Commercialisation of large sapphire substrates
The president of Sumitomo Metal Mining (SMM), Nobumasa Kemori has announced a decision to establish a mass production line within its fully-owned subsidiary Okuchi Electronics based in Isa City, Kagoshima Prefecture, Japan. Sapphire substrates are used in the fabrication of GaN for use in white and blue LEDs. Demand for white LEDs is growing for use in applications such as backlighting in large-screen LCD televisions and is also expanding rapidly in the general lighting market due to the use of LEDs saving energy and reducing environmental impacts. Accordingly, the sapphire substrate market is expected to see further growth. Having planned entry into large sapphire substrates for some time, SMM has made the decision to install a new large fabrication furnace within Okuchi Electronics and mass-produce 6-inch-diameter sapphire substrates. The planned value of the capital investment is about ¥1.2 billion (US $120 million) including investment already completed. Through the investment, SMM will construct a continuous production system extending from fabrication of large sapphire crystals to substrate processing. At present, 2- to 4-inch-diameter sapphire substrates are prevalent in the market. However, due to demands for cost reductions from LED manufacturers, demand for larger-diameter substrates is forecast to expand. Production of 6-inch-diameter substrates requires the fabrication of large-size crystals, but according to SMM, production is technologically difficult and can be performed stably by only a small number of manufacturers worldwide. Sumitomo Metal Mining has secured mass production capability based on its crystal fabrication technology built over many years. In the future, the company will enhance its development of materials in the environmental and energy sectors and will advance growth strategies in its materials business.