Search

Micro electrical discharge machining process is widely used for making small holes and machining micro molds. Recently, micro-EDM process was applied to the deburring process in the microdevices. Burrs at the edge of the devices were removed effectively with minimizing damage of machined surface. The electric field strength between the electrode and the workpiece was analyzed according to the geometry of burrs. The analyzed electric strength was compared to the dielectric strength of kerosene. The electrical discharge mechanism at the burr instead of the surface of the workpiece plane was explained by the electric field strength distribution. The characteristics of micro-EDM deburring process in the microdevices were studied. Adujusting the electrode tool position precisely, the burrs on the surface remained could be removed successfully. In this research, through the electric strength analysis, the applying the micro-EDM process to the deburring process was suggested.

Electrochemical discharge machining (ECDM) process utilizes the spark discharge produced by gas film formation during electrolysis. In conventional ECDM process precise control of the spark generation is difficult because of the randomness of gas film formation which results in the significant deterioration of process qualities such as excessive overcut, poor machining accuracy and low machining repeatability. The undesirable overcut phenomenon strictly hinders the dimensional miniaturization of ECDM process especially when the diameter of applied tool is much smaller than 100 mum. In this study a side insulated tool and dilute electrolyte concentration is proposed to reduce the undesirable overcut and thus, to improve the machining resolution of ECDM process. Experiments are conducted with various machining parameters, such as spark ignition voltage, electrolyte concentration and tool insulation. As a result the feasibility of miniaturization in ECDM process is successfully improved by reducing the excessive overcut phenomena.