ANALYSES AND COMPARISION FOR STABLE COVER LAYER THICKNESS DISTRIBUTION OF BLURAY DISC IN SPIN-COATING PROCESS

摘要

In this paper, to get a uniform bluray disc cover layer thickness, analysis and comparison of the cover layer thickness distribution after the spin-coating process through flow analyses using FDM and experiments are described. The bluray disc, a next-generation optical disc format over 25GB, consists on a 1.1mm thick substrate and 0.1mm thick cover layer. Generally, cover layer on the bluray disc is made by the polymer spin coating process. However, it is hard to secure sufficient coating uniformity around the rim on the cover layer. In order to get the uniform thickness deviation and to minimize the bead around the rim, the edge of the disc substrate can be modified into various shapes around the rim on the disc and analyzed with various parameters, such as surface tension, viscosity, and rotation speed, etc. The optimal shape of the rim was tried to get by 3 dimensional computer simulation of the polymer expulsion process.