JPH03155935A - Manufacture of laminated sheet - Google Patents

Abstract

PURPOSE:To prepare a porous fluoroplastic sheet base material laminated sheet generating no warpage with heat by a method wherein a long laminate formed by superposing a long metal foil to the upper or under surface of a stack consisting of a required number of long resin impregnated porous fluoroplastic sheets and long resin impregnated glass base materials is cured while continuously transferred and subsequently cut into a required dimension to be heated. CONSTITUTION:For example, a long tetrafluoroethylene resin porous sheet having width of 105cm and thickness of 0.05mm and a glass cloth base material having width of 105cm and thickness of 0.1mm are respectively impregnated with an unsaturated polyester resin so as to adjust the amount of the resin to 45wt.% to form a long resin impregnated base material 1 and, for example, five base materials 1 are superposed on upon another and, for example, a copper foil 2 coated with an adhesive having thickness of 0.035mm is arranged to the upper and under surfaces of the laminates so as to oppose the adhesive layer to the long resin impregnated base materials 1 and continuously laminated by laminating rolls to form a long laminate 4. This laminate is sent to a curing oven 5 to be heated and cured, for example, at 180 deg.C in a pressure free state and subsequently cut by a cutter 6. Since this laminate has thermal deformation temp. of 80 deg.C, the laminate is reheated at 90 deg.C in a heating furnace 7 and the allowed to stand to cool to prepare a double-side copper clad laminated sheet 8 having thickness of 0.8mm.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a laminate used in electronic equipment, electrical equipment, computers, communication equipment, etc.

[Conventional technology]

Conventionally, laminates used for electrical equipment, etc. are obtained by heating and pressing a laminate consisting of a resin-impregnated base material and metal foil using a multi-stage press for a long period of 1 to 2 hours. However, there is a disadvantage that molding distortion remains in the laminate and warping occurs due to the heat generated when processing the laminate into a printed wiring board or when electronic components are mounted on the printed wiring board, causing problems in the automated process. Ta. This tendency was particularly strong in the case of fluororesin porous sheet base laminates intended to satisfy high frequency characteristics.

[Problem that the invention seeks to solve]

As described in the prior art section, the laminates obtained by the multi-stage pressing method tend to warp during the processing process. The present invention has been made in view of the above-mentioned problems in the prior art, and its object is to provide a method for manufacturing a fluororesin porous sheet base laminate that does not cause warpage.

[Means for solving problems]

The present invention continuously transfers a long laminate in which a required number of long resin-impregnated fluororesin porous sheets and a long resin-impregnated glass substrate are stacked, and a long metal foil is stacked on the upper and/or lower surfaces of the stack. After curing, the laminate is cut into required dimensions and further heated above the heat distortion temperature, which eliminates or minimizes the need for pressure and reduces residual distortion by reheating. The present invention will be described in detail below.

Porous sheets of the long resin-impregnated fluororesin porous sheet used in the present invention include tetrafluoroethylene resin, tetrafluoroethylene perfluorovinyl ether copolymer, tetrafluoroethylene hexafluoropropylene copolymer, A fluororesin sheet made of tetrafluoroethylene ethylene copolymer, trifluorochloride ethylene resin, etc. with many micropores, and the sheet thickness is 0.0
1-1ff, pore size 50-95mm, average pore diameter 0.3
~10 microns is preferable in terms of performance. Glass cloth, glass nonwoven fabric, or glass vapor is used as the long resin-impregnated glass substrate, and resins used to impregnate the glass substrate and porous sheet include phenol resin, epoxy resin, unsaturated polyester resin, diallyl phthalate resin, and vinyl. Estermit resin, epoxy acrylate resin, polyimide resin, polyphenylene oxide resin,
It is impregnated with fluororesin, etc. alone, modified products, or mixtures.Resin impregnation may be performed only with the same type of resin, or primary or secondary impregnation with a different type of resin. In the secondary impregnation with a resin, a plurality of impregnations may be performed, such as impregnation with a resin having a higher viscosity than the primary impregnation, so that more uniform impregnation can be achieved. A curing agent, a crosslinking agent, a polymerization initiator, a curing diluent, a filler, a reinforcing agent, etc. can be added to the resin as necessary.

Furthermore, the above-mentioned resin may be used as it is, but it is preferable to use it after defoaming it under reduced pressure, in order to suppress the generation of air bubbles in the resin-impregnated cloth. Copper is used as long metal foil,
Single, alloy, or composite foils of aluminum, iron, nickel, zinc, etc. are used, and if necessary, a bonding agent layer can be provided on one side of the metal foil to further improve adhesiveness.

Curing time and curing temperature vary depending on the type of resin and can be selected depending on the resin used.

Further, it is necessary to reheat the material after cutting to a temperature higher than the heat distortion temperature. The pressure applied during curing must be unmatched or contact pressure.

Hereinafter, one embodiment of the present invention will be explained in more detail based on the illustrated embodiment.

Embodiment FIG. 1 is a simplified process diagram showing an embodiment of the method for manufacturing a laminate according to the present invention.

As shown in Figure 1, width 105α, thickness Q, Q51+10
Long polytetrafluoroethylene resin porous sheet (vaporizer 85%,
Average pore diameter 0.6 microns), width 105cI11, thickness 0
．． Five sheets of each of the long resin-impregnated base materials 1 each impregnated with unsaturated polyester resin in a resin amount of 45 layers (hereinafter simply referred to as "part") were alternately stacked on each fin's glass cloth base material. A long laminate in which adhesive-coated copper foil 2 with a thickness of 0.035 m 1 JI is placed on the upper and lower surfaces of the substrate, with the adhesive side facing the long resin-impregnated base material 1, and continuously laminated with a laminating roll 3. 4 was sent to the curing furnace 5 and heated and cured at 180°C under no pressure.

After cutting in the furnace 6, the heat deformation temperature of this material was 80°C, so it was reheated to 90°C in the heating furnace 7, and then left to cool to a thickness of l.
), a double-sided copper-clad laminate 8 of 13 ff was obtained.

Comparative Example 1 The same long resin-impregnated base materials as in the example were each 105 x 10
Five pieces of copper foil cut into 51 pieces each were stacked alternately, and the same copper foil as in the example above was placed on the upper and lower surfaces of each piece, and heated at 165°C and 30Kq/d for 60 minutes. A double-sided copper-clad laminate with a thickness of 9.8 fl was obtained by pressing.

Comparative example 2 The cut products of Examples were used as products without being reheated.

The performances of the laminates of Examples and Comparative Examples 1 and 2 are shown in Table 1.

〔Effect of the invention〕

The present invention is constructed and discussed as described above. The method for manufacturing a laminate having the structure described in the claims has the advantage of producing a laminate with less warpage.

[Brief explanation of the drawing]

FIG. 1 is a simplified process diagram showing an embodiment of the method for manufacturing a laminate according to the present invention. 1 is a long resin-impregnated base material, 2 is a long metal foil, 3 is a laminate roll, 4 is a long laminate, 5 is a curing furnace 6 is a cutter 7
8 is a heating furnace, and 8 is a laminate.

Claims (1)

[Claims] (1) Continuously transferring a long laminate in which a long metal foil is layered on the top and/or bottom surface of the required number of long resin-impregnated fluororesin porous sheets and long resin-impregnated glass substrates. A method for manufacturing a laminate, which comprises cutting into required dimensions after curing, and further heating to a temperature higher than the heat distortion temperature.