| 摘要 |
PROBLEM TO BE SOLVED: To provide a flexible printed wiring board including a solder resist layer having enough flexibility without manifesting tackiness in a working process at an ordinary temperature. SOLUTION: The solder resist layer comprises a first layer formed on the side of the printed wiring board, and a second layer formed outside the first layer. The first layer is formed of a flexible solder layer, and the second layer is formed of a solder resist not manifesting tackiness at the time of heating. The first layer is formed of a solder resist having a glass transition temperature lower by≥30°C than that of the solder resist that forms the second layer, and the thickness of the second layer is thinner than the thickness of the first layer. The first layer is formed of a solder resist having a higher elongation rate by≥50% than that of the solder resist that forms the second layer. COPYRIGHT: (C)2006,JPO&NCIPI
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