根据衍射原理,设计并制备了平顶整形元件, 将激光能量由高斯分布转变为平顶分布。利用532 nm脉冲激光进行了硅晶圆激光划片实验, 研究了激光能量、划片速度及聚焦位置对划片效果的影响。结果表明, 基于平顶光束的激光划片, 可实现宽约为16 μm、深约为18 μm的划槽, 且槽底部平坦, 槽壁陡直; 与高斯光束相比, 平顶光束下热影响区明显减小。

According to the diffraction principle, a flattened shaping element is designed and prepared, which converts a Gaussian distribution of laser energy to a flat-top distribution. The laser dicing test of silicon wafers is carried out by using the 532 nm pulsed laser and the influences of laser energy, dicing speed and focusing position on the wafer cutting effect are investigated. The results show that based on the laser dicing by flattened beams, a groove with a width of about 16 μm and a depth of about 18 μm can be obtained, whose bottom is flat and wall is steep. In addition, the heat affected zone under the flattened beam is obviously smaller than that under the Gaussian beam.