Robot Hand Deflection Sensing for Warp-Safe Substrate Transfer
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Solution Overview
Problem
Existing transfer systems face the risk of substrate damage due to contact when substrates accommodated in cassettes are deflected, such as bent or warped wafers or panels.
Innovation Solution
A transfer system equipped with a robot and a controller that includes a hand with a sensor to detect substrate deflection, a lift mechanism to adjust height, and a calculation unit to determine the deflection amount, preventing contact by adjusting loading heights based on detected deflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If substrates are transferred using a robot hand without deflection detection, then the transfer process is simple and fast, but substrates may be damaged when they are deflected (bent or warped)
Solution Approach 1:
The system performs preliminary detection of substrate deflection before the transfer operation. The sensor detects the lower surface of the substrate to determine its deflection state in advance, allowing the controller to adjust the hand's approach accordingly before contact occurs, thereby preventing substrate damage without adding complexity to the transfer mechanism itself
Solution Approach 2:
The sensor provides feedback information about the substrate's deflection state to the controller. Based on this feedback, the controller adjusts the hand's movement and positioning to accommodate the deflection, creating a closed-loop control system that adapts to varying substrate conditions while maintaining reliable transfer
2Ease of operation
If the robot hand directly contacts substrates without detection, then the transfer operation is simple, but contact damage occurs when substrates are deflected
Solution Approach 1:
The sensor acts as an intermediary between the robot hand and the substrate. It detects the substrate's deflection state and transmits this information to the controller, which then adjusts the hand's movement. This intermediary detection mechanism allows the system to maintain simple direct contact operations while preventing damage through informed control adjustments
3Reliability
If deflection detection is implemented using a sensor and controller, then substrate damage is prevented, but the system complexity increases
Solution Approach 1:
The system uses the robot hand's own movement and positioning capabilities to perform the detection function. The hand moves down from the placement height, and the sensor detects the separation height at which the substrate separates from the hand. This self-service approach uses existing system components for detection, minimizing additional complexity while ensuring substrate safety
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
Prevents substrate damage by accurately detecting and adjusting for deflection, ensuring safe and efficient transfer of substrates even when they are bent or warped.
Implementation Method 1
The hand includes a sensor that detects a distance to a lower surface of the substrate
Data Source
AI summary
A transfer system includes a robot and a controller that controls an operation of the robot. The robot includes a hand that transfers a substrate, and a lift mechanism that moves up and down the hand. The hand includes a sensor that detects a distance to a lower surface of the substrate. The controller includes a storage unit, a detection unit, and a calculation unit. The storage unit stores placement information including a placement height at a placement position of the substrate. The detection unit detects a separation height at which the substrate is separated from the hand when the hand is moved down from the placement height. The calculation unit calculates a deflection amount of the substrate based on a difference between the placement height and the separation height.