A curious observation of phenomena occurring during lapping/polishing processes

Abstract

We demonstrate that the kinematics of the polishing process is more intriguing than an idealized planetary movement as all the previous studies reported. In reality, the workpiece is pseudo-constrained by the planetary carrier and because of this its relative motion to the polishing pad also incurs a ‘parasitic’ movement that previously has not been observed. Here, we report and model this parasitic movement and quantify its effect upon the workpiece surface roughness. Using a motion capture system, the principal and ‘parasitic’ movements between the sample and polishing tool have been tracked and our models validated. It is proved that considering this parasitic movement the prediction of workpiece surface morphology can be significantly improved when compared with the idealized approach (i.e. planetary). Our observations and modelling framework open the avenue to carefully consider the compliance between the tools and workpiece in other manufacturing processes for accurate predictions of the process outcomes.

Surface Form Accuracy Evaluation in Abrasive Lapping of Single-Crystal Silicon Wafers

“…The particle trajectories moving on the target surface in the abrasive lapping process have a great influence on the uniformity of the material removal rate and the surface form accuracy (Sanchez et al, 2011;Yang et al, 2019). Tam et al numerically investigated the effects of four different fractal particle trajectories on the lapping uniformity, and they found that the material removal rate and the distribution of the surface texture were significantly different (Tam and Cheng, 2010).…”