Ultrafast laser microstructuring provides unique manufacturing advantages being clearly deterministic, highly reproducible and inherently precise. By utilising the very high laser repetition rates available from modern ultrafast lasers (up to MHz), throughput can be maximised.
Most commercially available laser sources already offer power output (several tens of μJ/pulse), well in excess of what is typically required for high precision machining with single beams. Subsequent laser attenuation during process optimisation cancels the advantage of high repetition rate, reducing efficiency and resulting in wasted energy and unnecessary costs.
Oxford Lasers is involved in this project to address this problem offering a versatile beam shaping solution by combining liquid crystal on silicon reflective spatial light modulators (SLM) with ultrafast lasers. An SLM is a dynamic diffractive optical element that can transform the incident beam intensity distribution into any desirable pattern for micromanipulation. For example, by splitting an energetic ultrafast laser beam into many lower energy beamlets, each capable of individual precision micro-structuring, one can demonstrate tenfold throughput gain or higher depending on material. The project will also demonstrate syncronised machining of different materials on the same wafer and selective layer removal in multilayered stacks with varying shapes by suitably tailoring spatial and temporal intensity across multiple beamlets.
Potential applications to benefit could be found in photovoltaics, plastic electronics, medical device and microelectronics manufacturing among other high volume applications .
Image copyright: LLEC
