Liu Fei, Yu Aiwu, Wu Chongjun, Liang Steven Y
College of Mechanical Engineering, Donghua University, Shanghai 201620, China.
Shanghai Aircraft Manufacturing Co., Ltd., Shanghai 201620, China.
Micromachines (Basel). 2023 Jul 31;14(8):1542. doi: 10.3390/mi14081542.
Due to the characteristics of high brittleness and low fracture toughness of monocrystalline silicon, its high precision and high-quality cutting have great challenges. Aiming at the urgent need of wafer cutting with high efficiency, this paper investigates the influence law of different laser processes on the size of the groove and the machining affected zone of laser cutting. The experimental results show that when laser cutting monocrystalline silicon, in addition to generating a groove, there will also be a machining affected zone on both sides of the groove and the size of both will directly affect the cutting quality. After wiping the thermal products generated by cutting on the material surface, the machining affected zone and the recast layer in the cutting seam can basically be eliminated to generate a wider cutting seam and the surface after wiping is basically the same as that before cutting. Increasing the laser cutting times will increase the width of the material's machining affected zone and the groove width after chip removal. When the cutting times are less than 80, increasing the cutting times will increase the groove width at the same time; but, after the cutting times exceed 80, the groove width abruptly decreases and then slowly increases. In addition, the lower the laser scanning speed, the larger the width of the material's machining affected zone and the width of the groove after chip removal. The increase in laser frequency will increase the crack width and the crack width after chip removal but decrease the machining affected zone width. The laser pulse width has a certain effect on the cutting quality but it does not show regularity. When the pulse width is 0.3 ns the cutting quality is the best and when the pulse width is 0.15 ns the cutting quality is the worst.
由于单晶硅具有高脆性和低断裂韧性的特点，其高精度、高质量切割面临巨大挑战。针对高效切割晶圆的迫切需求，本文研究了不同激光工艺对激光切割槽尺寸及加工影响区的影响规律。实验结果表明，激光切割单晶硅时，除了产生切割槽外，在切割槽两侧还会产生加工影响区，两者的尺寸都会直接影响切割质量。去除材料表面切割产生的热产物后，切割缝中的加工影响区和重铸层基本可以消除，从而产生更宽的切割缝，且去除后的表面与切割前基本相同。增加激光切割次数会使材料加工影响区宽度和去除切屑后的槽宽增加。当切割次数小于80次时，增加切割次数会同时增加槽宽；但是，当切割次数超过80次后，槽宽会突然减小，然后缓慢增加。此外，激光扫描速度越低，材料加工影响区宽度和去除切屑后的槽宽越大。激光频率增加会使裂纹宽度和去除切屑后的裂纹宽度增加，但会减小加工影响区宽度。激光脉冲宽度对切割质量有一定影响，但不呈现规律性。当脉冲宽度为0.3 ns时切割质量最佳，当脉冲宽度为0.15 ns时切割质量最差。
