Influence of truncated micro-pyramid cavity for LED packaging heat dissipation

This research describes the truncated micro-pyramid reflective cavity for light emitting diodes (LEDs) packaging and increasing LEDs' heat dissipation. Research went through different microstructure profiles related to thermal effect in LEDs' packaging. Microstructures based on the silicon bulk micromachining provide unique truncated micro-pyramid reflective cavity geometry for LEDs assembly. Etching (100) crystal silicon in bulk micromachining provides a stable surface quality and replication advantages for the reflective cavities. Simulation works include the optical simulation by using commercial design software Trace Pro3.3 and thermo flow analysis software FLOTHERM 4.2 to obtain an optimum beam profile and geometrical dimensions for heat dissipation. The truncated micro-pyramid cavity and its array were produced using bulk micromachining through lithography process and silicon anisotropic etching. Then, placing LEDs into the silicon pyramid cavities and wire bonding LEDs onto printing circuit board (PCB) are the final works. This truncated pyramid cavity provides the reflective plane and heat dissipation for LED packaging.