In situ measurement and spatiotemporal evolution of contact pressure in chemical mechanical polishing using a flexible sensor array

The uncertainty of chemical mechanical polishing (CMP) poses challenges to the investigation of material removal mechanisms, and the distribution and variation of pressure during polishing directly affects the material removal efficiency. To address the current difficulty in obtaining global and local pressure distributions during the polishing process, this paper constructs a CMP polishing pressure measurement system based on an array-type flexible pressure sensor and applies it to polishing experiments to study the temporal variation characteristics of spatial pressure at different positions. Calibration experimental results show that under a representative load of 25 N, the system achieves a repeatability error of ±1.17 %FS, an inter-node coefficient of variation of 4.43 %, and a maximum hysteresis error of 1.99 %FS; the end-to-end visible response time is 0.746 ± 0.064 s. Under CeO2 slurry conditions, pressure-centroid-based radial statistics show an overall-mean maximum of approximately 130 kPa at a centroid radius of about 2 mm; individual time-resolved radial-bin means reach approximately 315 kPa, while the profiles converge to about 35–40 kPa beyond approximately 6 mm. The results verify the feasibility and effectiveness of the constructed pressure measurement system in practical CMP polishing processes, and provide important experimental evidence for polishing pressure regulation and process parameter optimization.