Single Optical Unit Multi-Axis Position Sensing
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Solution Overview
Problem
Existing position-measuring devices for semiconductor manufacturing machines require multiple optical units for self-calibration, leading to increased complexity and volume, and additional expenditures due to the need for redundant measurements to compensate for mechanical and thermal deformations.
Innovation Solution
A position-measuring device with a measuring standard-reflector unit featuring differently configured regions allows for selective switching of measuring directions using a single optical unit, enabling positional signal generation along various axes without the need for additional optical units, thereby reducing system complexity and volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple optical units are used for self-calibration, then measurement precision is improved, but device complexity increases
Solution Approach 1:
A single optical unit is designed to perform multiple functions: it can measure positions along different axes (x, y, z) and can operate in different measurement modes (single measurement, self-calibration) by switching between different measuring directions. This eliminates the need for separate optical units for each measurement axis, reducing system complexity while maintaining measurement precision through software-controlled direction switching.
Solution Approach 2:
The system dynamically switches between different measuring directions by controlling the deflection of measurement beams through movable deflectors. This dynamic reconfiguration allows one optical unit to adaptively measure positions along multiple axes and perform self-calibration operations, replacing what would traditionally require multiple fixed optical units.
2Reliability
If multiple optical units are used for redundant measurements, then reliability is improved, but volume of the system increases
Solution Approach 1:
The single optical unit is designed to provide redundant measurements by switching between different measuring directions and modes. It can perform both normal position measurements and self-calibration measurements, ensuring measurement reliability without requiring additional optical units that would increase system volume.
Solution Approach 2:
The system combines normal position measurement functions and self-calibration functions into a single optical unit. By merging these functions and using software control to switch between operational modes, the system achieves the reliability benefits of redundant measurements while avoiding the volume increase that would result from physically separate optical units.
3Manufacturing precision
If additional optical units are added for self-calibration, then manufacturing precision is improved, but cost increases
Solution Approach 1:
Instead of manufacturing and installing multiple separate optical units for different measurement axes and calibration functions, the system uses a single optical unit that can be programmed to perform multiple functions. This reduces manufacturing costs while maintaining positioning accuracy through software-controlled measurement direction switching and self-calibration procedures.
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 approach enables accurate and cost-effective position sensing in multiple directions with reduced system complexity and volume, allowing for efficient self-calibration without additional optical units, enhancing the precision and reliability of positional measurements.
Implementation Method 1
a measuring reflector, to which measurement beams of the multi-axis interferometer are incident
Implementation Method 2
During assembly and use, the measuring reflectors, measuring standards, and reflectors used in the various position-measuring devices are subject to mechanical, as well as thermal stresses and may also undergo slow deformation in the process
Data Source
AI summary
A position-measuring device, as well as a system having such a position-measuring device, is used for determining the position of a first object relative to a second object, the first and the second object being movable relative to one another along at least two measuring directions. The position-measuring device has an optical unit that is linked to one of the two objects and includes at least one light source, a detector system, as well as further optical elements in a defined configuration. In addition, the position-measuring device includes a measuring standard-reflector unit, which is provided on the other object, and has at least two differently formed regions in one track that are optically scannable by the optical unit for position sensing. The different formation of the regions makes switching among the various measuring directions possible during position sensing, and positional signals can be generated by the optical unit relative to the relative movement of the two objects for each measuring direction.