Substrate Lift-Pin Positioning for Eccentricity-Free Vacuum Chucking
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Solution Overview
Problem
Existing substrate processing apparatuses risk damaging or contaminating the lower surface of substrates during positioning, and can cause the substrate to become eccentric, leading to improper processing.
Innovation Solution
A substrate processing apparatus that includes a suction holding mechanism, a rotation mechanism, lift pins, vertical and horizontal movement mechanisms, and a sensor to measure the eccentric state of the substrate. The lift pins support the substrate from the suction holding mechanism and move horizontally to adjust the substrate's position based on the measured eccentricity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a positioning mechanism slides the substrate with respect to the vacuum chuck unit, then the center of the substrate can be aligned with the rotation axis, but the lower surface of the substrate may be damaged or contaminated
Solution Approach 1:
The patent introduces lift pins as an intermediary mechanism between the substrate and the vacuum chuck unit. The lift pins raise the substrate from the vacuum chuck surface, creating a gap that prevents direct contact and potential damage during positioning. The substrate is positioned while elevated on the lift pins, then lowered onto the vacuum chuck without sliding contact that would cause contamination or damage.
Solution Approach 2:
The patent replaces the traditional sliding mechanical positioning mechanism with a combination of lift pins and vacuum holding. Instead of sliding the substrate across the vacuum chuck surface (mechanical contact), the substrate is lifted, positioned in space, and then gently lowered into place, substituting the harmful sliding action with a non-contact positioning approach.
2Productivity
If the substrate is held by the suction holding mechanism, then the substrate can be rotated about the rotation axis, but the substrate may become eccentric leading to improper processing
Solution Approach 1:
The patent employs a sensor to detect the position of the substrate relative to the rotation axis, providing feedback information about eccentricity. Based on this feedback, the system adjusts the lift pin positions or substrate holding to correct eccentricity, ensuring the substrate center aligns with the rotation axis before processing begins, thereby maintaining both efficiency and precision.
Solution Approach 2:
The patent makes the positioning system dynamic by allowing adjustment of lift pin positions and substrate holding force during the process. The system can adaptively correct eccentricity by dynamically adjusting the support points (lift pins) or vacuum distribution, enabling real-time correction of alignment issues while the substrate is being prepared for rotation.
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 configuration reduces damage and contamination to the substrate's lower surface and minimizes eccentricity, ensuring accurate and effective processing.
Implementation Method 1
a suction holding mechanism configured to suck a back surface of the substrate and hold the substrate horizontally
Data Source
AI summary
The substrate processing apparatus includes a suction holding mechanism, a rotation mechanism, a plurality of lift pins, a vertical movement mechanism, and a horizontal movement mechanism. The suction holding mechanism sucks and holds a substrate. The rotation mechanism rotates the suction holding mechanism holding the substrate about the rotation axis. The vertical movement mechanism moves the plurality of lift pins in the vertical direction. A sensor measures the eccentric state of the substrate W held by the suction holding mechanism. The vertical movement mechanism supports the substrate from the suction holding mechanism by moving the plurality of lift pins and the horizontal movement mechanism moves the plurality of lift pins based on the eccentric state of the substrate measured by the sensor in a state where the substrate is supported.