In recent years, solar LED street lamps have set off an unprecedented revolution in the lighting industry. Solar LED street lamp has the characteristics of energy saving, high efficiency and no pollution, and has become a comprehensive replacement of incandescent lamp products. Solar LED street lamps play a very important role in outdoor lighting. When the night comes, outdoor street lamps are the first to light up.
But the reform of the solar LED street lamp is not happen overnight, in the process of reform also encountered many problems, therefore, in the process of solar LED street lamp to replace ordinary street lamp, must pay attention to methods, specific issues specific analysis, such ability in energy conservation and energy consumption at the same time, the maximum use of solar energy LED street lamps, play its proper role.
However, solar LED street lamps are definitely more energy efficient than ordinary energy-saving lamps. Although now, solar LED street light from the price may be higher, but with the progress of technology and the maturity of the market, the market price of the solar LED street light also will be change, wait for the development of solar LED street lamp technology more mature, more stable performance and at the same time when prices are more affordable, and vigorously promote solar LED street lamp taking everything into consideration may be more practical.
The quality and efficiency of street lamps will directly affect the use of resources, maximize the advantage of solar LED street lamps, and provide the largest support for energy conservation and emission reduction policies.
The light efficiency of solar LED street lamp and the conversion of light source with high heat dissipation efficiency improve the light efficiency of high-power LED lamp and reduce the heat consumption. The same power consumption can have higher brightness; If the brightness is the same, it's the same as the heat dissipation. This is a natural advantage for LED chips that are resistant to heat. However, since only about 30 percent of the energy that is actually converted to light radiates light, most of that energy remains in the form of heat on LED chips.
The substrate material and solid crystal mode of LED chips themselves are also becoming more and more efficient heat conduction:
1. The unique silicon carbide substrate of American CREE company is the substrate of LED chip with the highest thermal conductivity at present. The 40x40mil size chip can withstand a maximum current of 1000MA.
2. Traditional sapphire substrate chip, do not show weakness, developed the method of wafer installation chip. Turn the two electrodes on the surface to the bottom and weld them directly to the metal conductive substrate with silver paste. In this way, heat transfer is more direct than in the past with heat-conducting silver glue. In addition, recently, Korea, Taiwan's high-power LED chips also have to add a layer of metal coating in the sapphire substrate method, so that you can use silver paste instead of silver glue to solid crystal. After curing, the thermal conductivity of silver paste is close to pure silver and higher than that of silver glue.
Improvement of heat conducting copper sheet -- diamond - copper composite material
If the LED chip is not directly placed on the solid crystal online subgrade board in the form of COB, it will find a material with fast thermal conductivity as the intermediate medium to connect with the cooling fin. Copper, which conducts heat only slightly less well than silver among metals, is cheaper, so it is currently the most common heat-transfer material for high-power LED chips.
However, the thermal expansion coefficient of copper (about 19) differs greatly from that of sapphire substrate (about 5). So using copper as a conductor of heat for a chip can cause chips to crack under harsh conditions. Chip size is limited. Now the diamond - copper composite sheet has been developed in China. Higher thermal conductivity than pure copper; The thermal expansion coefficient is lower than that of copper. It is expected that after mass production, the price can be accepted by the manufacturers of high-power LED chip integrated blocks. According to the latest experimental report, compared with the 100W integrated module, the module with pure copper chip has a temperature of 75 degrees Celsius, while the module with diamond-copper composite chip has a temperature of 65 degrees Celsius.