Laser drilling in silicon carbide and silicon carbide matrix composites

Abstract

Silicon carbide (SiC) presents excellent semiconductor and physicochemical properties. The fabrication of through-holes in SiC and SiC matrix composites is beneficial to the new generation of microelectromechanical systems and the heat dissipation of aerospace materials. Owing to the hard and brittle characteristics of SiC, the conventional mechanical processing methods can no longer satisfy the higher processing quality requirements. Meanwhile, the high-precision of laser processing and its noncontact nature renders it a suitable SiC processing method. Based on the classification of pulse widths, this paper summarises the removal mechanisms of SiC using nanosecond and ultrafast laser. The characteristics of the laser-drilled SiC and SiC matrix composites with different pulse scales are analysed. In addition, drilling is performed using lasers of different pulse widths in a liquid-assisted environment, and the drilling morphology, depth, taper, heat-affected zone, recast layer, and roughness are compared. Finally, laser drilling techniques for SiC and SiC matrix composites are summarised and discussed.