Load Port Stage Thrust Control for Stable FOUP Docking
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Solution Overview
Problem
The existing load port systems face challenges in preventing substrates from moving due to inertial forces when moving from the UNDOCK to the DOCK position, especially with larger and heavier substrates, as the required thrust can cause substrates to shift during the transition.
Innovation Solution
A load port system with a controller that applies a first thrust until immediately before reaching the DOCK position and a second, greater thrust after reaching the position, along with a shock absorber to reduce speed and a lock unit to secure the storage container, minimizing inertial movement of substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a large thrust is applied to move the stage from UNDOCK to DOCK position, then the stage can reach the DOCK position and press the FOUP against the wall surface, but the substrates move due to inertial force
Solution Approach 1:
The thrust application is segmented into multiple phases: a first thrust is applied from the UNDOCK position to immediately before the DOCK position, and a second thrust is applied from that point to the DOCK position. This segmentation allows the system to achieve the required pressing force while minimizing inertial effects on substrates during the transition.
Solution Approach 2:
The stage is moved to a predetermined position immediately before the DOCK position as an intermediate step. At this position, the lid of the FOUP is opened in advance, and then the second thrust is applied to press the FOUP against the wall surface. This preliminary positioning and lid opening action prevents substrate movement during the final pressing operation.
2Weight of moving object
If the thrust is increased to accommodate heavier substrates, then the stage can handle larger substrates, but the substrate movement due to inertial force becomes more problematic
Solution Approach 1:
The thrust application is divided into two distinct phases with different magnitudes. The first thrust handles the movement of heavier substrates from UNDOCK to the predetermined position, while the second thrust applies the necessary force to press the FOUP against the wall surface after the lid is opened. This prevents excessive inertial forces from affecting substrate stability.
Solution Approach 2:
The lid of the FOUP is opened in advance when the stage reaches the predetermined position immediately before the DOCK position. This preliminary action allows the second thrust to be applied effectively to press the FOUP against the wall surface without causing substrate movement, even when handling heavier substrates.
Data Source
AI summary
A load port for loading and unloading substrates between a transport chamber and a storage container includes: a plate-like portion constituting a wall surface of the transport chamber and including an opening in communication with an interior of the transport chamber; a stage configured to mount the storage container thereon such that a lid of the storage container faces a door of the opening; and a controller configured to control a driving device that moves the stage forward and rearward with respect to the plate-like portion, wherein the controller is further configured to control, when moving the stage toward the plate-like portion, the driving device to: apply a first thrust directed toward the plate-like portion to the stage until immediately before the stage reaches a predetermined position; and then apply a second thrust, which is greater than the first thrust and directed toward the plate-like portion, to the stage.