| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately measure a thickness of a glass substrate in a non-contact manner without sampling the glass substrate from a process, in a manufacturing method of a glass substrate for a magnetic recording medium in which multiple glass substrates are divided into groups based on the measurement result of a thickness of the multiple glass substrates, and precision polishing is applied at a time for every group to the multiple glass substrates divided into the groups. <P>SOLUTION: A manufacturing method of a glass substrate for a magnetic recording medium includes: a thickness measuring step of measuring a thickness of multiple glass substrates 10; and a precision polishing step that the multiple glass substrates 10 are divided into groups based on the measurement result in the thickness measuring step, and precision polishing is applied at a time for every group to the multiple glass substrates 10 divided into the groups. In the thickness measuring step, the glass substrates 10 are irradiated with light L having a prescribed wavelength band in the thickness direction, and interference light between light (a) reflected by a surface of the glass substrates 10 in the thickness direction and light b reflected by a rear surface thereof in the thickness direction is received. The received interference light is analyzed for every wavelength, which, by spectral interference, allows measurement of the thickness of the glass substrates 10 irradiated with the light L. <P>COPYRIGHT: (C)2012,JPO&INPIT |
