The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 20, 1997
Filed:
Feb. 27, 1996
Peter M Baumgart, San Jose, CA (US);
Karl A Flechsig, Los Gatos, CA (US);
Michael F Lee, Los Altos, CA (US);
Wing P Leung, Arcadia, CA (US);
Ullal V Nayak, San Jose, CA (US);
Thao A Nguyen, San Jose, CA (US);
Timothy C O'Sullivan, San Jose, CA (US);
Andrew C Tam, Saratoga, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method is provided for making crater shaped bumps on a magnetic disk. The crater shaped bumps have a diameter in the range of 10 to 25 .mu.m and a peripheral ridge with a height h.sub.r above a nominal surface of the calibration disk in the range of 75 to 120 nm. Close tolerance crater shaped bumps with this configuration can be made by impinging two or more pulses of laser energy on the same location of the disk. By increasing the number of pulses the height of the peripheral ridge progressively increases. By employing multiple pulses, the height of the peripheral ridge is increased while the diameter of the crater shaped bump stays substantially constant. Further, by employing multiple pulses diameters and heights of crater shaped bumps can be produced with close tolerances within a diameter range of 5 to 20 .mu.m and a height range of 2 to 120 nm.