| 摘要 |
PURPOSE:To strengthen the resistant property of an interlayer insulating film to a thermal shock and a heat cycle by a method wherein polyimides whose coefficient of thermal expansion is different are used selectively in such a way that the coefficient of thermal expansion of an upper-layer film and a lower-layer film of a multilayer film forming the interlayer insulating film becomes sequentially large with reference to the coefficient of thermal expansion of a center layer film. CONSTITUTION:An interlayer insulating film 12 in which polyimides whose coefficient of thermal expansion is different have been laminated as a multilayer is used; a lower- part conductor 3 is formed on the surface of an insulating substrate 2; and an upper- part conductor 5 is formed on the interlayer insulating film 12 with which a lower-part conductor 4 is covered. The polyimides whose coefficient of thermal expansion is different are used selectively in such a way that the coefficient of thermal expansion of an upper-layer film 15 and a lower-layer film 13 of a multilayer film becomes large with reference to the coefficient of thermal expansion of a center layer film 14. Consequently, when a thermal shock and a thermal stress are exerted, the distribution of an internal stress at the interlayer insulating film 12 becomes gentle in the thickness direction inside the interlayer insulating film 12. Thereby, a crack is prevented at the interlayer insulating film 12. |
