Solution to light decay problem of LED street lamp

The key problem of LED street lamp light attenuation lies in temperature, but LED street lamps are usually defeated in this link. As the luminous power of LED street lamps is greater than that of household lamps, manufacturers have made great efforts in the design of heat dissipation substrate fins and heat dissipation modules. After assembly, they need to add baking varnish to protect the heat dissipation modules of lamps from climate erosion. Unexpectedly, the paint of this external protection has sealed the heat of the heat dissipation module back, causing poor heat dissipation and LED epitaxial light decay. LED epitaxial luminous heat energy belongs to a small range of concentrated heat energy. When high-power street lamps are applied, the power input power is also large, and the interface temperature of LED is quite high. Under the long-term continuous operation of street lamps, if the heat dissipation module cannot effectively dissipate heat, it will affect the service life and luminous performance of the LED. For example, the serious light attenuation of the current LED street lamp is caused by these factors. LED street lamps are used outdoors and have environmental and climatic interference factors, so most manufacturers protect the radiator shell of LED street lamps with anodic treatment or spray paint to avoid the erosion of acid and alkali substances. The life of the anode treatment is not long, and it will oxidize and discolor after a long time. If you want to remove the heavy industry, it will not only take time and labor, but also increase the maintenance cost; The protection cost of the paint is low, and the protection effect is good. However, the general paint has no heat dissipation function, and the paint itself will form a barrier effect, which is equivalent to increasing the thermal impedance of the LED street lamp radiator, on the contrary, because the heat energy is blocked in the radiator, the LED luminous power is reduced, which leads to serious light decay. The above has been a serious problem in the LED lighting industry, which is almost the main reason why the public works LED street lamps cannot pass the acceptance of the procurement unit. Suggestions for solving the light failure of LED street lamps: to solve these existing problems, street lamp manufacturers are advised to start from the basic materials and fundamentally solve the problem of high-power LED heat source from the inside out. For example, when the light-emitting component is bonded to an aluminum substrate, the thermal conductive adhesive plays a key role. Some manufacturers think that the thermal conductivity of the thermal conductive adhesive film or the thermal conductive adhesive pad is better, and the thicker the film, the better, but no thermal resistance problem is considered. No matter how good the thermal conductivity is, it is useless to touch the thermal resistance of the film thickness. What's more, the thermal conductive adhesive film or soft thermal conductive gasket cannot really fit with the substrate, and there are actually many pores on the bonding surface. These pores are viewed under an electron microscope, like cavitation, another form of thermal barrier. In the presence of so many thermal resistances that interfere with heat conduction, the efficiency of heat dissipation and heat conduction is virtually reduced. Use the heat-conducting adhesive, the recommended soft ceramic heat-conducting adhesive. The soft ceramic thermal conductive adhesive for screen printing construction is different from the traditional bonding thermal conductive adhesive film. The soft ceramic thermal conductive adhesive is soft semi-liquid. When the screen printer scraper is coated on an aluminum substrate, thermal conductive particles will penetrate into the pores on the surface of the substrate and fill them up. In this way, a completely flat plane without pores will be formed, which will be completely closed when bonded with the LED epitaxial carrier. In this way, the thermal resistance is reduced to a low level, and the heat can be quickly conducted out, thus naturally reducing the ambient temperature of LED grains, prolonging the service life of epitaxial crystals and greatly delaying the occurrence of light attenuation. In addition, due to the ductility of the soft ceramic thermal conductive paint for screen printing construction, it will change with the thermal expansion and cold contraction of the aluminum substrate during high-temperature baking or back welding, and the stress is very small, which will not cause the aluminum substrate to bend, it will not explode. Soft ceramic heat dissipation paint for LED lamps is recommended for external protection of LED lamps. This kind of spraying soft ceramic heat dissipation paint can be directly sprayed on the outside of LED lamps, has simple construction operation, can adapt to heat dissipation structures of various shapes, and can also be adjusted into different colors, in response to the needs of landscape design. The soft ceramic particles in the spray-type heat-dissipating paint are nano-processed, and the fine particles are not only easy to be operated by the spray gun, but also the thermal conductive particles on the same coating area are many and dense, the area where the temperature volatilizes and disperses also becomes larger, so that the heat energy of LED lamps can be quickly conducted out. Soft ceramic heat dissipation paint is a thermosetting material, conforms to RoHS environmental protection and safety standards, has simple construction procedures and does not need any special machines and tools, and can withstand the high temperature of LED for a long time without qualitative change after baking. LED street lamps, landscape lamps, or LED advertising billboards used outdoors will also face wind and rain, acid rain, bird droppings, air dust, black smoke emissions hELlip; And so on. Therefore, this kind of sprayed soft ceramic heat dissipation paint must have the characteristics of acid and alkali resistance, and the current acid and alkali resistance value range is PH3 ~ 11, can effectively protect the appearance of LED outdoor lamps from erosion. The cost structure of LED lamps is continuously improved with the development of Packaging Technology, carrier plate design and heat dissipation module structure, and the cost is also reduced with the development of technology and market demand. However, there are not many manufacturers investing in material improvement, which is mainly related to the history and habits of Taiwan's industrial and commercial development. Taiwanese manufacturers are good at process and design, and have less ink on material base research and development. Therefore, in solving technical problems or reducing costs and other issues, it is more biased towards procurement thinking or management thinking. However, US and Japanese manufacturers will think about the application materials at the time point, reduce costs, improve quality and increase profits from the perspective of innovation.