Vacuum Heating And Temperature Correction

With the development of various new optoelectronic devices and the improvement of existing technologies,the important position of optical films has been further strengthened,and the preparation technology of films has been widely concerned.In the vacuum coating process,the substrate temperature is an important factor to determine the film quality.For many years,the temperature of the substrate is mostly measured by thermocouple,but the thermocouple cannot directly contact with the substrate when measuring temperature,resulting in a certain deviation between the measured temperature and the substrate surface temperature.However,the substrate temperature has a very significant impact on the basic properties of the film.Therefore,it is an important research issue to obtain the actual temperature of the substrate surface,conduct in-depth research on the film and improve the quality of the film.Based on the principle of vacuum heating,the overall design scheme of thermal radiation heating substrate and electronic bombardment heating substrate are proposed.According to the requirements of its use in vacuum environment,the material selection analysis is determined,and the mechanical structure of thermal radiation heating and electronic bombardment heating is designed.The heating device and temperature measurement device in thermal radiation heating and electronic bombardment heating are mainly introduced.The mechanical drawing software is used to draw the part drawings,and the assembly of thermal radiation heating device and electronic bombardment heating device is completed after the parts are processed.In order to obtain the surface temperature of the substrate in vacuum heating,the temperature of the circular 1-inch substrate,the circular 2-inch substrate and the circular 3-inch substrate heated by thermal radiation,the sample holder and the circular 2-inch substrate heated by electron bombardment are measured by contact thermocouple and non-contact infrared thermometer,respectively.After obtaining the substrate temperature,origin software is used to analyze the data to find out the law between the substrate temperature measured by thermocouple and the substrate surface temperature.The research shows that when the substrate is heated by thermal radiation,the surface temperature of the substrate is 50°C～70°C lower than that measured by thermocouple.The surface temperature of the substrate heated by electron bombardment is 50°C～400°C higher than that measured by thermocouple.In these two heating methods,the surface temperature of the substrate is in correspondence with the temperature difference of the substrate measured by the thermocouple of the system.After many experiments,it is found that the corresponding relationship between the substrate temperature measured by thermocouple and the substrate surface temperature has good reproducibility,which further confirms the reliability of the experiment.Through this study,it is concluded that the substrate temperature measured by thermocouples commonly used in vacuum coating industry is quite different from the actual substrate surface temperature.The temperature correction experiment has more accurate control of the substrate temperature in vacuum coating,which provides a new solution for the substrate temperature control in vacuum coating technology.