With its high efficiency, energy saving, environmental protection, fast response, and adjustable spectrum, LEDs have largely replaced traditional light sources in indoor and outdoor low-power application scenarios. However, the replacement rate of ultra-high power and high power density LED lamps, such as high pole lamps and stadium lamps, is still relatively low. The main reason restricting its widespread use is due to the heat dissipation and heat resistance of LED materials.
As LEDs move toward miniaturization and high power, this trend leads to more heat generation within a limited volume. Semiconductor components are usually very sensitive to heat, long-term heating or excessive heat will bring stability and service life problems. LEDs will generate a lot of heat while emitting light. If the generated heat is not dissipated in time, the LED chips will age or burn out rapidly.
Because the current of high-power LEDs is much larger than that of low-power LEDs in the past, the heat flow path of the chip part, the heat of the chip product passes through the metal block at the bottom, and is transferred to the copper substrate and aluminum substrate of the PCB through the solder, and then the thermal interface material is used. Reduce the contact thermal resistance between the PCB and the heat sink, and quickly transfer heat to the heat sink. Commonly used thermal interface materials mainly include thermal silica sheets, thermal grease, thermal gel, etc. In addition to thermal interface materials, heat pipes and cooling sheets can also be commonly used for high-power LED heat dissipation.
