Contact start/stop characteristics on photolithographic magnetic recording media

Abstract

Currently, hard disk drives (HDDs) are widely used as large-capacity digital storage devices in computer systems. However, the microscopic top-surface topography of texturalized magnetic recording media has not yet been adequately defined, even though this is an important factor governing the contact start/stop (CSS) lifetime at the head-disk interface of an HDD. As a result, there are occasional HDD failures due to insufficient topographical control. This paper describes the CSS characteristics of media with well-defined microscopic land patterns on the top surface, achieved by using a highly-reproducible photolithographic technique. CSS tests were performed on the media, which were combined with MnZn ferrite and Al 2O 3. TiC head sliders. By optimization of the land-pattern parameters, there was success in obtaining media with a very long CSS lifetime of more than 30 000 cycles, irrespective of head-slider material. These experimental results show that, by using optimized photolithographic media with a land diameter, land ratio, land height and land interval of 3 μm, 0.5%, 30 nm and 38 μm respectively, it became possible to suppress the increase in stiction coefficient caused by medium-surface wear to less than about 0.1 for both Al 2O 3. TiC and MnZn ferrite sliders, even after more than 30 000 CSS cycles. It is concluded that use of photolithographic media considerably reduces the amount of recording medium and head-slider parameter adjustment needed to enhance the CSS lifetime of an HDD.