1982: Film media increases disk storage density

Carbon coating enhances reliability of magnetic film media

An individual disk, sometimes called a platter, of a hard disk drive (“hard” to distinguish it from the flexible “floppy” variety) comprises a rigid substrate of non-magnetic metal, glass, or ceramic coated on both sides with a magnetic medium. Particles of gamma phase ferric oxide (γ-Fe2O3) combined with binder, lubricant and other materials formed the, so called, “particulate” or “oxide” media employed on early disk and tape storage devices.

Researchers noted that magnetic media deposited as a film by plating or sputtering processes yielded superior coercivity and low noise characteristics compared to particulate coating. The smooth surface also allowed reduced flying height of the read/write head and therefore increased potential areal storage density. But when established HDD suppliers, such as CDC, Fujitsu, Hitachi, IBM, and NEC, adopted thin-film read/write heads to increase recording density they continued to use particulate disks due to concerns about wear and corrosion of sputtered media under high humidity and temperature conditions.

Francis King at Datapoint developed a “diamond-like” carbon overcoating process on a cobalt-nickel plated disk that solved the early reliability concerns with film media. Syed Iftikar, Marvin Garrison and Venu Menon at SyQuest commercialized the technology for the Q100 removable disk cartridge used in the SQ306 drive in 1982 with an areal density of 5.22 Mbits per square inch. Tu Chen and Scott Chen founded Komag in 1983 to produce carbon overcoated sputtered disks for start-up drive vendors to the PC industry, such as Maxtor, Quantum and Seagate. Other film disk startups included Akashic, Domain, Lin Data, and TriMedia. Hewlett Packard began commercial shipment of the HP 97501A with a carbon coated 10 MB disc in 1985. IBM added an organic vapor lubricant to the carbon layer and introduced film disks in 1987. The rest of the industry adopted film disks by 1990.

Rev: 11.28.15

  • Maloney, W. T. “RF-sputtered chromium-cobalt films for high-density longitudinal magnetic recording” IEEE Transactions on Magnetics (Vol: 15, No: 6, November 1979)
  • King, Francis K. "Datapoint Thin-Film Media" IEEE Transactions on Magnetics (Vol: 17, No: 4 July, 1981) pp: 1376 - 1379
  • “Syquest Technology Background Information” Simon/Public Relations (November 1983)
  • Yanagisawa, M., N. Shiota, H. Yamaguchi and Y. Suganuma. “Corrosion-resisting Co-Pt thin film medium for high density recording” IEEE Transactions on Magnetics (Vol. 19, No: 5 Sept 1983) pp. 1638-1640•
  • Roman, Andrew “3.9 –in. Winchester features removeable media,” Mini-Micro Systems (June 1982) pp. 239-244
  • Iftikar, Syed with F. King. “SyQuest SQ306 Q100 Removable Cartridge Drive” CHM Storage SIG Research Notes (December 2011) []
  • Chen, Tu. The Evolution of Thin Film Magnetic Media and Its Contribution to the Recent Growth in Information Technology, Computer History Museum (2013) pp: 105-171
  • Wang, Shan W. and Alexander M Taratorin. Magnetic Information Storage, Technology Academic Press (1999) pp. 179-192.
  • Johnson, K. E., C. M. Mate, J. A. Merz, R. L. White, A. W. Wu. “Thin-film media - Current and future technology” IBM Journal of R & D (Vol: 40, No: 5, 1996) Page 511
  • Stevens, Louis D. “Data Storage on Hard Magnetic Disks” in Eric D Daniel, et. al., ed. Magnetic Recording: The First 100 Years, IEEE Press (1999) p. 295
  • Kryder, Mark H. “Magnetic thin films for data storage” International Workshop on Science and Technology of Thin Films for the 21st Century (Vol: 216, No: 1 28 August 1992) pp: 174–180
  • Cord, B., et. al. "Application of magnetic thin films for high-density data storage" Thin Solid Films (Vol: 175, August 1989) pp: 287–293
  • Wang, Shan X., Alexander M. Tarartorin. “Magnetic Recording Media” Magnetic Information Storage Technology, Academic Press (1990) pp. 177 - 2006
  • “HP 97501 carbon over-coated sputtered media in a disk drive” (Retrieved on 5.3.15 from: http://chmhdd.wikifoundry.com/page/HP+97501
  • “An Informal Panel Discussion on the History of Magnetic Thin Film Recording Media” IEEE Magnetics Society (November 12, 2013) [Retrieved on 2.23.15 from: http://ewh.ieee.org/r6/scv/mag/MtgSum/Meeting2013_11S.html]