Research On Opto-mechanical Structure Optimization Technology Of Infinite Image Distance Optical System

Chips are integrated circuit carriers and are widely used in the civil and military fields.With the continuous improvement of chip performance indicators,the requirements for detection technology are increasing.Therefore,high precision,high speed and inexpensive chip flaw detectors attract attention.Among many technologies,machine vision technology,which integrates fields such as optics,machinery,image processing and control,has the advantages of a non-contact,simple and low-cost structure.After a survey found that in view of the special lens design micro chip detection,infinity as from video microscope optical system can fully meet the application process,from microscopic system in the sense of infinity as is a kind of multi-function microscope,it can be through an external port and inscribed interface combinations of different microscope system,and the microscopic system imaging quality is better,won't appear like the migration and diffusion,the focal length will not affect.Infinite image distance parallel light path between the objective lens and the auxiliary lens formed axially detection range of the system can be improved,but also will not affect the performance of the optical quality of the system,the rich detection device,in a certain sense can replace conventional microscope head.In this topic,the chip inspection system is designed into an optical-mechanical structure in the form of microscopic imaging.Aiming at the deficiencies of the single structure of the microscopic imaging system,an infinite image distance is adopted as the basic optical structure of the system.At the same time,some components such as polarizers and filters can be inserted without affecting the optical quality of the entire system.Check the performance of the device.Based on chip size and resolution requirements,the objective and auxiliary objectives of the detection optics are designed and OSLO optical analysis software is used to optimize the set of optical structures.The simulation results show that the objective is of the three-part photographic type and the auxiliary objective is of the double bond thick meniscus type.The system resolution is312.5 lp / mm,which meets the 7 resolution design requirements.Based on the Monte Carlo analysis method,the analysis of the system of optical components is performed tolerances,component tolerances are allocated based on the results of the analysis and the final mechanical structure is determined.Finally,the designed infinite image distance microscopic optical system is tested.The test results show that the designed optomechanical chip detection system has a resolution of 266 lp / mm.This is equivalent to a simulation analysis and meets the detection requirements.In the design,the first step depending on design requirements,select and design suitable optical component,which includes the selection and design of the auxiliary lens and a microscope objective;second step of the overall image distance infinity optical system design,the first three-step test the effectiveness of the design and characteristics of the optical mechanism of the microscope.The final form is: the front group uses an infinite image distance three-piece photographic objective lens;the rear group is a double glued-thick meniscus auxiliary objective lens with f'=200mm,and the detector uses a CCD with a photosensitive surface size of 12.8mm×9.6mm.Industrial camera with a pixel size of 6.5?m×6.5?m.