LED package: Stent row package, chip packaging, module packaging of several of these encapsulation methods are common and frequently used.
A conventional existing packaging methods and applications
Stent row package is the earliest use for the production of a single LED devices, which is the common lead light emitting diodes (including piranha package), it is suitable for the instrument lights, city lighting engineering, advertising screen, Hulan, traffic lights, and more common in China now for some products and areas.
SMD package (SMD) is a leadless package, small, thin, very suitable to do the phone's keypad display lighting, backlighting of the TV, and the need for lighting or instructions of electronic products in recent years, the patch package to large size and high power in the direction of a patch package for three or four Led chip can be used to assemble the lighting products. Module packaging is also a multi-chip package, alumina or aluminum nitride board with a smaller size, high packing density packaging of dozens or hundreds of led 1w chips, the internal line is a mixed type, ie multiple chips in series, there are several road parallel. This package is to expand the power used for lighting products. Module package due to higher packaging density, generated by the application of heat, heat is the most important issue to resolve the application. Production device of the above package for the production of lighting fixtures have a common feature: thermal resistance of the Road more difficult to produce high-quality lighting, and the module itself and the connection of the radiator processing requirements are relatively high . Package yellow phosphor (YAG) and epoxy resin are different than the column mixed directly point to the hair on the blue LED chip, and then heat curing. The advantages of the common practice is to save material, the drawback is not conducive to heat, the phosphor will be aging. Epoxy resin and the phosphor is not the thermal conductivity of good material, and wrapped the entire chip will affect the cooling. Using this method for manufacturing LED lighting is clearly not the best solution.
Foreign production of high-power chips, more than 0.5 watts of white chips are on the blue chips coated with a uniform layer of YAG phosphor slurry, the exterior looked a yellow cube (except for the welding of two gold pad phosphor, this method can improve the light efficiency than the previous method, widespread use in foreign countries.) in the package as long as the white chip welding can be designed circuit board, eliminating the Tu apply the processes of phosphor. Brought to the lighting manufacturers, chip suppliers of domestic production but not yet mass-produced such white LED chip.
China is the country of the early development of LED lights, for domestic use is also good, because the national emphasis on "low-carbon economy", in 2009, China's implementation of the city of ten thousand LED lights, many cities have experimental section of the test led power 10w street lamp feasibility, China is a street light application of a breakthrough, and abroad (Osram, Nichia, Samsung and other companies) based on indoor lighting as a breakthrough, these two kinds of line Who has the advantage, has yet to see the outcome. China to start with LED street lighting for the application direction of the national conditions due to lower national income, while the higher cost of LED interior lighting, people can not accept. LED lights use the government out of money, the LED street lamp manufacturers took a fancy to it. In fact, the working conditions of the LED lights more than indoor LED lighting harsh, demanding, can do the quality of clearance (heat, life, color, reliability, etc.), then come back to do the indoor LED lighting and easier to a. Foreign LED giants are rolling out models hundreds or even thousands of LED interior lighting, the price between 20-75 dollars, power from a few watts to 20 watts. But their package mentioned earlier, only Philips, so that the phosphor coating on the LED lamp, and was named one of 2009 the most innovative LED lighting products.
I believe that: All LED lighting manufacturing should adopt a multi-chip package and module package (module packaging is a high-density multi-chip package), and it is best to direct encapsulation of the LED chip, lamp main body, so that the thermal resistance of the channel number at least, you can get a better cooling effect. Or the lamp main body made of deposited copper foil circuit body, its thermal resistance is also lower, LED lighting power at least a few watts, so are multi-chip packaging technology in the past does not apply must be used new methods and processes. Multiple packaged LED devices to assemble the LED lamps, it is difficult to create high-quality and highly reliable LED lamps, engaged in the manufacture of led 10w technology can understand this.
Second, the phosphor coating process innovation
The phosphor coating of the module package, see or phosphor paste applied directly above the chip, the phosphor with a module is more consistent, but may appear different modules for mass production seen with the eye color, the better approach is the use of LED phosphor film or diaphragm, the thin-film and diaphragm scale production, consistency, and LED lights are multi-chip package, the light emitted by mixed after fluorescence powder membrane or diaphragm is converted to white, its color can be eliminated. The film and the diaphragm is:
Through the light, the thickness of between 0.1 ---- 0.5mm phosphor uniform, smooth appearance.
Light conversion efficiency, better stability, long life, good aging resistance.
3 can be made into a film base and film base, made of thin slices can also see the implementation of the conditions and costs. The requirements of the film base is colorless and transparent, anti-aging good.
4 molding processing convenience, the size of any cutting, and low cost.
Another method is mixed in proportion to the phosphor and transparent plastic injection molding machine and mold the direct production of the shade with a phosphor to Blu-ray will be converted into white light shade. Such more save and more convenient shade conversion is a mixture of blue, white is the color output, and the light is softer does not produce glare.
, In order to better solve the problem of cooling of led power 50w lighting design and package together to consider the packaging and LED cooling heat sink made of a whole, effective in reducing the thermal resistance of the channel number, which is a very effective and improve The approach of the heat lamps.
Currently available LED fluorescent lamp is not with the heat sink, such lamps can not do high-power and high-quality and long life. The right product design should take into consideration the heat sink, industrial production is to squeeze out the radiator of LED fluorescent lamp, die semi-circular aluminum fins, and then cut the desired length depending on the size of the power, then the system out of aluminum copper foil circuit, the chip on copper, goldsmith line connection or use to help set the machine to help set. Effect of this heat lamps, and only two thermal resistance, one to two thermal resistance less than the commonly used packaging method, effectively reduce the temperature of the chip, to improve the quality of High Power LED 50W fluorescent lamp life can play a role.
Another method is to design on the aluminum sudden bar milling out a number of rectangular, with the common (0.8-1.0mm thick) the Pcb circuit board in accordance with the aluminum rectangular open rectangular hole, Pcb circuit board paste or riveting the aluminum on the LED chip is fixed in the aluminum rectangular protrusion stage, and then the gold wire connected to the circuit and chip on the PCB. This the best production process, thermal resistance is only a cooling effect of the best manufacturers for the production of LED lamps should give priority to the use of such programs, followed by re-aluminum on the copper foil circuit. Such innovations, in order to effectively solve a long strip of LED heat lamp, in order to improve the quality and life of the LED lamp.
Continuous exploration and upgrading technology, the future development of LED lighting showing the trend of the sun is shining.