フェムト秒パルスレーザ照射によるPZTの高アスペクト比マイクロ溝加工

抄録

Lead zirconate titanate (PZT) is a piezoelectric ceramic material widely used for sensors and actuator components in the industry. There is an increasing demand for fabricating high aspect ratio microgrooves in PZT. However, conventional grooving methods make it difficult to fabricate such grooves due to the formation of wall tapers, which leads to functional defects in devices. In this study, we proposed a method to fabricate high aspect ratio microgrooves by femtosecond pulsed laser irradiation, which produces low thermal effects and generates high-quality grooves with a minimized taper angle. The fundamental processing characteristics were investigated by changing the laser fluence, the number of scans of the laser, and the laser scan pattern. It was found that the taper angle converged to a specific value by increasing the number of scans, and that the aspect ratio increased and the taper angle decreased when using a rectangle scan pattern. Based on these results, high aspect ratio grooves with an aspect ratio of 3.25, a taper angle of 1.8°, and a surface roughness of Ra 0.5 μm were successfully processed by using favorable processing conditions. The result of this study shows the potential of processing high-precision high aspect ratio grooves and slits with steep or perpendicular walls on PZT and other ceramic materials.