JPH04323032A - Manufacture of laminated board - Google Patents

Abstract

PURPOSE:To reduce the occurrence of smear defects in a laminated board and manufacture laminated boards with good productivity and high thickness accu racy. CONSTITUTION:Continuous base materials 1 are impregnated with polybenzimidazole resin 2 and a plurality of sheets thereof are superimposed while being forwarded and further continuous metal foils 3 are put thereon. while being forwarded continuously, this is heated under non-pressure so as to harden and laminate the polybenzimidazole resin 2 integrally, after that, it is cut into a predetermined length to thereby obtain a laminated board A. Such a polybenzimidazole resin has a heat deformation temperature and thus smears occur less than usual. Because of a continuous method, the productivity becomes high and the laminated boards A are laminate-molded one by one, therefore, the dispersion of board thickness between respective laminated boards becomes small.

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 a laminate used for manufacturing heat-resistant printed wiring boards.

0002

[Prior art] Electrical equipment, electronic equipment, computers,
BACKGROUND ART Heat-resistant printed wiring boards used in communication equipment and the like are commonly made from epoxy resin laminates. This epoxy resin laminate is made by impregnating a base material such as glass cloth with epoxy resin, drying it, and cutting it to the required size to create a prepreg, then stacking multiple sheets of prepreg and adding the required amount to one or both sides of the prepreg. It is manufactured by stacking copper foils cut to size and then heating and pressing them to form a laminate.

0003

[Problems to be Solved by the Invention] However, since epoxy resin has a relatively low heat distortion temperature, when drilling holes in an epoxy resin laminate, the epoxy resin may shrink due to shear heat generation at the inner periphery of the hole. There was a problem in that the resin melted and smear defects were likely to occur. In addition, when manufacturing as described above, the productivity is low because molding is a batch process, so about 15 sheets of prepreg and copper foil are stacked on top of each other with stainless steel plates interposed between them, and then this is placed on a hot platen. Laminate molding is carried out by stacking 20 to 30 layers of materials and pressurizing them.
When a large number of laminates are laminated at the same time in this way, a problem arises in that the thickness of each laminate becomes highly uneven.

The present invention has been made in view of the above points, and aims to reduce the occurrence of smear defects in laminates, and to manufacture laminates with high productivity and high thickness accuracy. This is the purpose.

[0005]

[Means for Solving the Problems] A method for manufacturing a laminate according to the present invention involves impregnating a long base material 1 with a polybenzimidazole resin 2, and continuously feeding a plurality of impregnated base materials 1. As the sheets are stacked, a long metal foil 3 is further stacked, which is further continuously fed and heated under no pressure to harden the polybenzimidazole resin 2, and the above-mentioned base materials 1 and the metal foil 3 are laminated and integrated, It is characterized in that it is then cut into required dimensions.

The present invention will be explained in detail below. The polybenzimidazole resin 2 is an aromatic heat-resistant resin obtained by polymerizing diaminobenzidine and diphenyl isophthalate, for example.
is preferably dissolved in a solvent such as NN'dimethylformamide, NN'dimethylacetamide, N-methylpyrrolidone, hexamethylsulfamide, dimethylsulfoxide, etc., and used as a varnish having a concentration of about 30 to 60% by weight. The base material 1 may be a woven fabric or non-woven fabric made of glass fiber, synthetic fiber, paper, or the like, and is used as a long strip wound into a roll. Further, as the metal foil 3, copper foil, aluminum foil, iron foil, nickel foil, zinc foil, other alloy foils, etc. can be used alone or in combination, and are used in the form of a long strip wound into a roll. It is something that An adhesive layer may be provided on the side of the metal foil 3 that is overlapped with the base material 1.

[0007] In manufacturing a laminate, first, a plurality of base materials 1 are unrolled from a roll and fed continuously, and each base material 1 is placed in an impregnating bath 10 containing a varnish of polybenzimidazole resin 2. Each base material 1 is impregnated with the polybenzimidazole resin 2 by passing the polybenzimidazole resin 2 through it while immersing it. The base material 1 impregnated with the polybenzimidazole resin 2 in this manner is further continuously fed, and when the polybenzimidazole resin 2 is dissolved in a solvent, it is passed through a drying heater 11 to evaporate the solvent. The plurality of impregnated base materials 1 that are continuously fed in this way are passed between laminating rolls 12 in an undried state and overlapped, and furthermore, at this time, the metal foil 3 is let out from the rolls and fed continuously. The material is then passed between laminating rolls 12 and superimposed on one or both outer surfaces of the stacked base materials 1. In this way, a plurality of polybenzimidazole resin-impregnated base materials 1 and metal foils 3 are stacked one on top of the other and are continuously fed into a heating furnace 13 such as a tunnel type heating furnace. Each base material 1 and the metal foil 3 are in contact only by contact pressure due to their own weight, etc., and the polybenzimidazole resin 2 is cured by passing through a heating furnace 13 under no pressure. The heating conditions in the heating furnace 13 are as follows:
Preferably, the temperature is 0 to 180°C and the time is set to 5 to 30 minutes. By curing the polybenzimidazole resin 2 impregnated into the base material 1 in this way, a plurality of base materials 1
and metal foil 3 can be laminated and integrated, and by cutting this into required dimensions with a cutter 14, it is possible to obtain a polybenzimidazole resin laminate A with metal foil 3 stretched on the surface. It is possible.

[0008]

[Function] In the polybenzimidazole resin laminate A obtained as described above, since the polybenzimidazole resin has a high heat distortion temperature, it melts due to shear heat generated during drilling, resulting in smear defects. This can be reduced. In addition, laminate A can be manufactured with high productivity using a continuous method, and since laminate A is laminated one by one, it is possible to reduce variations in thickness between each laminate. can.

[0009]

EXAMPLES The present invention will now be illustrated by examples. Example 1 While continuously feeding a base material made of a long glass cloth with a width of 105 cm and a thickness of 0.15 mm as shown in FIG.
It was impregnated with a 5% strength by weight solution of polybenzimidazole resin in dimethylacetamide. Three sheets of this impregnated base material are successively fed and passed between laminating rolls, and a long metal foil made of adhesive-coated copper foil with a thickness of 0.035 mm is successively passed through the laminating rolls as shown in Figure 1. Three impregnated base materials and metal foils were placed on top and bottom of the three impregnated base materials, and these were passed through a tunnel-type heating furnace at a temperature of 180° C. for 15 minutes without pressure to heat and harden them. This heat-cured plate was cut with a cutter every 100 cm to obtain a double-sided copper-clad polybenzimidazole resin laminate with a thickness of about 0.6 mm.

Comparative Example 1 A prepreg was prepared by impregnating a base material made of glass cloth with a length of 105 cm, width of 105 cm, and thickness of 0.15 mm with a 45% by weight solution of epoxy resin in methyloxytol and drying. Layer the required number of prepreg sheets and add 105cm in length and 105cm in width above and below.
m, metal foils made of copper foil with a thickness of 0.035 mm were stacked, and this stack was sandwiched between stainless steel plates with a thickness of 1 mm, 15 sets were inserted into the stages, and a molding pressure of 35 kg / cm2, temperature 170℃, time 120
A double-sided copper-clad epoxy resin laminate with a thickness of approximately 0.6 mm was obtained by heating and press-molding under conditions of 10 minutes.

When each of the laminates obtained in Example 1 and Comparative Example 1 was drilled and inspected for the occurrence of smear, it was found that smear occurred in the laminate of Comparative Example 1, but in the case of Example 1. No smear occurred on the laminate. Furthermore, when the thickness of each of the 20 laminates obtained in Example 1 and Comparative Example 1 was measured, the thickness of the laminate of Comparative Example 1 varied within a range of 0.55 mm to 0.65 mm; The width of the laminate was 0.59 mm to 0.61 mm, and the variation in thickness was small.

0012

Effects of the Invention As described above, the present invention impregnates a long base material with polybenzimidazole resin, continuously feeds the impregnated base material, stacks a plurality of sheets, and further coats a long metal foil. The polybenzimidazole resin was cured by being heated under no pressure while being continuously fed, and the above-mentioned base materials and metal foil were laminated and integrated, and then cut to the required dimensions, so the polybenzimidazole resin Imidazole resin has a high heat distortion temperature and can reduce the occurrence of smear defects caused by melting due to shear heat generated when drilling laminates, and laminates can be manufactured with high productivity using a continuous method. In addition, since the laminated plates are laminated and molded one by one, it is possible to reduce variations in plate thickness between each laminated plate and improve plate thickness accuracy.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of the manufacturing process of the present invention.

[Explanation of symbols]

1 Base material 2 Polybenzimidazole resin 3 Metal foil

Claims (1)

[Claims] [Claim 1] A long base material is impregnated with polybenzimidazole resin, and the impregnated base material is continuously fed and stacked, and then a long metal foil is further layered, and this is further continuously fed. A method for manufacturing a laminate, which comprises curing the polybenzimidazole resin by heating under no pressure while feeding it, laminating the above-mentioned base materials and metal foil together, and then cutting the resin into a required size.