1、LED General situation of industry

(1)LED brief introduction

LED is“Light Emitting Diode”abbreviation，Light-emitting diode (LED) is a new type of semiconductor solid-state light-emitting device. When a positive voltage is applied at both ends, the carriers in the semiconductor recombine and cause photons to emit, thus producing light. LED made of different materials will emit different wavelengths of light, thus forming different colors. LED has the characteristics of low energy consumption, small size, long life, pollution-free, fast response, low driving voltage, strong seismic resistance, high color purity, and is known as a new generation of lighting source and green light source.

As the fourth generation semiconductor light source, LED has the following advantages:

(1) High light efficiency, low energy consumption: photoelectric conversion efficiency can reach more than 50%, while incandescent lamp is only 10% - 20%. In addition, the power of single LED is generally 0.05-1W. Clothing can be tailored to meet different needs and reduce energy consumption by clustering. As a light source, the power consumption of single LED is only 1/8-1/10 of that of common incandescent lamp at the same brightness.

(2) Long lifetime: The theoretical lifetime of light flux attenuation to 50% is 100,000 hours.

(3) Reliable and durable: no tungsten wire, glass shell and other easily damaged parts, abnormal scrap rate is very low, maintenance costs are low.

(4) Flexible application: small size, flat packaging, easy to develop into light, thin and short products, to make point, line, surface of various forms of specific application products.

(5)Safety: Unit operating voltage is between 2.8 and 5 V.

(6)Green environmental protection: Waste can be recycled, no pollution, no mercury, in production and use will not lead to toxic metal pollution environment.

(7)Short response time: Suitable for frequent switching and high frequency operation.

2、LED industry chain

The industry chain of LED includes five main links: LED substrate fabrication, LED epitaxy growth, LED chip fabrication, LED packaging and LED application. Generally, substrate fabrication, epitaxy growth and chip manufacturing are regarded as the upstream of the LED industry, packaging as the midstream, and application as the downstream. LED epitaxy growth and LED chip manufacturing are key links in the whole industry chain.