Diamond-like carbon applications in high density hard disc recording heads

Between 1965 and 1993 areal bit density in hard disc recording heads grew at a rate of 45% per year. Subsequently the rate of growth increased to 65% through 1998. In the past 2 years, the density growth has increased yet again to an amazing 100% per year. Increasing areal density requires growth in both track and linear density. Products currently in production have areal density in the range of 10 to 15 Gbit/inch(2). At a continuing density growth rate of 100% per year, 100 Gbit/inch(2) production will become a reality in year 2003, less than 3 years hence. Reduction in head-to-media magnetic spacing follows areal density growth. Protective coatings on both the heads and the media contribute to spacing, one of the clear challenges going forward is reduction of the coating thickness while maintaining the functional properties of corrosion protection and tribology enhancement. Traditional direct ion beam DLC deposition coatings do not have the required properties at thickness below 30 Angstrom. New coating technology is required to meet the needs of the recording head industry. This paper will address the coating requirements as well as the test methods used to evaluate coatings. (C) 2001 Elsevier Science B.V. All rights reserved.