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1. (WO2013145461) METHOD FOR PRODUCING HDD GLASS SUBSTRATE

Pub. No.:    WO/2013/145461    International Application No.:    PCT/JP2012/082492
Publication Date: Fri Oct 04 01:59:59 CEST 2013 International Filing Date: Sat Dec 15 00:59:59 CET 2012
IPC: G11B 5/84
C03C 21/00
G11B 5/73
Applicants: HOYA CORPORATION
HOYA株式会社
Inventors: KAJITA, Hiroshi
梶田 大士
Title: METHOD FOR PRODUCING HDD GLASS SUBSTRATE
Abstract:
Provided is a method that is for producing an HDD glass substrate having a thermally assisted recording method and that is able to suppress a decrease in compressive stress of the glass substrate surface during high-temperature film formation processing. The method for producing an HDD glass substrate having a thermally assisted recording method and having an amount of magnetic head floatation of no greater than 3 nm is provided with: a step for forming the glass substrate (1); and a step for contacting the glass substrate (1) to a chemical strengthening treatment liquid. The concentration of alkaline earth metals contained in the chemical strengthening treatment liquid (100) is 50-10,000 ppb inclusive.