Substrate Processing Apparatus Branch Pipe Exhaust Flow Control
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in maintaining a consistent atmosphere discharge rate due to unintended inflow of exhaust into internal spaces, particularly when valve elements close, leading to inefficiencies in gas flow management.
Innovation Solution
The apparatus incorporates upstream and downstream dampers, switching members, and a sealing structure to control the flow of atmosphere through branch pipes, allowing for precise management of gas flow by switching between different routes for external atmosphere inflow and preventing unintended inflow, thereby maintaining consistent discharge rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a valve element closes the exhaust intake port, then the exhaust flow into the corresponding individual exhaust pipe is controlled, but unintended inflow of exhaust into the internal space of the main body portion occurs through gaps between the valve element and the inner peripheral surface
Solution Approach 1:
A seal member is introduced as an intermediary element between the valve element and the main body portion. This seal member fills the gap between the valve element's outer peripheral surface and the main body portion's inner peripheral surface, preventing exhaust gas from leaking into the internal space while allowing the valve element to maintain its flow control function.
Solution Approach 2:
The seal member is designed as a flexible ring-shaped component that can deform to conform to the mating surfaces. This flexibility allows the seal member to effectively close gaps between the valve element and main body portion, preventing harmful exhaust leakage while accommodating manufacturing tolerances and thermal expansion.
2Object-generated harmful factors
If the valve element is designed to closely fit the inner peripheral surface to prevent gaps, then unintended exhaust inflow is suppressed, but the operation of the valve element becomes difficult and may cause sticking
Solution Approach 1:
The sealing function is separated from the valve element and assigned to a distinct seal member. This segmentation allows the valve element to maintain a clearance design for smooth operation, while the seal member provides the necessary sealing action to prevent exhaust leakage, thus resolving the conflict between operational ease and leakage prevention.
Solution Approach 2:
The seal member acts as a mediator between the valve element and the main body portion, enabling the valve element to operate with adequate clearance without direct contact that would cause sticking, while still achieving effective sealing through the intermediary seal member.
3Ease of operation
If the gap between the valve element and the inner peripheral surface is increased to facilitate smooth operation, then the valve element operates more easily, but exhaust gas leaks into the internal space of the main body portion
Solution Approach 1:
By dividing the sealing function into a separate seal member, the valve element can be designed with larger clearance for smooth operation without compromising sealing effectiveness. The seal member compensates for the increased gap, maintaining reliable exhaust flow control.
Solution Approach 2:
The flexible seal member can effectively bridge larger gaps between the valve element and main body portion, allowing the valve element to operate with greater clearance while maintaining reliable sealing and preventing exhaust leakage.
Data Source
AI summary
Each of branch pipes has an internal space into which an atmosphere flows from a main pipe. A downstream damper is provided on the downstream side of an upstream damper in each of the branch pipes, and opens/closes the branch pipe. An upstream switching member switches a state of an upstream space between a state where the upstream space permits an inflow of an external atmosphere and a state where the upstream space prohibits the inflow of the external atmosphere. A downstream switching member switches a state of a downstream space between a state where the downstream space permits an inflow of the external atmosphere and a state where the downstream space prohibits the inflow of the external atmosphere.