Research On Ductile Machining Conditions Of Single Crystal Silicon And Application On Micro-lens Array

In recent years,single crystal silicon plays an important role in many products such as solar power products,integrated circuits and infrared optical systems.However,as a hard and brittle material,micro cracks and pits are easy to occur during the cutting process due to the brittle fracture,which directly affects the quality of the machined surface.In order to meet the requirements of better performance and wider range of application,not only good surface quality is required,but also complex micro-structure surfaces such as micro-grooves and micro-lens arrays are required.The nano-indentation technology and Vickers indentation technology are used to test the material properties of single crystal silicon,and three important material performance indexes including elastic modulus,hardness and fracture toughness are calculated.Based on the cutting force model,the critical cutting thickness prediction model for brittle-toplastic transition is established using the model of cutting specific energy.The influences of machining parameters and tool parameters on the critical thickness are analyzed.The model is verified by cutting experiments.This can provide a guidance for the processing parameters selections for single crystal silicon microstructure applications.The single crystal silicon milling experiment is carried out,and the range of processing parameter is determined based on the critical cutting thickness.Scanning electron microscopy and raman spectroscopy are used to observe the chip and the machined surface.The effects of different tool types on the surface formation mechanism and chip morphology are analyzed.The Raman spectrum information of the machined surface is processed and analyzed to characterize the machining damage,and the effects of the feed per tooth,tool type,and lubrication conditions on the surface morphology and processing damage are analyzed.In addition,tool wear during machining of different tool types is analyzed.Mathematical modeling of different micro-lens array surfaces is performed,and the milling trajectory planning is combined with four micro-lens array processing strategies.A micro lens surface error evaluation procedure is established to facilitate the evaluation of the processed micro lens array.The measured data is preprocessed by template matching technique.Combined with reinforcement learning technology,the surface matching model is established to fit the measured data with the design data.The milling experiments are carried out.The effects of different machining parameters and machining trajectories on the milling performance of the micro-lens array are analyzed,and the lens surface error is evaluated with a laser confocal microscope.Research on the ductile region cutting of single-crystal silicon,and its application on machining micro-lens arrays,will help improve the performance,service life,and use range of single crystal silicon products.