High power LED bead chips convert 30 to 35 electrical energy into light energy during operation, while the remaining 65 to 70 energy is converted into thermal energy. LEDs have a very active impact on temperature. Generally speaking, LEDs can prevent functional degradation or even failure only when the junction temperature is below 125 degrees Celsius. 70% of the drawbacks come from high LED temperature, and the defect rate doubles for every 20 degrees Celsius temperature increase when the load is at half the rated power.

heat transfer

The heat conduction of high-power LED bead lamps has three sub links: chip to epitaxial, epitaxial to packaging substrate, and substrate to heat sink or casing. The current issue with LED heat dissipation technology is that LED nodes are constrained by temperature, with a maximum temperature of 125 degrees Celsius in general; The planned value is 90 degrees Celsius, and the temperature difference with the ambient air is only 55 degrees Celsius.

High power LED lamp beads cannot use fans for heat dissipation, but instead use natural convection heat dissipation. Moreover, LED heat dissipation planning must also meet the optical requirements of LED lighting fixtures. In addition, LED heat dissipation planning must also meet the lighting design requirements in order to have better selling points, and lighting design planning constrains heat dissipation planning.

If high-power LED light beads are placed loosely for simple heat dissipation, reducing optical power is not worth the loss. The cost of LED heat dissipation is very high, and the volume and weight constraints prevent LED lighting fixtures from being filled with a large amount of high thermal conductivity thermal conductive materials, including high thermal conductivity silicon film, silicone grease, solder, phase change materials, and so on; During this period, thermal conductive silicone sheets and high thermal conductive silicone gaskets have the highest cost-effectiveness, making them the preferred thermal and heat dissipation materials.