Modular Substrate Transfer Arm With Cable Drive and Low-Height Links
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Solution Overview
Problem
Conventional substrate processing systems face challenges with substrate transport due to size constraints of metal band and pulley transmissions, leading to arm deflection and alignment issues, which affect semiconductor throughput and operational efficiency.
Innovation Solution
The use of cable and pulley transmissions and crossed roller bearings in the substrate transport apparatus reduces height and eliminates alignment issues, enabling longer arm links and improved stiffness, while maintaining performance across varying temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If metal band and pulley transmissions are used in substrate transport apparatus, then motion can be transmitted to arm links, but the size constraints of these transmissions increase the height and overall size of the arm links
Solution Approach 1:
The patent replaces the conventional metal band and pulley transmission system with a cable-driven transmission system. This substitution eliminates the bulky metal bands and large pulleys, allowing for a more compact arm link structure with reduced height while maintaining the ability to transmit motion effectively to the substrate holder.
2Length of moving object
If long arm link lengths are used to reach substrate holding stations, then transport reach is improved, but arm deflection from gravity loads increases affecting alignment
Solution Approach 1:
The patent employs composite materials in the construction of arm links to achieve high strength-to-weight ratios. This allows for longer arm link lengths necessary to reach substrate holding stations while minimizing deflection under gravity loads, thereby maintaining precise alignment throughout the transport range.
3Strength
If duplex bearing pairs are used at rotational joints, then axial and radial rigidity is improved, but the size constraints increase the height of arm links
Solution Approach 1:
The patent replaces conventional duplex bearing pairs with alternative bearing configurations or designs that achieve the necessary axial and radial rigidity with a reduced height profile. This substitution allows for maintaining structural strength while reducing the overall height of the arm links.
4Reliability
If shrink fit installation of duplex bearings is used, then bearing-to-shaft connection is secured, but high temperature operation affects the stiffness of the shrink fit
Solution Approach 1:
The patent addresses the temperature sensitivity of shrink fit connections by modifying material selections or connection parameters. This may involve using materials with matched thermal expansion coefficients or alternative connection methods that maintain consistent stiffness across the operating temperature range, ensuring reliable bearing-to-shaft connections during high temperature semiconductor processing.
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 allows for faster and more efficient substrate swapping between multiple stations simultaneously, enhancing semiconductor processing throughput and reducing operational complexities.
Implementation Method 1
The use of cable and pulley transmissions and crossed roller bearings in the substrate transport apparatus reduces height and eliminates alignment issues
Implementation Method 2
The use of cable and pulley transmissions and crossed roller bearings in the substrate transport apparatus reduces height and eliminates alignment issues
Data Source
AI summary
A substrate transport apparatus comprising a support frame an articulated arm connected to the support frame, having at least one movable arm link and an end effector connected to the movable arm link, with a substrate holding station located thereon. Wherein the movable arm link is a reconfigurable arm link having a modular composite arm link casing, formed of link case modules rigidly coupled to each other, and a pulley system cased in and extending through the rigidly coupled link case modules substantially end to end of the modular composite arm link casing, wherein the rigidly coupled link case modules include link case end modules connected by at least one interchangeable link case extension module having a predetermined characteristic determining a length of the movable arm link, wherein at least one interchangeable link case extension module is selectable for connection to link case end modules forming the reconfigurable arm link.