| 摘要 |
PROBLEM TO BE SOLVED: To provide a bonding material having a small rate of change in a breakdown elongation and an excellent heat fatigue resistance after a high temperature shelf test, considering that a bonding material layer in a wiring board composing electronic component modules is apt to crack owing to enlarging in a rate of change in a breakdown elongation by the curing and degrading of the resin caused by a long term heat hysteresis. SOLUTION: The bonding material comprises an epoxy resin mixture, a hardener initiating reaction at a temperature in the range of 100-200 deg.C, a thermoplastic resin having a weight-average molecular weight of 10,000-500,000, a polyether-based elastomer to crosslink with the epoxy resins and an inorganic insulating filler, with a breakdown elongation change ratio after the high temperature shelf test being -50 to 50%, when measured by the method prescribed in JIS-C-5012. |
