摘要:
A method for providing a high quality glass substrate that if free of residual polishing particles. The method includes polishing the surface of the glass plate with a polishing agent containing cerium oxide particles, washing the glass plate with washing agent containing the three components of acid, a reducing agent, and fluorine ion. The washing agent is provided with an etching effect by the acid, a reducing and decomposing effect by the reducing agent, and a dissolving enhancing effect by the cerium oxide by fluorine ion. The synergistic effect of the three components provides the washing agent with an extremely high ability for washing away cerium oxide and foreign matter from the surface of the glass plate through a small amount of etching such that potential scratches are not produced.
摘要:
There is provided a substrate for information recording media and a manufacturing method thereof, which allow an information recording medium to be driven reliably and stably even when the flying height is made lower than conventionally to cope with increased recording density of the data zone. Precision polishing is carried out on a glass substrate using a polishing agent. After the precision polishing, surface treatment is carried out using an etching liquid containing both hydrofluoric acid and a fluoride salt.
摘要:
A process for producing a glass substrate for a magnetic recording medium by forming a surface roughness in a main surface of a glass plate that has been formed into a disk shape, includes: imparting a processing mark having a permanent strain to the main surface of the glass plate in a circumferential direction thereof; and chemically etching the whole main surface of the glass plate, so as to form the surface roughness.
摘要:
A glass substrate for an information recording medium has an acid resistance represented by an etching rate of at most 45 nm/min. upon contact with a hydrofluoric acid having a temperature of 50° C. and a concentration of 0.1 weight %. The glass substrate has a recording surface having an average surface roughness Ra smaller than 0.3 nm.
摘要:
A substrate for information recording media is disclosed which has optimized shapes of surface recesses and protrusions and thereby contributes to a reduction in flying height and causes neither head crushing nor thermal asperities. The substrate for information recording media has surface recesses and protrusions wherein the height thereof at a contact proportion for the recesses and protrusions of 0.4% is from 2 to 7 nm when the height of the recesses and protrusions at a contact proportion therefor of 50% is taken as a base. The contact proportion is a value based on the bearing ratio determined with an atomic force microscope.