Hitachi Global Storage Technologies Netherlands B.v.

Eduardo Padilla

Xiao Z Wu

Tsai-Wei Wu

Huey-Ming Tzeng

Linden James Crawforth

Richard Dale Bunch

Jacey Robert Beaucage

Paul Arthur Goddu

Jeffrey P Gunder

Embodiments of the present invention pertain to a evaluating the quality of a lapping plate. In one embodiment, an information receiver receives information while the lapping plate is being used to lap a slider. The information indicates the quality of a lapping plate. A quality determiner that evaluates the quality of the lapping plate based on the information while the lapping plate is being used to lap the slider.

Apparatus for evaluating the quality of a lapping plate

Embodiments of the present invention pertain to a evaluating the quality of a lapping plate. In one embodiment, information that indicates the quality of a lapping plate is received while the lapping plate is being used to lap a slider, and the information is used to evaluate the quality of the lapping plate while the lapping plate is being used to lap the slider.

Method of evaluating the quality of a lapping plate

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.

Method of achieving very high crown-to-camber ratios on magnetic sliders

A system and apparatus precisely controls the amount of flatness or curvature in a lapping plate. 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.

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Hayward, CA, United States of America

Eduardo Padilla