Substrate Transfer Hand Scanning for Warpage Contact Avoidance
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Solution Overview
Problem
Existing transfer systems risk damaging substrates such as wafers or panels due to contact when they are significantly deflected or warped during loading and unloading processes.
Innovation Solution
A transfer system equipped with a robot having a hand and a reflective sensor that performs horizontal scanning to detect and avoid contact with substrates, using a controller to calculate and adjust the insertion height to prevent damage, even when substrates are deflected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the robot hand is moved closer to the cassette to improve transfer precision, then the transfer accuracy is improved, but the risk of contact with deflected substrates increases
Solution Approach 1:
The system performs preliminary scanning of the substrate surface using a sensor before the robot hand approaches. This advance detection identifies deflected substrates, allowing the control unit to adjust the insertion height or position beforehand, thus preventing contact while maintaining transfer precision.
Solution Approach 2:
A sensor acts as an intermediary between the robot hand and the substrate. The sensor detects substrate position and deflection without physical contact, providing information to the control unit to adjust the robot's movement, thereby preventing harmful contact while enabling precise transfer.
2Productivity
If the robot operates at high speed to improve productivity, then the transfer efficiency is improved, but the detection and avoidance of contact becomes more difficult
Solution Approach 1:
The sensor continuously scans the substrate surface during the robot's approach and transfer motion. This continuous detection ensures that even at high speeds, any substrate deflection or potential contact point is detected in real-time, allowing immediate adjustment while maintaining high transfer efficiency.
Solution Approach 2:
The system replaces mechanical contact-based detection with optical or electromagnetic sensing. This non-contact detection method allows for high-speed operation without the inertia and delay associated with mechanical sensors, enabling both high productivity and accurate contact avoidance.
3Device complexity
If no sensor scanning is performed to simplify the system, then the device complexity is reduced, but substrate damage cannot be prevented
Solution Approach 1:
The system uses the existing robot structure and control unit to perform scanning functions. The sensor is integrated into the robot hand or mounted nearby, utilizing the same movement and control systems already present, thus adding minimal complexity while achieving reliable substrate protection.
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 damage to substrates by ensuring the robot's hand can be inserted without contacting warped substrates, allowing safe and reliable transfer operations.
Implementation Method 1
The hand includes a reflective sensor that detects an object on a distal end side facing the cassette
Data Source
AI summary
A transfer system includes a robot that loads and unloads a substrate to and from a cassette that accommodates a plurality of substrates in multiple stages; and a controller configured to control an operation of the robot. The robot includes: a hand that transfers the substrate, a horizontal movement mechanism that moves the hand in a width direction of the cassette in a front side of the cassette, and a lift mechanism that moves up and down the hand in the front side of the cassette. The hand includes a reflective sensor on a distal end side thereof facing the cassette to detect an object in the cassette. The controller operates the horizontal movement mechanism causing the reflective sensor to perform a horizontal scanning such that the reflective sensor facing the substrate scans in the width direction of the substrate accommodated in the cassette.