First, led history
50 years ago, people already understood the basic knowledge of semiconductor materials to produce light. In 1962, General Electric's Nick Holonyak Jr. developed the first practical application of visible light-emitting diodes. LED is the abbreviation of English light emitting diode. Its basic structure is an electroluminescent semiconductor material placed on a leaded shelf and then sealed with epoxy resin, ie solid package, so it can protect The role of the internal core wire, so the LED's seismic performance is good.
The LED was originally used as an indicator light source for instrumentation. Later, various light-colored LEDs were widely used in traffic lights and large-area displays, resulting in good economic and social benefits. Taking a 12-inch red traffic light as an example, in the United States, a long-life, low-efficiency 140-watt incandescent lamp was used as a light source, which produced 2000 lumens of white light. After passing the red filter, the light loss is 90%, leaving only 200 lumens of red light. In the newly designed lamp, Lumileds used 18 red LED light sources, including circuit losses, to consume 14 watts of electricity, which would produce the same light effect. Automotive signal lights are also an important area for LED light source applications.
Second, the principle of LED chips
LED (Light Emitting Diode), a solid-state semiconductor device that converts electricity directly into light. The heart of the LED is a semiconductor wafer with one end attached to a holder, one end being the negative pole and the other end connected to the positive pole of the power supply, so that the entire wafer is encapsulated by epoxy. The semiconductor wafer consists of two parts, one part is a P-type semiconductor, in which the hole dominates, and the other end is an N-type semiconductor, which is mainly electrons here. But when the two semiconductors are connected, they form a "P-N junction." When a current is applied to the wafer through the wire, the electrons are pushed toward the P region. In the P region, the electrons recombine with the holes, and then the energy is emitted in the form of photons. This is the principle of LED illumination. The wavelength of light, which is the color of light, is determined by the material that forms the P-N junction.
Third, the main chip manufacturers
Osram of Germany, lumens of the United States, CREE, AXT, Taiwan's Guangjia, Guolian (FPD), Dingyuan (TK), Huaying (AOC), Hanguang (HL), Addison, Guanglei (ED), There are Seoul in Japan, Japan, Toshiba in Japan, Dalian Lumei, Fudi, Sanan, Hangzhou Silan Mingxin, and Imitation Japanese. They are well-known chip suppliers. under.
Taiwan LED chip maker: Epistar (Epistar) referred to as: ES, (Lianquan, Yuankun, Lianyong, Guolian), Guangga Optoelectronics (Huga), New Century (GenesisPhotonics), Arachio Optoelectronics (AA), Abbreviation: AOC, Tekcore, Kellett, Fuxin, Guanghong, Jingfa, Shichuang, Zhoulei, Liansheng (HPO), Hanguang (HL), Guanglei (ED), Dingyuan (Tyntek): TK , Fu Fuzhou Technology TC, Canosa (FormosaEpitaxy), Guotong, Lian Ding, New Optoelectronics (VPEC) and so on. Ledtech Electronics, Unity OptoTechnology, ParaLight Electronics, Everlight Electronics, BrightLED Electronics, Kingbright, Lingsen Precision Industries, Ligitek Electronics, Lite-On (Lite-OnTechnology), Hongqi (HARVATEK), etc.
Continental LED chip manufacturers: Sanan Optoelectronics abbreviation (S), Shanghai Blu-ray (Epilight) abbreviation (E), Silan Mingxin (SL), Dalian Lumei (LM), Diyuan Optoelectronics, Huacan Optoelectronics, Nanchang Xinlei Shanghai Jinqiao Dachen, Hebei Lide, Hebei Huineng, Shenzhen Orende, Shenzhen Century Jingyuan, Guangzhou Puguang, Yangzhou Huaxia Integration, Gansu Xintiandian Company, Dongguan Fudi Electronic Materials, Qingxin Optoelectronics, Jingneng Optoelectronics, Medium-light optoelectronics, dry-light photoelectric, Jingda Optoelectronics, Shenzhen Fangda, Shandong Huaguang, Shanghai Lanbao and so on.
Foreign LED chip manufacturers: CREE, HP, Nichia, Toyota Synthetic, Oceanic Acid, Toshiba, Showa Denko (SDK), Lumileds, Smileds, Genelite, Osram, GeLcore , Seoul Semiconductor, etc., Puri, Korea, Epivalley, etc.