Wafer Mapping Sensor with Protrusion Detection for Multi-Size Containers
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Solution Overview
Problem
Existing wafer mapping apparatuses are unable to handle differently-sized wafers stored in various containers efficiently, leading to collisions and contamination in clean processing rooms due to the complexity of using multiple apparatuses for each container size.
Innovation Solution
A common wafer mapping apparatus with a mapping sensor and two protrusion sensors, where the mapping sensor has a horizontal radiation axis and the protrusion sensors detect wafer protrusions in different directions to prevent collisions, allowing the apparatus to handle wafers of varying sizes in differently-sized containers while minimizing the number of actuators and reducing contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single wafer mapping apparatus is used for differently-sized wafers, then device complexity is reduced, but the risk of collision with wafers increases
Solution Approach 1:
The protrusion sensor detects wafer protrusions in advance before the mapping sensor reaches that position. This preliminary detection allows the system to take preventive action (stop or adjust the mapping sensor movement) before a collision can occur, thus maintaining reliability while using a single apparatus
Solution Approach 2:
The protrusion sensor acts as an intermediary detection element between the wafer and the mapping sensor. It detects wafer positions and protrusions indirectly, providing warning signals that allow the mapping sensor to adjust its path and avoid collisions without directly contacting the wafers
2Adaptability or versatility
If the mapping sensor span is reduced to fit smaller containers, then adaptability to different container sizes is improved, but the detection capability for larger wafers is compromised
Solution Approach 1:
The solution adds a new detection dimension by introducing the protrusion sensor that detects wafer positions in the horizontal direction (front-to-back protrusion), complementing the mapping sensor's vertical scanning capability. This multi-dimensional detection approach maintains measurement precision across different wafer sizes while keeping the mapping sensor span adaptable to smaller containers
3Measurement precision
If multiple wafer mapping apparatuses are used for different container sizes, then measurement precision for each wafer size is maintained, but device complexity increases
Solution Approach 1:
The single wafer mapping apparatus is designed with multi-functional capability through the addition of the protrusion sensor. This sensor enables the system to handle multiple wafer sizes and container types with the same level of detection accuracy that previously required separate dedicated apparatuses for each wafer size
Solution Approach 2:
The protrusion detection function and the mapping sensor function are merged into a single integrated apparatus. The protrusion sensor and mapping sensor work together in coordination, combining their capabilities to achieve comprehensive wafer detection across different sizes without requiring separate apparatuses
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 the use of a single wafer mapping apparatus for differently-sized wafers, preventing collisions and reducing contamination by effectively detecting wafer protrusions and optimizing the placement of sensors to avoid interference, thus simplifying the load port structure and maintaining a clean environment.
Implementation Method 1
a mapping sensor which emits a detection wave having a radiation axis extending in a left-right horizontal direction
Implementation Method 2
a first protrusion sensor which emits a detection wave having a radiation axis extending in the left-right horizontal direction
Implementation Method 3
a second protrusion sensor which emits a detection wave having a radiation axis extending in an up-down moving direction of the mapping sensor
Data Source
AI summary
The left-right span between a light projection section (5a) and a light receiving section (5b) of a mapping sensor (5) having an optical axis extending in a left-right horizontal direction is arranged to be narrower than the span of a front opening of a open cassette (12) which is a smaller one of differently-sized containers conveyed to a load port, and the mapping sensor is attached to a mapping device (4). A first protrusion sensor (6) having an optical axis (L2) extending in the left-right horizontal direction is attached to the mapping device (4) to be separated from the mapping sensor (5) in a moving direction of the mapping sensor (5). Furthermore, a second protrusion sensor (7) having an optical axis extending in the up-down moving direction of the mapping sensor (5) is provided.