JPH0557803A - Manufacture of resin impregnated base material - Google Patents

Abstract

PURPOSE:To improve resistance to heat, resistance to moisture absorption of a laminate, a printed wiring board and the like by impregnating a base material with resin, drying and cooling a resin impregnated base material during the drying process, and then redrying. CONSTITUTION:Inorganic fiber such as glass, organic fiber such as polyester, polyamide or others, on a natural fiber such as cotton, paper or others is used as a base material, and said base material is impregnated in a manner of forming 50% resin amount after being dried to phenol resin varnish as 50% resin amount after being dired. Then the base material is heat dried in a drying oven, and then cooled in a cool air cooling bath, and fed into the drying oven again for heat drying. The base material is cut into the required dimension after being cooled to manufacture a resin impregnated base material. The generation of unimpregnated sections is eliminated by said process, and its resistance to heat, resistance to insulation and the like can be improved in the case of being used as an electric laminate, a printed wiring board and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electronic equipment, electric equipment,
The present invention relates to a method for producing a resin-impregnated base material used for electrical laminates, printed wiring boards and the like used in computing equipment, communication equipment and the like.

[0002]

2. Description of the Related Art Conventionally, a resin-impregnated base material used for electrical laminates, printed wiring boards, etc. is a long base material such as paper or glass cloth impregnated with resin, and the resin impregnation amount is set in a clearance such as a squeeze roll. However, it is difficult to evenly impregnate the base material with the resin, and if there is a non-impregnated part, it may cause a non-impregnated part. Heat resistance, insulation of wiring board,
It has been a factor that reduces the moisture absorption resistance.

[0003]

As described in the prior art, in the conventional resin-impregnated base material, unimpregnated portions are apt to occur, and the heat resistance, the insulation property of the electrical laminate and the printed wiring board,
It has been a factor that reduces the moisture absorption resistance. The present invention has been made in view of the above problems in the conventional art,
An object of the invention is to provide a method for producing a resin-impregnated base material in which no unimpregnated portion is generated.

[0004]

The present invention is characterized in that a base material is impregnated with a resin, then sent to a drying step, the resin-impregnated base material is temporarily cooled in the middle of the drying step, and then dried again. The above object can be achieved by the method for producing a resin-impregnated base material according to the present invention. The present invention will be described in detail below.

The base material of the resin-impregnated base material used in the present invention includes inorganic fibers such as glass and asbestos, organic fibers such as polyester, polyamide, polyacryl, polyvinyl alcohol, polyimide and fluororesin, and natural fibers such as cotton. Woven fabric, non-woven fabric, mat, paper, etc. Resins such as phenol, epoxy, unsaturated polyester resin, polyimide, fluororesin, and polyphenylene oxide are used as the resin with which the base material is impregnated, and if necessary, talc, clay, silica, calcium carbonate, aluminum hydroxide. Inorganic powder fillers such as can be added. The resin may be impregnated into the substrate regardless of whether it is impregnated on the entire surface or impregnated on one surface. Furthermore, the resin impregnation amount is 40 after drying.
It is preferably ˜60% by weight (hereinafter referred to simply as “%”). The amount of resin can be adjusted with a squeeze roll or the like. A heating furnace such as hot air, infrared irradiation or the like is used for the drying step, which is optional, but at least the drying step must be divided into two or more steps. Temporary cooling during the drying step is preferably performed in a cooling tank such as cold air, and is preferably cooled to 30 to 60 ° C. However, it is desirable that the resin-impregnated base material in the first half of the entire drying step be in an uncured state during cooling during the drying step.

The present invention will be described below based on examples.

[0007]

Example: A resin amount of kraft paper of 116 g / m ² is 50%.
The phenol resin varnish of was impregnated so that the amount of resin after drying was 50%, heated in a drying oven at 155 ° C. for 5 minutes, cooled in a cold air cooling bath at 50 ° C., and then cooled at 155 ° C. It was sent to a drying furnace, heated at 155 ° C. for 15 minutes, cooled, and then cut into a required size to obtain a resin-impregnated base material. Next, a laminated body was prepared by placing one adhesive-bonded copper foil having a thickness of 0.018 mm on the upper surface of the eight resin-impregnated base materials with the adhesive side facing inward at a molding pressure of 100 Kg / cm ² and 160 ° C. The laminate was heat and pressure molded for 1 minute to obtain a laminated plate having a thickness of 1.6 mm.

[0008]

[Comparative Example] A resin-impregnated base material was obtained in the same manner as in Example 1 except that a cooling bath was not used, and a laminate having a thickness of 1.6 mm was obtained.

The performances of the laminates of Examples and Comparative Examples are shown in Table 1. The insulation resistance along the layer is 2 in boiling water at 100 ℃.
Numerical value after immersion for a long time, moisture absorption solder heat resistance is 60 ° C, humidity is 9
Numerical value, water absorption after treatment for 24 hours in 5% air is 23 ℃
Is the value after immersion in water for 24 hours.

[0010]

[0011]

The present invention is constructed as described above.
In the method for producing a resin-impregnated base material having the structure described in the claims, it has been confirmed that there is no unimpregnated portion and the heat resistance, insulation property and moisture absorption resistance of the laminated board and the wiring board are improved.

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Claims (1)

[Claims] 1. A base material is impregnated with a resin and then sent to a drying step,
A method for producing a resin-impregnated base material, which comprises temporarily cooling the resin-impregnated base material during the drying step and then drying the resin-impregnated base material again.