Monitoring procedure for application of deposit by evaporation

摘要

The varying characteristic of the quartz crystal is used to indicate deposit thickness. The procedure for real time measurement of the thickness of a deposit in evaporation equipment uses a quartz crystal (11) whose frequency of oscillation is modified by the thickness of the deposit on the quartz. The process includes sampling the deposited material at intervals. A coefficient of proportionality is established between the period of the quartz crystal and the thickness, enabling determination of the deposit thickness during the times when the material is not accessible during deposition.