Abstract: Provided is a method for forming a through-hole including: forming a laminated body including a fluororesin layer having a first main surface and a second main surface, a first adhesive layer, a first reinforcing resin layer and a first conductor layer provided on the first main surface, a second adhesive layer, a second reinforcing resin layer and a second conductor layer provided on the second main surface; forming an opening in the first conductor layer and irradiating the opening with a laser beam to form a bottomed conduction hole with the second conductor layer exposed on a bottom surface of the conduction hole, wherein a thermal decomposition temperature of the second cured adhesive layer is lower than those of the first reinforcing resin layer and the second reinforcing resin layer, and a thickness of the second cured adhesive layer is 10 ?m or more and 200 ?m or less.

Abstract: Provided is a method for manufacturing a substrate for flexible printed wiring board, comprising a laminated body forming step and an integration step, wherein in the laminated body forming step, on an upper surface and a lower surface of a fluororesin layer having a modified surface, a first and second reinforcing resin layers having a coefficient of thermal expansion smaller than that of the fluororesin layer are respectively stacked through a first thermosetting adhesive, on the first reinforcing resin layer and/or the second reinforcing resin layer, a conductor layer is stacked through a second thermosetting adhesive, to form a laminated body, and in the integration step, the laminated body is heated and integrated at a temperature not lower than a curing temperature of the first and second thermosetting adhesives and lower than a melting point of the fluororesin layer.

Abstract: Provided is a method for forming a through-hole including: forming a laminated body including a fluororesin layer having a first main surface and a second main surface, a first adhesive layer, a first reinforcing resin layer and a first conductor layer provided on the first main surface, a second adhesive layer, a second reinforcing resin layer and a second conductor layer provided on the second main surface; forming an opening in the first conductor layer and irradiating the opening with a laser beam to form a bottomed conduction hole with the second conductor layer exposed on a bottom surface of the conduction hole, wherein a thermal decomposition temperature of the second cured adhesive layer is lower than those of the first reinforcing resin layer and the second reinforcing resin layer, and a thickness of the second cured adhesive layer is 10 ?m or more and 200 ?m or less.

Abstract: Provided is a method for manufacturing a substrate for flexible printed wiring board, comprising a laminated body forming step and an integration step, wherein in the laminated body forming step, on an upper surface and a lower surface of a fluororesin layer having a modified surface, a first and second reinforcing resin layers having a coefficient of thermal expansion smaller than that of the fluororesin layer are respectively stacked through a first thermosetting adhesive, on the first reinforcing resin layer and/or the second reinforcing resin layer, a conductor layer is stacked through a second thermosetting adhesive, to form a laminated body, and in the integration step, the laminated body is heated and integrated at a temperature not lower than a curing temperature of the first and second thermosetting adhesives and lower than a melting point of the fluororesin layer.