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SDK Restarts Domestic Production of Al Substrates for HDs

November 11, 2003

Showa Denko K.K. (SDK) has restarted domestic production of aluminum substrates for hard disk media, centering on high-capacity product lines.
SDK is currently producing 3.5” aluminum substrates for HDs through its subsidiary Showa Denko HD (Malaysia) Sdn. Bhd. at the rate of 2.2 million pieces a month. Meanwhile, SDK suspended substrate production in Oyama, Tochigi Prefecture, Japan, in October 2001. Since then, Oyama has been the center for establishing the production technology of HD substrates for high-performance server applications and developing the next-generation HD substrates.
To meet growing demand for HDs and satisfy customer requirements for higher performance, however, SDK has recently restarted commercial production of substrates in Oyama. SDK will produce in Oyama a total of 1.4 million pieces a month of aluminum substrates (2.5, 3.3 and 3.5 inches) for hard disk media used in high-performance servers and for the media with 80 GB/piece capacity. The production line is operated by a team of 140 people, including some contracted workers.
Under the ongoing medium-term consolidated business plan the “Sprout Project,” SDK is putting special emphasis on the electronics market. Although substrate/HD operations are included in the category of “businesses that need restructuring,” both operations are showing improved performance as a result of quick responses to market needs.


Aluminum substrates are produced by plating a nickel/phosphorus layer on a blank (doughnut-shaped, stamped aluminum sheet) and by mirror-polishing the product.
Hard disk media are produced by forming a magnetic layer and other layers on the substrate through vapor deposition and incorporated in the hard disk drive as recording media.