As well as different facilities. Is a solid-state semiconductor device that can convert electricity directly into light. Its voltage is 1.9-3.2V, red, yellow light voltage is the lowest, LED heart is a semiconductor chip, one end of the chip attached to a bracket, one end is negative, SMD LED the other end connected to the positive power supply, so that the entire chip is Epoxy encapsulated. Semiconductor chip consists of two parts, part of the P-type semiconductor, in which the dominant hole inside, the other end is the N-type semiconductor, SMD LED mainly electronic here. But when the two semiconductors are connected, they form a P-N junction between them. When the current through the wire acting on the chip, the electron will be pushed to the P area, in the P area with the hole in the electronic composite, and then will be issued in the form of photon energy, which is the principle of LED light. SMD LED And the wavelength of light is the color of light, which is determined by the material that forms the P-N junction.
LED (Light Emitting Diode) is a light-emitting diode, there are many, one of which is SMD LED. Other such as in-line LED, piranhas, high-power LED and so on. The SMD form of the package is divided into CHIP, TOP, SIDEVIEW and so on several.
Electrical connection to take the form of 2-pin straight, SMD LED is the traditional, low-end products, because the package heat resistance, chip cooling is not easy, so the light attenuation fast, short life. The advantage is cheap, can be made into a small light angle
Electrical connection to take 2, 4 or 6 pin patch, is the current commonly used light source. According to the size of the package shape, divided into 0805,1206,3528,3535,5050,5060 and other specifications, the larger the package shape, better heat dissipation, can withstand the corresponding power is also greater, SMD LED the more light output.
Is a 4-pin lead-in package, thermal performance and reliability are better than ordinary 2-pin inline, can withstand 50 ~ 70mA of operating current, the current commonly used light source.
The use of large-size chips and enhanced thermal channel technology design and production of LED, usually divided into 0.5W \ 1W \ 3W \ 5W and other specifications, a single 1WLED can withstand more than 300mA of current, and output more than 100 lumens of luminous flux, widely used In the field of commercial commercial lighting, traffic control, photography, night vision and other fields. High-power LED prices are still high, with the technology gradually mature, it will hope to completely replace the traditional lighting source, SMD LED leading the world into a solid light source era.
(SMA, surface mount adhesives) for wave soldering and reflow soldering, mainly used to fixed components on the printed circuit board, SMD LED the general use of dispensing or stencil printing method to distribute, to the surface of the adhesive Maintain the position of the component on the printed circuit board (PCB) to ensure that the components are not lost during transmission on the assembly line.
Paste the components into the oven or reflow machine after heating hardening. It is not the same with the so-called solder paste, once heated and hardened, SMD LED and then heating will not melt, that is, the hot film curing process is irreversible. The effect of the SMT patch will vary depending on the heat curing conditions, the connectors, the equipment used, and the operating environment. When used in accordance with the production process to choose patch glue.