Trace Storage Technology Corp.

An-Hung Tan

Yuan-Ming Chang

Jason S Lin

Han-Ming Wang

Chi-Chih Chen

Cheng-Der Lin

The present invention provides a texture measuring method of a hard disk plate. The method comprises performing a laser etching process to form a pinhole at each of a plurality of predetermined positions in a predetermined area on the hard disk plate, measuring the pinhole at each of the predetermined positions to obtain a first measurement value, performing a mechanical texturing process on the predetermined area of the hard disk plate to form circular textures on the predetermined area, and measuring the pinhole at each of the predetermined positions to obtain a second measurement value wherein the first and second measurement values are used to determine the extent of texturing performed on the predetermined area of the hard disk plate.

Texture measuring method of a hard disk plate

Nowadays, in fabricating a magnetic recording medium, a disk substrate is first mechanically polished to form an even surface. Next, a laser texturing process is performed to produce a textured annular landing zone on the disk substrate. A magnetic layer is then formed on the disk substrate to complete the fabrication process. However, abnormal asperity usually remains on the surface of the disk substrate. Further, as the amount of exposure time in the air increases, an oxide film is inevitably formed on the surface of the disk substrate. Both of them degrade the surface smooth of the disk substrate, resulting in poor control of the size and structure of the laser texture. In addition, due to the irregular distribution of the mechanical polished texture on the disk substrate, a subsequently formed magnetic layer can not easily achieve the desired properties. This invention therefore provides a light texture process for fabricating a magnetic recording medium. The process is characterized in forming light textures by a two-step light texturing process before forming the laser texture on a disk substrate. The process is intended to remove abnormal asperity and oxide film on the disk substrate, as well as form a plurality of circumferential light textures on the surface of the disk substrate. The roughness of the circumferential light textures is less than that of the laser texture. As the surface smooth of the disk substrate is improved, the size and structure of the laser texture are more controllable. Furthermore, it is easier to form a magnetic layer having desired properties because the circumferential light textures are distributed in a regular way.

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Ping Chen, Taiwan

An-Hung Tan