Seagate Technology Incorporated

Zhengda Pan

Jialuo Jack Xuan

Chung Yuang Shih

Chung-Yuang Shih

Dallas W Meyer

Bo Wei

Thanh Duc Nguyen

A glass-ceramic substrate for magnetic recording media is textured employing a continuous wave laser light beam to uniformly heat a surface zone, thereby forming a continuously roughened zone defined by recrystallized microcrystals. Embodiments include impinging a continuous wave CO laser light beam on a rotating glass-ceramic substrate to uniformly heat an annular zone at a temperature between the crystallization temperature and melting point of the glass-ceramic substrate followed by air cooling to induce a continuous surface roughness having an Ra of about 5 &angst; to about 20 &angst;, thereby enabling a glide height of about 0.2 to 0.5 &mgr; in.

Crystal zone texture of glass-ceramic substrates for magnetic recording disks

Laser-scribing brittle substrates along a curvilinear path is effected by impinging and moving at least two laser light beam spots along the substrate surface, the first spot preheating the substrate and the second smaller spot heating the substrate to the laser-scribing temperature below the softening temperature of the substrate. Embodiments include forming dual spots employing a crystal material or employing dual fiber optic cables each optically linked to a lens. In another embodiment, three spot lasers spots are formed employing a three-spot diffractive lens, the third spot formed behind the second laser-scribing spot and heating the surface to a temperature lower than the laser-scribing temperature. Embodiments further include laser-scribing substantially circular glass, ceramic or glass-ceramic substrates for magnetic recording media.

Laser-scribing brittle substrates

Magnetic data storage disks, particularly along dedicated transducing head contact regions, are laser textured according to a process in which beam shaping optical components impart an elliptical or otherwise elongated cross-section to the laser beam. Consequently, individual texturing features such as rims and nodules are elliptical or elongate, with more gradual height gradients in directions parallel to their major axes. The texturing features further are oriented with respect to the direction of transducing head accelerations and decelerations, which yields high performance in terms of reduced dynamic friction, reduced stiction and better wear characteristics. Texturing features are formed in a variety of patterns, including patterns with adjacent features contacting one another. A further refinement involves forming features with substantially different slopes on opposites sides of a maximum height region.

Magnetic media with texturing features formed by selectively non-uniform laser beams

A laser-optical wave mixing technique is provided for forming a high density textured data zone in an efficient and accurate manner. A single coherent laser beam of wavelength &lgr; is split into two beams with roughly the same intensity. These two beams are then overlapped with a cross angle of 2&thgr; and focused at the disk surface, resulting in an intensity grating thereon. The intensity grating creates a wave-form pattern consisting of a series of high-energy laser beam lines that will heat the target surface and make surface topographical changes accordingly.

Laser-texturing data zone on a magnetic disk surface by using degenerative two wave mixing

Magnetic data storage disks, particularly along dedicated transducing head contact regions, are laser textured according to a process in which beam shaping optical components impart an elliptical or otherwise elongated cross-section to the laser beam. Consequently, individual texturing features such as rims and nodules are elliptical or elongate, with more gradual height gradients in directions parallel to their major axes. The texturing features further are oriented with respect to the direction of transducing head accelerations and decelerations, which yields high performance in terms of reduced flying height, improved glide avalanche, reduced dynamic friction, reduced stiction and better wear characteristics. Texturing features are formed in a variety of patterns, including patterns with adjacent features contacting one another. A further refinement involves forming features with substantially different slopes on opposites sides of a maximum height region.

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Newark, CA, United States of America

Zhengda Pan