Japan Purple Ming semiconductors, on silicon backplane developed a GaN-type light-emitting diode (LED) chips. Among them, the blue LED's output power is the largest 10mW, and spread-based blue LED chip is almost the same as the power, "rather than on the production floor in the sapphire blue LED chips, manufacturing costs less than half" (the company). According to reports, have been able to reduce manufacturing costs, is compared with the sapphire plate, silicon plate is only about the price of 1 / 10, other than silicon backplane backplane Sapphire soft, more easily processed. New light-emitting wavelength of 450nm. Chip size is 0.3mm square. 20mA drive when the light for 1.5 ~ 2cd. In addition to the blue LED, the purple-ming semiconductor silicon backplane also produced a green LED.
Typically, in the generation of GaN on silicon membrane bottom, as GaN and silicon, as well as the thermal expansion rate difference between the larger lattice constant, so prone to cracks and other defects. This time, through the interaction of silicon backplane AlInGaN with multi-layer stack of materials other than AlInGaN as a buffer layer to suppress the occurrence of defects. Use the same tactics, the Japanese Sanken Electric (Sanken Electric) and Nagoya University are working together on the development of production in the silicon backplane of the GaN-type LED. Sanken Electric silicon backplane through interactive multi-layer stack as AlN and GaN buffer layer.
As the silicon to absorb more easily than sapphire light, so the blue LED in the buffer layer structure on the set of reflection. Compared with sapphire, silicon has a high thermal conductivity of the advantages of production in the silicon backplane of the GaN-type LED will be improved heat dissipation characteristics. Sapphire with different insulation, as the silicon can be conductive, it also has the n-type electrode can be installed in the LED chip most of the advantages of the lower part. Typically, the floor made with Sapphire LED, Sapphire is an insulator as a result, the LED must be part of the upper part of many cases to install the n-type electrode. The use of silicon backplane, then the abolition of the cutting process, it is expected that yield will be enhanced. It is also, due to the hardness of silicon and SiC lower than sapphire, so easy to cut, so it easy to increase the yield. |