Patent ID: 8502112
Filing Date: 2013-08-06
Classification: B23K,G03F

Abstract:
1. A method of forming an astigmatic focal beam spot for machining a substrate, the method comprising: generating a raw laser beam; expanding the raw laser beam to produce an expanded beam; modifying the expanded beam to produce an astigmatic beam that is collimated in a first axis and converging in a second axis; and focusing the astigmatic beam to form an astigmatic focal beam spot on a substrate, the focused astigmatic beam having a first focal point in the first axis and a second focal point in the second axis, the second focal point being separate from the first focal point such that the astigmatic focal beam spot is focused on the substrate in the first axis and defocused in the second axis, the astigmatic focal beam spot having a width along the first axis and a length along the second axis, the width being less than the length such that the astigmatic focal beam spot is narrower in the first axis and wider in the second axis, and wherein the width of the astigmatic focal beam spot on the substrate is about 5 μm or less.