Wafer angular deviation automatic method based on vision

Abstract

The invention discloses a wafer angular deviation automatic method based on vision. The wafer angular deviation automatic method based on vision comprises the following steps: arranging a wafer on an absorptive disk of a four-axis numerical control machine tool platform system; adopting Hough changing to conduct detecting and positioning on images of the wafer shoot by a microcamera of the four-axis numerical control machine tool platform system; shooting an image on an A point of the wafer to determine positions of a feature straight line and a feature point of the wafer, and adjusting positions of the wafer according to an angle formed by the feature straight line and X- axis or Y-axis of the four-axis numerical control machine tool platform system; respectively shooting images on a B point of the wafer and a C point of the wafer again to conduct Hough change detection, checking whether the wafer is accurately positioned by judging whether an incline angle beta of midpoint connecting lines of feature straight lines of the B point of the wafer and the C point of the wafer is zero. The wafer angular deviation automatic method based on vision can accurately positions of the wafer and scribe lines, is high in reliability and rapid in reaction rate, promotes automation and intellectualization of wafer scribing technology, can control valid accuracy to 2 mu, shortens positioning time of the wafer, and improves machining efficiency of the wafer.

Description

technical field [0001] The invention relates to a wafer angle position correction method, in particular to a vision-based automatic wafer angle deviation correction method. Background technique [0002] Along with the development of microelectronics products, more micro-level chips are required, so it is necessary to perform high-precision micro-cutting and scribing on the corresponding wafers. By adjusting the angular position of the wafer, ensure that the wafer position is in the marked coordinate system to achieve accurate scribing. Visual inspection technology can realize the detection of microstructure size. For micron-scale scribing of wafer chips, the wafer positioning system based on machine vision can realize intelligent high-precision detection and positioning of wafers. The positioning accuracy of the wafer directly affects the efficiency and yield of the entire IC manufacturing system. An effective wafer positioning dicing method can realize the automation and h...

AI Technical Summary

Problems solved by technology

Because the chip on the wafer is too small, after zooming in by the focus of the microscopic camera, there is only a small area of ​​the wafer in the clear field of view of the camera, and there are only 2 to 4 complete lattices in the field of view of the camera , so it is difficult to accurately locate the scribing position of the wafer, and the error at the center of the circle causes an error in the radial direction

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