Substrate Carrier Centering Mechanism for Thermal Expansion
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Solution Overview
Problem
Existing substrate carriers face challenges in maintaining precise orientation and centering of substrates during industrial processes, particularly due to thermal expansion issues and varying substrate characteristics, as previous centering devices either allow asymmetric expansion or rely on substrate weight for alignment, leading to inaccurate positioning and frictional forces.
Innovation Solution
A substrate carrier equipped with two inwardly preloaded springs opposite each other, which enables symmetrical centering and defined force independent of substrate weight, allowing for precise alignment and compensation of thermal expansion, along with a mechanism for automatic spring movement to facilitate substrate insertion and removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If spring-loaded projections are used for centering, then centering force is provided, but asymmetric expansion is allowed only in the direction of the springs
Solution Approach 1:
The centering device is segmented into multiple independent spring elements (at least two springs) arranged at different positions and orientations. This segmentation allows each spring to independently accommodate expansion in its specific direction while collectively providing comprehensive centering force, resolving the contradiction between providing centering force and allowing asymmetric expansion.
Solution Approach 2:
The spring-loaded projections are designed to be movable rather than fixed, allowing them to dynamically adjust their position and orientation in response to substrate expansion. This dynamic capability enables the centering device to adapt to multi-directional expansion while maintaining effective centering force through the elastic deformation of the springs.
2Measurement precision
If weight force of substrate is used for centering, then centering is achieved, but positioning accuracy depends on substrate width and lateral friction is effective
Solution Approach 1:
The centering mechanism replaces the gravity-based weight force system with an elastic spring force system. The springs provide a controlled, adjustable centering force that is independent of substrate weight and width, eliminating the dependency on gravitational force and associated frictional effects. This substitution enables more precise positioning by using elastic deformation rather than weight-based positioning.
3Temperature
If substrate carrier and substrate expand differently during heating, then thermal processing is enabled, but orientation precision is compromised
Solution Approach 1:
The centering device utilizes the parameter change of elastic deformation in springs to compensate for thermal expansion differences. As temperature increases and the substrate expands, the springs deform elastically to maintain the centered position, dynamically adjusting the centering force to account for the changed dimensional parameters. This allows the system to maintain orientation precision despite differential thermal expansion between the substrate carrier and substrate.
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
Ensures accurate and frictionless positioning and handling of substrates during processes like coating, even under temperature variations, by providing a symmetrical and force-defined centering mechanism that overcomes static friction, maintaining precise alignment and facilitating efficient processing.
Implementation Method 1
the centering device comprises two inwardly preloaded springs opposite each other
Implementation Method 2
The provision of two springs opposite each other enables symmetrical centering
Implementation Method 3
it can be crucial that the orientation of the substrate relative to the substrate carrier is clearly defined and precisely maintained. Problems can arise, on the one hand, from any tolerances of the substrates or, on the other hand, from heating problems during a specific process step if the substrate carrier and substrate expand to different extents.
Data Source
AI summary
The present invention relates to a substrate carrier for accommodating and transporting a substrate, to a changing station comprising such a substrate carrier as well as to a method for treating a substrate.