JPH06260765A - Multilayer wiring board and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a method of manufacturing a multilayer wiring board excellent in low halo properties. CONSTITUTION:A feature of a multilayer wiring board is that an outermost metal foil is provided through the intermediary of a resin layer onto the upside and/or underside of each of inner material layers cured as far as 90% or below in degree of cure and each provided with a circuit, and then the resin layers are cured as far as 90% or below in degree of cure, and a feature of this wiring board manufacturing method is that a through-hole is made on the multilayer wiring board, a circuit is formed, then the board is fully cured, and then processes after a plating process are carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer wiring board and a multilayer wiring board used in electronic equipment, electric equipment, calculators, communication equipment and the like.

[0002]

2. Description of the Related Art In recent years, a low halo property is required as a measure for improving reliability of electric and electronic equipment. For this reason, meticulous attention is required in the process of punching the electrical laminate, which significantly reduces the work efficiency. As a countermeasure, there is a method of forming copper oxide on the copper surface of the circuit and then reducing it, but it is effective, but it has a drawback that the process is complicated and the process control is difficult and the cost is increased.

[0003]

As described in the prior art, all the conventional methods for improving the low halo property are difficult and work efficiency is remarkably reduced. The present invention has been made in view of the above problems in the prior art, and an object of the present invention is to provide a multilayer wiring board and a multilayer wiring board that easily realize a low halo property without lowering work efficiency. Especially.

[0004]

According to the present invention, after a resin foil is provided on each upper surface and / or each lower surface of an inner layer material having a circuit formed with a required number of resin curing degrees of 90% or less, a metal foil is provided as an outermost layer. ,
A multilayer wiring board characterized by being cured so that the degree of resin curing of the resin layer is 90% or less, and forming a hole in the multilayer wiring board, forming a circuit, and then completely curing and then performing the plating and subsequent steps. Because of the method for manufacturing a multilayer wiring board characterized by
The present invention will be described in detail below since the above object was achieved by suppressing cracks during drilling.

The inner layer material used in the present invention is phenol resin,
Inorganic powder filling such as talc, clay, silica, calcium carbonate, aluminum hydroxide, antimony trioxide, antimony pentoxide, etc. as needed for resins such as epoxy resin, polyimide resin, unsaturated polyester resin, polyphenylene oxide resin, fluororesin, etc. Agent, glass fiber, asbestos fiber, pulp fiber, synthetic fiber, ceramic fiber and other fibrous fillers are added. As the base material, it is possible to use glass, inorganic fibers such as asbestos, organic fibers such as polyester, polyamide, polyacrylic, polyvinyl alcohol, polyimide and fluororesin, woven cloth of natural fibers such as cotton, non-woven fabric, paper and mat. it can. The base material may be impregnated only with the same resin, but a plurality of impregnations such as primary impregnation with the same resin or different type resin and secondary impregnation may be performed to make the impregnation more uniform. Thus, a metal foil consisting of a single, alloy, or composite foil of copper, aluminum, brass, nickel, iron, etc. is provided on the upper and / or lower surface of the required number of resin-impregnated base materials obtained by impregnating the base material with resin and drying. Although the inner layer material is obtained by forming a circuit on a laminated electric laminate, it is necessary to set the degree of resin curing to 90% or less. As the resin-impregnated base material disposed on the upper surface and / or the lower surface of the inner layer material, the resin-impregnated base material as described above can be used as it is. Is 90% or less. In order to reduce the degree of resin curing to 90% or less, it is necessary to cure at a temperature of 95% or less of the molding temperature required for complete curing and / or a time of 45% or less of the molding time required for complete curing, and thus a low halo A multi-layer wiring board having excellent properties is obtained. Next, through holes are formed in the multilayer wiring board, and after forming a circuit, after-curing is performed to completely cure the wiring.
The complete curing method may satisfy the deficiency when the resin curing degree is stopped at 90% or less. Subsequent work is to obtain a multilayer wiring board by performing the steps after plating according to the usual method.

The present invention will be described below based on examples.

[0007]

Example 1 To 100 parts by weight of a bisphenol A type epoxy resin having an epoxy equivalent of 475 (hereinafter simply referred to as "part"), 4 parts of dicyandiamide and 0.
An epoxy resin varnish added with 2 parts and 100 parts of methyl oxytol was impregnated into a plain woven glass cloth having a thickness of 0.018 mm so that the resin adhesion amount was 45% after drying, and dried to obtain a resin-impregnated base material. Next, a laminate having four copper-impregnated base materials and copper foils each having a thickness of 0.018 mm provided on the upper and lower surfaces thereof was heated and pressed at 160 ° C. for 30 minutes under a molding pressure of 30 kg / cm ² , and the thickness was reduced to 0. A double-sided copper-clad laminate having a size of 0.9 mm was obtained.
Next, a circuit is formed on the upper and lower surfaces of the laminated plate, and the same resin-impregnated base material as described above is interposed on both surfaces, and then a thickness of 0.018
Molding pressure is 30 kg / cm
² , the resin curing degree is 85 after laminating at 160 ℃ for 30 minutes
% Multi-layered wiring board is obtained, two of the multi-layered wiring boards are stacked, and 6
After drilling with a drill machine at 5000 rpm and a feed rate of 25 microns / rpm, through-hole plating was performed to obtain a multilayer wiring board.

[0008]

[Embodiment 2] The same multilayer wiring board as in Example 1 is opened under the same conditions as in Example 1, after-cured at 170 ° C. for 60 minutes, and a multilayer wiring board having a resin curing degree of 100% is plated with a through hole to obtain multilayer wiring. I got a plate.

[0009]

Comparative Example A multilayer wiring board and a multilayer wiring board were processed in the same manner as in Example 1 except that the molding conditions at the time of secondary molding were 175 ° C. for 120 minutes and the curing degree of the resin-impregnated base material was 100%. Got

T of the multilayer wiring boards of Examples 1 and 2 and Comparative Example
Table 1 shows g, halo size, and chemical resistance. The degree of cure was evaluated by DSC, and the halo was measured by peeling the outer layer prepreg and measuring the size of the halo with an optical microscope.

[0011]

[Table 1]

[0012]

The present invention is constructed as described above.
A multilayer wiring board having the configuration described in the claims,
It was confirmed that the multilayer wiring board had a low halo property and was excellent in the present invention.

Claims (2)

[Claims] 1. A resin curing degree of a resin layer after arranging a metal foil as an outermost layer through a resin layer on each upper surface and / or each lower surface of an inner layer material having a required number of resin curing degrees of 90% or less. Is 9
A multilayer wiring board, characterized by being hardened so as to be 0% or less. 2. A method for manufacturing a multilayer wiring board, comprising: forming a hole in a multilayer wiring board having a resin layer having a resin curing degree of 90% or less; forming a circuit;