Su-8 Micro-Mask on 3D Freeform Surface of Brittle Materials for Ajm : Optimal Conditions of SU-8 Mask for Micro-Abrasive Jet Machining of 3D Freeform Brittle Materials

Micro-blasting has established itself among the mainstream machining processes for difficult-to-cut workpieces like glasses, carbides, ceramics, etc., by using abrasive particles. Initially, during micro-blasting process non-machined areas are covered by protective mask. Today, either mask fabrication practice or micro-blasting process, none is secretive in the area of micro-manufacturing, but in the previous work, those processes were well suited and optimized for producing micro-features on planar workpieces. However, the demand for micro-features on 3D freeform substrate in MEMs and lab-on-a-chip devices imposes development of more refined non-planar micro-manufacturing techniques. In these concerns, this research focused on devising an appropriate photoresist mask required by micro-AJM processes on surface of a 3D freeform workpiece. The author investigated fundamental erosion mechanisms based on the SU-8 mask properties. Under optimal settings, the mask hardness and surface roughness were 25.04 HV and 1.14m respectively. Through micro-AJM process, the engraved micro-features size on surface of 3D freeform workpiece was 447.1 m- width and 11.6 m- depth.