Pendulum Valve Lip Seal Rotation Axis
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Solution Overview
Problem
Conventional pendulum valves in semiconductor manufacturing processes face issues with sealing force degradation due to O-ring distortion and particle generation from lubricant reaction with plasma gas, leading to reduced performance and contamination risks.
Innovation Solution
A dual-structured pendulum valve design where a fixed housing is tightly coupled to the valve housing through an O-ring, and a rotating shaft is installed rotatably using a lip seal as the rotation axis, preventing unnecessary particle discharge while maintaining sealing integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional shaft structure with O-ring sealing is used, then the valve can be manufactured simply, but the O-ring distorts over time causing sealing force degradation and particle generation
Solution Approach 1:
The shaft is divided into two separate components: a fixed housing that remains stationary and a rotation shaft that rotates independently. This segmentation eliminates the relative motion between the sealing element and the housing, preventing O-ring distortion and particle generation while maintaining reliable sealing characteristics.
2Ease of operation
If lubricant is applied to reduce friction, then the operation becomes smoother, but the lubricant reacts with plasma gas to harden and generate particles
Solution Approach 1:
The invention extracts and eliminates the lubricant from the system by using a magnetic bearing that operates without lubrication. The magnetic bearing uses magnetic fields to support and rotate the rotation shaft, achieving smooth operation without any lubricant that could react with plasma gas to form hardened substances.
3Device complexity
If the shaft rotates directly within the valve housing, then the structure remains simple, but particles and hardened substances are discharged into the chamber
Solution Approach 1:
The invention introduces a fixed housing as an intermediary component between the rotation shaft and the valve housing. This fixed housing contains the rotation shaft and prevents particles and hardened substances from escaping into the chamber, while the magnetic bearing further isolates the rotation mechanism from direct contact with the chamber environment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design effectively suppresses the discharge of particles and hardened substances, maintaining the sealing characteristics of the pendulum valve and preventing contamination, thereby enhancing operational reliability and reducing maintenance needs.
Implementation Method 1
a rotation shaft (an internal shaft) coupled to the inside of the lip seal so that one end is coupled to the gearbox and the other end is coupled to one end of the valve gate, and rotates the valve gate by being rotated by the driving force transmitted through the gearbox by using the lip seal as a rotation axis
Implementation Method 2
a fixed housing configured such that a shaft coupled to a valve gate for adjusting the amount of gas is closely fixed to a valve housing through an O-ring
Data Source
AI summary
The present invention relates generally to a pendulum valve that is installed in a connection pipe connecting a vacuum pump between the chamber of a dry etching apparatus and the vacuum pump in the etching line of a semiconductor manufacturing process and adjusts the amount of gas, and more particularly to a pendulum valve that includes a fixed housing configured such that a shaft coupled to a valve gate for adjusting the amount of gas is closely fixed to a valve housing through an O-ring and a rotation shaft (an internal shaft) coupled to the inside of the fixed housing, so that only the rotation shaft separate from the value housing is rotated by using a lip seal as a rotation axis, thereby suppressing the discharge of unnecessary particles and hardened substances while maintaining the sealing characteristics of the pendulum valve.