Collins Adam R, O'Connor Gerard M
Opt Lett. 2015 Oct 15;40(20):4811-4. doi: 10.1364/OL.40.004811.
Laser cutting of thin glass (<100 μm) has proven problematic. We describe an alternative laser scribing method that utilizes surface stress raisers. An ultrashort laser source is used to precisely pattern a plurality of aligned elliptical recesses on the glass. The apex of an ellipse concentrates applied tensile stresses. Depending on the elliptical dimensions, the stress concentration factor can be several tens of magnitude. The orientation of the ellipses defines a preferred scribing path. Tensile stress is applied orthogonally to the path and causes mode I fracture. The resulting scribe is of higher quality and strength than are possible with a full body laser cut. The optical setup is simple, low in cost, and compatible with future roll-to-roll manufacturing. The stress field around a stress raiser was analyzed using finite element method analysis. Consequently, the stress raiser process offers an alternative to other processes which employ high numerical aperture optics for thin glass scribing.
事实证明，对薄玻璃（<100μm）进行激光切割存在问题。我们描述了一种利用表面应力增强器的替代激光划片方法。使用超短激光源在玻璃上精确地刻蚀出多个对齐的椭圆形凹槽。椭圆的顶点会集中施加的拉应力。根据椭圆尺寸的不同，应力集中系数可达几十倍。椭圆的方向定义了一条优选的划片路径。拉应力垂直于该路径施加，并导致I型断裂。由此产生的划痕比全身激光切割所能达到的质量和强度更高。光学装置简单、成本低，并且与未来的卷对卷制造兼容。使用有限元方法分析了应力增强器周围的应力场。因此，应力增强器工艺为其他采用高数值孔径光学器件进行薄玻璃划片的工艺提供了一种替代方案。
