JPH04247690A - 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 as needed after oxidation treatment of a copper circuit and is subjected to spray treatment in alkali 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. After oxidizing the copper circuit, wash with water if necessary,
The above object has been achieved by a method for manufacturing a multilayer printed wiring board characterized in that the multilayer printed wiring board is subjected to a reduction treatment after being sprayed with an alkali solution.The present invention will be described in detail below.

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), washing with water if necessary, spraying with an alkaline solution such as sodium hydroxide or potassium hydroxide, and then generating using an alkaline reducing agent, amine borane, metal, etc. It is reduced using a reducing agent such as hydrogen. The time, temperature, concentration, spray pressure, etc. of the oxidation treatment, alkaline spray treatment, and reduction treatment vary depending on the treatment conditions, and are not particularly limited, but the concentration of the alkaline solution is PH1.
It is preferable that it is 3 or more. The required number of inner layer materials can be used depending on the number of circuit layers. The resin layer placed on the surface of the inner layer material is epoxy resin, phenol resin,
General resins such as unsaturated polyester resins, silicone resins, polyphenylene sulfide resins, polyethylene terephthalate resins, polybutylene terephthalate resins, polyimide resins, polybutadiene resins, fluorine resins, etc. alone, modified products, and mixtures. If necessary, inorganic powder fillers such as talc, clay, silica, calcium carbonate, and aluminum hydroxide, and fibrous fillers such as glass fiber, asbestos fiber, pulp fiber, synthetic fiber, and ceramic fiber can be used. A resin layer can be formed by coating a liquid resin, placing a film, sheet, prepreg, etc., and a coating layer, film, sheet, 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. As the base material for the prepreg, any woven fabric, 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 immersing in a blackening treatment solution consisting of sodium chlorite, sodium hydroxide, and trisodium phosphate at 90°C for 100 seconds, spraying with a potassium hydroxide aqueous solution of pH 14 at a spray pressure of 3 kg/cm2 for 10 seconds, After immersing in amine borane solution at 60°C for 50 seconds, it was soaked at 110°C for 30 seconds.
After drying for a minute, an inner layer material was obtained. 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 further, on the outermost side, two sheets of epoxy resin glass prepreg with a thickness of 0.035
A laminate with copper foil of mm thickness was molded at a pressure of 40 kg/c.
m2 and laminated at 170° C. for 120 minutes to obtain a four-layer printed wiring board.

[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 alkaline spray 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 if necessary, and then subjected to alkaline spray treatment and reduction treatment.