Wafer Transport Position Detection Before Aligner Transfer
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Solution Overview
Problem
Existing wafer transportation systems face issues with positional deviations, leading to potential collisions with surrounding members and improper detection by sensors, which can cause operational failures in aligner apparatuses.
Innovation Solution
A transport system comprising a robot with a sensor-equipped hand that detects the wafer's position before transferring it to an aligner apparatus, using sensors like aligner sensors or protrusion detecting sensors to determine and correct positional deviations, ensuring accurate placement and preventing collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a robot transports a wafer without position detection, then the transportation operation is simple and fast, but the wafer may have positional deviation causing collision with surrounding members or improper placement on the aligner apparatus
Solution Approach 1:
The sensor detects the wafer's position on the robot hand before the wafer is transferred to the aligner apparatus. This preliminary detection allows the system to identify positional deviations early in the transport process, enabling corrective actions to be taken before the wafer reaches the aligner, thus preventing collisions and improper placement without adding complex corrective mechanisms to the aligner itself.
Solution Approach 2:
The determination unit receives detection values from the sensor and determines whether the wafer position is within a predetermined acceptable range. This feedback mechanism allows the system to monitor wafer position in real-time during transport and make necessary adjustments, ensuring reliable placement while maintaining a relatively simple transport system architecture.
2Manufacturing precision
If the wafer position is not detected during transport, then the transport operation is faster, but the wafer may collide with surrounding members or fail proper alignment
Solution Approach 1:
Position detection is performed on the robot hand during the transport process, before the wafer reaches the aligner apparatus. This timing allows the system to identify and correct positional issues while there is still time to adjust, ensuring precise placement without requiring post-placement correction that would waste time.
Solution Approach 2:
The patent replaces complex mechanical positioning mechanisms with a sensor-based detection system. Instead of using elaborate mechanical guides or adjustment mechanisms to ensure precise wafer placement, the system uses optical or other non-contact sensors to detect position and uses determination logic to ensure accuracy, thereby minimizing additional transport time while achieving high positioning precision.
3Reliability
If no position detection is performed, then the system structure remains simple, but the aligner apparatus may experience operational failures due to wafer positional deviation
Solution Approach 1:
The sensor acts as an intermediary between the robot transport system and the aligner apparatus. Rather than making the robot hand itself more complex with integrated sensors or making the aligner apparatus complex with pre-alignment mechanisms, a separate detection system is introduced that monitors wafer position during transport and provides feedback, ensuring aligner reliability without significantly increasing the complexity of either the robot or aligner.
Solution Approach 2:
The determination unit provides feedback on whether the wafer position is acceptable for aligner operation. This simple binary feedback mechanism (position within range or not) allows the system to ensure aligner reliability without requiring complex real-time control systems, maintaining relative simplicity while preventing operational failures.
Data Source
AI summary
A transport system includes a robot, sensors (an aligner sensor, a protrusion detecting sensor) and a controller. The robot having a hand which supports a wafer and transports the wafer to an aligner apparatus. The sensor detects the position of the wafer before the robot delivers the wafer to the aligner apparatus while supporting the wafer on the hand. The controller determines the positional deviation of the wafer based on a detection value of the sensor.