LED Light Emitting Diode (LED) is a solid-state semiconductor devices, which can convert electricity directly into to light. LED’s heart is a semiconductor chip, one side of the chip is attached to a stent, the end is negative, the other side connect the positive terminal of the power, and the whole chip is packaged by epoxy resin. Semiconductor chip consists of two parts, one is P-type semiconductor, the hole is in it dominant, the other part is the N-type semiconductor, in this part is mainly electronics. And a PN junction is formed between them when the two semiconductor connected. When the current acting on the chip through the wire, electronics will be pushed to P zone, in this areas where electronics recombinated with the hole, then emit energy by the form of photon, which is the principle of LED. The wavelength of the light or the color is determined by the material of PN junction.
LED chip is a core component of LED, referring to the PN junction. Its main functions are: convert the electrical energy into light, the main material is Monocrystalline.
LED chip classification:
By usage: mainly divided into high-power LED chip and low-power LED chip.
By Color: mainly divided into three types: red, green, blue (raw materials for producing white light).
By Shape: generally divided into square pieces and wafer.
By Size: low-power chips are generally divided into 8mil, 9mil, 12mil, 14mil, etc.
How to judge LED chip:
led chip prices: Generally, square chip higher than the wafer, high power led chip higher than the low-power chips.
led chip quality: The evaluation of led chip quality are mainly by the die brightness and light attenuation. In the packaging process are mainly evaluated by the rate of finished product.