JPH02303195A - Multilayer printed wiring board - Google Patents

Abstract

PURPOSE:To obtain a multilayer printed-wiring board whose hole processing property and heat-resistant property are excellent by a method wherein laminated bodies where outer-layer materials are arranged on the surface and/or the rear surface of an inner- layer material including a nonwoven base material via prepregs are laminated and united. CONSTITUTION:Laminated bodies where outer-layer materials are arranged on the surface and/or the rear surface of an inner-layer material including a nonwoven base material are laminated and united. As the inner-layer material, a base material including at least one layer of the nonwoven base material such as an inorganic fiber nonwoven cloth such as a glass nonwoven cloth, a sheet of glass paper or the like, an organic synthetic nonwoven cloth such as a polyester, a polyamide, a polyvinyl alcohol, a polyacryl or the like is impregnated with a resin varnish composed of a single substance, a denatured substance or a mixed substance of a phenolic resin, a cresol resin, an epoxy resin or the like to which a filler such as calcium carbonate, aluminum hydroxide or the like is added; this assembly is dried. Metal foils are arranged on the surface and/or the rear surface on which the required number of prepregs is piled up; they are united; after that, electric circuits are formed on the metal foils.

Description

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

[Conventional technology]

Conventional multilayer printed wiring boards are made of paper or glass cloth based prepreg and an inner layer material obtained by processing a laminate made of the prepreg, and those made of paper base material are punched.
The glass cloth base material is drilled to create holes such as through holes. The advantages and disadvantages of paper substrates are that they are easy to drill holes and have good production efficiency, but have limited heat resistance, while glass cloth substrates have excellent heat resistance but are difficult to drill holes and have poor production efficiency. there were.

[Problem that the invention seeks to solve]

As mentioned in the conventional technology, regarding the conventional multilayer printed wiring board,
However, it had one advantage in terms of performance and workability.

The present invention has been made in view of the above-mentioned problems in the prior art, and its purpose is to provide a multilayer printed wiring board with excellent hole machinability and heat resistance.

Means for Solving Problems c] The present invention is a multi-layered product characterized by being formed by laminating and integrating a laminate in which an outer layer material is disposed on the upper surface and/or lower surface of an inner layer material including a nonwoven fabric base material via a prepreg. Because it is a printed wiring board, it was able to achieve the above purpose, and hereafter referred to as the original F3A.
will be explained in detail.

The inner layer material used in the present invention is a base material containing at least one layer of a nonwoven fabric such as an inorganic fiber nonwoven fabric such as glass nonwoven fabric or glass vapor, or an organic synthetic fiber nonwoven fabric such as polyester, polyamide, polyvinyl alcohol, or polyacrylic. Individual resins, Frezy Alt resins, epoxy resins, unsaturated polyester resins, polyimide resins, polybutadiene resins, polyphenylene oxide resins, fluorinated resins, polybutylene terephthalate resins, polyethylene terephthalate resins, polyphenylene sulfide resins, etc.
Required number of prepregs made by impregnating and drying a resin face made of a modified substance or mixture with fillers such as calcium carbonate, aluminum hydroxide, clay, talc, silica, alumina, pulp, or cotton powder as necessary. Metal foil is integrally placed on the upper and/or lower surfaces of the overlapping layers, and then an electric circuit is formed on the metal foil. The above resins are used as the prepreg, but in addition to the above base materials, glass, inorganic fibers such as asbestos, polyester,
Woven fabrics or paper made of organic fibers such as polyamide, polyvinyl alcohol, and polyacrylic fibers and natural fibers such as cotton can be added. As the outer layer material, one piece F metal clad laminate,
Metal foil can be used. As the lamination molding method, any lamination molding method such as a multistage press method, a press method, a multi-roll method, a double belt method, a continuous pressureless molding method, etc. can be used.

The present invention will be explained below based on examples.

Example: Copper foil with a thickness of Q and 035n was placed on the upper and lower surfaces of one sheet of epoxy resin glass nonwoven fabric prepreg with a thickness of 0.8 fl through one sheet of epoxy resin Dallas fabric prepreg with a thickness of 0.1 fl, respectively. Double-sided copper-clad stack 1i made by integrating all F-layers of the stack body
An electric circuit is formed on the double-sided copper foil surfaces of one plate to form an inner layer material, and one sheet of epoxy resin glass cloth prepreg with a thickness of Q and 2 fl is interposed on the upper and lower surfaces of the inner layer material, respectively, to a thickness of 0.018 mm.
A laminate with copper foil of 1.5 m is molded at a molding pressure of 40 k, 16 m.
Lamination molding was performed at 5° C. for 60 minutes to obtain a 4-layer printed wiring board.

Comparative Example: As an inner layer material, 5 sheets of epoxy resin glass cloth prepreg with a thickness of 0.2 mm were used, with a thickness of 0.0351 mm above and below! ! ! A four-layer printed wiring sheet metal was obtained in the same manner as in the example except that a double-sided copper-clad laminate formed by integrally laminating copper foil of R was used.

Table 1 shows the characteristics of the four-layer printed wiring boards of Examples and Comparative Examples.

〔Effect of the invention〕

The present invention is constructed and layered as described above. The multilayer printed wiring board having the configuration described in the claims has the effect of having good heat resistance and improving hole-drilling processability.

Patent questioner Matsushita Electric Works Co., Ltd.

Claims (1)

[Claims] (1) A multilayer printed wiring board characterized by being formed by laminating and integrating a laminate in which an outer layer material is disposed on the upper and/or lower surface of an inner layer material including a nonwoven fabric base material via a prepreg.