PORT WASHINGTON, NY, September 18, 1996 -- TDK, one of the world's leading manufacturers of data recording media, today announced that it has developed a key technology necessary for the mass-production of rewritable DVD media (DVD-RAM). The new technology, dubbed Quick Bulk Initialization Structure, dramatically improves the efficiency of DVD-RAM manufacture by minimizing the time and complexity involved in a critical phase of DVD-RAM production.
As explained by Dr. Tominaga of TDK Corporation's Research and Development Department, the amorphous alloy used as a recording layer in a phase change disc must be converted from its amorphous state to a crystalline state before a disc can accept data. Because the alloy typically used in phase change media is deposited on the disc substrate in an amorphous state, each disc has to undergo a separate, time-consuming initialization process in which a high- energy laser is used to crystallize the alloy over the entire disc surface. This process involves the use of extremely expensive high-power laser equipment, whose laser source must be periodically replaced as it ages.
By using its patented AVIST phase-change recording alloy, TDK minimizes the time and energy necessary for initialization by controlling the amount of the element Antimony in the AVIST material. Antimony crystallizes almost completely during the alloy deposition process (sputtering), and only a minimal amount of external laser power applied in a very quick post- manufacturing step is necessary to complete the crystallization process.
Tim Sullivan, TDK VP of Marketing, notes that QBIS is another milestone in the process necessary to commercialize rewritable DVD media. Says Sullivan, "Without the QBIS system, DVD-RAM media would have been an expensive laboratory curiosity, not a viable commercial product. With our AVIST phase-change alloy and our new bulk initialization technology, the data storage industry can be assured of a ready supply of DVD-RAM media when the format is introduced next year."