Research on Optical Properties of CPI Film Second Surface Mirror
The secondary surface mirror of colorless transparent polyimide(CPI)film was prepared using magnetron sputtering coating process,with CPI film as substrate and Ag or Al as reflecting layer.The reflectance curve of secondary surface mirror film was analyzed by using Lambda 950 spectrophotometer.The reflectivity differences of secondary surface mirror of CPI film,silver plating on polyfluoroethylene propylene(F46)film and aluminum plating on polyimide thin film(PI)were studied in infrared and visible light bands.The results show that the secondary surface mirror of silver plating on CPI film is similar to that of F46 film in visible light band,up to 95%.Compared with the traditional PI aluminum coating,the reflectivity of CPI aluminum coating is obviously improved.In infrared light band,the reflectivity of CPI thin films is not as good as that of F46 thin films,which is comparable to that of traditional PI thin films.The absorption and emission ratio(αs/ε)of silver coating on CPI film is 0.19,which is close to that of the silver coating on F46 film,and the temperature resistance is better than that of F46 film.
thermal control coatingcolorless transparent polyimidesecond surface mirroroptical property