Optimization of Processing Parameters for Water-Jet-Assisted Laser Etching of Polycrystalline Silicon

Abstract

Liquid-assisted laser technology is used to etch defect-free materials for high-precision electronics and machinery. This study investigates water-jet-assisted laser etching of polysilicon material. The depths and widths of the etched grooves were investigated for different water-jet incident angles and velocities. To select optimal parameters for a composite etching processing, the results of many tests must be compared, and at least one set of good processing parameter combinations must be identified. Herein, the influence of different parameters on the processing results is studied using an orthogonal test method. The results demonstrate that the depths and widths of the processing grooves were nearly identical at water-jet angles of 30°and 60°; however, the 60° incidence conferred a slight advantage over 30° incidence. The section taper, section depth, and surface topography were optimized at a water-jet velocity of 24-m/s, 1.1-ms laser pulse width, 40-Hz frequency, and 180-A current. Under these conditions, the section taper and groove depth were 1.2° and 1.88 mm, respectively. The groove surfaces exhibited no splitting, slagging, or other defects, and no recast layers were visible.

Effects of Laser Machining Aluminum Alloy in Different Media

“…The convection heat exchange between liquid–material–laser is relatively strong and laser energy loss is greater [ 29 ]. The actual energy of the laser irradiated on the surface of the material is smaller than the laser energy in air.…”

Study on the Influence of Surface Temperature Field of Aluminum Alloy Etched by Laser Water Jet Composite Machining

“…Water-jet-assisted laser processing is the addition of a water jet to traditional laser processing, which can not only maintain the advantages of laser processing but also remove the slag and debris produced in laser processing by making use of the impact effect of the water jet, to a certain extent, improving the quality of material processing [ 22 ]. Due to the high temperature of the laser action area, the water jet impinging the laser action area will produce a vapor film between the processing areas, and the energy in the processing process will be lost through the convection heat transfer in the vapor film.…”

“…In water-jet-assisted laser etching, the higher the velocity of the water jet is, the higher the flow velocity of the water jet acting on the material surface, which enhances the cooling effect of the water jet on the material surface. However, in actual experiments, the water jet velocity will not increase continuously, and relevant studies [ 22 , 23 ] have shown that an excessively high water jet speed will reduce the laser processing effect. Therefore, the maximum initial velocity of the water jet set by the simulation is 18 m·s −1 .…”

“…The experimental results show that the processing parameters have a direct influence on the groove depth and micro-morphology, in which the laser pulse energy and water-jet pressure play a major role in all the influencing factors. Chen et al [ 21 , 22 ] used low-pressure water-jet-assisted laser etching of polysilicon materials and studied the changes of etching groove depth, volume, and laser energy utilization efficiency under multiple process parameters. The results show that low-pressure water-jet-assisted laser etching technology can improve the problems of traditional laser etching, such as micro-cracking, slagging, and recast layer formation, to improve the quality of machined parts.…”

Special Issue “Composite Materials in Design Processes”

“…topic [16,17] of the research group. The papers [18,19] focus on the electric deposition of composite coatings and coupled waterjet and laser surface treatments.…”