LIMO's (Dortmund, Germany) innovative g2T scan system combines two different optical concepts for the first time--the transformation of Gaussian beams into homogeneous top hat profiles with a scan-method involving galvo mirrors and a specially designed f-theta objective lens.
This system is constructed for laser direct materials structuring with conventional single-mode lasers specifically at 532 nm, in particular for solar cell manufacturing.
Standard spot sizes of 50 x 50 µm2 are able to structure high-precision grooves with smooth edges in contrast to the typical sawtooth-patterns caused by Gaussian beams. Moreover, the process window is enhanced and thermal damages are reduced by the homogeneous profile.
A precise ablation of thin films is possible without damaging layers below. In comparison to Gaussian beams, the throughput can also be increased by utilization with g2T profiles due to smaller pulse-to-pulse spatial overlaps.
The scan field size amounts to 155 x 155 mm2 so that standard solar cells can be structured cost effectively in one production run with high throughput.