Zero-stiffness vibration isolator with flexible membrane angle decoupling and its vibration isolation system

Abstract

The invention provides a zero stiffness vibration isolator for flexible membrane angle decoupling and a vibration isolation system formed by the same and belongs to the technical field of precision vibration isolation. A sleeve of a vibration isolator main body and a lower installation plate are lubricated and supported through an air floating surface, angular motion freedom degree between an upper installation plate and the lower installation plate is decoupled through a flexible membrane, a position closed-loop feedback control system is formed by a voice coil motor, a displacement sensor, a limit switch, a controller and an actuator to perform accurate control on the relative position of the upper installation plate and the lower installation plate. The zero stiffness vibration isolator for the flexible membrane angle decoupling and the vibration isolation system formed by the zero stiffness vibration isolator have the advantages of being free of three-dimensional stiffness, high in positioning accuracy and angle decoupling and capable of obtaining very low inherent frequency and prominent low frequency / ultra-low frequency vibration isolation performance, thereby effectively solving problem of high-performance vibration isolation in ultra-precise measurement devices and processing devices, in particular to step scanning photoetching machines.

Description

technical field [0001] The invention belongs to the technical field of precision vibration isolation, and mainly relates to a zero-stiffness vibration isolator with flexible membrane angle decoupling and a vibration isolation system composed of it. Background technique [0002] With the continuous improvement of ultra-precision machining and measurement accuracy, environmental vibration has become an important factor restricting the improvement of the accuracy and performance of ultra-precision machining equipment and measuring instruments. In particular, the ultra-large-scale integrated circuit processing equipment represented by the step-scan lithography machine is extremely technically intensive and complex, and the key technical indicators have reached the limit of the existing technology, representing the highest level of ultra-precision processing equipment. Precision vibration isolation has become the core key technology in this type of equipment; the line width of th...

AI Technical Summary

Problems solved by technology

The problems of this method are as follows: 1) Due to the constraints of material properties and structural stiffness, the amplitude of vertical and horizontal stiffness reduction of the vibration isolator is limited; 2) The vertical and horizontal positioning accuracy of the air spring vibration isolator is very poor, It cannot meet the requirements of the photolithography process; 3) To achieve a lower horizontal stiffness requires a larger pendulum length, resulting in excessive height of the vibration isolator, prone to string-film resonance, and poor stability

The problems of this solution are: 1) In the disclosed technical solution, the vibration isolator cannot achieve precise positioning; 2) In the patent EP1803965A2, there is no degree of freedom of angular movement around the horizontal axis between the upper and lower mounting plates. The angular stiffness and natural frequency are very high; patents EP1803970A2 and US20080193061A1 use rubber blocks to provide angular freedom of rotation around the horizontal axis for the upper and lower mounting plates, but due to the high angular stiffness of the rubber blocks, the angular freedom of motion cannot be effectively achieved Degree decoupling, the friction between the decoupling mechanism components of the angular motion freedom introduces additional stiffness, which restricts the vibration isolation performance

However, the proposed technical solution still does not solve the problem of decoupling the precise positioning of the vibration isolator and the angular motion freedom of the upper and lower mounting plates.

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