Intermediate NEG Vacuum Chamber Layout for Vibration Isolation
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Solution Overview
Problem
Existing vacuum pumping systems for achieving high or ultra-high vacuum conditions in equipment chambers face challenges such as mechanical vibrations from turbomolecular pumps, increased system volume and complexity, and inefficient energy consumption, particularly in space-constrained applications like SEM and TEM.
Innovation Solution
An auxiliary pumping system comprising a primary pump connected to an intermediate vacuum chamber, which houses a high-pressure Non-Evaporable Getter (NEG) pump, with specific conduit and flange configurations to minimize vibration impact and optimize performance, reducing size and energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a turbomolecular pump is installed far from the vacuum chamber to avoid mechanical vibrations, then vibration impact on the chamber is reduced, but evacuation performance and pumping speed decrease due to the long conduit required
Solution Approach 1:
A vibration isolation element (elastomer or viscoelastic material) is introduced as an intermediary between the turbomolecular pump and the vacuum chamber flange. This intermediary absorbs and dampens mechanical vibrations while maintaining the physical connection, allowing the pump to be positioned close to the chamber without transmitting harmful vibrations. The elastomer element acts as a mechanical filter that blocks vibration transmission paths.
Solution Approach 2:
The mounting interface is segmented into multiple contact points (at least two separated by a distance) rather than a single rigid connection. This segmentation distributes and reduces the transmission of vibrational forces to the vacuum chamber, while still maintaining adequate pumping speed through the optimized flange-pump connection geometry.
2Productivity
If a high-pressure NEG pump is used to reduce system volume and improve performance, then pumping efficiency increases, but the system requires more complex activation procedures including external heaters and insulating materials that increase volume and complexity
Solution Approach 1:
The NEG pump is designed to activate automatically upon connection to the vacuum chamber without requiring external heater devices or complex control systems. The pump housing contains no insulating materials that would limit getter material performance, allowing the NEG material to self-activate when exposed to the vacuum environment, thereby reducing both system complexity and volume.
Solution Approach 2:
The activation function is merged into the pump housing design itself rather than requiring separate external heater components. The housing structure integrates the activation mechanism, eliminating the need for external power cords, coil segments, and insulating materials, thus reducing overall system volume and complexity while maintaining high-pressure pumping capability.
3Productivity
If the ratio between getter pump volume and intermediate vacuum chamber volume is optimized within 0.022-0.540, then pumping performance is maximized, but the system requires precise dimensional control increasing manufacturing complexity
Solution Approach 1:
The patent defines an optimized volume ratio range (0.022-0.540) between the getter pump and intermediate vacuum chamber that maximizes pumping performance. This parameter optimization balances the competing requirements of compactness and evacuation efficiency, providing a design guideline that achieves high performance without requiring extreme precision, as the acceptable range is sufficiently broad to accommodate normal manufacturing tolerances.
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
The system effectively reduces mechanical vibrations, minimizes system size, and lowers energy consumption while maintaining high performance, making it suitable for various applications with limited space.
Implementation Method 1
a high-pressure Non-Evaporable Getter (NEG) pump contained in the intermediate vacuum chamber
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention concerns an auxiliary pumping system (1000) for evacuating an equipment chamber (1), comprising a primary pump (12), an intermediate vacuum chamber (10) connected to the primary pump (12) through a vacuum conduit (14), and a high-pressure Non-Evaporable Getter (NEG) pump contained in the intermediate vacuum chamber (10), wherein the vacuum conduit (14) has a length comprised between 5 and 200 cm and the ratio between the volume of the high-pressure NEG pump and the volume of the intermediate vacuum chamber (10) is comprised between 0.022 and 0.540.