Substrate Centering Mechanism Using Thermal Expansion Compensation
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Solution Overview
Problem
Existing centering devices for aligning substrates with substrate holders suffer from reduced accuracy due to changes in ambient temperature, which affect the positional relationship between contact members, leading to misalignment and decreased processing quality.
Innovation Solution
The centering device employs a multi-mover system with a multi-support and slide member made of materials with differing coefficients of linear expansion, and a symmetrical shape to maintain accurate alignment by minimizing the impact of temperature changes, ensuring the substrate is sandwiched by contact members to align with the substrate holder's center.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the contact members are made of rigid materials with fixed positional relationships, then the centering mechanism is simple and easy to manufacture, but the positional relationship between contact members changes due to temperature fluctuations, reducing centering accuracy
Solution Approach 1:
The patent applies parameter changes by selecting materials with different coefficients of linear expansion for the multi-support and slide member. This allows the positional relationship between contact members to be maintained despite temperature fluctuations, as the differential expansion compensates for thermal distortion and preserves centering accuracy.
Solution Approach 2:
The patent uses composite materials by combining the multi-support and slide member made of different materials with distinct thermal expansion properties. This composite structure leverages the differential thermal behavior of the materials to maintain dimensional stability and positional accuracy under varying temperature conditions.
2Reliability
If the ambient temperature remains constant, then the positional relationship between contact members is stable, but temperature fluctuations cause expansion or contraction, leading to misalignment and reduced processing quality
Solution Approach 1:
The patent directly applies the thermal expansion principle by utilizing materials with different coefficients of linear expansion for the multi-support and slide member. The differential expansion between these components compensates for temperature-induced dimensional changes, maintaining the positional relationship and preventing misalignment of the substrate center with the substrate holder center.
Solution Approach 2:
The patent converts the harmful effect of temperature fluctuations into a beneficial mechanism. By using materials with different thermal expansion properties, the temperature changes that would normally cause misalignment are transformed into a compensatory effect where the differential expansion maintains the precise positional relationship between contact members.
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 stabilizes centering accuracy by suppressing the influence of ambient temperature fluctuations, maintaining precise alignment of substrates within the substrate processing apparatus.
Implementation Method 1
the multi-support and the slide member are made of materials having respective coefficients of linear expansion with a difference dLE therebetween
Data Source
AI summary
A multi-mover provided in a centering device and a substrate processing apparatus moves a second contact member and a third contact member integrally in a first horizontal direction while the second contact member and the third contact member surround a center of a substrate holder together with a first contact member in a plan view vertically from above. The multi-mover includes: a multi-support configured to support the second contact member and the third contact member integrally; and a slide member mounted in a manner slidable in the first horizontal direction relative to a guide member fixedly arranged at a predetermined position while the slide member is coupled to the multi-support. The multi-support and the slide member are made of materials having respective coefficients of linear expansion with a difference dLE therebetween that fulfills the following inequality: dLE<AE/(0.8597×dTM).