International Business Machines Corporation

Thomas S Petersen

Bruce P Kruger

Steven F Starcke

In a process for manufacturing a rigid magnetic recording disk, the disk's rigid substrate member is subjected to a force that produces plastic deformation in a manner so as not to remove material therefrom. In this way, the disk is provided with a surface topography that contains a controlled texture, for example in the area of the disk's start/stop track. In an embodiment of the invention, an ultrasonic probe and a disk shaped substrate member are placed in close proximity within a container that holds a fluid abrasive slurry, i.e. a suspension of hard particles in a liquid. Operation of the ultrasonic probe, as the substrate member rotates, causes the slurry to texture an adjacent portion of the substrate member by means of plastic deformation and in the absence of material removal from the substrate member. Operation of the probe thus provides texturing of the disk at an inner diameter track area thereof, for example in the disk's start/stop area. Since no material is removed from the substrate member, a step is not produced between the disk's start/stop area and the disk's outer data area. Alternate means for agitating the slurry, such as a hollow tip ultrasonic probe, a jet of slurry, and a jet of another fluid, such as an inert gas, are described.

Texturing the surface of a recording disk using particle impact

A magnetic disk is rotated while a tape of initially abrasive free permeable cloth tape is fed around a roller in engagement with a radial region of the disk surface. A slurry with free abrasive particles is applied to the tape prior to engagement of the tape with the disk. The roller is radially oscillated and the oscillation frequency is related to the disk rotation speed to abrade grooves in the disk surface in a pattern in which grooves vary from the circumferential direction by no more than a maximum angle of 5 to 45, preferably 8, degrees. The slurry application is halted and a rinse liquid is applied to the disk surface while the feeding of clean tape continues. Thin film layers including a magnetic medium are deposited on the abraded disk surface. The groove pattern may be abraded on the entire magnetizable area of the disk surface or may be restricted to the head landing area.

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Rochester, MN, United States of America

Thomas S Petersen