| 摘要 |
PURPOSE:To make the stable heat treatment of a film possible by eliminating the running of the film off from holding parts and the breakage of the film by a method wherein at least two sheets of the film, which is obtained by casting polyimide solution or polyamide acid solution over a base plate and drying, are simultaneously fed to a heat treatment furnace. CONSTITUTION:At least two sheets of dry film 3, which is obtained by drying polymer solution cast over a base plate in a drying furnace and, after that, peeling off the base plate, are simultaneously charged in a heat treatment furnace 1 so as to heat-treat the sheets under a state that both the edge parts 6 of the respective sheets of film are held in a state being in contact with each other. As a result, no phenomenon such as the running of the film off from edge holding parts 6, breakage of the film and the like during heat treatment occurs and the heat treatment of the film can be performed under stable state. On the other hand, the film portions 7 excluding the edge holding parts are strongly applied by tension in width direction due to the contractile force of the film and consequently no adhesion of the film occurs in the direction of the thickness of the film. |
