JP2503630B2 - Method for manufacturing multilayer printed circuit board - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a multilayer printed circuit board used in electronic devices, electric devices, computers, communication devices and the like.

[Conventional technology]

Conventional multilayer printed circuit boards are not based on epoxy resin
It is generally laminated and molded at 175 to 180 ° C, and the circuit pattern of the inner layer material floats on the surface due to hardening and cooling of the resin, and the surface roughness becomes large, which lowers the positional accuracy when drilling holes.

[Problems to be solved by the invention]

As described in the related art, the surface roughness of a multilayer printed circuit board is so bad that it is multilayered, which is a problem in recent fine patterning. 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 method for manufacturing a multilayer printed circuit board having good surface roughness and high positional accuracy during drilling.

[Means for solving problems]

According to the present invention, a desired number of epoxy resin-based prepregs are arranged on the upper surface and / or the lower surface of a required number of inner layer materials, and a laminate having an outer layer material as the outermost layer is formed from the glass transition temperature of the epoxy resin-based prepreg resin. Due to the method of manufacturing a multilayer printed circuit board, which is characterized by laminating and integrating at a high temperature of 5 to 30 ° C., the resin is cured and integrated sufficiently, and the excessive shrinkage of the resin is prevented, and the surface roughness and the position at the time of punching Now that the accuracy has been improved, the present invention will be described in detail below.

The inner layer material used in the present invention is an electric circuit on one side or both sides of a laminate of thermosetting resin or thermoplastic resin such as phenol resin, epoxy resin, unsaturated polyester resin, polyimide resin, fluorine resin, and polyphenylene oxide resin. Is formed. The prepreg used in the present invention is an epoxy resin-based prepreg containing an epoxy resin as a main component. The base material of this prepreg is woven fabric, non-woven fabric, mat or paper made of inorganic fibers such as glass and asbestos, organic synthetic fibers such as polyester, polyamide, polyvinyl alcohol and acrylic, and natural fibers such as cotton, or a combination thereof. Material. The amount of resin impregnated into the base material is preferably 40 to 60% by weight (hereinafter simply referred to as%) in terms of the amount of resin after drying.
As the outer layer material, the one-sided metal-clad laminate of the laminate used for the inner layer material or the thickness of copper of 18 to 105 microns, aluminum,
A single, alloy, or composite foil of nickel, zinc, iron, etc. can be used, and a metal foil having an adhesive layer provided on one side with chemical treatment or physical treatment on one side or both sides as necessary. is there. It is necessary that the temperature during the lamination molding is 5 to 30 ° C. higher than the glass transition temperature of the prepreg resin.
That is, if the temperature is less than 5 ° C, curing and integration of the resin will be insufficient,
This is because when the temperature exceeds 30 ° C, the resin shrinks greatly. The glass transition temperature is measured by the DSC (differential scanning calorimeter) method.

 The present invention will be described below based on examples.

Examples 1 to 3 and Comparative Example First, on a glass cloth having a thickness of 0.15 mm, 28 parts of diaminodiphenylmethane and benzyl were added to 100 parts by weight of epoxy resin (Epicote 828 manufactured by Shell Chemical Co., Ltd.) (hereinafter simply referred to as “part”). The amount of resin after drying an epoxy resin varnish made by adding 0.2 parts of dimethylamine and 50 parts of methyl oxytol (glass transition temperature after curing 140 ° C, measured by DSC method, 20 ° C / min)
It was impregnated to 50% and dried to obtain a prepreg. Next, a laminated body in which two of the above prepregs are provided on each of the upper and lower surfaces of an inner layer material having electric circuits formed on both sides of a 0.8-mm-thick double-sided copper clad laminate, and then a copper foil of 0.018 mm thickness is arranged. The molding pressure is 50 Kg / cm ² , and the molding temperature is 155 for Example 1.
C., 160 ° C. for Example 2 and 165 for Example 3.
And a comparative example was laminated and molded at 180 ° C. for 90 minutes each to obtain a four-layer printed circuit board.

The performance of the multilayer printed circuit boards of Examples 1 to 3 and Comparative Example is shown in Table 1.

[Advantages of the Invention] The present invention is configured as described above. In the method for manufacturing a multilayer printed circuit board having the structure described in claim 1, there is an effect of improving the surface roughness and the positional accuracy at the time of punching.

Claims (1)

(57) [Claims] 1. A laminated body in which a required number of epoxy resin-based prepregs are arranged on the upper surface and / or lower surface of a required number of inner layer materials and an outer layer material is disposed as the outermost layer, and a glass transition of the epoxy resin-based prepreg resin is performed. A method for manufacturing a multilayer printed circuit board, which comprises laminating and integrating at a temperature of 5 to 30 ° C. higher than the temperature.