컴플라이언스를 갖는 웨이퍼 탐침 시스템용 미동 매니퓰레이터

Abstract

A six DOF fine manipulator based on magnetic levitation is developed. Since most of magnetic levitation systems are inherently unstable. a proposed magnetically levitated fine manipulator is implemented by use of an antagonistic structure to increase stability From mathematical modeling and experiment, the equations of motion are derived. In addition. a six DOF sensing system is implemented by use of three 2-axis PSD sensors. A model reference-H∞ controller is applied to the system for the position control. In application of the fine manipulator, a wafer probing system is proposed to identify nonfunctional circuits. The probing system requires compliance to avoid destruction of DUT(device under test). A feedforward-PD controller is carried out to offer one DOF compliance to the fine manipulator. The performances of the controllers are presented by the terms of the position accuracy. the settling time and the force accuracy.