Influence of diamond abrasives on material removal of single crystal SiC in mechanical dicing

Abstract

Mechanical dicing is a critical step in producing electronic chips and devices. Single crystal silicon carbide (SiC) is a vital wafer material in modern electronic chips because of its exceptional physical properties, such as wide bandgap and high breakdown voltage. However, the high hardness of SiC makes it extremely challenging to achieve the dicing quality required for the reliable functioning of electronic chips. The removal characteristics of single crystal SiC in mechanical dicing process remains largely unclear. This work aims to systematically investigate the influences of diamond abrasives in ultrathin blades on the dicing force, chipping size, surface roughness, and material removal of single crystal SiC in mechanical dicing. Experimental results indicate the diamond abrasives considerably affect the chipping formation and the material removal of SiC workpieces by changing the undeformed chip thickness. Theoretical analysis based on the classic brittle-ductile transition model reveals that single crystal SiC can be removed in a ductile-like mode using relatively large abrasive size and low concentration, as long as the undeformed chip thickness is sufficiently smaller than the calculated critical depth of cutting. In addition, the mounting method of single crystal SiC workpieces and the wear characteristics of diamond blades play a crucial role in the removal behaviours and, therefore, the dicing quality. An example was given to demonstrate the feasibility of simultaneously improving the dicing quality and the removal rate via appropriately increasing concentration and reducing sizes of abrasives in ultrathin blades. Ultimately, the findings in this research provide a guideline for further optimization of the dicing tools and parameters for other hard-and-brittle solids.