FOUP Lid Sensor for Load Port Abnormality Detection
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Solution Overview
Problem
Conventional load ports lack a means to detect if the FOUP lid is properly attached to the FOUP body during semiconductor wafer transfer, leading to potential exposure of wafers to a low cleanliness atmosphere and damage.
Innovation Solution
Incorporation of a FOUP lid sensor, such as an optical sensor with an inclined optical axis, to detect the detachment of the FOUP lid from the FOUP body after unloading is completed, ensuring the lid is properly attached before transferring the FOUP.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If no FOUP lid detection means is provided, then the load port structure remains simple, but the FOUP lid detachment cannot be detected leading to wafer exposure to low cleanliness atmosphere
Solution Approach 1:
The patent replaces complex mechanical detection mechanisms with a simple optical sensor system. The FOUP lid sensor uses light detection to determine lid attachment status, substituting potential mechanical switches or contact-based detection systems with a non-contact optical method that is both simpler and more reliable.
Solution Approach 2:
The patent introduces an intermediary observer that monitors sensor output and translates it into actionable detection results. This observer layer separates the raw sensing function from the decision-making process, allowing the system to handle detection logic independently from the physical sensing mechanism, thereby improving reliability without proportionally increasing complexity.
2Reliability
If FOUP lid sensor is added to detect detachment, then detection reliability improves, but device complexity increases
Solution Approach 1:
The patent employs an optical sensor system that uses light interaction to detect FOUP lid status without mechanical contact. This substitution of mechanical detection with optical detection achieves high reliability while keeping the physical addition to the system minimal, as optical sensors can be integrated into existing structural elements.
Solution Approach 2:
The observer component serves multiple functions: it monitors sensor output, determines lid attachment status, triggers appropriate responses, and can interface with various control systems. This multi-functionality consolidates what could be multiple separate systems into a single integrated component, improving reliability without proportional complexity increase.
3Object-affected harmful factors
If conventional sensors are used without FOUP lid detection, then device complexity remains low, but wafer protection against contamination is insufficient
Solution Approach 1:
The patent uses optical sensing to detect FOUP lid status, providing wafer contamination protection without mechanical contact. This approach prevents detection system components from potentially contaminating the clean environment while maintaining high detection reliability, directly addressing the harmful factor of wafer contamination risk.
Solution Approach 2:
The system performs preliminary detection of FOUP lid attachment status before wafer transfer operations commence. By detecting potential contamination risks in advance and preventing operations when the lid is improperly attached, the system protects wafers from contamination without requiring complex real-time monitoring during the entire transfer process.
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
Enables reliable detection of FOUP lid detachment, maintaining a clean environment and preventing wafer damage during transfer by ensuring the lid is securely attached before moving the FOUP.
Implementation Method 1
the FOUP lid sensor is configured to detect a position of the FOUP lid
Data Source
AI summary
There is provided a load port provided to a loading/unloading port of a semiconductor-processing apparatus to transfer a semiconductor wafer, including: a FOUP support configured to support a FOUP that includes a FOUP lid and move the FOUP in a front-rear direction with respect to the loading/unloading port; a lid configured to open and close the loading/unloading port; a FOUP lid sensor provided to perform a detection operation between a position of the lid in a closed state and a position of the FOUP lid when unloading is normally completed by retreating the FOUP by a predetermined distance with respect to the loading/unloading port; and an observer configured to observe that the FOUP lid sensor has performed the detection operation after the unloading is completed.