Effects of grooves substrate on thermal interface for the LED module

In a typical LED package module, a grease layer forms the interface between the substrate and copper heat spreader. We propose to carve grooves on the aluminum substrate to form an array of protruding posts. Three types of grooves are designed to measure interface thermal resistance. A preliminary feasibility study shows obvious improvement in the thermal resistance of the interfaces for the formation of thinner bond line thickness. Accelerating testing results in HS020 chamber also demonstrate improved reliability against grease pump-out with protruding posts surfaces.