Micro-milling/micro-EDM combined processing technology for complex microarray cavity fabrication

An integrated method of micro-milling and micro electrical discharge machining (EDM) is proposed for micro-structures array manufacture in this paper. In order to obtain micro-cavity array with high accuracy and consistency, in situ machining on the same coordinate system ensures the positioning precision. After studying micro-milling graphite, the effect of parameters on the machining accuracy is found. Further, suitable mode is chosen for high-dimensional consistency and good surface quality array electrodes according to comparison of one-by-one and layer-by-layer milling tool trajectory. Workpiece lifting control is used to strengthen the debris clear; then, it is verified beneficial of lifting through flow simulation and adding discrete particles. In order to solve poor precision of the micro-cavity contour caused by electrode wear, a multi-step machining by group electrodes is proposed, rough machining for material removal and finishing machining for trimming. Finally, a micro-cavity with clear edge, small fillets, and high shape accuracy is obtained. This method improves the machining performance of the array micro-structures and shows good prospects in micro-fabrication.