Patent ID: 7618895
Filing Date: 2009-11-17
Classification: H01L

Abstract:
1. A method for etching doughnut-type glass substrates, which comprises: (1) laminating a plurality of doughnut-type glass substrates, each substrate having a circular hole at its centers, so that the circular holes of the laminate form a cylindrical hole, and (2) applying an etching treatment to inner peripheral edge surfaces of the plurality of the laminated doughnut-type glass substrates all at once by contact with an etching liquid or an etching gas; wherein the etching liquid or the etching gas is supplied from one end of the cylindrical hole, made to flow in the cylindrical hole, and discharged from the other end of the cylindrical hole so that it is not in contact with exposed main surfaces of the doughnut-type glass substrates at both ends of the laminate consisting of the doughnut-type glass substrates.