| 摘要 |
PROBLEM TO BE SOLVED: To obtain a multilayer board in which no destruction of connection parts is caused by thermal fatigue. SOLUTION: The multilayer board 1 is formed by alternately laminating polyimide films 11-16 and copper films 21-26. By setting the coefficient of thermal expansion of the polyimide films 11-16 to 2-5 ppm/ deg.C, the coefficient of thermal expansion of the whole multilayer board 1 becomes less than 10 ppm/ deg.C. Since it is near the coefficient of thermal expansion of semiconductor devices to be mounted, no destruction is caused at its connecting parts to the semiconductor devices. The multilayer board 1 can be used for both an interposer and a motherboard. |
