As an excellent semiconductor optoelectronic device, LED has been unanimously recognized in the market for its advantages of small size, low power consumption, long service life and environmental protection, and has become a new generation of ideal solid-state energy-saving lighting sources.
High-power LED packaging has been a research hotspot in recent years due to its complex structure and process, which directly affects the performance and life of LEDs.
However, with the development of LEDs with high light intensity and high power, the problem of heat dissipation has become increasingly prominent, which seriously affects the light output characteristics of LEDs and the life of the device, and has become a key problem that must be solved in high-power LED packaging. The root cause of the heat dissipation problem of LED is the high power density of the chip, and the heat dissipation efficiency of the chip has not been improved in time.
Heat dissipation is a key problem for LED lamps to solve, and a heat conduction process before this is even more critical. The LED chip will generate a lot of heat when it is working. If it cannot be dissipated quickly and efficiently, the LED chip with too high junction temperature will seriously affect its own service life. At present, there are quite effective means to improve the heat dissipation capacity of LED lamps. We can coat a layer of thermal grease between the LED aluminum substrate and the aluminum heat sink to reduce the thermal resistance of the contact surface between them, thereby improving its own thermal conductivity. heat dissipation capacity.
Why apply a layer of thermal conductive silicone grease to improve the heat dissipation performance of LED lamps? Because the main heat dissipation method of LED lamps is to dissipate heat through the LED radiator. The same is true for the heat generated by the LED chip. The LED chip will first conduct the heat to the aluminum substrate, and then the aluminum substrate will conduct the heat to the aluminum heat sink. However, the aluminum substrate is often fixed on the aluminum heat sink by screws. The structure fixed in this way often forms an air gap between them, and the thermal resistance of the air is very large, which is higher than other thermal resistances. It is dozens of times larger, so it is necessary to apply thermal grease to fill the gap to increase the area of the contact surface, thereby increasing the heat flux, reducing the thermal resistance, and improving the heat dissipation performance of the LED lamp.
In fact, the quality of heat dissipation depends on the material of the heat sink. Thermal grease thermal paste is a thermal medium, the better the thermal conductivity, the more heat is exported, and the better the cooling effect.