| 摘要 |
PROBLEM TO BE SOLVED: To avoid the danger that insulation failure is likely to occur in a wiring board using an insulating layer comprising an organic material when heat is rapidly applied just after the wiring board is exposed in particular to a high temperature high humidity environment for a long period of time. SOLUTION: The insulating layer 2 contains epoxy resin, thermoplastic resin dissolved in a roughening solution and having weight average molecular weight of 10,000 to 500,000, elastomer having glass transition temperature of -60 to -20°C, and inorganic insulating powder. The insulating layer has 1 to 9 recessed parts per 100μm<SP>2</SP>where elongation after fracture is 5 to 20%, the diameter is 0.1 to 6μm, and the depth 0.1 to 5μm. COPYRIGHT: (C)2006,JPO&NCIPI |
