| 摘要 |
PURPOSE:To obtain a base film, which has soldering heat resistance and extremely small water absorption properties and is excellent in dimensional stability, by a method wherein the film is made of thermoplastic polyester, the melting point of which is 280 deg.C or higher. CONSTITUTION:A film, which is made of thermoplastic polyester having a melting point of 280 deg.C or higher, is used in flexible printed wiring board so as to obtain low cost base film, which has soldering heat resistance and extremely small water absorption properties and, in addition, is resistant to chemicals during the manufacture of the flexible printed wiring board. Since the formable temperature of polyester having high melting point is higher in general and, in some cases, overlaps with the decomposition temperature of ester linkage, preferably thermoplastic polyester, the difference between the forming temperature and decomposition temperature of which is comparatively larger, is used. Concretely, polyester resin consisting of 1,4-cyclohexanedimethanol component and terephthalic acid component (or PCT resin) is exampled. |
