Detection of silicon chip state in box and its center relocation method

Abstract

This invention relates to a method for testing a silicon chip state in a box and re-location of its center, in which, the test method includes: designing a light intensity threshold value 1₀,1₁, testing the light intensity of any pair of sensors timely of 1_S1, if 1_S1=!₀, then there is no silicon chip, when 1₀ > 1_S1 >1₁, then there is one, when 1_S1 is smaller or equals to 1₁, there are laminated silicon chips, if the two sensors have different light shading time, then the chips are at the tilted state, the method for re-locating the center includes: when the edges of the chips are tangential to the light-fields of the two sensors at the same time, then the position of a transport mechanical hand on the X direction is P₀, when the edges of the chips are tangential to the light-fields of the two sensors, then its position is P₁, if P₁= P₀, then the chips are at the ideal position, if not, the difference between them is the distance should be compensated on the X direction.

Description

technical field [0001] The invention belongs to the technical field of IC manufacturing, in particular to a method for detecting and relocating the state of a silicon wafer. Background technique [0002] Silicon wafer detection and repositioning are important components of the wafer transport system of IC manufacturing equipment such as lithography machines. Silicon wafer detection needs to detect whether there are silicon wafers in the corresponding slot and whether their position is normal before the transfer hand picks up the wafers, and find out that the silicon wafers are overlapped, silicon wafers are tilted and other state errors, so that the transfer hand can take the wafers correctly. The repositioning of the center of the silicon wafer has two main functions: 1. Make the silicon wafers be accurately fed into the cassette, and correct the deviation of the wafer center during the unloading process; 2. Roughly locate the center of the silicon wafer taken out of the ca...

AI Technical Summary

Problems solved by technology

Compared with the pre-alignment of silicon wafers, the accuracy of relocation is relatively low. The detection and relocation of silicon wafers are

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