| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of cracks, etc., in a solder resist layer due to the difference between the thermal expansion of the solder resist layer and other parts by incorporating an inorganic filler in the resist layer. SOLUTION: In a printed wiring board in which at least one layer of conductor circuit is formed on a substrate and a solder resist layer 14 is formed as the uppermost layer, an inorganic filler is incorporated in the resist layer 14. Using the printed wiring board, the difference between the coefficients of linear expansion of the resist layer 14 and an interlayer resin insulating layer 2, etc., surrounding the resist layer 4 becomes smaller, because the coefficient of thermal expansion of the resist layer 14 is lowered by the inorganic filler incorporated in the layer 14. Consequently, the cracking, peeling, etc., of the solder resist layer 14 can be prevented in the manufacturing process of the printed wiring board or after electronic parts are mounted on the manufactured printed wiring board. |
