Laser-Assisted High-throughput microLED Assembly

With the growing demand for ever-smaller devices, such as mini- and microLED displays with higher resolution rates, there is an unstoppable trend towards miniaturisation 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 fail to deposit ultrafine pattens of die attach material and handle such tiny components at required high rates, this calls for development of alternative high-throughput assembly technologies.

Holst Centre is continually pushing the boundaries of hybrid printed electronics technologies to open new frontiers and enable new promising applications. Leveraging on over a decade-long experience in development and maturing of Laser Induced Forward Transfer (LIFT) technology and bringing it to the next level, we have developed a new laser-assisted printing technology – Volume-Controlled Laser Printing (VCLP) – capable of high-throughput deposition of ultrafine interconnects, such as conductive adhesives and solder pastes, from structured carrier plated covered with a proprietary permanent release layer. At Holst Centre we believe that high-throughput deposition of ultrafine interconnect patterns using VCLP technology opens up new possibilities for various applications, particularly, flip chip integration of micro-LED displays.

To complement VCLP interconnect printing technology and complete high-throughput integration of microcomponents, at Holst Centre we have developed another laser-assisted technology targeted to selectively and accurately transfer microcomponents from carrier wafers populated with high-density arrays of microcomponents. The technology has no fundamental limits to scale down to transfer of sub-10 µm microcomponents with dicing street as narrow as 5 µm. We have already demonstrated that our innovative and proprietary release stack developed at Holst Centre enables high-throughput, fast and well-controlled transfer of microcomponents, as small as 40x40x10 µm3 with 20 µm dicing street.