What factors should be considered in the heat source treatment of LED street lamps
In order to solve the heat source problem of LED street lamps, the material and composition structure of LED street lamps must be optimized, and the problem of high-power LED heat sources must be solved from the inside to the outside. LED street lamp manufacturers ED street lamps have much higher light color rendering than high-pressure sodium lamps. The color rendering index of high-pressure sodium lamps is only about 23, while the color rendering index of LED street lamps is more than 75. From the perspective of visual psychology, it can reach the same brightness and the illuminance of LED street lamps is average. It can be reduced by more than 20% compared with high-pressure sodium lamps. Low maintenance cost of LED street lights: Compared with traditional street lights, the maintenance cost of LED street lights is extremely low. After comparison, all input costs can be recovered in less than 6 years. The LED street lamp has an automatic control energy-saving device, which can achieve the greatest possible reduction in power and energy saving under the condition of meeting the lighting requirements of different periods. It can realize computer dimming, time period control, light control, temperature control, automatic inspection and other humanized functions. When the light-emitting module is combined with the aluminum substrate, the thermal conductive glue plays a key role. Some LED street lamp manufacturers believe that the thermal conductivity of the thermal film or gasket is better, and the thicker the film, the better, but the thermal resistance is not considered. No matter how good the thermal conductivity is, the thermal resistance of the contact film thickness is useless. In addition, the thermally conductive film or soft thermally conductive pad cannot really match the substrate, and there are a lot of pores on the surface of the adhesive layer. These pores are regarded as pores under the electron microscope, which is another form of thermal resistance. When a large amount of thermal resistance interferes with heat conduction, the heat dissipation efficiency and heat conduction efficiency are almost reduced.
When using thermally conductive adhesives, the thermal resistance should be low. It is recommended to use soft ceramic thermal conductive glue for screen printing. The screen-printed soft ceramic thermally conductive adhesive is different from the traditional laminated thermally conductive adhesive film. The soft ceramic thermal conductive adhesive is soft and semi-liquid. When the screen printer blade is coated on the aluminum substrate, the thermally conductive particles will penetrate into the holes on the surface of the substrate and fill them up. This results in a completely flat, non-porous plane, which will fully conform to the LED epitaxial carrier. In this way, the thermal resistance is minimized and heat can be conducted quickly, which naturally reduces the ambient temperature of the LED die, and also prolongs the life of the epitaxial crystal and greatly delays the occurrence of light attenuation. In addition, due to the ductility of the soft ceramic thermal conductive coating applied by screen printing, it changes with the thermal expansion and contraction of the aluminum substrate during high-temperature baking or reflow. The stress is very small, and the aluminum substrate will not be bent or caused. Will it be shattered?
It is recommended to use soft ceramic heat-dissipating paint for LED lamps for the external protection of LED lamps. The sprayed soft ceramic heat dissipation paint can be directly sprayed on the outside of the LED lamps, and the construction is simple and easy to operate. It can adapt to various shapes of heat dissipation structures, and can also be adjusted to different colors to meet the needs of landscape design. The soft ceramic particles in the sprayed heat dissipation paint are nano-processed. The fine particles are not only easy to operate with the spray gun, but also make the heat conductive particles on the same coating area more and more dense, and the area where the temperature evaporates is also enlarged. Let the heat energy of the LED lamps be quickly conducted out. The soft ceramic heat-dissipating paint is a thermosetting material that complies with RoHS environmental protection and safety regulations. The construction procedure is simple and does not require any special equipment. After baking, it is thermoset and can withstand the high temperature of the LED for a long time without qualitative deterioration. LED street lights, LED landscape lights, or LED advertising billboards used outdoors will also face acid and alkali damage such as wind and rain, acid rain, bird droppings, air dust, black smoke emission hELlip; and so on. Therefore, this kind of spray-type soft ceramic heat dissipation paint must have the characteristics of acid and alkali resistance, and the range of acid and alkali resistance is between PH3~11, which can effectively protect the appearance of LED outdoor lamps from being corroded.
With the development of packaging technology, load board design and heat dissipation module structure, the cost structure of LED street lights is constantly improved, and the cost is reduced with the development of technology and the continuous reduction of market demand. However, there are not many manufacturers investing in improving materials. This is mainly related to the history and habits of Taiwan's industrial and commercial development.
