thermosetting resin,
Specifically, cyanato resin (Japanese Patent Publication No. 41-1928, 45-11712, 44-1222, German Patent No. 1190184, etc.), cyanate ester-maleimide resin, cyanate ester-maleimide-epoxy resin ( Special Publication No. 54-30440, etc., Special Publication No. 52-3127
No. 9, IJSP-4110364, etc.), cyanate ester-epoxy resin (Japanese Patent Publication No. 46-41112), modified maleimide resin whose main components are polyfunctional maleimide and epoxy compounds, isocyanate compounds, etc.
8-8279), isocyanate-oxazolidone resin containing an isocyanate compound and an epoxy compound as main components (JP-A-55-75418), polyfunctional epoxy resin containing as a main component a trifunctional or higher polyfunctional epoxy compound,
Modified 1,2-polybutadiene resin, diallyl phthalate resin, silicone resin, etc. are exemplified, and in particular, cyanato resin (Japanese Patent Publication No. 41-1928, 45-11712, 44-1222, German Patent No. 1190184, etc.) , cyanate ester-maleimide resin, cyanate ester-maleimide-epoxy resin (Special Publication No. 54-30
No. 440, etc., Special Publication No. 52-31279, USP-41
10364, etc.), cyanate ester-epoxy resin (Japanese Patent Publication No. 46-41112), etc., containing cyanate ester as an essential component are preferred. These thermosetting resins are appropriately combined with known additives for each resin, such as catalysts and curing agents such as amines, acid anhydride necks, organic metal salts, and organic peroxide necks; Known silicone type,
Mold release agents and waxes such as fluorine thread; Flexibility agents such as diene rubber, low-crystalline to non-crystalline saturated polyester resins, and high molecular weight elastomers such as polyurethane; Known materials such as silicone-based Examples include antifoaming agents and coupling agents.

The metal powder or metal fiber (B) of the present invention, which is blended into the above resin in an amount of 70% by weight or more, is mainly used for the purpose of imparting thermal conductivity to the resin mold, and is not particularly limited. , Specific examples include iron, aluminum, copper,
These include copper alloys, aluminum alloys, iron alloys, and silver.

The above ingredients are mixed at a temperature of 20 to 130'C using a roll, Banbury mixer, Henschel mixer, extruder, or other known kneading machine for 1 minute to 10 hours to form a uniform composition. After finishing the kneading, the temperature is 100° according to the present invention.
A heat-resistant addition-polymerizable thermosetting resin composition that is in the form of a sticky liquid or paste at temperatures below C, for example, about 50 to 90°C, is used for manufacturing resin molds.

The resin mold of the present invention can be made by casting the composition as it is or using a reinforcing material in combination with a desired model, pre-curing or curing, and post-curing if desired.
It is manufactured by post-processing parts that are compatible with the applied molding method, such as gates, and attaching them.

The desired model is one that has the same shape as a molded object, such as a flat plate with many small holes for front and back conduction, a flat plate with partially uneven parts, a temporary plate with a curved surface, a bent plate, etc. There is no particular restriction as long as it can withstand the mold and the heating during preliminary curing.

A typical example of the casting method is as follows: Step 1: First, depending on the properties of the material of the model and the casting resin, a release agent is applied to the entire surface of the model, including the small holes, and dried. do.

Process ■: Usually, in a container that can be vacuum-suctioned and heated as appropriate, a hardening paste-like material used for making molds, such as plaster, is spread on a rectangular temporary to a predetermined thickness. , After placing the model prepared in step (2) tightly on top of the hard bottle to be attached, with the fixed side facing upward, insert a small hole in the model with the same diameter as the small hole, with the ends protruding from both sides of the model. Attach a hard bottle to one side of the resin mold so that it is sufficiently fixed, surround the paste-like material with a rectangular column-shaped plate, harden the paste-like material, and then place the mold on top of it. A metal pipe or the like will be placed as a cooling medium flow path.

Step ①: The heat-resistant addition-polymerizable thermosetting resin composition of the present invention is poured from the top, and after degassing or defoaming by vacuum suction, the molding pressure is 0 to 30 kg/cJ, and the temperature is 60°C.
As described above, it is heated and pressurized at a temperature of 180° C. or less, particularly in the range of about 60 to 150° C., to gel or semi-cure or harden it, thereby making it self-retentive.

Step ■: Take it out of the container, completely remove the hardened glue, apply a mold release agent to the model and casting resin surface, and place a mold of about 1 to 1 o 11 with holes of the same diameter as the hard bottle. After inserting a metal plate or metal rod for reinforcement, placing it again into the container used in step ①, and placing a metal pipe etc. as a medium flow path for mold cooling on top of it, the heat-resistant The addition polymerization type thermosetting resin composition is poured from the top, and after degassing or defoaming by vacuum suction, it is made self-retaining in the same manner as in step (2).

Step (2): The resin mold obtained above is usually not completely cured, so it is post-cured to obtain a hardened resin mold.

The conditions for post-curing are appropriately selected depending on the heat-resistant addition polymerization type thermosetting resin composition of the present invention to be used.
It is cured at 50 to 250°C for about 1 to 20 hours in a constant temperature bath.

Process ■: Post-process and attach gates and other parts.

It is.

In the above process, the split mold was cast in two stages, gelled, or semi-cured or hardened. It is also possible to set parts such as a gate and a thin film for mold release as appropriate, and perform the casting process in two steps.

Using the resin mold manufactured by the above method, the heat-resistant thermoplastic resin described above is molded to form a molded body for a plastic molded printed wiring board of the present invention.

Molding depends on the conditions of the heat-resistant thermoplastic resin that can be soldered, but the molding cycle must be such that the temperature of the side of the resin mold used that contacts the molded object does not exceed the glass transition temperature of the resin in the resin mold. The cycle is longer than normal metal molds.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, the parts in the examples are based on the enclosed standard unless otherwise specified.

Example-1 Creating a model Two small holes with a hole diameter of 0 and 9 inches were made in a glass cloth base epoxy resin laminate of 50 is x 50 mm and 2 mm thick.
．． 100 pieces were opened in a grid pattern using a 54 mm pinch, and a fluorine-based mold release agent (trade name: Daifree?'1S-743, manufactured by Daikin Kogyo A'4) was applied and dried.

A paste-like material made of a mixture of plaster and vinyl acetate emulsion was spread 30 mm thick on a 100111+1x100 mm board, and the model was placed in the center. After bringing it into close contact,
Insert a high spin with a diameter of 0.9 mm and a length of 4 cm into the small hole so that the protrusion length from the model is 30 II m.
Polycarbonate with a thickness of 5 mm, with and without holes for the entrance and exit of the cooling copper pipe, and a height of 130 mm.
It was erected to a height of m5 to form a box shape, and a mold release agent was applied to the inner surface. Next, a cooling copper pipe having an inner diameter of 5 cm and bent into a U-shape several times was placed around this high spin, and the cooling medium flow path portion was placed so as to be drawn out from the above-mentioned entrance/exit hole.

2. After mixing 30 parts of 2-bis(4-cyanatophenyl)propane and 70 parts of 150 mSO aluminum powder, the mixture was heated and stirred at 80°C for 5 minutes to form a fluid composition (hereinafter referred to as A composition A1) was obtained.

Bisphenol A type epoxy resin (trade name: Epicote 828) in which 0.03 part of iron acetylacetonate is dissolved in advance.
, viscosity 120-150PS at 25°C, epoxy equivalent 184-194, 25 parts of Yuka Shell Epoxy Co., Ltd. and 75 parts of 300 mesh copper powder are mixed at room temperature,
A fluid composition (hereinafter referred to as curing agent B1) was obtained.

175 parts of A obtained above and 8125 parts of A were melt-mixed at 60° C. to obtain a casting resin composition (hereinafter referred to as R1).

lt'l ('h (!1.'l Casting and Fixed Side Casting) Heat the R1 prepared above to 60°C and pour it into the above casting mold until all the high spin is embedded.
After defoaming by vacuum suction to 3 mm If g at 0°C for 1 hour, the resin was heated at 60°C for 10 hours to gel the casting resin.

Next, take out the contents from the polycarbonate box, remove all the hardened glue, and place the casting resin on the bottom surface of the polycarbonate box. A mold release agent similar to that used above was applied to the entire surface of the model, and a similar hollow pipe for cooling was placed, followed by casting, vacuum degassing, and heating gelation in the same manner as above.

After opening the mold cast above and taking out the model, 18
It was cured after 10 hours in a constant temperature bath at 0°C. Incidentally, the glass transition temperature of the cured product of the casting resin used in the mold was 175°C, and the heat distortion temperature was 200°C.

Next, a gate for injection molding, etc. is processed into this cured resin mold, and this is placed in a metal holder with casting resin R1.
to obtain a resin mold for injection molding.

Set the resin mold obtained above in an injection molding machine and use polysulfone resin (manufactured by Union Carbide, product name: P-17Qo).
was molded at an injection pressure of 1, 200 kg/c++I, a cylinder temperature of 340° C., and a molding cycle of 2 minutes while cooling the resin mold.

Manufacture of plastic molded printed wiring board The molded body obtained above was immersed in a mixed solution of 50% by volume of 35% hydrogen peroxide and 50% by volume of 98% sulfuric acid at 40°C for 110 minutes, neutralized, and washed with water.

After drying the molded body, the entire surface was activated with palladium using a tin chloride and palladium chloride solution, and a copper layer with a thickness of 20 degrees was deposited using a thick electroless copper layer, followed by photoetching. A double-sided conductive printed wiring board was created using the method.

Example-2 In Example-1, 30 parts of bis(4-maleimidophenyl)propane and the same bisphenol A as in Example-1 were used as a heat-resistant addition-polymerizable thermosetting resin composition for casting.
60 parts of type epoxy resin and 50 parts of diphenylmethane diisocyanate (trade name, MDI-CR1 manufactured by Mitsui Toatsu Kagaku 01) were mixed uniformly, and to this mixture, 400 parts of 150 mesh aluminum powder and 2-ethyl-4-methylimidazole were added. 0.5 part was added and mixed at 60°C to obtain a casting resin (hereinafter referred to as R2).

Using R2 above, use an aluminum plate instead of the polycarbonate plate for the box, and set the gelation temperature to 170℃.
A resin mold was obtained in the same manner except that.

The glass transition temperature was 220°C.

Example-3 In Example-1, 30 parts of bis(4-maleimidophenyl)propane and the same bisphenol A as in Example-1 were used as a heat-resistant addition polymerizable thermosetting resin composition for casting.
After mixing with 70 parts of mold epoxy resin at 120°C for 130 minutes, it was cooled to 50°C, and 5 parts of dichlorodiaminodiphenylmethane, 0.5 parts of dicumyl peroxide, and 300 parts of iron powder were mixed to form a casting resin ( Hereinafter referred to as R3) was obtained.

A resin mold was obtained in the same manner using R3 above, except that an iron plate was used in place of the polycarbonate for the box, and the gelling temperature was changed to 160°C. Glass transition temperature is 200°
It was C.

Example-4 In Example-1, diallylphthalate prepolymer was used as a heat-resistant addition polymerizable thermosetting resin composition for casting.
25 parts and 75 parts of diallyl phthalate monomer at 80°
After uniformly mixing C1, it was cooled, 350 parts of copper powder was uniformly mixed, and then t-butyl peroxyhenzuate 2
The mixture was mixed at 40°C for 20 minutes to form a casting resin (hereinafter referred to as R4).
) was obtained.

Using the above R4, a resin mold was obtained in the same manner except that an iron plate was used in place of the polycarbonate for the box, and the gelation temperature was 150"C.The glass transition temperature was 160°
It was C.

Example-5 As a casting model, the thickness is 3 with 50 dragon
mm(7) acrylic resin plate, 50 small holes with hole diameters of 0 and 7 mm were made in a grid pattern using a 2.54 am pinch, and a fluorine-based mold release agent (trade name: Daifree MS-743, manufactured by Daikin Industries, Ltd.) was added. ) was applied and dried, and then 0.
Using a high-spin with a diameter of 7 mm and equipped with copper pipes similar to those in Example 1, a casting resin composition containing 27 parts of 2°2-his(4-cyanatophenyl)propane and bis( After mixing 3 parts of 4-maleimidophenyl methane, 70 parts of 150 mesh stainless steel powder, and 0.5 part of wax, the mixture was heated and stirred at 80°C for 5 minutes to form a fluid composition. 75 parts of this composition and Examples
Example 1 was carried out in the same manner as in Example 1, except that a resin composition for casting (hereinafter referred to as R2) was obtained by melt-mixing 8125 parts of a curing agent obtained in the same manner as in Example 1 at 60 °C. A resin mold having a glass transition temperature of 178°C was obtained.

The resin mold obtained above was placed in an injection molding machine, and polyether sulfone resin (manufactured by ICI, USA, product name: 420P) was added at an injection pressure of 1, 300 kg/crA, a cylinder temperature of 350°C, and a molding cycle of 2.5. The procedure was the same except that the resin mold was molded while cooling.

[Operation and effects of the invention]

The method for manufacturing a plastic molded printed wiring board of the present invention as described above uses a hard resin mold instead of a metal mold, so it is extremely easy to create the mold.
In addition, the resin mold has excellent heat resistance (Tg, thermal deterioration), abrasion resistance, etc., and is also excellent in workability.
Compared to conventional metal molds, high-mix, low-volume production is extremely low-cost and highly productive, opening up new uses for plastic molded printed wiring boards.

Claims (1)

[Claims] In a method for manufacturing a printed wiring board with front and back conductivity, the method includes creating a molded body for a plastic molded printed wiring board in which a large number of small holes are formed for front and back conduction, and forming a conductor layer on the molded body to create a wiring network, The molded article has the property that the composition before curing becomes fluid at a temperature of 100°C or lower, and the cured resin has a glass transition temperature of 150°C or higher and contains 70% by weight or more of metal powder or metal fiber. It is made from a heat-resistant addition-polymerizable thermosetting resin composition, using a resin mold with hard pins embedded in the small holes, and using a molded body made by molding a heat-resistant thermoplastic resin. A unique manufacturing method for plastic molded printed wiring boards.