Determination of sawing temperature in multi-diamond wire sawing of mono-crystalline silicon carbide

Abstract

4H-silicon carbide (4H-SiC) is a superior polytype SiC known for its wide bandgap, excellent thermal stability, and outstanding electrical and mechanical properties. However, slicing thinner 4H-SiC wafers using diamond wire sawing (DWS) process generates significant heat due to the extended contact length between the diamond wire and work material. This heat adversely affects the surface quality of as-sawn wafers, accelerates diamond wire wear, and poses challenges in accurately measuring the sawing temperature due to the heat dissipation through the unsliced ingot thickness. To address this, the study employed a rocking mode sawing strategy to mitigate the temperature rise caused by the prolonged contact length, while Fourier’s thermal conduction law and finite element analysis (FEA) were employed to accurately evaluate the sawing temperature. The study compares the measured sawing temperatures under rocking mode and traditional sawing conditions with Fourier’s and FEA simulations. Additionally, the effect of sawing temperature on the surface quality of the as-sawn wafer and diamond wire wear has been examined. Results demonstrate that the rocking mode sawing strategy effectively minimizes sawing temperature by 8.266 % in contrast to the traditional sawing process, attributed to its reduced contact length. Fourier’s thermal conduction law analysis proved instrumental in accurately determining sawing temperature. Notably, the rocking mode sawing strategy substantially enhanced the surface quality and reduced the diamond wire wear rate in contrast to the traditional sawing process.