Plessey has succeeded in wafer level bonding of its GaN-on-Silicon monolithic microLED wafers with JDC’s eSP70 silicon patented backplane technology, resulting in microLED displays that contain addressable LEDs.
Wafer level bonding poses great technical challenges and has not previously been achieved between a GaN-on-Silicon LED wafers and a high-density CMOS backplanes.
Plessey initially achieved the world’s first mechanically successful wafer to wafer bond in early April 2019. This success has now been followed by a fully functional, electrical and mechanical bond, resulting in a fully operational microLED display.
Plessey’s microLED display features an array of 1920x1080 (FHD) current-driven monochrome pixels on a pitch of 8 microns. Each display requires more than two million individual electrical bonds to connect the microLED pixels to the controlling backplane. The JDC backplane provides independent 10-bit single colour control of each pixel – Bonding a complete LED wafer to a CMOS backplane wafer, incorporates over 100 million micro level bonds between the wafers.
Dr Wei Sin Tan, Director of Epitaxy and Advanced Product Development at Plessey, said: “This is a momentous milestone in the development of our monolithic microLED display technology. To the best of our knowledge this is truly a world first and we are extremely proud of this tremendous achievement. This is what the industry has been waiting for and opens up a new market for microLED emissive display applications.”
