The white LEDs are made using gallium nitride grown on 200-mm diameter wafers of silicon. Toshiba said it plans to ramp capacity up to 10 million LEDs per month and said it wants to secure a 10 percent market share by 2016.
Production of LED chips is typically done on 2- to 4-inch sapphire wafers. Bridgelux Inc. (Livermore, Calif.) developed a method of manufacturing gallium nitride LEDs on 200-mm silicon wafers, which provides a cost advantage. With backing for Bridgelux from Toshiba, that process was brought to Kaga Toshiba Electronics Corporation, a discrete products manufacturing facility in northern Japan. Plessey Semiconductors Ltd. (Plymouth, England) has also adopted a GaN-on-Si process for LED production but is presently ramping with 6-inch diameter wafers.
The first product of the Toshiba GaN-on-Si line is the TL1F1 series of LEDs that produce 112 lumens at 350-milliamps current. The packaged parts measure 6.4-mm by 5.0-m by 1.35-mm.
Courtesy EE Times USA