At the "Japan's 3rd LED and Organic EL Lighting Exhibition" held at the Ariake International Convention and Exhibition Center in Tokyo from January 16 to 18, 2013, Tamura Manufacturing Co., Ltd. and its subsidiary Lightwave Corporation exhibited their use of gallium oxide ( β-Ga2O3) white LED. This LED uses a phosphor in combination with a GaN-based semiconductor blue LED chip fabricated on a β-a2O3 substrate. The difference lies in that it has the characteristic of easily increasing the light output power compared with the ordinary blue LED chip manufactured on the sapphire substrate. Tamura Manufacturing Co., Ltd. and Lightwave exhibited two white LEDs using 0.3mm square blue LED chips and 2mm square blue LED chips at the venue. 0.3mm square products are 400mA drive type, 2mm square products are 6A drive type. The brightness of the 2mm square product is about 500lm, "the goal is to increase to 2000 ~ 3000lm which is difficult to achieve with sapphire substrate type products." Since the sapphire substrate is insulating, the sapphire substrate type product must adopt a lateral structure in which the anode electrode and the cathode electrode are laterally arranged. The β-Ga2O3 substrate has high conductivity, so it is possible to adopt a vertical structure in which an anode and a cathode are formed on the front and back surfaces of the LED chip, respectively. Compared with the horizontal structure, the vertical structure can not only reduce the element resistance and thermal resistance, but also easily make the current distribution uniform. The smaller the element resistance and thermal resistance, the less heat generated by the LED chip, so it is suitable for the case of large current drive. Although GaN substrates are also suitable for making high-power LEDs, "the cost of using β-Ga2O3 substrates is lower." Currently, GaN substrates are manufactured using a vapor growth method called the HVPE method, while the β-Ga2O3 substrate uses a solution growth method. Theoretically, the solution growth method is more suitable for realizing quality improvement and large size of the substrate. At present, the diameter of the β-Ga2O3 substrate that has been commercialized is 2 inches. Tamura Manufacturing plans to trial-produce a 4-inch product in 2014 and officially launch the product in 2015. In addition, it will challenge the development of a 6-inch product. Incremental Encoder,Linear Scale Encoder,Dual Concentric Rotary Encoder,Dc Servo Motor Encoder Yuheng Optics Co., Ltd.(Changchun) , https://www.yhencoder.com
