Load Port Isolation Compartment Oxygen Purge
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Solution Overview
Problem
Conventional load ports in electronic device manufacturing systems can trap oxygen, which leaks into equipment front end modules (EFEMs) and contaminates substrates, despite efforts to maintain a nitrogen-only environment.
Innovation Solution
A load port system with an isolation compartment and a dedicated purge supply within the compartment to remove trapped oxygen using non-reactive gas, such as nitrogen, either by forcing it out with a fan or pulling it out using a fan in the EFEM, ensuring a reactive gas-free environment during substrate transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional load port design is used, then the structure is simple, but oxygen from the cleanroom leaks into the EFEM and contaminates substrates
Solution Approach 1:
The load port is divided into separate isolation compartments (first isolation compartment and second isolation compartment) that are isolated from the EFEM volume. This segmentation allows independent purging of each compartment without affecting the entire EFEM, enabling effective oxygen prevention while maintaining manageable system complexity
Solution Approach 2:
Isolation compartments act as intermediary barriers between the oxygen-containing cleanroom environment and the nitrogen-filled EFEM. These compartments can be independently purged with nitrogen or vacuumed to remove oxygen before substrate transfer occurs, preventing oxygen leakage into the EFEM while maintaining structural simplicity
2Reliability
If the EFEM is flooded with nitrogen to prevent oxidation, then substrates are protected from oxygen, but reactive gas (oxygen) becomes trapped in the isolation compartment and can leak into the EFEM
Solution Approach 1:
The purging system performs preliminary action by removing oxygen from the isolation compartment before substrate transfer operations begin. The vacuum pump or nitrogen purge supply actively removes reactive gas from isolation compartments in advance, preventing oxygen from leaking into the EFEM during subsequent operations
Solution Approach 2:
The system incorporates sensors that monitor oxygen levels in the EFEM and provide feedback to the controller. When oxygen is detected or potential leakage is anticipated, the controller activates the vacuum pump or nitrogen purge supply to remove oxygen from isolation compartments, creating a closed-loop control system that maintains substrate protection
3Ease of operation
If operators work in the cleanroom with oxygen environment, then human operation is enabled, but oxygen contamination of substrates occurs during loading/unloading
Solution Approach 1:
The harmful oxygen is extracted and isolated in separate isolation compartments that are physically separated from the EFEM volume. Operators can work in the oxygen-containing cleanroom environment while the isolation compartments contain any oxygen that might escape, preventing it from reaching substrates in the nitrogen-filled EFEM
Solution Approach 2:
Isolation compartments serve as intermediary zones between the operator workspace (oxygen environment) and the substrate processing area (nitrogen environment). These compartments can be independently purged or vacuumed to remove oxygen, allowing operators to safely handle carriers while preventing oxygen contamination of substrates
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
Effectively prevents oxygen contamination of substrates by ensuring the EFEM remains in a nitrogen-only environment, maintaining substrate integrity during processing.
Implementation Method 1
purge the isolation compartment of reactive gas trapped within the isolation compartment using a non-reactive gas supply disposed within the isolation compartment
Data Source
AI summary
A load port system includes an isolation compartment coupled to an equipment front end module (EFEM). Reactive gas is to be removed from the isolation compartment. The load port system further includes an elevator disposed in the isolation compartment. The elevator is coupled to an elevator arm that extends from the isolation compartment into the EFEM through an opening to raise and lower a carrier opener within the EFEM.