Komag Corporation

Dan Frusescu

Shoji Suzuki

David Treves

David Vigdor Salamon

Daryl M Shiraki

Rony Thomas

Jayadev P Patel

Tuan H Hua

A method for texturing a substrate comprises rotating the substrate while applying laser pulses thereto. Of importance, the rotational velocity of the substrate is varied during texturing to change the spacing of the resulting laser bumps in accordance with a periodic function. This helps reduce or eliminate vibration in a read-write head after the substrate is formed into a magnetic disk, and the magnetic disk is in use.

Patterned laser zone texture

A method in accordance with our invention for providing texture bumps on a substrate comprises the step of forming elliptical ridge-shaped bumps on the substrate. In one embodiment, substrate is used in the manufacture of a magnetic disk used in a disk drive. The elliptical bumps cause less vibration of the read-write head than circular bumps. The elliptical bumps also provide reduced friction between the disk and a read-write head during use.

Method of forming a magnetic hard disk with elliptical shaped laser bumps

A calibration disk for calibrating the fly height of a head, includes spaced circumferencial bands on the disk extending in a concentric fashion from adjacent an outer diameter of the disk to near an inner diameter of the disk. Each of the bands include radial and circumferencial spaced asperity emulating bumps having a population sufficient to produce a constant and continuous output signal from a glide head when the glide head flies lower than a maximum height of the bumps. The height of the bumps within individual bands are substantially uniform, and the average heights of the bumps in each band differ from each other. The configuration of the bumps on the calibration disk advantageously avoids errors caused by disk waviness, runout, and contamination. Further, using the differing heights of the bumps on the calibration disk, a glide head can be calibrated on the glide tester without using an independent fly height measurements for the glide head. Thus, errors in the fly height measurement and the delay in mounting each glide head to a fly height tester are avoided.

Calibration disk having discrete bands of calibration bumps

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Santa Clara, CA, United States of America

Dan Frusescu