What is LED?

        LED (LightEmittingDiode), meaning light emitting diode in Chinese, is a solid-state semiconductor device that can convert electrical energy into visible light. It can directly convert electricity into light. It has small size, low power consumption, long service life, high brightness, Features such as low heat, environmental protection and durability. Mainly used in various indoor and outdoor display screens, dashboards, brake lights, tail lights, electronic watches, mobile phones, etc. inside automobiles.

　　 Which parts of the LED industry chain include?

　　 The LED industry chain mainly includes 4 parts: LED epitaxial wafers, LED chip manufacturing, LED device packaging and product applications. In addition, it also includes related supporting industries.

　　 Generally speaking, epitaxy belongs to the upstream of the LED industry chain, chips belong to the midstream, and packaging and applications belong to the downstream. The upstream is a capital- and technology-intensive field, while the entry barriers for the midstream and downstream are relatively low.

　　What is LED epitaxial wafer?

　　 The basic principle of LED epitaxial wafer growth is: on a substrate heated to an appropriate temperature, mainly sapphire, SiC, and Si, the gaseous substance InGaAlP is transported to the surface of the substrate in a controlled manner, and a specific single crystal film is grown. At present, the LED epitaxial wafer growth technology mainly adopts the organic metal chemical vapor deposition method.

　　LED epitaxial wafer substrate material is the cornerstone of the development of semiconductor lighting industry technology. Different substrate materials require different LED epitaxial wafer growth technology, chip processing technology and device packaging technology. The substrate material determines the development route of semiconductor lighting technology.

　　 At present, there are only two kinds of substrates that can be used for commercialization, namely sapphire and silicon carbide. Other substrates such as GaN, Si, and ZnO are still in the R&D stage and are still far from industrialization.

　　What is an LED chip?

　　 LED chip, also called LED light-emitting chip, is a solid-state semiconductor device whose main function is to convert electrical energy into light energy. The main material of the chip is monocrystalline silicon.

　　Semiconductor wafer consists of two parts, one part is P-type semiconductor, in which holes dominate, and the other end is N-type semiconductor, here are mainly electrons. But when these two semiconductors are connected, a P-N junction is formed between them. When the current acts on the chip through the wire, the electrons will be pushed to the P area, where the electrons and holes recombine, and then emit energy in the form of photons. This is the principle of LED light emission. The wavelength of light is also the color of light, which is determined by the material forming the P-N junction.

　　What is LED package?

　　LED packaging refers to the packaging of light-emitting chips, which is quite different from integrated circuit packaging. Not only is it required to protect the wick, but also to be able to transmit light. Therefore, LED packaging has special requirements for packaging materials.

　　 LED packaging technology is mostly developed and evolved on the basis of discrete device packaging technology, but it has great particularity. Generally, the die of the discrete device is sealed in the package, and the function of the package is mainly to protect the die and complete electrical interconnection. The LED packaging is to complete the function of outputting electrical signals, protecting the normal operation of the die, and outputting visible light. It has both electrical parameters and optical parameter design and technical requirements. It is impossible to simply use discrete device packaging for LEDs.

　　LED packages include lead type packages, surface mount packages, power packages and other forms.

　　 What LED application products include?

      the message says. Information display, digital display, various displays, and LED display information display, advertising, scoreboard, etc. of electronic instruments, equipment, household appliances, etc.

       traffic light. Signal lights for urban traffic, highways, railways, airports, navigation and river navigation.

　　 Car lights. Automotive interior and exterior lights, turn signals, brake lights, fog lights, headlights, interior instrument display and lighting, etc.

　　LED backlight. Small size backlight: less than 10 inches, mainly used for mobile phones, MP3, MP4, PDA, digital cameras, camcorders and fitness equipment, etc.; medium size backlight: between 10 inches and 20 inches, mainly used for laptops and computer monitors And various monitors; large-size backlight: more than 20 inches, mainly used for color TV display screens