Magnetic disk substrate and method for manufacturing the same

Details Magnetic disk substrate and method for manufacturing the same Magnetic disk substrate and method for manufacturing the same

1994-09-16

1997-05-06

Resan, Stevan A.

Stock material or miscellaneous articles

Circular sheet or circular blank

428 642, 428 653, 428141, 428426, 428432, 428694ST, 428694SG, 428900, G11B 500

Patent

active

056269358

ABSTRACT:
A magnetic disk substrate is made of a glass-ceramic having crystal phases of lithium disilicate (Li.sub.2 O.2SiO.sub.2) and alpha-quartz (SiO.sub.2). The crystal phase of alpha-quartz is formed of grown crystal grains each having a globular grain structure made of aggregated particles. Each globular grain has a size within a range from 0.3 .mu.m to 3 .mu.m. Surface roughness (Ra) of a polished surface of the magnetic disk substrate is within a range from 15 .ANG. to 50 .ANG. which is an optimum range of surface roughness for the magnetic disk.

REFERENCES:
patent: 3231456 (1966-01-01), McMillan et al.
patent: 3962514 (1976-06-01), Rittler
patent: 3977857 (1976-08-01), Mattox
patent: 4083727 (1978-04-01), Andrus et al.
patent: 4833001 (1989-05-01), Kijima et al.
patent: 4859505 (1989-08-01), Nakayama et al.
patent: 4908727 (1990-03-01), Ezaki et al.
patent: 4985306 (1991-01-01), Morizane et al.
patent: 5080948 (1992-01-01), Morita et al.
patent: 5087481 (1992-02-01), Chen et al.
patent: 5093173 (1992-03-01), Nakagawa et al.
European Search Report, Berlin, Aug. 31, 1994, Examiner Kuehne, H-C.
Patent Abstracts of Japan; vol. 10, No. 226 (C-364) Aug. 7, 1986 (Hoya Corp) Apr. 1, 1986.
Patent Abstracts of Japan, vol. 10, No. 97 (P-446) Apr. 15, 1986 (Sumitomo Tokushiyu Kinzoku KK), Nov. 14, 1985.
Patent Abstracts of Japan, vol. 011, No. 268 (C-444) Aug. 29, 1987 (M. Toshimichi et al.) Apr. 3, 1987.
Patent Abstracts of Japan, vol. 14, No. 472 (P-1116) Oct. 15, 1990 (Hitachi Ltd) Jul. 24, 1990.

Affiliated with

Also associated with

Rating

Magnetic disk substrate and method for manufacturing the same does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Magnetic disk substrate and method for manufacturing the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic disk substrate and method for manufacturing the same will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2130983