| 摘要 |
<p>A flexible board comprises metal foil 1 and provided thereon a laminated polyimide-based resin layer 2 of a three-layer structure comprising a first polyimide-based resin layer 2a, a second polyimide-based resin layer 2b, and a third polyimide-based resin layer 2c, wherein the following equation is satisfied. <MATH> where k1 is the coefficient of linear thermal expansion of the first polyimide-based resin layer 2a on the side of the metal foil 1, k2 is the coefficient of linear thermal expansion of the second polyimide-based resin layer 2b, and k3 is the coefficient of linear thermal expansion of the third polyimide-based resin layer 2c. <IMAGE></p> |
