A NEW WAY OF ANALYZING MOTION SYSTEM REPEATABILITY FOR NANOMETER PRECISION: 6-DOF POINT REPEATABILITY

摘要

Advancements in manufacturing processes and metrology sensors along with the continuing demand to advance technologies and products is driving a greater need for motion systems that are both highly accurate and repeatable at the nanometer level. All motion systems operate in 3-dimensional space and have errors in six degrees of freedom. However, often motion systems are only characterized by performance data of a single or subset of these six degrees of freedom. This practice leaves several error sources unaccounted for in performance data and specifications. Repeatability performance for metrology inspection and manufacturing systems must be analyzed and specified using a point repeatability method that accounts for 3-dimensional spatial errors in order to provide true representation of nanometer precision performance. This paper examines the need for and method of point repeatability testing of single and multi-axis motion systems accounting for six degrees of freedom errors.