Title:	Ductile Cutting Mode in Diamond Wire Sawing of Silicon
Author(s):	H. Wu, C. Yang, S. Melkote, S. Danyluk
Keywords:	Diamond Wire Sawing, Ductile Mode Cutting, Cutting Depth, Cutting Force
Topic:	WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Subtopic:	Silicon Feedstock, Crystallisation and Wafering
Event:	28th European Photovoltaic Solar Energy Conference and Exhibition
Session:	2BV.3.43
Pages:	1470 - 1473
ISBN:	3-936338-33-7
Paper DOI:	10.4229/28thEUPVSEC2013-2BV.3.43
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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This paper seeks to explain the reasons for the evidence of ductile mode of material removal commonly observed in diamond wire sawing of photovoltaic (PV) silicon wafers. This is achieved through a simplified theoretical analysis of the interaction of the diamond grits with the silicon. The cutting depth per diamond grit is analyzed based on the volume of material removed by each grit in the cutting channel. The analysis indicates that there is a square root relationship between the cutting depth per grit and the sawing parameters. Specifically, the cutting depth per grit is shown to be directly proportional to the feed rate and grit spacing along the wire, but is inversely proportional to the grit size and wire speed. For a typical diamond wire sawing condition, the cutting depth per grit is calculated to be in the range of 41 to 143nm, which is in the regime of ductile mode of material removal for silicon. The interaction between the diamond grits and silicon for a typical cutting depth per grit is further analyzed by finite element modeling and the grit-material contact force is found to be in the range of 3 to 12mN, which is similar to the critical load for ductile mode of material removal in lapping and polishing.