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:
Sep. 13, 2005
Filed:
Sep. 30, 2003
Jacey Robert Beaucage, San Jose, CA (US);
Paul Arthur Goddu, San Jose, CA (US);
Jeffrey P. Gunder, Los Altos, CA (US);
Eduardo Padilla, San Leandro, CA (US);
Huey-ming Tzeng, San Jose, CA (US);
Tsai-wei Wu, San Jose, CA (US);
Jacey Robert Beaucage, San Jose, CA (US);
Paul Arthur Goddu, San Jose, CA (US);
Jeffrey P. Gunder, Los Altos, CA (US);
Eduardo Padilla, San Leandro, CA (US);
Huey-Ming Tzeng, San Jose, CA (US);
Tsai-Wei Wu, San Jose, CA (US);
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
A method of precisely controlling the amount of flatness or curvature in a lapping plate is disclosed. The lapping plate is formed from two layers of metal alloys, such as tin-antimony and steel. A bimetallic effect is exploited to induce a linear expansion in the plate so that the flatness or curvature of the plate is manipulated with thermal cycling. The plate is machined and charged under very specific and tightly controlled temperatures to produce a very robust, flat plate charge. As temperature cycling induces a linear expansion along a single plane across the plate, the resultant flatness change is scalar with temperature, and can be repeated and controlled. When the plate laps magnetic sliders, the plate can be thermally cycled to produce a conical surface and a high crown-to-camber ratio can be achieved.