High-speed and high-precision control of laser stealth dicing equipment based on interpolation and fitting

Abstract

As an advanced wafer dicing technology, stealth dicing has the advantage of better-cutting quality and faster-cutting speed than traditional blade dicing technology and has a broad application prospect for the future cutting of large and ultra-thin silicon wafers. The stealth dicing equipment involves two processes, i.e., wafer altimetry and follow-through processing in silicon wafer cutting, the altimetry accuracy of which determines the processing precision. In this paper, polynomial fitting, linear interpolation, and cubic spline interpolation are applied to predict the altimetry data at different speeds to achieve high-speed and high-precision altimetry under various speed conditions. The research shows that the prediction accuracy of the three methods is less than 1 μm. The linear interpolation has the highest accuracy during the altimetry speeds of 500 mm/s ~ 1500 mm/s. The polynomial fitting can achieve better prediction results by selecting the best fitting parameter when the altimetry speeds are 1500 mm/s ~ 2500 mm/s. The cubic spline interpolation is more suitable for the processing of data sampled at altimetry speeds between 2500 mm/s and 3000 mm/s.