Cover Ring Guide Pin Recess Alignment for PVD Chamber
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In physical vapor deposition (PVD) processes, the repeated raising and lowering of the cover ring in a vacuum chamber leads to lateral shifts, causing a change in the separation between the cover ring and the ground shield, which is detected as a system error, necessitating frequent repositioning and disrupting operations.
Innovation Solution
The implementation of guide pins on the ground shield that fit into corresponding recesses on the cover ring maintains the desired separation between the two components, ensuring correct positioning and minimizing operator intervention by allowing the cover ring to self-center and maintain the required gap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the cover ring is repeatedly raised and lowered during PVD operations, then substrate processing can be performed, but lateral shifts occur causing change in separation between cover ring and ground shield
Solution Approach 1:
Guide pins are introduced as intermediary elements between the cover ring and ground shield. These guide pins fit into corresponding recesses and maintain a consistent radial separation (e.g., 2.2 mm to 2.5 mm) between the cover ring and ground shield, preventing lateral shifts while allowing vertical movement for substrate processing.
Solution Approach 2:
The guide pins and recesses create a self-centering mechanism where the cover ring automatically returns to its correct radial position after being raised and lowered. The geometry of the guide pins fitting into recesses with tapered sidewalls provides self-alignment, eliminating the need for manual repositioning and maintaining separation consistency.
2Manufacturing precision
If manual repositioning of the cover ring is performed, then separation accuracy is restored, but operational disruptions and faults increase
Solution Approach 1:
The self-centering mechanism formed by guide pins and recesses automatically maintains correct positioning of the cover ring relative to the ground shield. The tapered sidewalls of the recesses guide the cover ring back to its proper radial position, eliminating the need for manual intervention and preventing operational disruptions.
Solution Approach 2:
The guide pin-recess geometry provides continuous mechanical feedback that maintains the correct separation between cover ring and ground shield. The physical constraint of the guide pins fitting into recesses with specific dimensional tolerances ensures the cover ring cannot deviate from its intended position, providing passive feedback control.
3Ease of operation
If guide pins with tapered sidewalls are used, then self-centering is achieved, but component complexity increases
Solution Approach 1:
The positioning function is segmented into separate elements: guide pins on the ground shield and corresponding recesses on the cover ring. This segmentation allows each component to be manufactured independently with standard tolerances, and the tapered geometry (e.g., 0.5° to 2° sidewalls) provides self-centering without requiring complex integrated mechanisms.
Data Source
AI summary
A processing chamber includes a ground shield and a cover ring. The ground shield includes an annular body, and at least one guide pin extending from the annular body. The cover ring is positioned on the ground shield, and includes an annular body including at least one recess. At least a part of the at least one guide pin is receivable in the at least one recess, an inner cylindrical ring extends from the annular body, and an outer cylindrical ring extends from the annular body and is radially separated from the inner cylindrical ring by a horizontally extending portion of the annular body.