FORMING METALLIC MOLD FOR OPTICAL DISK SUBSTRATE

摘要

PURPOSE:To improve the optical characteristics of an optical disk substrate to be formed by using a material having the heat conductivity and the linear expansion coefficient equal or approximate to those of a stamper to form a part or the whole of a metallic mold member. CONSTITUTION:The material having the heat conductivity equal or approximate to that of a stamper 2 or the material having the heat conductivity and the linear expansion coefficient equal or approximate to those of the stamper 2 is used to a part or all parts 5-7 and 1 of a metallic mold having a touch to the stamper 2 containing an information pattern. As a result, the resin (optical disk substrate 3) held in a cavity has a reduced degree of a temperature profile even though the temperature is controlled to heat up or cool the metallic mold. Furthermore the coefft. of contraction of the mold is reduced. Thus it is possible to improve the optical characteristics particularly the double refraction index of a disk substrate to be formed.