Research On Temperature Field Analysis And Process Parameter Optimization Of Sapphire Substrate Polishing

Sapphire is a single crystal of alumina with excellent optical,physical and chemical properties.It is widely used in LED substrate,laser system,military window and smart phone screen.Its processing quality and precision directly affect the performance of the device.In particular,the temperature field of the polishing process affects the activity of the polishing liquid,the agglomeration of the abrasive particles and the properties of the polishing pad,which affect the polishing quality and production efficiency.Based on the analysis of relevant literatures at home and abroad,the finite element model of chemical mechanical polishing temperature field of sapphire substrate was established and computer simulation was carried out to discuss the influence of process parameters on polishing temperature field.A wireless real-time measurement system for polishing surface temperature of sapphire substrate was developed.The polishing temperature field experiment was carried out.The results show that it is basically consistent with the simulation results,which verifies the correctness of the simulation model.Single factor and orthogonal experiments were designed for the actual production conditions.The polishing process parameters of the sapphire substrate were optimized,and the optimal process parameters were obtained.The experimental verification was applied to the actual production.The main work of this paper is as follows:The first chapter introduces the excellent performance and wide application of sapphire.Then it discusses the research status at home and abroad from three aspects of polishing temperature field,measurement method and process optimization,and puts forward the research purpose and technical route of this topic.In the second chapter,the finite element model of chemical mechanical polishing temperature field of sapphire substrate was established.The temperature field cloud images at different time points were obtained.The influence of process parameters(polishing pressure,polishing disk speed and cooling water temperature)on polishing temperature was studied.The third chapter develops a wireless real-time measurement system for the polished surface of sapphire substrate.The selection of the temperature measurement method,the determination of the measurement object,the determination of the signal transmission scheme,the selection of the corresponding hardware,such as sensors,temperature recorders,Bluetooth adapters,interface cables,the construction of the experimental platform,and the use of the temperature measurement system The polishing temperature field experiment verified the correctness of the simulation model.By adjusting the temperature of the ice machine to control the polishing temperature,the relationship between polishing temperature and polishing quality was obtained,which proved that the polishing temperature was reasonable around 35 0C.The fourth chapter carries out the experimental research on the optimization of the polishing process of sapphire substrate.The material removal rate and surface roughness were used as the evaluation indexes.The influence of polishing parameters on the polishing effect of sapphire substrate was studied by single factor and orthogonal experiments.The optimal process parameters were found and verified by experiments.A method for improving the overall flatness was explored.The fifth chapter summarizes the research results of the full text,and looks forward to the future research content.