Substrate Transfer Fork Height Control Using Distance Sensor Feedback
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Solution Overview
Problem
Existing substrate processing systems face challenges in precisely controlling the height of transfer device forks, which can lead to inaccuracies in substrate transfer and processing.
Innovation Solution
A method for controlling a substrate processing system that involves using a distance sensor to detect the height of the first fork relative to the placing table, adjusting the height, and setting it as a transfer height. This process is repeated for the second fork based on the difference in touch positions detected by lift pins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the fork height is controlled using taught positions during setting or maintenance, then the substrate transfer can be accurately performed, but the manufacturing precision of fork height positioning deteriorates due to accumulated errors and lack of real-time adjustment
Solution Approach 1:
The patent replaces the mechanical teaching system with an optical measurement system. Distance sensors (optical devices) are used to measure the actual distance between the fork and placing table in real-time, substituting the mechanical position teaching method with non-contact optical measurement to achieve higher precision fork height control
Solution Approach 2:
The patent implements feedback control by continuously measuring the fork height using distance sensors and adjusting the fork position based on the measured values. The system compares the measured distance with the target distance and makes real-time adjustments to maintain precise fork height positioning during substrate transfer operations
2Manufacturing precision
If the fork height is not precisely controlled, then the system operation is simpler, but the substrate transfer accuracy deteriorates and may cause contact with other components
Solution Approach 1:
The patent uses optical distance sensors to replace complex mechanical measurement and adjustment mechanisms. The non-contact optical measurement system simplifies the overall device structure while achieving high precision fork height control, avoiding the need for complex mechanical teaching systems and manual adjustment mechanisms
Solution Approach 2:
The system performs self-adjustment of fork height using automated distance measurement and control. The distance sensors automatically measure the fork position and the control system autonomously adjusts the fork height without requiring manual intervention or complex external calibration equipment, enabling the system to self-correct positioning errors
3Measurement precision
If real-time distance measurement is implemented, then the fork height control precision is improved, but the device complexity increases due to additional sensors and control mechanisms
Solution Approach 1:
The patent replaces complex mechanical measurement systems with simpler optical distance sensors. The optical measurement method provides high precision fork height detection without requiring complex mechanical linkages, gears, or contact-based measurement devices, thereby improving measurement precision while keeping the added complexity minimal
Solution Approach 2:
The distance sensors serve multiple functions: they measure fork height, detect positioning accuracy, and provide feedback for control adjustments. This multi-functionality reduces the need for separate measurement and control components, thereby improving measurement precision without proportionally increasing device complexity
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
The method enables precise control of the fork heights, ensuring accurate substrate transfer and processing by preventing contact with other components in the processing chamber, thereby reducing downtime and improving system efficiency.
Implementation Method 1
detecting a distance between the first fork and the placing table by a distance sensor provided at the first fork
Data Source
AI summary
Provided is a method for controlling a substrate processing system comprising: detecting a distance between the first fork and the placing table by a distance sensor provided at the first fork; adjusting a height position of the first fork based on the detection value of the distance sensor; setting the adjusted height position of the first fork as a transfer height of the first fork; detecting a first touch position where lift pins of the placing table are brought into contact with the first object; unloading the first fork holding the first object; detecting a second touch position where the lift pins of the placing table are brought into contact with the second object; setting a transfer height of the second fork based on a difference between the first touch position and the second touch position; and unloading the second fork holding the second object.