Magnetic Damping Layout for Lithography Vibration Control
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Solution Overview
Problem
Conventional vibration damping methods in projection exposure apparatuses are frequency-dependent, lead to contamination, and fail to provide adequate damping across the widest possible frequency ranges, resulting in performance instability and potential damage from mechanical vibrations.
Innovation Solution
A damping arrangement using a ferromagnetic element within an inhomogeneous magnetic field, allowing for magnetization reversal and energy dissipation into heat, which is independent of frequency and does not require mechanical contact, utilizing structured soft-magnetic elements and flexible mounting to achieve effective vibration damping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional vibration damping methods (friction or resonant systems with plastic components) are used, then damping effect is achieved, but frequency-dependent damping and contamination occur
Solution Approach 1:
The patent replaces mechanical contact-based damping systems (friction dampers, rubber components) with a magnetic field-based damping system. The magnetic field interacts with ferromagnetic elements to provide damping without physical contact, eliminating contamination and particle formation while achieving frequency-independent damping across the full vibration spectrum.
Solution Approach 2:
The patent changes the fundamental parameter of damping from mechanical contact force to magnetic field interaction. By using an inhomogeneous magnetic field that penetrates ferromagnetic elements, the system achieves damping through magnetic hysteresis and eddy currents rather than mechanical friction, eliminating contamination while maintaining damping effectiveness.
2Reliability
If eddy current damping with conductive elements in magnetic fields is used, then damping effect is achieved, but speed- and frequency-dependent damping occurs
Solution Approach 1:
The patent merges multiple damping mechanisms into a single magnetic field-based system. By combining the effects of magnetic hysteresis in ferromagnetic elements with eddy current damping, the system achieves frequency-independent damping that works effectively across all vibration frequencies, unlike conventional eddy current dampers that are speed-dependent.
Solution Approach 2:
The patent replaces speed-dependent mechanical eddy current damping with a magnetic field system where the inhomogeneous field penetrates ferromagnetic elements. This substitution eliminates the speed dependency inherent in conventional eddy current dampers, providing consistent damping across all frequencies including static and low-frequency vibrations.
3Weight of moving object
If materials with low structural damping (aluminum, Zero-dur) are used for components, then weight and structural properties are improved, but vibration damping is insufficient leading to instability
Solution Approach 1:
The patent introduces a magnetic field as an intermediary damping mechanism that acts on ferromagnetic elements attached to or integrated with lightweight components. This intermediary system provides the necessary vibration damping without requiring the components themselves to have high structural damping, allowing continued use of lightweight materials like aluminum and Zero-dur.
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 solution provides comprehensive frequency-independent damping, reduces particle formation, and prevents mechanical contact-related issues, enabling effective vibration control and protection against vibrations without deforming components.
Implementation Method 1
the ferromagnetic element can undergo magnetization reversal regionally, since the magnetic flux density in the ferromagnetic element changes over time, which can ultimately result in a dissipation of the kinetic energy into heat
Implementation Method 2
through which a magnetic field passes at least partly. In this case, the magnetic flux density is inhomogeneous at least regionally
Implementation Method 3
structured soft-magnetic elements and flexible mounting to achieve effective vibration damping
Data Source
AI summary
A projection exposure apparatus for semiconductor lithography includes at least one component which is provided with a damping arrangement for dissipating mechanical vibration energy. The damping arrangement includes a ferromagnetic element, through which a magnetic field passes at least partly. The magnetic flux density is inhomogeneous at least regionally. The ferromagnetic element is mounted in such a way that it is movable with a movement component in the direction of the inhomogeneity of the magnetic field.