Large Range High Precision F-Theta Scanning System

In recent years,the industrial processing has developed rapidly,which makes the processing accuracy continuously improving for all kind of products.The most familiar industry is the advanced electronic products such as cellular phones and notebook PCs,which have become more and more compact、lightweight also more sophisticated.What driving these trends are the highly integration semi-conductor devices,in order to increase the integration density,multi-layer configuration and diversity of PWBs are mounted.In keeping this trend,requiring the PWB hole diameter to be reduced and their circularity to be improved.Additionally,boring technique should be applicable for various types of board material.In this aspect,microdrills are used for bigger holes,while laser drills are used for smaller holes,however the F-theta scan system is the most widely used system.In general,laser drilling can drill 5-200um diameter holes,also depending on board materials and processing.In advanced processing,requires the spot size from dozens micrometers to several micrometers or less,in this way it can intergrate more on unit area.This thesis firstly surveyed the demands of adcanced laser processing industry and the problems of existing products,lots of F-theta systems don’t have a very good performance,some have high performance but their workpiece is not big enough also its applicability is narrow,therefore the thesis is developing a large area and high precision scan system is perposed,meanwhile it can be intergrated with DOE.The system belong to high precision scan system which is used for advanced ptocessing industry,the huge field can make processing more effcient;The spots over the field are all within defraction limited,also with high homogeneity,spot roundness is beyond 92%,yeild beyond 98%.It has widely uses,such as used for drilling of miniature circuit boards,also can be used for the processing of glass and other microstructures.At the beginning this thesis did some calculation,analysised the coordinate which is very useful for the improvement in the later stage;during the designning,analysised different infulences on the top-Hat which is generated by DOE,and use zernike function for auxiliary analysis which takes advantages of its orthogonality;torlancing is the core step of optical system,which determines the system is good or not,this design carries on the targets analysis,then optimize and limited the tolerance,this aim to making sure the design can be successful transformation.Finally,the whole machine was tested strictly,and the results were compared with the theoretical values.The results show that the full field spots are not only reached the diffraction limit,but also meet the theoretical requirements.