JPH04247692A - Manufacture of multilayer printed-circuit board - Google Patents

Abstract

PURPOSE:To enable adhesion property of an inner layer, oxidation resistance, and pattern reliability to be improved in a multilayer printed-circuit board used for electrical equipment, electronic equipment, computer equipment, and communication equipment. CONSTITUTION:In a multilayer printed-wiring board which is in one piece by placing an outer-layer material through a resin layer on an upper surface and a lower surface of a required number of inner-layer materials, the inner-layer material is washed with water and dried as needed after oxidation treatment of copper circuit and is dipped into an acid liquid and then is subjected to reduction treatment.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing multilayer printed wiring boards used in electrical equipment, electronic equipment, communication equipment, computing equipment, and the like.

0002

[Prior Art] Conventional multilayer printed wiring boards are obtained by lamination molding with resin layers interposed between inner layer materials or between inner layer materials and outer layer materials. There was a need for improved adhesion and acid resistance. For this reason, a reduction treatment was performed after the oxidation treatment of the copper circuit, but there was a problem in that minute foreign matter such as fine copper compounds was generated on the circuit surface and between the circuits, resulting in a decrease in pattern reliability.

0003

As described in the prior art section, the conventional reduction treatment after the oxidation treatment of copper circuits has the drawback of low pattern reliability. The present invention has been made in view of the above-mentioned problems in the conventional technology, and its purpose is to provide a multilayer printed wiring board with excellent adhesiveness between the inner layer material and the resin layer, acid resistance, and pattern reliability. The purpose is to provide a manufacturing method.

0004

[Means for Solving the Problems] The present invention provides a multilayer printed wiring board in which an outer layer material is disposed on the upper surface and/or lower surface of a required number of inner layer materials via a resin layer. The above object is achieved by a method for producing a multilayer printed wiring board, which is characterized in that the copper circuit is oxidized, washed with water if necessary, dried, immersed in an acid solution, and then subjected to a reduction treatment. The present invention will now be described in detail.

In the inner layer material used in the present invention, a circuit surface formed by etching a single-sided or double-sided metal-clad laminate to form a circuit is treated with a treatment solution such as chlorite, sodium hydroxide, potassium hydroxide, or phosphate. After oxidation treatment (so-called blackening treatment), if necessary, wash with water and dry, then immerse in an acid solution such as an inorganic acid such as hydrochloric acid, sulfuric acid, acetic acid, formic acid, phosphoric acid, or an organic acid.
It is reduced using a reducing agent such as hydrogen generated using an alkaline reducing agent, amine borane, metal, etc. The time, temperature, concentration, etc. of the oxidation treatment, acid solution immersion, and reduction treatment vary depending on the treatment conditions and are not particularly limited, but the acid concentration is PH1 to 5, preferably PH2 to
4 is desirable. The required number of inner layer materials can be used depending on the number of circuit layers. The resin layer disposed on the surface of the inner layer material includes epoxy resin, phenol resin, unsaturated polyester resin, silicone resin, polyphenylene sulfide resin, polyethylene terephthalate resin, polybutylene terephthalate resin, and polyimide resin. , polybutadiene resins, fluorocarbon resins, etc. alone, modified products, and mixtures can be used. If necessary, inorganic powder fillers such as talc, clay, silica, calcium carbonate, aluminum hydroxide, etc. can be used. It can contain fibrous fillers such as glass fibers, asbestos fibers, pulp fibers, synthetic fibers, and ceramic fibers, and the resin layer is formed by applying liquid resin, placing films, sheets, prepregs, etc. , a coating layer, a film, a sheet, a prepreg, etc. may be used in combination, but when used in combination, it is desirable from the viewpoint of adhesiveness to preferably use the same type of resin. The base material for prepreg is woven fabric,
Any nonwoven fabric, mat, paper, etc. can be used. As the outer layer material, single-sided metal-clad laminates, double-sided metal-clad laminates with a circuit formed on only one side, and single, alloy, or composite metal foils of copper, aluminum, brass, nickel, iron, etc. can be used.

The present invention will be explained below based on examples.

[0007]

[Example] After forming a circuit by etching on both sides of a 1 mm thick double-sided copper-clad glass cloth base epoxy resin laminate,
After being immersed in a blackening treatment solution consisting of sodium chlorite, sodium hydroxide, and trisodium phosphate at 90°C for 100 seconds, immersed in a PH4 acetic acid aqueous solution at 30°C for 10 seconds, and then in an amine borane solution at 60°C. After dipping for 50 seconds at 110
The inner layer material was obtained by drying at ℃ for 30 minutes. Next, two epoxy resin glass prepregs each having a thickness of 0.1 mm are placed on the upper and/or lower surfaces of the inner layer material, and furthermore, on the outermost side thereof, a thickness of 0.1 mm is placed.
．． A laminate with copper foil of 0.35 mm thick was molded under a molding pressure of 40 mm.
Kg/cm2, laminated for 120 minutes at 170°C.
A layered printed wiring board was obtained.

[0008]

[Comparative Example] A four-layer printed wiring board was obtained in the same manner as in the example except that after the blackening treatment, the reduction treatment was performed immediately without the acid solution treatment.

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

0010

[Effects of the Invention] The present invention is constructed as described above. The method for manufacturing a multilayer printed wiring board having the configuration described in the claims has the effect of improving pattern reliability while maintaining inner layer material adhesion and acid resistance.

Claims (1)

[Claims] Claim 1: In a multilayer printed wiring board in which an outer layer material is disposed on the upper and/or lower surfaces of a required number of inner layer materials via a resin layer, the inner layer material is formed by oxidizing the copper circuit. A multilayer printed wiring board characterized in that it is washed with water and dried if necessary, immersed in an acid solution, and then subjected to a reduction treatment.