Feasibility Study on Real Time Electrostatic Charge Monitoring in Wafer Form Process with Potential Triboelectrification Motion at Dicing Saw

In dicing saw process, electrostatic charge is generated mostly at the spinner section due to frictional electrification owing to cleaning with deionized water, drying with dry air and separation electrification during workpiece separated from spinner table. The change phenomena of electrostatic charges held on workpiece throughout the triboelectrification motion is crucial yet without any inline monitor triggering system. Thus dicing saw machine spinner section was selected as primary feasibility study for real time electrostatic charge monitoring with the help of fault detection and classification (FDC). By communicating the electrostatic sensors with host system and FDC, several FDC window modelling able to setup for live data monitoring. Electrostatic charge trend study was conducted with different ionizer air flowrates and deionized water resistivity to validate the effectiveness of the inline monitoring system. With appropriate FDC triggering limit, this inline monitoring system is capable to detect any degraded or faulty ionizer, abnormal workpiece electrostatic charge, wrong ionizer settings and abnormal water resistivity while providing signal and data trend for electrostatic charges behavior. With this shift left approach and mechanism, electrostatic discharge (ESD) event can be detected early to minimize and reduce the losses and cost of scrap.