Abstract
The significance of liquid for abrasive wire sawing has been demonstrated by researchers with considerable studies. However, its performance in the spreading behavior is limited by the development trend of larger area wafer and narrower slicing kerf. Nevertheless, studies on the liquid spreading behavior in the wire sawing kerf are awfully limited. In this paper, a 3D CFD (Computational Fluid Dynamics) model was presented to simulate the liquid spreading behavior in the kerf. Where a VOF (Volume of Fluid) method with a CSF (Continuum Surface Force) model is used to simulate multiphase flow, and an empirical correlation for characterizing the liquid dynamic contact angle is introduced using UDF (User Defined Functions). Parametric simulations were performed on the kerf area, kerf width, liquid viscosity, liquid surface tension and liquid velocity at the inlet area of the kerf. Verification experiments are conducted for the validity of the simulation model. From both simulation and experimental results, three typical liquid spreading regimes in the kerfs are found, which perform distinct different effects on wire sawing. Moreover, the limiting conditions of the three spreading regimes are identified by non-dimensional analysis, then a prediction model is proposed for the liquid spreading regime, by given a set of Weber number and Capillary number. For wire sawing, the increase in the wafer area will not change the liquid spreading regime in the kerf, but the reduction of the kerf width will significantly hinder the liquid spreading behavior. By adjusting the physical properties and supply conditions of the liquid, the spreading regime can be effectively converted to facilitate wire sawing.
Simulation and Experimental Research on the Liquid Spreading Behavior in the Wire Sawn Kerf
