Micro-Machining of Magnetic Metal Film using Electro-Discharge Technique

摘要

We present the results of experimental investigation on the micromachining of magnetic metal film by using electro-discharge technique. In the range of discharge energy from 10~(-7) to 10~(-9) J, we examined the surface roughness, the crater diameter, the heat affected layer (HAL) thickness and the removal rate, as the applied voltage and the capacitance of the circuit are varied. The optimized machining conditions are: the capacitance is 40 pF, the voltage is 70 V at rough machining and then 50 V at finishing machining. This new technology has been applied to micro-machine Fe-Ta-N film of a magnetic recording head for forming the track width. The resultant head generates a magnetic fild suitable for high density recording and has realized the digital video cassette recorder, which is now on the market.