Discussion on the problem of LED street light attenuation

Summary: Temperature is actually the key problem of LED street light decay, and LED street lights are stuck in this link. Because the luminous power of LED st
Temperature is actually the key problem of LED street light decay, and LED street lights are stuck in this link. Because the luminous power of LED street lamps is greater than that of household lamps, manufacturers have worked hard on the design of heat dissipation substrate fins and heat dissipation modules. After assembly, they must be painted on the outside of the lamp heat dissipation module to prevent weather erosion. Unexpectedly, the spray paint for external protection seals the heat of the heat dissipation module back, resulting in poor heat dissipation and led to LED epitaxial light decay.
To solve these existing problems, it is recommended that street lamp manufacturers start with basic materials and solve the heat source problem of high-power LEDs from the inside out. For example, when the light-emitting component is bonded to the aluminum substrate, the thermal conductive adhesive plays a key role. Some manufacturers think that the thermal conductivity of the thermal conductive film or thermal conductive pad is better, and the film thickness should be as thick as possible, but they did not think about the thermal resistance. No matter how good the thermal conductivity is, the thermal resistance of the film thickness is useless.
What's more, the thermally conductive adhesive film or soft thermally conductive gasket cannot really adhere to the substrate, and there are actually many pores on the bonding surface. These pores look like hollow air pockets when viewed under an electron microscope, which is another form of thermal resistance. With so much thermal resistance that interferes with heat conduction, the efficiency of heat dissipation and heat conduction is virtually reduced.
We can reduce the thermal resistance through thermally conductive adhesives. Thermally conductive adhesives can quickly conduct heat away, which naturally reduces the ambient temperature of the LED die, prolongs the life of the epitaxy and greatly delays the occurrence of light decay.
In addition, in the external protection of LED lamps, we can also use heat dissipation paint. The heat dissipation paint allows the lamps to withstand the high temperature of the LED for a long time without qualitative deterioration. LED street lights, landscape lights, or LED advertising billboards used outdoors are also exposed to acid and alkali damage such as wind and rain, acid rain, bird droppings, air dust, black smoke emission hELlip, and so on. Therefore, the choice of heat dissipation paint must have the characteristics of acid and alkali resistance. The current range of pH resistance is between PH3 and 11, which can effectively protect the appearance of LED outdoor lamps from being corroded.
The cost structure of LED lamps has been improved with the development of packaging technology, carrier board design, and heat dissipation module structure, and the quality has been continuously improved, and the cost has also decreased with the development of technology and market demand.