Research on the machining characteristics of composite pulse power supply for the electrical discharge machining of semiconductor silicon crystal

摘要

Aiming at the problem of low efficiency in cutting silicon crystals with traditional wire electrical discharge machining (wire EDM) equipment, this paper proposes a method to improve the efficiency of electrical discharge cutting for silicon crystals by using composite pulse power to process semiconductors. This paper established a wire EDM equivalent circuit model, analyzed the magnitude of the discharge sustaining voltage on metal and semiconductor in wire EDM, studied the current-voltage characteristics of silicon crystals under a composite power supply, and compared the machining performance with and without the new power supply. The experiments show that, compared with the single power supply, the composite power supply can increase the machining current, and the existence of its high-voltage module can increase the probability of forming the discharge channel, which is convenient for wire EDM; using this power supply, the traditional servo system based on voltage detection can be used to distinguish the three typical machining states (short circuit, normal discharge, and no-load) in wire EDM for semiconductor machining, realize an effective servo feed, and improve machining stability; compared with the single power supply with an open voltage of 80 V, the new power supply with an open voltage of 80 V for the low-voltage module and 120 V for the high-voltage module has a certain increase in surface roughness, the processing efficiency is increased by 75%, and the kerf width is increased by 3.4%.