| 摘要 |
PROBLEM TO BE SOLVED: To obtain a sufficient flexibility life even under the operating condition in a high temperature by making an average value of a compound shearing elasticity coefficient in a specific condition of each contact agent layer directly contacting both surfaces of a conductive layer. SOLUTION: This flexible wiring board comprises a basic member of three layered, for examples, a plastic film BP, a contact agent layer BAd and a metallic foil M, and a covering layer C comprising two layers of a plastic film CP for the covering layer and a contact agent layer CAd to be laminated. Here, a value of compound shearing elasticity coefficient of each contact agent layer BAd and CAd at 60 deg.C and 25 Hz is made to be 1.0×1010 to 4×1010 dyn/cm2. In the case a value of compound shearing elasticity coefficient being less than 1.0×1010 dyn/cm2, a sufficient flexible life cannot be obtained. Or in the case of exceeding 4×1010 dyn/cm2, a phenomenon of becoming the life shorter is easily generated caused by brittleness, and also flexibility as a flexible wiring board is lost.
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