Vacuum coating machine film thickness measurement and monitoring methods

The most direct method for controlling coating vacuum coating machine is a quartz crystal balance method (QCM), this instrument can directly drive the evaporation source, through the PID control loop drive bezel to keep the rate of evaporation. As long as the instrument is connected with the system control software, it can control the entire coating process. But (QCM) accuracy is limited, partly due to its mass being monitored is coated rather than its optical thickness.

Also, while QCM very stable at lower temperatures, but at higher temperatures, it becomes very sensitive to temperature. In the long heating process, it is difficult to prevent falling into this sensitive area sensor, resulting in a significant error on the film. Dongguan Huicheng Vacuum Technology Co., Ltd. in vacuum coating equipment production has more than ten years experience in this introduction of modern vacuum coating machine film thickness measurement and monitoring methods.

Optical monitoring is the preferred way to monitor high-precision coating, it is because it can more precisely control the film thickness (if used properly). Improved accuracy due to many factors, but the most fundamental reason is that the optical thickness monitoring. OPTIMALSWA-I-05 single-wavelength optical monitoring system is the use of indirect measurement and control, combined with Dr. Wang developed advanced optical monitoring software to improve the optical response of the theories and methods of film thickness variation to reduce the sensitivity of the ultimate error, provide feedback or transmission selection mode and the wide range of monitoring wavelength. Particularly suitable for a variety of coating film thickness monitor comprises a non-structured film monitor.