Highlight the importance of white LED lamp heat dissipation problem
1.the impact of heat on the high-brightness LED
The heat is concentrated in the chip with small size, the chip temperature is increased, the non-uniform distribution of the thermal stress is caused, the efficiency of the chip is decreased and the lasing efficiency of the phosphor is decreased. When the temperature exceeds a certain value, the failure rate of the device increases exponentially. Statistics show that for every 2 C rise in component temperature, reliability is reduced by 10%. When multiple LEDs are densely arranged to form a white light system, the heat dissipation problem is more severe. Solving thermal management issues has become a prerequisite for high-brightness LED applications.
2.the chip size and the relationship between heat
The most direct way to increase the brightness of the power LED is to increase the input power, and in order to prevent saturation of the active layer, the size of the p-n junction must be increased accordingly; increasing the input power inevitably causes the junction temperature to rise and the quantum efficiency decreases. Single-tube power depends on the device to improve the ability to heat out from the pn junction, while maintaining the existing chip materials, structure, packaging process, the chip current density and the same heat dissipation conditions, increase the chip size, Temperature will continue to rise.