With the global warming caused by greenhouse gas emissions, people have increased their awareness of energy conservation and environmental protection. The use of new energy-saving electroluminescent diodes has attracted the attention of the international community.
Due to the advantages of small size, high luminous efficiency, low energy consumption, high brightness and environmental protection, countries have increased funding for LED R&D and corresponding policy support. In the past decade, LED technology has developed rapidly.
At present, LED has been widely used in media screens, car lights, backlight sources, signage and indicative lighting, landscape lighting, and indoor flood lighting .
Usually 15 to 20 percent of the high power LED input power is converted into light, and the remaining 80 to 85 percent of the electrical energy is converted into heat. If the heat concentrated in the chip with a size of only 1 mm × 1 mm × 0.25 mm cannot be dissipated in time, the temperature of the chip and the stress distribution are uneven.
When the junction temperature of the LED exceeds the high temperature that the device can withstand, the light output characteristics of the LED will decay forever. Studies have shown that the operating temperature of LEDs rises from 63 to 74, and the lifetime of LEDs is 3/4 less.