P型太阳能级硅电火花线切割机理及工艺研究

Mechanism and Process of Wire-Cut Electrical Discharge Machine on P-Type Solar Silicon

根据半导体的特殊电性能建立了抽象的放电加工模型,该模型分别用二极管、可变电阻、稳压管、电阻等器件模型近似代表半导体与金属进电端的接触势垒、半导体的体电阻、极间放电的维持电压以及工作液电阻;根据所建立的模型分析发现,半导体电火花线切割具有单向导通性、击穿电压高等特点,并且加工过程中进电端会出现钝化现象。为此,研制了针对P型太阳能级硅切割的专用夹具,并对电阻率为2.1Ω.cm的P型太阳能级硅锭进行了电火花线切割,切割效率大于100 mm2/min。

An abstract electrical discharge machining model is established according to the special electrical properties of the semiconductor.The model includes diodes,variable resistors,voltage regulator tubes,resistors,and other devices similar to the representative model of contacts barrier of the semiconductor and the metal,body resistors of semiconductor,discharge remain voltage between electrodes, and resistors of dielectric.Semiconductor cutting by wire-cut electrical discharge machine（WEDM） has the characteristics of unilateral conduction and high breakdown voltage according to the established model,and passive phenomenon also exists in its conduction side.Thus,the special fixture is made for cutting P-type silicon solar,and resistance of 2.1 Ω·cm for the P-type solar silicon ingots is cut by WEDM,and the cutting efficiency is more than 100 mm2/min.