JPS62286298A - 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 3. Detailed Description of the Invention [Field of Industrial Application] The present invention is a type of simple mold, which is manufactured by a certain hard resin mold and has a large number of small holes for front and back conduction. This is a method for manufacturing a plastic molded printed wiring board in which a wiring network is formed on a heat-resistant thermoplastic resin molded body by a known method, 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 manufactured heat-resistant plastic molded products were 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.

[Means for solving problems]

That is, the present invention provides a method for manufacturing a printed wiring board by injection molding a heat-resistant plastic using a hard resin mold to create a molded body, and then applying an electroless plating process to the molded body, in which the hard resin mold includes: , a reference mark part made of a heat-resistant addition-polymerizable thermosetting resin composition and incorporating a large number of hard pins for forming small holes, and provided with pins or holes that serve as reference marks for forming a printed wiring network. Using a hard resin mold in which two or more of the printed wiring boards are formed outside the part to be used as the printed wiring board, through-holes for front and back conduction and wiring networks are formed in the obtained molded product by a conventional method, and then the fiducial mark part is formed. This is a method for producing a plastic molded printed wiring board, which is characterized by removing.

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 molded by compression molding or injection molding. A molded article in the shape of a flat plate, a plate with a curved surface, a plate with a bent surface, etc. is subjected to surface swelling, oxidation, or other surface treatments using a solvent as necessary, and is then treated with a known active material containing Pd, Ag, Cu, etc. After activating with an activating agent, electroless plating is performed to form a Cu or Ni layer on the surface, electrolytic plating is applied as appropriate, a resist is applied, and a pattern is baked and etched using a reference mark; After surface treatment, A method of applying a known photo-activated catalyst, selectively activating it by irradiating it with light using a reference mark, and electroless plating only the activated portion; forming through-holes and wiring networks for front and back conduction using other known methods. This is a printed wiring board.

Heat-resistant plastics that can be soldered include heat-resistant thermoplastic resins such as polysulfone, polyetherimide, polyether sulfone, polyphenylene sulfide, polyphenylene ether, polyester-based and other liquid crystal polymers; polycarbonate, polyphenylene; Internetwork polymers made by mixing thermoplastic resins such as ether and cyanate ester compounds in a ratio of about 30/70 to 70/30 and adding a catalyst (Japanese Patent Application Laid-open No. 142297/1983); Compositions made by adding glass fiber, wollastonite, calcium carbonate, mica, other reinforcing materials, fillers, etc. to the resin; epoxy resins, phenolic resins, cyanate resins, and other injection moldable thermosetting resins The heat resistance of these resin molding materials as they are or after being heated and cured is such that they can withstand the soldering process at 260°C.

The resin mold of the present invention used to mold the above-mentioned molded product is made of a heat-resistant addition polymerization type thermosetting resin composition, has hard pins embedded in the small holes, and has a printed wiring network. This is a resin mold in which two or more reference mark portions having reference pins or holes used for forming reference marks are provided outside the portion to be used as the printed wiring board.

The heat-resistant addition polymerization type thermosetting resin used for manufacturing the resin mold must have a property that the composition before curing becomes fluid at a temperature of 100°C or less, and a glass transition temperature of the cured resin of 150°C. Those capable of achieving C or higher are preferable, specifically heat-resistant epoxy resins and cyanato resins (Japanese Patent Publication No. 41-1.
No. 928, No. 45-11712, No. 44-1222, German Patent No. 119018. cyanate ester-maleimide resin, cyanate ester-maleimide-epoxy resin (Japanese Patent Publication No. 54-30440, etc., Japanese Patent Publication No. 52-31279, USP-4110364, etc.),
Cyanate ester-epoxy resin (Special Publication No. 46-[11
No. 2), modified maleimide resins whose main components are polyfunctional maleimide and epoxy compounds and isocyanate compounds (Japanese Patent Publication No. 8279-1982), isocyanate-oxazolidone resins whose main components are isocyanate compounds and epoxy compounds (Japanese Patent Publication No. 8279), Examples include polyfunctional epoxy resins containing trifunctional or higher polyfunctional epoxy compounds as main components, modified 1,2-polybutadiene resins, diallyl phthalate resins, silicone resins, etc. In particular, cyanato resins, Those containing cyanate ester as an essential component, such as cyanate ester-maleimide resin, cyanate ester-maleimide-epoxy resin, and cyanate ester-epoxy resin, are preferred. For these thermosetting resins, known additives are appropriately used in combination with each resin, such as catalysts and hardening agents such as amines, acid anhydrides, organic metal salts, and organic peroxides. ;Known silicone-based, fluorine-based, etc. mold release agents, waxes, nitrogen-based rubbers,
Examples include flexibility imparting agents such as low-crystalline to non-crystalline saturated polyester resins and elastomers with low molecular weights such as polyurethane; known antifoaming agents and coupling agents such as silicone-based agents.

Queen's heat-resistant addition polymerizable thermosetting resin is preferably used as a composition containing metal powder or metal fiber in an amount of usually 70% by weight or more and 40 to 65% by volume. This is mainly used for the purpose of imparting thermal conductivity to the resin mold and is not particularly limited, but specific examples include:
Iron, iron-based alloys, 2.

Kel, nickel-based alloys, cobalt, cobal-IJI gold, aluminum, aluminum-based alloys, copper, copper-based alloys, etc. 6 We also use inorganic fillers such as silica, aramid fibers and carbon for reinforcing resin molds and other purposes. A method in which organic or inorganic fibers such as fibers are also used is also preferred.

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 kneading, the temperature is 100°C according to the present invention.
Hereinafter, a heat-resistant addition-polymerizable thermosetting resin composition that is viscous liquid or paste at a temperature of, for example, about 50 to 90°C is prepared and used for manufacturing a resin mold.

The resin mold of the present invention is 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, and applying the molding. It is manufactured by post-processing and installing parts compatible with the method, such as gates.

The desired model is one that has the same shape as a molded object, such as a flat plate with a large number of small holes for front and back conduction, a flat plate with partially uneven parts, a curved plate, a bent plate, etc. , two or more reference mark portions with pins or holes that serve as reference marks for forming a printed wiring network are provided outside the portion to be used as the printed wiring board, and are resistant to heating during casting and preliminary curing. There are no particular restrictions.

Here, the placement of the reference mark is not particularly limited as long as it does not interfere with the formation of wiring networks or the mounting of electronic components, etc.; am and at a position where it can be removed as appropriate after the wiring network is formed, that is, at a position that will become the outer periphery of the plastic molded printed board body (for example, as shown in Fig. 1), and the reference mark portion It is sufficient that there be at least two in the integral molded body as shown in FIG. As a reference mark, the diameter or side length is 2 to 101 m.
The diameter of the through hole or pin is a cylinder with a diameter of about 2 to 10 mm, or a square column with a side of about 2 to 1 cm, and the protrusion from the wiring network part of the model (both sides) is preferably about 2 to 10 baking soda. The material to be attached may be the same as the model, or may be metal.

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, if desired, a release agent is applied to the small holes and two or more reference marks of the model. Apply to the entire surface including the skin and let dry.

Process ■: Usually, in a container that can be vacuum-suctioned and heated as appropriate, a hardening paste-like material used for molding, such as plaster, is spread on a rectangular plate to a predetermined thickness. , After placing the model prepared in step ① on top of the hard pin with the fixed side facing upward, insert a small hole in the model with the same diameter as the small hole and the ends protruding from both sides of the model. And a hard pin is attached to one side of the resin mold so that it is sufficiently fixed. Furthermore, if desired, a hard pin for the reference hole is also attached in the same manner. Next, the paste mold is surrounded by a rectangular columnar plate-like material, the paste mold is hardened, and a metal pipe or the like is placed above it to serve as a medium flow path for cooling the mold.

Usually, high-speed steel (high spin) is suitable for the hard pin, and the diameter is 0, 1. +n or more is preferred.

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 O~30 kg/cIIt, and the temperature is 6.
It is heated and pressurized at a temperature of 0° C. or more and 180° C. or less, particularly about 60 to 150° C., to gel or semi-cure or to form a gelatinous material, 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, hard pin and casting resin surface, and apply a mold release agent to the model, hard pin, and casting resin surface.
Set about 10 pieces of metal plates and metal rods for reinforcement,
After setting the container again in the container used in step (2) and placing a metal pipe etc. as a medium flow path for mold cooling, the heat-resistant addition polymerizable thermosetting resin composition of the present invention is poured from above. After pouring and 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 addition, the above process describes a method of casting a split mold in two stages, gelling it, or semi-hardening or hardening it, but it is also possible to make a more complicated mold by casting in three or more stages or reverse Another method is to place the model, hard pins, medium flow path, etc., parts such as a molding gate, and a thin mold release film as appropriate in a casting container, and then perform the casting in two steps. It is something that can be done.

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 plastic that can be soldered, but the molding cycle is usually such that the temperature of the side of the resin mold used that is in contact with the molded object does not exceed the glass transition temperature of the resin in the resin mold. The cycle is longer than that of metal molds.

〔Example〕

The present invention will be explained below with reference to Examples. In addition, parts in the examples are based on weight unless otherwise specified.

Example-1 Model Creation 5 (Cutting a glass cloth base epoxy resin laminate with a thickness of 211 mm using an hmx8Q dragon, cut 50 pieces of sleeve-shaped pieces with a width of 1 cm and a length of 3 cm at both ends of one side of a square of 50 m. The board is held, and two small holes with a hole diameter of 0 and 9*vn are made in the square part.
．． Open 100 pieces in a grid pattern with 54 dragon pitches, make a hole with a diameter of 611 cm 1 cm from the tip of the sleeve, and glue a metal rod of the same shape into this hole so that 3 dragons protrude from both ends to form the reference mark section. And so. A fluorine-based mold release agent (trade name: Daifree MS-743, manufactured by Daikin Industries, Ltd.) was applied to this and dried.

On a board of 100 mm x 120 mm of resin casting for the manual side, spread a paste-like material made of a mixture of plaster and vinyl acetate emulsion 30 mm thick, and in the center. After placing the model in close contact with the model, insert a high-spin rod with a diameter of 0.9 mm and a length of 4 cm into the small hole so that the protruding length from the model is 30 cm. Height: 130mm with and without entry/exit holes
It was made into a box shape by standing it upright, and a mold release agent was applied to the inside surface. Next, a copper pipe bent several times into a U-shape with an inner diameter of 5 mm for cooling 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 7 cetyl 7 setone iron is dissolved in advance
, viscosity 120-150PS at 25°C1 epoxy 9184-194, oil-based shell epoxy@g) 25 parts and 300 mesh copper powder 75 parts 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).

For video and hard side heating R1 prepared above was heated to 60°C, poured into the above casting mold until all the high spin was embedded, and heated to 60°C.
After vacuum suction to 3wmHg at ℃ and defoaming for 1 hour,
It was heated at ℃ for 10 hours to gel the casting resin.

Next, take out the contents from the polycarbonate box, remove all the hardened glue, place the molding resin on the bottom of the polycarbonate box, and place the molding resin on the bottom surface of the polycarbonate box. After applying the same mold release agent as used above and arranging the same copper pipe for cooling, cast again in the same manner as above.
Vacuum defoaming and heating gelation were performed.

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. The glass transition temperature of the cured resin used in the mold is 175°C.
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.

Manufacture of molded body The resin mold obtained above was set in an injection molding machine, and polysulfone resin (manufactured by Union Carbide, product name: P-1700)
was molded at an injection pressure of 1, 200 kg/ci, a cylinder temperature of 340° C., and a molding cycle of 2 minutes while cooling the resin mold.

Koudanλl2! The molded body obtained above was mixed with 35% hydrogen peroxide, 50% by volume, and 98% sulfuric acid, 50% by volume.
Neutralize by immersing in a volume% mixed solution at 40°C for 110 minutes,
Washed with water.

After drying the molded body, the entire surface was activated with palladium using a tin chloride and palladium chloride solution, and then a 20-thick copper layer was deposited by thick electroless copper plating. Furthermore, after applying a photodegradable photosensitive etching resist to the entire surface of the deposited area, a negative film for forming a wiring network having reference holes prepared in advance is set by inserting the reference holes into the reference pins of the molded body. After irradiating it with ultraviolet rays, the photosensitive area was removed, the exposed copper was removed using a known etching method, the resist was peeled off, and the reference mark area was cut to obtain a good double-sided conductive printed wiring board. .

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 diphenylmethane diisocyanate (trade name: ADI-CR1 manufactured by Mitsui Toatsu Chemical Co., Ltd.)
To this mixture, 400 parts of 150 mesh aluminum powder and 0.5 part of 2-ethyl-4-methylimidazole were added, and the mixture was mixed at 60°C to form a casting resin (hereinafter referred to as R2). ) was obtained.

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

The glass transition temperature of the resin mold was 220°C.

A good double-sided conductive printed wiring board was obtained in the same manner as in Example 1 except that this resin mold was used.

Example-3 As a casting model, the printed wiring board part is 6゜n
9ONX 1.6mm (thickness) Te, hole diameter 0, 7u
+, 2.541n pinch grid-like small holes (total number of holes 15
0 pieces), holes for attaching other parts, - Holes for attaching printed wiring boards and lips (hole diameter 5 pieces) near both ends of the long side.
4 molded bodies each having a diameter of 10 mm, a rib diameter of 10 mm, and a height of 6 mm are arranged, and there are 2 reference marks with reference pins (3 mm in diameter and 4 mm in height each) on the center line. A model was created as shown in FIG. 1 (in FIG. 1, small holes and holes for other parts were omitted). Using this model, a resin mold was obtained according to Example-1.

The resin mold obtained above was set in an injection molding machine, and polyether sulfone resin (manufactured by IC1, USA, product name: 420P) was injected at an injection pressure of 1, 300 kg/cnl, and a cylinder temperature of 350'C1, and a molding cycle of 2.5. A molded body was obtained in the same manner except that the resin mold was molded while cooling.

Using this molded body, a pattern for four pieces for this molded body,
A through hole for double-sided conduction and a wiring network were formed in the same manner as in Example-1 except that a pre-prepared negative film having holes corresponding to the reference hole and the mounting part was used, and the reference mark part was removed and separated into individual parts. A printed wiring board with good double-sided conductivity was obtained.

[Operation and effects of the invention]

As explained above in the detailed description and examples, the method for producing a plastic molded printed wiring board of the present invention is extremely easy to create a mold, and the resin mold has high heat resistance (Tg, thermal deterioration) and wear resistance. It has excellent properties such as flexibility and workability, so compared to conventional metal molds, high-mix, low-volume production can be carried out at extremely low cost and with high productivity. Furthermore, since the reference mark for the wiring network is integrally formed on the outside of the molded body and removed after use, it is easy to set the position of the wiring pattern, increasing the degree of freedom in design, etc., and increasing productivity. This also improves the finish and opens up new uses for plastic molded printed wiring boards.

[Brief explanation of drawings]

FIG. 1 shows a plan view of a plasti-molded printed wiring board molded article having a fiducial mark portion according to the present invention, and FIG. 2 shows a side view thereof. In FIG. 1, small holes and other component mounting holes are omitted. The numbers in the diagram are: 1 Niblint wiring board part, 2: Reference mark part, 3: Reference pin, 4: Printed wiring board mounting hole, 5 Varnish blue, 6
: Runner, 7: Gate. Patent Applicant Mitsubishi Gas Chemical Co., Ltd. Agent Patent Attorney (9070) Sadafumi Tebori Figure 1 Figure 2

Claims (1)

[Claims] In a method of manufacturing a printed wiring board by injection molding heat-resistant plastics using a hard resin mold to create a molded body and applying an electroless plating process to the molded body, the hard resin mold may be a heat-resistant addition polymerization type. The print is made of a thermosetting resin composition and has two or more reference mark portions embedded with a large number of hard pins for forming small holes, and provided with pins or holes that serve as reference marks for forming a printed wiring network. A hard resin mold provided outside the part to be the wiring board is used, and after forming through-holes for front and back conduction and a wiring network in the obtained molded product by a conventional method, the reference mark part is removed. A manufacturing method for plastic molded printed wiring boards.