Research And Application Of Embedded Wafer Detecting Control System By Machine Vision

As the research"Based On Digital Image Processing IC Wafer Microsurgery Automatic Detection System" of Guangdong Province 2004 Annual Technology Projects (2004A10403008),In order to improve the speed and precision of locating of system and improve the speed of image gathering, vision detection technology is studied for IC with embedded system, which synthesizes embedded technology, digital image manipulation technology, error analysis theory, oscillation controlling technology and so on. Vision detection technology will solve the problem such as the precision of workpiece flat being not enough high in AOI for IC, the effect of in focus extent of image gathering and the precision of locating by system oscillation, and the real time of image focus judging in computer being not well, as a result, the quality and efficiency of inspection. for IC is improved. This article aims studying several main problems of the following: first, the study for the precise locating technology with high speed and high precision of IC micro detection workpiece flat, which was analyzed by movement error and oscillation controlling technology of workpiece flat. Second, the study for IC microphotography technology will solve the problem that the field of vision is very small and the data is so great because of high microscope's magnification, by improving the real time character of image focus judging and Z-axis focus control, therefore, the goal of image photography and gathering by PC was reached. Last, the study for the software design of inspection system and the realization of multitask controlling under embedded operation system Nucleus Plus, improved the stabilization of system and the ability of upgrade and transplant.Based on the partition of inspection system task in reason, this article rebuilds the inspection system we own , and image focus judging and focusing automatically control were realized in embedded system, which reduces the step of data transmission and command control, and which improves the speed of micro IC image gathering and improves the efficiency of inspection.There are the main factor of locating precision of inspection workpiece flat for IC,the error of linearity movement, the error of angle in movement and so on, which were analyzed further, mathematic modules of linearity movement error and turn angle error are established. The modules provide academic warrant for compensating the error of workpiece flat and the study of practical application, therefore, which improves the locating precision of inspection system.After analyzing kinds of oscillation theory, such as suppositional displacement theory ^ movement oscillation equation with multi-dimension > inherent frequency and main oscillation type% and the relation between oscillation and inherent frequency, this article studies oscillation analysis estimate > oscillation control technology and the system oscillation factor of affecting the quality of IC micro image gathering and the precision of locating, and provides theory instruction for control system design and the workpiece mechanical structure with the ability of resisting oscillation.Embedded inspection system with IC micro image gathering and 3-D workpiece flat control was designed, and the real time character of data exchange was improved by controlling two interface RAM alternately read and write with EPM7128 and S3C2410X, and by transmitting image data real time with DMA channels of S3C2410X CPU;the speed of image gathering and the efficiency of system inspection were improved by controlling Z axis focus and judging focus real time of IC micro image with embedded system, and controlling locating mode of X-Y workpiece flat.It is important to control focus and realize image focus judge in embedded system, and to control movement locating of workpiece flat X-Y axis, to improve the inspection efficiency of IC, and the study achievement has a important significance for the field of micro system automatic inspection and analysis, and which has practicality value and extensive application foreground.