SMD LED surface mount light emitting diode is what I mean, SMD SMD will help improve production efficiency, and the different facilities. Is a solid-state semiconductor device, it can be directly converted to electric light. Its voltage to 1.9-3.2V, lowest voltage red, yellow, heart of the LED is a semiconductor chip, the chip attached to a bracket on the end, negative electrode at one end and the other end to connect the power of positive, the whole wafer was encapsulated by epoxy resin. Semiconductor chip is composed of two parts, the part of the p-type semiconductor, in the dominant position it inside the hole, and the other end is the n-type semiconductor, here is mainly electronic. But when I connect the two semiconductor, a p-n junction formed between them. When a current passes through the wire act on the chipwhen electron is pulled into a p-region, electrons with holes in the p-compound then energy as a photon, which is the principle of LED light. And the wavelength of the light is the color of the light, is decided by the formation of p-n junction of thematerial.