JPH03285391A - Manufacture of multilayer wiring board - Google Patents

Abstract

PURPOSE:To restrain the generation of the blisters of inner layer circuits and improve production efficiency by laminating a required number of laminates wherein the surfaces and the rears of the inner layer members are provided with hardenable resin layers, after the resin layers are hardened, prepregs are arranged on the upper and/or lower surfaces of the inner layer members with the hardened resin layers and metallic foil sheets for an outer layer are arranged on outermost layers. CONSTITUTION:Epoxy resin varnish composed of 100 part epoxy resin by weight, 4 part dicyandiamide by weight, 0.2 part benzyldimethylamine by weight and 50 part methyloxindol by weight is applied to both sides of each inner layer member wherein electric circuits are formed on both sides of a glass fabric-based epoxy resin and both sides of a copper sticked laminated sheet, both as inner layer materials, and the epoxy resin varnish is dried by heating it to obtain the inner layer member with the hardened resin layer. A laminate wherein copper foil sheets are arranged on both sides of the inner layer member with the hardened resin layer via respective two epoxy resin impregnated glass fabric prepregs is sandwiched in between metal mold plates made of stainless steel and laminate forming is applied to the laminate for 120 minutes to obtain a multilayer wiring substrate. The prepreg used for the manufacture of the one for electric use can be used as it is. As the metallic foil sheet for an outer layer, the foil sheet of a metal, such as copper only, its alloy or complex metal is used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multilayer wiring board used in electrical equipment, electronic equipment, computers, communication equipment, etc.

[Conventional technology]

A conventional multilayer wiring board consists of a laminate in which a required number of inner layer metal foils are placed on the upper and/or lower surfaces of the inner layer material via prepreg, sandwiched between inner plates, and the outermost layer is stacked together. is sandwiched between mold plates for laminated molding, but since there is an inner plate between the mold plates, the number of laminates interposed between the mold plates has to be reduced, resulting in low productivity. There were drawbacks. However, if the inner plate is removed and only the laminate is stacked in multiple sets and sandwiched between mold plates for lamination molding, the circuit part of the inner layer material will float on the surface of the metal foil for the outer layer, making it unusable as a multilayer wiring board. do not have. For this reason, an attempt has been made to suppress the floating of the inner layer circuit by using a copper foil with an aluminum carrier as the metal foil for the outer layer, but this is not sufficient and an additional process for removing the aluminum is required. Attempts have also been made to perform laminated molding at low pressures, but there has been a problem in that the incidence of molding defects is high.

[Problem that the invention seeks to solve]

As described in the prior art section, in order to improve the productivity of multilayer wiring boards, there are many drawbacks to using copper foil with an aluminum carrier as the metal foil for the outer layer or performing lamination molding at low pressure.

The present invention has been made in view of the above-mentioned problems in the technology, and its purpose is to provide a method for manufacturing a multilayer wiring board that can efficiently produce a multilayer wiring board with less occurrence of lifting of inner layer circuits. It is about providing.

[Means for solving problems]

The present invention is a laminate in which a required number of inner layer materials are provided with a curable resin layer on the front and back surfaces, and after curing, prepreg is arranged on the upper and/or lower surface of the inner layer material with the cured resin layer, and a metal foil for the outer layer is provided on the outermost layer. The method for producing a multilayer wiring board is characterized by sandwiching the required number of circuits between mold plates and laminating them to obtain the required number of multilayer wiring boards, so it is possible to prevent the inner layer circuits from floating with the cured resin layer. The present invention will be described in detail below.

Inner layer materials used in the present invention include woven fabrics, nonwoven fabrics, cloaks, paper, and other base materials made of inorganic fibers such as glass and asbestos, organic synthetic fibers such as polyester, polyamide, polyvinyl alcohol, and acrylic, and natural fibers such as cotton. Materials include phenolic resin, cresol resin, epoxy resin, unsaturated polyester resin, melamine resin, polyimide, polybutadiene, polyamide, polyamideimide, polysulfone, polyphenylene sulfide, polyphenylene oxide, polybutylene terephthalate, polyether ketone, fluororesin, etc. An electric circuit is formed on the metal foil of an electrical laminate made by integrally disposing metal foil on the upper and/or lower surfaces of the required number of prepregs impregnated with a resin such as a modified material, a mixture, etc., and dried. The curable resin layer includes thermosetting resins such as phenolic resin, cresol resin, epoxy resin, unsaturated polyester resin, polyimide resin, thermosetting polyphenylene oxide resin, etc.
A coating layer of a curable resin such as a curable resin, an adhesive resin sheet layer, etc., and preferably has a thickness of 0.0 after curing.
The thickness is preferably 25 to 0.1 mm. The curable resin layer is cured by thermosetting, UV curing, or a combination thereof to obtain an inner layer material with a cured resin layer. As the prepreg, those used in the production of the above-mentioned electrical laminates can be used as they are, and may be the same as the prepreg used for the inner layer material, or may be of a different type. The number of sheets to be used is also arbitrary, but it is preferable to use 1 to 3 sheets. As the metal foil for the outer layer, single, alloy, or composite metal foils such as copper, aluminum, iron, nickel, and zinc are used, and the thickness is not particularly limited, but is preferably 0.01 mm.
The length is preferably 8 to 0.07 m. The mold plate may be made of iron, aluminum, copper, nickel, zinc, or the like alone, alloy, or composite mold plate, and the thickness is not particularly limited, but it is preferably 6 to 15 m. As for the lamination and integration means, a press, a multistage press, etc. are preferable, but are not particularly limited.

The present invention will be explained below based on examples.

〔Example〕

Electric circuits are formed on both sides of a 70 micron thick copper-clad laminate made of glass cloth base epoxy resin with a thickness of 0.5 cm. Epoxy resin is applied to the front and back surfaces of the inner layer material to a thickness of 0.05 cm after curing. Resin (manufactured by Shell Chemical Co., Ltd., product number Ebiko)
1001) After applying an epoxy resin face consisting of 100 parts by weight (hereinafter simply referred to as parts), 4 parts of perilla diamide, 0.2 parts of benzyldimethylamine, and 50 parts of methyloxotol, it was cured by heating at 150'C for 60 minutes. A layered inner layer material was obtained. Next, on the upper and lower surfaces of the inner layer material with a hardened layer, 30 sets of laminates were prepared, in which copper foil with a thickness of 0.018 mm was placed through two sheets of epoxy resin-impregnated glass cloth prepreg with a thickness of 0.1 mm on each side. It was sandwiched between 10-hole stainless steel mold plates made by Hata and laminated and molded at a molding pressure of 30 kg/crA and 165° C. for 120 minutes to obtain 30 multilayer wiring boards.

[Comparative Example 1] A 0.1 mm thick 0.1 mm thick epoxy resin-impregnated glass cloth prib was applied to the upper and lower surfaces of the same inner layer material as in the example.
．． One set consisted of a laminate with copper foil of 018 on sandwiched between 2 mm thick stainless steel inner plates, and sandwiched between 10'4JJ@thick 1oI11!1 stainless steel mold plates at a molding pressure of 30 kg. /c11116
Lamination molding was performed at 5°C for 120 minutes to obtain 10 multilayer wiring boards.

[Comparative Example 2] Thirty multilayer wiring boards were obtained in the same manner as in Comparative Example 1, except that 30 sets of the same laminates as in Comparative Example 1 were laminated as they were without using an inner plate.

Comparative Example 3 Thirty sets of the same laminate as in Comparative Example 1 were laminated without using an inner plate, and the molding pressure was 10 kg/cd.
Thirty multilayer wiring boards were obtained in the same manner as in Comparative Example 1, except that 30 multilayer wiring boards were obtained.

Table 1 shows the performance of the multilayer wiring boards of Examples and Comparative Examples 1 to 3.

〔Effect of the invention〕

The present invention is constructed as described above. In the method for manufacturing a multilayer wiring board described in the claims, there is less occurrence of floating of inner layer circuits, and there is an effect that productivity can be improved.

Claims (1)

[Claims] (1) A laminate in which a required number of inner layer materials are provided with a curable resin layer on the front and back surfaces, and after curing, prepreg is placed on the top and/or bottom surface of the inner layer material with the cured resin layer, and a metal foil for the outer layer is provided as the outermost layer. 1. A method for producing a multilayer wiring board, which comprises sandwiching a required number of multilayer wiring boards between mold plates and laminating them to obtain a required number of multilayer wiring boards.