SHUNTING LAYER ARRANGEMENT FOR LEDS

摘要

A shunting pattern on a surface of an LED die comprises an array of metal dots having widths that are on the order of 2Lt-5Lt (where Lt is transfer length) so as not to block a significant amount of light, yet have low contact resistance to the semiconductor current spreading layer. Contact resistance is not significantly reduced with widths greater than 2Lt. Each dot represents a current injection area. For a minimum 2Lt width and 50 square dots per mm2, the top surface area of an LED die will have about 1% of its surface covered by the dots. To cause the current to be evenly distributed over the top surface of the LED, the dots are connected with a grid of very thin metal connectors, having widths much less than 2Lt. In one embodiment, a wire bond electrode is formed near the middle of the top surface of the LED to create a more uniform current distribution.