JPS63148698A - 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 is a method of manufacturing a printed wiring board using a plastic molded body having a large number of through holes produced by injection molding, and is particularly an economical method. This method uses a mold for injection molding, and can be suitably applied to high-mix, low-volume production.

[Conventional methods and their problems]

BACKGROUND ART Conventionally, as a mold used in a method for manufacturing a heat-resistant plastic molded product having a through hole, a steel mold for a normal mold or a simple mold made of a low melting point metal has been used.

Conventional steel molds have the disadvantage of having a large number of pore-machined parts that are extremely difficult to process, in terms of accuracy, or in terms of cost. In addition, in the case of a low melting point metal, it is essential that the through hole is formed into a mold in which a hard pin is embedded and fixed, but there is a drawback that the fixed hard pin is likely to loosen due to heat or pressure.

The present invention solves the above problems and manufactures a low-cost heat-resistant plastic molded printed wiring board by easily manufacturing a mold capable of forming various types of complicated through-holes at a low cost and in a short time. This was completed after intensive consideration of the method.

[Means for solving the problems] [The present invention involves injection molding heat-resistant plastic to create a plastic molded body having a large number of through holes, forming a conductor layer on the molded body, and fabricating a printed wiring board. In the manufacturing method, as a mold for producing a molded body, a fixed metal mold plate having at least a molten resin introduction part and a space for mounting a mold part, and communicating with the fixed metal mold plate as necessary. An injection molding die comprising a stripper metal template having a molten resin introduction part and a space for mounting a mold part, and a movable metal template having a space for mounting the mold part. A set is prepared, and is made of a metal and a hardened resin composition consisting of a type I in which a recess for a cavity is formed and a type II in which a through hole for movable hard pin for hole formation and a recess for a cavity is formed as desired. A pair of molds made of one piece, and a hard pin mold III to which the hard pin for hole formation was fixed,
(a) An injection molding mold which is assembled in this order by fixing the mold I to the fixed metal template, the mold II to the stripper metal template, and the hard pin mold III to the movable metal template, or (bl, hard pin type III to fixed side metal template, type II
This is a method for manufacturing a plastic molded printed wiring board, characterized by using an injection molding mold which is assembled in this order by fixing the mold (1) to a stripper metal template and the movable metal template (2) to a movable metal template.

The present invention will be explained below.

The plastic molded printed wiring board of the present invention is a flat plate having a large number of small holes for front and back conduction and other holes formed by injection molding using solderable heat-resistant plastic, or a partially uneven board. A molded body in the shape of a flat plate, a plate with a curved surface, a plate with a bend, etc. is subjected to surface swelling, oxidation, or other surface treatments with a solvent as necessary, and is treated with known active substances including Pd, Ag, Cu, etc. After activation with a activating agent, Cu and Ni are deposited by electroless plating or vapor deposition.
A method of forming a layer selectively or on the entire surface and finally forming a desired circuit; after surface treatment, a known photoactive catalyst is applied and selectively activated by light irradiation, leaving only the activated portions blank. Electrolytic plating method; This is a printed wiring board formed by forming through holes for front and back conduction and a wiring network using other known methods.

Heat-resistant plastics that can be soldered include heat-resistant thermoplastic resins such as polysulfone, polyetherimide, polyether sulfone, polyphenylene sulfide, polyphenylene re-ether, polyester, and other liquid crystal polymers; polycarbonate, polyphenylene ether Polyfunctional unsaturated compounds, low molecular weight 1,2-polybutadienes, epoxy resins, cyanate ester compounds, other thermosetting monomers, etc. are usually added to thermoplastic resins such as 70 to 30%. Internetwork polymer (JP-A-54-1
No. 42297), etc.; compositions made by adding glass fiber, wollastonite, calcium carbonate, mica, other reinforcing materials, fillers, etc. to these resins; epoxy resins, phenol resins, cyanate resins, etc. Examples include thermosetting resin molding materials that can be injection molded, and their heat resistance as is or after heat curing is sufficient to withstand soldering at 260°C.

The mold of the present invention for producing a molded article by injection molding the above-mentioned resin includes a fixed metal mold plate forming at least a molten resin introduction part and a space for mounting a mold part, and optionally A stripper metal mold plate having a molten resin introduction part communicating with the fixed metal mold plate and forming a space for mounting the mold part, and a movable metal mold having a space for mounting the mold part. Prepare a guiscent for injection molding consisting of a plate,
If desired, the receiver for the hard pin for forming a hole for a plastic molded body is made of a mold (2) in which a recess for a hole and a cavity is formed, a through hole for the movement of the hard pin for hole formation, and a mold in which a recess for a cavity is formed if desired. (a), a pair of molds made of an integral piece of metal and a cured resin composition, and a hard pin mold III in which the hole-forming hard pins are fixed with a curable composition; An injection mold formed by fixing I to the fixed metal template, mold II to the stripper metal template, and rigid bottle mold III to the movable metal template, and assembling them in this order, or (b), Hard pin type III to fixed side metal template, type II
is fixed to the stripper metal template, and mold (2) is fixed to the movable metal template, and assembled in this order to form an injection mold.

Here, the die set refers to ordinary metal materials for molds - iron,
It is made of a plate made of iron alloy or other metal, and each has a space or hole of a predetermined size for fixing a pair of molds for the cavity, and a hard pin mold III. . In particular, the stripper metal plate is installed to prevent ``bagging'' due to poor vertical and horizontal alignment when the mold is opened and closed during injection molding.

A pair of molds I and (2) for the cavity are made of a single piece of metal and a hardened resin composition.

Here, the thermosetting resin composition forming the cured resin composition includes a cyanate ester resin composition, a modified maleimide resin (specially Kosho 48
-8279), isocyanate-oxazolidone resin containing an isocyanate compound and an epoxy compound as main components (JP-A-55-75418), epoxy resin, modified 1,2-polybutadiene resin, diallyl phthalate resin, silicone resin, etc. Curable resin: This thermosetting resin is usually blended with metal powder, metal fibers, inorganic fillers such as boron nitride, etc. in a range of 65 to 15% by volume, and the glass transition temperature after curing is 100 ° C. Above, especially 1
A material that has fluidity at a temperature of 50°C or higher and 100°C or lower, and is made by impregnating this thermosetting resin into a woven or nonwoven fabric made of an appropriate combination of metal fibers, carbon fibers, glass fibers, etc. It is a molded article using prepreg, and preferably has a glass transition temperature of 100° C. or higher, particularly 150° C. or higher after curing.

Metals include aluminum, aluminum-based alloys, iron, iron-based alloys, copper, copper-based alloys, nickel, nickel-based alloys, and other metals.

The method for manufacturing an integrated product of the above metal and a cured resin composition and a mold cavity using the same is as follows (i)
-(vi) are exemplified.

(i) Create an integrated flat plate by bonding a metal flat plate or foil and a cured resin composition flat plate using an adhesive or an adhesive sheet, or by casting a resin composition on one side of the metal flat plate or foil. A method of forming a part of the desired cavity by machining, electrical discharge machining, etching, etc.

(ii) Create an integrated flat plate by bonding a metal flat plate or foil and a fiber-reinforced resin laminate using an adhesive or an adhesive sheet, and then form a part of the desired cavity by machining, electrical discharge machining, etching, etc. How to form.

(fit) A method in which a plurality of prepregs are layered and laminated on one side of a metal flat plate or foil to create an integrated flat plate, and a desired cavity is partially formed by machining, electrical discharge machining, etching, etc.

(iv) A method in which a flat metal plate or foil and a metal flat plate are bonded together using an adhesive or an adhesive sheet to create a flat plate, and a part of the desired cavity is formed by machining, electrical discharge machining, etching, etc.

(v) Create a desired model, obtain a resin mold by casting using resins J and Il, and coat the cavity surface with known electroless plating or, if necessary, electrolytic plating, etc. Method of forming metal layers.

(νi) Create a flat plate by casting and curing the resin composition, or
Alternatively, create a laminate by stacking multiple sheets of prepreg based on non-woven or woven fabrics such as carbon fiber or glass fiber, form a cavity surface by machining, and apply known electroless plating or as needed. A method of forming a metal layer on top of it by electrolytic plating, etc.

The mold manufactured by the above method usually has a concave part for the cavity for the plastic molded body, other desired irregularities, and if necessary, a hard pin holder for forming a hole with a depth of 1 to 5 mm. form in position. In addition, a through hole was formed at a predetermined position in the mold (2) to be fixed to the stripper metal template to allow the hard pin for hole formation to move.

In addition, the hard pin type (■) is usually made by aligning and fixing the pair of molds (■ and II) for the cavity as described above, applying a mold release agent to the surface of the mold (2), and inserting the hard pin. Method of temporarily fixing, casting a curable composition, and curing: Align and fix a pair of molds for the cavity as described above, and then mold a metal having a through hole at the same position as the through hole. A particularly preferred method from the viewpoint of dimensional accuracy is a method in which after aligning and arranging the plates and the like, a hard pin is inserted and the hard pin is fixed using the above-mentioned curable composition. However, methods other than those described above can naturally be used as long as the method allows high precision in fixing the position of the hard pin.

Any curable composition can be used as long as it has a certain degree of heat resistance, including heat-resistant plasters, cements, plastic refractories, low melting point alloys, and thermosetting resin compositions. The above-mentioned compositions for hard resin molds, which are a type of thermosetting resin compositions, are preferred from the viewpoint of handleability, impact resistance, curing shrinkage, etc.

Further, the hard pin is made of iron, stainless steel, high speed steel, etc., and is usually 0. innφ or larger, with a convex part of a larger diameter at one end to make the fixation stronger,
In order to improve mold releasability from the injected resin, a material with fluororesin baked onto the surface of at least a portion of the mold cavity is appropriately used.

Using the mold fortress described above, the mold of the present invention is assembled, set in an injection molding machine, and heat-resistant plastic is injection molded to obtain a molded body for a plastic molded printed wiring board.

Injection molding conditions and other conditions are appropriately selected depending on the type of plastic used. In addition, holes, grooves, irregularities, ribs, frames, etc. are appropriately formed in a part of the mold cavity for the purpose of attaching parts to the printed wiring board, forming a wiring network, reinforcing it, and attaching the printed wiring board. It is also easy to manufacture them as original materials, and these can be added to Types I and (2) as appropriate.

Furthermore, there are various injection molds depending on the type of gate, and the invention can be applied to these as appropriate.

〔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 Preparation of die set As a fixed-side metal template, a 40 mm thick steel plate with a depth of 15 dragon 9Q fin x 9 (hn square holes for fixing the resin introduction part and mold I for the cavity) was used. A 10 mm thick steel plate with holes of 90 x 90 angles for fixing the cavity mold ■ was used as the stripper metal template, and a 15 mm deep steel plate was used as the movable side metal plate for fixing the hard pin fixed type ■. 1 of 85
A steel plate with a thickness of 40mm and having a hole of +n x 35 +u angle was prepared.

These metal templates naturally have sprues, runners, and other parts for introducing molten resin, fixing parts for assembling and fixing them to the mold, guide pin bushes, and other parts, just like those used in ordinary molds. The auxiliary jig part was formed.

First, as a resin composition for the hard resin mold, 2.2-bis(
30 parts of a prepolymer prepared by heating and stirring 4-cyanatophenyl)propane at 150°C for 3 hours and 70 parts of 150 mesosh aluminum powder were mixed to obtain a composition. Bisphenol A type epoxy resin (trade name: Epicote 82 days, viscosity 120-150 PS a
It was prepared by mixing 25 parts of Yuka Shell Epoxy (2) at 60°C with a temperature of 25°C and an epoxy equivalent of 184 to 194.

Then, thickness 21111 + 100 x 100 *
Surrounding a heavy duty aluminum alloy plate, the resin composition for hard resin mold prepared above was heated to 60°C and cast,
After defoaming, heat at 80°C for 22 hours, then further heat to 170°C.
Aluminum heated and cured for 8 hours to a total thickness of 10 mm/
After creating an integrated board of cured resin, this is 90x9
I finished it to 0 dragon angle and made two flat plates.

Using this temporary piece, place the 50mm in the center of the aluminum alloy surface.
In order to form a cavity of 50 mm square and 2 fins thick, it was masked with a resist, and the aluminum sheet metal was eluted by an etching method to create a mold (2).

In the other plate, 100 through holes of 0.92 m1+φ were bored at desired positions corresponding to a part of the cavity to create a mold II.

Moreover, the hard pin mold (2) was manufactured by the method using the above-mentioned resin composition for hard resin molds.

Stack the molds ■ and II for the cavity created above on one side of the cavity with mold II as the top surface, and insert the molds 2 in length into the hole in mold H.
Insert a high-speed steel pin of 5 mm The frame of (S) was aligned and fixed.

Next, the resin composition for the hard resin mold was cast at 60°C, held for 4 hours while degassing under vacuum, and the resin was gelled. After hardening in a constant temperature bath for 8 hours, the external shape was processed to 85u+X8.
Hard bottle type III with 5mm x 15mm (casting part thickness)
was created.

Assembling the metal and manufacturing the molded body Assemble the Guicent obtained above by aligning the mold I to the fixed metal template, the mold II to the stripper metal template, and the hard bottle mold III to the movable metal template. I raised it and fixed it.

The stripper metal plate was attached to the movable metal plate, and the hard pins were placed so that they did not come out of the cavity surface of the stripper metal template at all when the mold was opened.

Set the above mold in an injection molding machine, and add polysulfone resin (manufactured by Union Carbide, product name: P-1700).
Pressure 1,200kg/a (, cylinder temperature 340℃,
Molding cycle: Molding was performed in 20 seconds.

Production of phantom plastic prints The molded article 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 510 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 then a copper layer with a thickness of 20 mm was deposited by thick electroless copper plating. Furthermore, after applying a photodegradable photosensitive etching resist to the entire surface of the deposited area, a pre-prepared negative film for forming a wiring network is sewn, exposed to ultraviolet light, and the exposed area is removed. The exposed copper was removed by a known etching method and the resist was peeled off to obtain a double-sided conductive printed wiring board.

Example 2 2.2-his(4-cyanatophenyl)propane 90
and 10 parts of bis(4-maleimidophenyl)methane were pre-reacted at 150°C for 2 hours, and to this was added 10 parts of bisphenol A type epoxy resin (trade name, EPON 828, epoxy equivalent weight 120-150) and as a catalyst,
After dissolving 0.03 parts of zinc octylate in methyl ethyl ketone to form a face, this was impregnated with a 0.41-thick carbon fiber woven fabric and dried to obtain a B-stage prepreg.

One sheet of this prepreg was layered on an aluminum plate with a thickness of 7.6 mm, and then an aluminum alloy plate with a thickness of 2 mm was layered. An integrated laminate of /carbon fiber reinforced resin/aluminum alloy plate was obtained.

The molds for cavities were manufactured in the same manner as in Example 1, except that the integrated laminate of aluminum Fi, carbon fiber reinforced resin, and aluminum alloy plate obtained above was used for manufacturing molds I and H for cavities. I, type ■ and hard pin type I
A good double-sided conductive printed wiring board was fabricated in the same manner as in Example 1, except that a 51 m thick aluminum plate was used as the fixed side metal plate for thickness adjustment in assembling the mold. Obtained.

[Operation and effects of the invention]

As explained above in the detailed description and examples, the method for manufacturing a plastic molded printed wiring board of the present invention involves fixing a mold cavity mold, a movable hard pin mold, and a hard pin mold to a die set. Since this is a method for producing a cavity for a molded body for a plastic molded printed wiring board, it is possible to easily produce molds for cavities and movable hard pins with good precision, which are difficult to produce. be.

Due to the above characteristics, plastic molded printed boards can be produced more economically and quickly, and can be produced in large quantities in small quantities at an extremely low cost compared to conventional metal molds.
Productivity is something that can be done. Moreover, in addition to small holes for double-sided conduction, it is also easy to make holes, grooves, irregularities, ribs, frames, etc. in a part of the mold cavity for wiring networks, parts attachment, wiring board attachment, reinforcement, and other purposes. This opens up new uses for plastic molded printed wiring boards, which have improved flexibility in design, productivity, and good finish.

Claims (1)

[Scope of Claims] 1. A method for producing a printed wiring board by injection molding heat-resistant plastic to create a plastic molded body having a large number of through holes, and forming a conductive layer on the molded body. As a mold for use, a fixed-side metal mold plate forming at least a molten resin introduction part and a space for mounting the mold part, and, if necessary, a molten resin introduction part connected to the fixed-side metal mold plate, is used. An injection molding die set consisting of a stripper metal template forming a space for mounting the mold part and a movable metal template forming a space for mounting the mold part is prepared. 1 made of a metal and a hardened resin composition, consisting of a mold I in which a recess was formed, a mold II in which a through hole was formed for the movement of the hard pin for hole formation, and a recess for a cavity if desired. A pair of dies, and a hard pin type III with the hard pin for hole formation fixed therein. An injection mold made by fixing each to a metal template and assembling in this order, or (b), hard pin type III to the fixed metal template, type II to the stripper metal template, and mold I to move. A method for producing a plastic molded printed wiring board, characterized by using injection molding molds which are each fixed to side metal templates and assembled in this order. 2. The manufacturing method according to claim 1, wherein the curable composition is a thermosetting resin composition for a hard resin mold.