According to Sumitomo Metal Mining (SMM)’s president, Nobumasa Kemori, the company has decided to set up a mass-produce 6-inch diameter sapphire substrates line within its fully-owned subsidiary Okuchi Electronics based in Isa City, Kagoshima Prefecture, Japan.

SMM intends to inject the capital investment of ¥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.

Currently, 2- to 4-inch-diameter sapphire substrates are popular in the market. But it’s a tendency that the demand for larger-diameter substrates is increasing due to needs for cost reductions from LED manufacturers.

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.