If the LED working environment is in a relatively cold place, the average temperature throughout the year may be only about 15 degrees, or lower, then the life of the LED will be longer. LED is afraid of heat, the higher the temperature, the shorter the life of the LED, the lower the temperature, the longer the life of the LED. The ideal operating temperature for an LED is of course between minus 5 degrees and zero degrees. But this is basically impossible. Therefore, after understanding the ideal working parameters of LED lamp beads, we should try our best to strengthen the functions of heat conduction and heat dissipation when designing lamps. In any case, the lower the temperature, the longer the life of the LED. For welding, the maximum temperature resistance of the PPA part of the LED lamp bead is about 260 degrees Celsius, so the welding temperature cannot exceed this temperature, and the time should be controlled to avoid thermal deformation and yellowing of the PPA. In terms of operating temperature, the higher the junction temperature of the LED chip, the lower the luminous efficiency. Generally, chip manufacturers allow junction temperatures not to exceed 120 degrees Celsius. Since the junction temperature refers to the temperature of the chip inside the lamp bead, it is not convenient to test. Considering the thermal resistance and contact thermal resistance of the circuit board, in the case of good thermal conductivity, the case temperature should not exceed 80 degrees Celsius. It is best to test the temperature of the positive and negative pins of the lamp bead after reaching thermal equilibrium to avoid poor heat conduction between the substrate and the heat sink. It is very hot, but the internal lamp beads have formed a smoldering phenomenon. The higher the working temperature of the LED lamp beads, the lower the light efficiency, the faster the decay, and the shorter the lifespan. It is recommended to combine the actual situation.