Integration And Mass Transfer Of Microleds

Conventional methods for the integration and mass transfer of red, green, and blue μLEDs onto integrated circuit boards are challenged by low yield. Unlike current display technologies, μLEDs require a significant number of individual devices and a specific construction depending on the color of the μLED. There is a need for new μLED integration techniques that address the manufacturing obstacles that slow the adoption of μLED technology.  

Researchers at the University of California, Santa Barbara have resolved the complexities of creating μLED displays by combining AllnGanP red μLEDs with InGaN-based blue and greed μLEDs on integrated circuit boards via wafer or flip-chip bonding. This method of integration involves fixing multiple μLEDs to a diced segment (tile) of the substrate which is the size of a single conventional LED. Transferring μLED arrays using tiles allows for parallel processing of μLEDs and integrated circuits, which is advantageous over serial processing in the conventional pick-and-place method. Thus, the invention offers advantages in rapid fabrication and integration times as well as eliminating the possibility of dead pixels by examining the μLED arrays separately on the diced substrate after bonding and using a procedure that leverages existing LED manufacturing processes.