What is the area of LED power chip?

LED Stadium Lights,LED high-power chips used for white light are generally around 40mil in the market. The so-called high-power chips generally use power of more than 1W.Since the quantum efficiency is generally less than 20%, most electric energy will be converted into heat energy, so the heat dissipation of high-power chip is very important, requiring a large area of chip.

What are the different requirements of chip process and processing equipment for GaN epitaxial materials compared with GaP, GaAs and InGaAlP?Why is that?

Common LED red and yellow chips and highlighted four-element red and yellow chip substrates are made of GaP, GaAs and other compound semiconductor materials, which can generally be made into n-type substrates.The wet process was used for lithography, and then the silicon carbide wheel blade was used to cut the chip.The blue and green chip of GaN material is a sapphire substrate. As the sapphire substrate is insulated, it cannot be used as a pole of LED. Two electrodes of P/N must be made simultaneously on the epitaxial surface through dry etching process and some passivation processes.Because sapphire is very hard, it is difficult to chip with emery blade.Its process is generally more and more complex than the GaP, GaAs material LED.