In the whole process of lighting up, the internal temperature of solar LED street lamps is normal. However, if the heat dissipation of street lamps is not well done, the internal temperature will cause serious harm to itself in the case of continuous rise, or even damage the street lamps. Therefore, how can we strengthen the heat dissipation function of road lamps in response to such problems?

(1) The heat dissipation from the PN junction of the led chip of the led road lamp to the epitaxial layer. In the growth stage of GaN materials, improve the material structure, improve the basic growth parameters, obtain high-quality epitaxial chips, strengthen the quantum output power in the device, reduce the heat generation from the source, and speed up the heat conduction from the PN junction of the led chip to the epitaxial layer.

(2) Heat dissipation from the epitaxial layer to the package substrate. In the led chip package, flip chip structure, eutectic solder package and metal circuit board structure are selected. For device packaging, select appropriate substrate materials, such as metal printed circuit board, ceramic, composite metal substrate and other packaging substrates with good thermal conductivity, to accelerate the heat transfer from the epitaxial layer to the packaging substrate.

(3) Heat dissipation from packaging substrate to external environment. At this stage, the light source of solar LED street lamp usually uses reflow soldering to weld high-power white LED on the metal packaging substrate by array method, and then the metal packaging substrate is tightly installed on the large aluminum and copper material heat sink fins. The heat generated by high-power white led is transferred to the cooling fins according to the metal packaging substrate, and the natural convection or artificial forced convection is used to achieve the purpose of heat dissipation.

(4) Heat island effect. If the radiator of solar LED street lamp is very large, it is easy to have "heat island effect", especially when relying solely on natural convection. The whole process of heat dissipation of road lamps is basically based on the convection heat exchange between radiator and air, and basically depends on natural convection when the external wind hazards are eliminated. The natural convection is that the cold air in contact with the radiator rises naturally after being heated by the radiator, and the surrounding cold air is constantly replenished to take away the heat according to the continuous circulation.

Therefore, when cooling solar LED street lamps, we can strengthen the heat dissipation function of street lamps according to the above four methods, so as to effectively avoid the possibility of damage caused by excessive internal temperature. At the same time, the road lamps must be overhauled regularly, which can effectively avoid the possibility that the road lamps will be completely scrapped due to long-term unattended repair due to failure.