Patent ID: 6903916

Claim:
A roll of laminate for capacitor layer of printed wiring board for withstand voltage inspection, which is obtained by fabricating a laminate web for capacitor layer by sequentially laminating a first electrically conductive layer formed from a metal foil web, a dielectric layer and a second electrically conductive layer formed from a metal foil web and bonding these layers in a laminated state into one piece, splicing a start end side of the laminate web for capacitor layer to a core tube, and winding the laminate web for capacitor layer up to a terminal end side thereof, wherein the laminate web for capacitor layer to be spliced to the core tube and wound up thereby is fabricated by laminating “a metal foil web which forms the first electrically conductive layer having a prescribed size,” “a metal foil web which forms the second electrically conductive layer having the same size as the first electrically conductive layer,” and “a dielectric layer having a size which is longer by not less than 4 mm in full length than the size of the metal foil webs of the first electrically conductive layer and the second electrically conductive layer” and bonding these layers in a laminated state, the first electrically conductive layer and the second electrically conductive layer being disposed so as to be in a symmetric position via the dielectric layer, the end face position of the two electrically conductive layers on the start end side and the terminal end side being the same, and the dielectric layer positioned between the first electrically conductive layer and the second electrically conductive layer protruding by not less than 2 mm from the start end side and terminal end side of the first electrically conductive layer and the second electrically conductive layer, and wherein by providing interlayer dielectric means on one side of this laminate web for capacitor layer, an electrical insulation condition is formed between areas of the laminate web for capacitor layer which overlap each other when the laminate web for capacitor layer is wound in a roll state.