Research On The Key Technology And Control Method Of Composite Deposition Process For Automotive Lamps

Surface coating is one of the most important procedures in design and manufacture of automotive lamp. According to the related standards of auto lamps and technical market situation of domestic and international distribution, the facing problems of theoretical research and industrial application in this field were discussed. For the related technologies of the composite coating processes and equipment manufacture of high-grade automotive lamps, several key technologies were researched or discussed in detail.According to the composite films structures and functional requirements of high-grade automotive lamps, the technical characteristics of several kinds of vacuum coating technologies, PVD(Physical vapor deposition) and CVD(Chemical Vapor Deposition), were compared with analysis. The technical route with PVD and PECVD(Plasma Enhanced Chemical Vapor Deposition) in a vacuum chamber to achieving the composite coating of lamps was proposed, and the large-scale coating equipment independently developed and the details of some essential components were introduced.According to the related factors and theoretical analysis models of the films uniformity distribution, the techniques and methods were put forward to improve the uniformity of films from the evaporation source structure, effective coating region, motion mode of workpiece, and uniform gas distribution in the vacuum chamber etc. Through the synchronously tracking coating test, the existing reasons of distribution in experimentation and some measures which should be taken to further improve the film uniformity in industrialized production were analyzed. Experiment results showed that the prepared film uniformity meet the optical performance requirements, achieving uniform deposition effects of the automotive lamps with complex topography structures.Through the discussion of bottom leveling process and adhesion problems before surface coating, the technology plan of online plasma cleaning for lamp was proposed through building the high voltage field in the chamber of large-scale vaccum coating equipment, in order to overcome the problems and shortcomings of the traditional pretreatments. By the effect analysis of different power conditions, the results showed that the appropriate palsma bombardment has significant improvement effect on the adhesion of films, and the qualitative test reached the headlight detection requirements.For the requirements of optical performance and environmental durability of the lamp reflector and its accessories, the physical properties of metallic film materials and optical protective materials were analyzed. The technical processes of thermal evaporation, magnetron sputtering and plasma polymerization were discussed for realizing the high reflective Al films and optical protecting films. In terms of the test standards of the auto lamp, the performance of reflectivity and resistance to acid, alkali and salt achieved significant effect.Based on the high-performance coating equipment participated by the author, which was researched and developed independently, the control scheme of work flow and computer control system built with IPC(Industrial Personal Computer) and PLC(Programmable Logic Controller) were brought forward, and the optimal control effect of each process was achieved through industrial test and application analysis.Finally, the main researching work and achievements were summarized, and some further research work in the related fields was prospected.