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:
There are provided a method of processing an amorphous material which is capable of forming surface projections of uniform height in desired positions on the amorphous material, and a magnetic disk substrate using the amorphous material. A predetermined pressure is applied to selected parts of a surface of an amorphous material using fine particles having a hardness higher than that of the amorphous material to form high-density compressed layers, and a surface layer of the amorphous material is removed using a treatment agent that has a different removal capacity in the compressed layers and a remaining uncompressed layer, thus making the compressed layers project out. For example, the treatment agent may be an etching solution having a different etching rate in the compressed layers and the uncompressed layer.
摘要:
There are provided a method of processing an amorphous material which is capable of forming surface projections of uniform height in desired positions on the amorphous material, and a magnetic disk substrate using the amorphous material. A predetermined pressure is applied to parts of a surface of an amorphous material to form high-density compressed layers, and a surface layer of the amorphous material is removed using a treatment agent that has a different removal capacity in the compressed layers and a remaining uncompressed layer, thus making the compressed layers project out. For example, the treatment agent may be an etching solution having a different etching rate in the compressed layers and the uncompressed layer.
摘要:
There are provided a method of processing an amorphous material which is capable of forming surface projections of uniform height in desired positions on the amorphous material, and a magnetic disk substrate using the amorphous material. A predetermined pressure is applied to selected parts of a surface of an amorphous material using fine particles having a hardness higher than that of the amorphous material to form high-density compressed layers, and a surface layer of the amorphous material is removed using a treatment agent that has a different removal capacity in the compressed layers and a remaining uncompressed layer, thus making the compressed layers project out. For example, the treatment agent may be an etching solution having a different etching rate in the compressed layers and the uncompressed layer.
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:
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 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:
Prior to conducting chemical strengthening treatment by contacting a glass with a potassium-containing chemical strengthening treating solution, oxidation treatment is conducted to iron-containing particles adhered to a surface of the glass as a pre-step, and the glass is then chemically strengthened. The oxidation treatment is a heat treatment conducted at 80-400° C. in the air. A glass substrate for an information recording medium is obtained by the method.