摘要 |
PURPOSE:To make a substrate flat with respect to a secular change and a thermal change by previously correcting the secular change of the form of the plastic substrate and a change quantity owing to thermal stress, film stress and the like at the time of forming a film on the substrate. CONSTITUTION:The secular change of the form of the plastic substrate 1 and the change quantity owing to thermal stress, film stress and the like at the time of forming the film on the substrate 1 are inserted into a metallic mold provided with mirror finished surface plates 4 and 6 having curvature radii which are previously corrected, and polycarbonate resin is used as costable resin, for example, whereby the substrate 1 is formed. Thus, the form of the substrate becomes flat by the secular change of the substrate and the change owing to thermal stress, film stress and the like at the time of forming the film on the substrate 1. Thus, the substrate 1 which causes no warpage and waving of face and mechanical characteristic of is extremely stable can be obtained. |