JPH02303194A - Manufacture of multilayer wiring board - Google Patents

Abstract

PURPOSE:To obtain a multilayer wiring board in which an uneven color of an inner-layer copper foil and an irregularity in a close contact property are not caused by a method wherein a treatment liquid, for the inner-layer copper foil, composed mainly of potassium persulfate and sodium hydroxide is ripened under specific conditions and the inner-layer copper foil is treated and, after that, is laminated and united together with an outer-layer material via a base material impregnated with a resin. CONSTITUTION:A treatment liquid, for an inner-layer copper foil, which is composed mainly of potassium persulfate and sodium hydroxide is ripened at 40 to 65 deg.C for 10 to 60min. After that, the inner-layer copper foil is treated and, after that, is laminated and united together with an outer-layer material via a base material impregnated with a resin. The treatment liquid for the inner-layer copper foil is composed mainly of potassium persulfate and sodium hydroxide; it is preferable to have the hollowing composition: 10 to 30g/l of potassium persulfate; 40 to 80g/l of sodium hydroxide; 1 to 6g/l of sodium sulfate.

Description

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

[Conventional technology]

Conventionally, the inner layer copper foil of multilayer wiring boards used in electrical equipment, etc. has been oxidized with sodium chlorite or potassium persulfate,
It is obtained by laminating and integrating an outer layer material through a resin-impregnated base material. However, if the inner layer copper foil is treated with sodium chlorite, the acid resistance and adhesiveness of the copper foil will decrease, and if the inner layer copper foil is treated with potassium persulfate, the soldering heat resistance and adhesiveness of the copper foil will decrease. For this reason, as disclosed in Japanese Patent Application No. 63-83414, it has been attempted to treat the inner layer copper foil with a mixed solution of potassium persulfate and sodium hydroxide to improve the acid resistance, adhesion, and soldering heat resistance of the inner layer copper foil. Ru. However, when the inner layer copper foil is treated with a mixed solution of potassium persulfate and sodium hydroxide, problems such as color unevenness and poor adhesion occur in the initial stage.

[Problem that the invention seeks to solve]

As described in the prior art section, if the inner layer silver foil is treated with a mixed solution of potassium persulfate and sodium hydroxide, the failure rate will increase at an early stage. The present invention has been made in view of the above-mentioned problems in the conventional technology, and its purpose is to prevent color unevenness and adhesion of the inner layer copper foil by obtaining an inner layer copper foil that is free from color unevenness and adhesion. It is an object of the present invention to provide a method for manufacturing a smooth multilayer wiring board with uniformity in properties.

Means for Solving Problems] The present invention is based on aging an inner layer copper foil treatment solution containing potassium persulfate and sodium hydroxide as main components at 40 to 65°C for 10 to 60 minutes, and then removing the inner layer copper foil. After the treatment, the multilayer wiring board manufacturing method is characterized by laminating and integrating with the outer layer material via the resin-impregnated base material, which eliminates the unstable period of the inner layer copper foil treatment solution. The present invention will be explained in detail below.

The inner layer copper foil treatment solution used in the present invention contains potassium persulfate and sodium hydroxide as main components, and preferably has the following composition.

Potassium persulfate 10-30 f/1 Sodium hydroxide 40-80 f/1 Sodium sulfate 1-60 da/l The above inner layer copper foil treatment solution is heated at 40-65°C for 10-6 days without using immediately after blending.
It is necessary to use it after aging for 0 minutes. That is 40
℃ for less than 10 minutes, the activity of the oxidizing agent is unstable, causing color unevenness and poor adhesion to the inner layer copper foil;
If the time exceeds 1 minute, the natural decomposition of the oxidizing agent will be large, and the inner layer copper foil treatment solution will not be able to be used effectively. As a ripening means, it is preferable to leave the inner layer copper foil treatment solution naturally or to let it soak in. It is also preferable to circulate the inner layer copper foil treatment solution while allowing it to cool. As the resin for the resin-impregnated base material, synthetic resins such as phenol resin, cresol resin, epoxy resin, unsaturated polyester resin, melamine resin, polyimide resin, polyphenylene oxide resin, and fluorinated resin are used. After drying, it can be applied to base materials such as inorganic fibers, organic synthetic fibers such as polyester, polyamide, polyvinyl alcohol, polyurethane, and polyimide, as well as natural fibers such as cotton, woven fabrics, nonwoven fabrics, magenta, sotho, net, gauze, paper, etc. It is impregnated and dried so that the resin amount is 40 to 60% by weight (hereinafter simply referred to as "regret"), and the resulting product has a thickness of 0. O
A required number of resin-impregnated base materials of f to IH are interposed. As the outer layer material, metal foil such as copper foil, aluminum foil, nickel foil, etc., or a single-sided metal-clad laminate is used. The laminating and integrating means may be any laminating means such as a press, a roll, a double belt, etc., and is not particularly limited.

The present invention will be explained below based on examples.

Example A copper-clad glass cloth base epoxy resin inner layer material having a thickness Q and a thickness IM having a copper foil of 0.35fl was mixed with an inner layer copper foil treatment solution having the following composition, and then Zoo-treated at 50°C for 30 minutes. ///
The inner layer copper foil treatment solution was circulated and aged for 190 seconds.

Potassium persulfate 201/1 Sodium hydroxide 60 f/1 Sodium sulfate
101/1 Next, fi45 containing resin on the top and bottom of the inner layer material
A laminate in which 0.0359 RmO copper foil was placed between two epoxy resin-impregnated glass cloth substrates each having a thickness of 0.1 mm was molded at a pressure of 40 Kq/d and at 160°C.
A four-layer circuit wiring board was obtained by heat-pressing molding for 90 minutes.

Comparative Example After blending the same inner layer copper foil treatment solution as in the example, the same inner layer material as in the example was immediately treated.
A layered circuit wiring board was obtained.

Table 1 shows the performance of the four-layer circuit wiring boards of Examples and Comparative Examples.

〔Effect of the invention〕

The present invention is constructed as described above. The method for manufacturing a multilayer wiring board having the structure described in claim 1 has the effect of improving color unevenness and adhesion of the inner layer copper foil.

Claims (1)

[Claims] (1) After aging the inner layer copper foil treatment solution containing potassium persulfate and sodium hydroxide as main components at 40 to 65°C for 10 to 60 minutes, and then treating the inner layer copper foil, pass it through the resin-impregnated base material to the outer layer material. 1. A method for manufacturing a multilayer wiring board, characterized in that it is laminated and integrated with a multilayer wiring board.