Laser Grooving Technology Study at Dicing Process in GaN Power Devices WLCSP

Abstract

Chipping free is a dream for GaN Epi wafer sawing process. With current high complexity of wafer technology plus the drive for cost reduction by narrowing the saw street width, it is a challenge which requires huge effort for wafer sawing process to achieve chipping free process. Higher density of metallization causing higher blade loading during mechanical sawing. The critical factors (dicing blade, index speed, spindle speed, cut in depth, test pattern in the saw street, etc.) affecting cutting quality were studied and optimized. This leads to chipping penetrating under the guard ring and damaging the active area [1].