Laser-Assisted High-throughput microLED Integration

.With the growing demand for ever-smaller devices, such as mini- and microLED displays with higher resolution rates, there is an unstoppable trend toward the miniaturization of components. High-speed, mass-production of these electronics is getting more and more difficult because the handling and accurate placement of these tiny components is very challenging. Each component needs to be carefully selected, transferred, and then accurately placed and assembled with interconnects – all at lightning speeds. As conventional industrial equipment fails to deposit ultrafine patterns of die attach material and handle such tiny components at required high rates, this calls for the development of alternative high-throughput assembly technologies. At Holst Centre, we have developed laser-assisted processes enabling high-throughput flip-chip integration of microLEDs. More specifically, we demonstrate the capability of high-throughout printing of die attach materials (solder pastes and conductive glues) at sub-20µm resolution and highly-selective and accurate mass transfer of microLEDs at assembly precision of 1µm (lateral) and 1° (rotation) and >99.9% yield.