MOLD FOR MOLDING PLASTIC DISK BASE

摘要

PURPOSE:To make taking off and on the molding surface easier, by fixing a thin film stamper having a mirror surface of high accuracy or a fine guide channel and prepared by electroforming by means of negative pressure. CONSTITUTION:A stamper 3 having a mirror surface is obtained by electroforming nickel on a glass plate polished to be a surface of high accuracy. Another stamper having a guide channel can be also obtained by electroforming nickel on a glass plate having a concave/convex pattern prepared by coating the glass plate with a photoresist, which is then exposed to a laser light and by developing the exposed part to make a concave/convex relief. The stamper and a back-up plate 1 are tightly contacted together and the air left between them is exhausted from their inner and/or outer circumference to adhere them tightly. A ring or a gasket is placed between a stamper pressing ring 5 and the stamper to prevent air penetration and to improve air-tightness and they are made in a body by tightening bolts 6 up to make taking off and on the molding surface easier.