Gas Supply Line Purging Layout for Accurate Flow Control
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Solution Overview
Problem
Existing gas supply systems in surface treatment apparatuses face issues with efficient purging of gases before and after flow rate controllers, inaccurate flow rate measurement, especially with gases like hydrogen fluoride, and potential safety hazards from manual valve failures.
Innovation Solution
A gas supply control device with a purge gas line bypassing the flow rate controller upstream, allowing purging from the most upstream position, and a system for flow rate calibration using standard gases, along with mechanical valves to ensure safety and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional gas supply system with manual valves and flow rate controllers is used, then gas flow can be controlled, but purging becomes inefficient due to dead volumes and manual valve failures create safety hazards
Solution Approach 1:
The patent removes manual valves from the gas supply system and replaces them with automated solenoid valves and flow rate controllers. This extraction of manual components eliminates safety hazards associated with manual operation while enabling efficient automated purging sequences that clear dead volumes effectively.
Solution Approach 2:
The patent replaces mechanical manual valves with electromagnetic solenoid valves controlled by a programmable logic controller (PLC). This substitution enables automated purging operations that can efficiently clear dead volumes without the safety risks of manual valve handling, while maintaining precise gas flow control.
2Ease of operation
If manual valves are used in the gas supply system, then simple gas flow control is achieved, but safety hazards arise from potential valve failures
Solution Approach 1:
The patent replaces manual mechanical valves with automated solenoid valves controlled by a PLC system. This substitution maintains simple gas flow control functionality while eliminating safety hazards associated with manual valve failures, as the automated system provides consistent, reliable operation with built-in safety interlocks.
Solution Approach 2:
The patent implements a self-service control system where the PLC automatically manages valve operations, purging sequences, and safety monitoring without manual intervention. This eliminates human error in valve operation while maintaining ease of gas flow control through automated programming and control logic.
3Device complexity
If purging is performed through the flow rate controller, then the existing gas path is used, but dead volumes remain and purging efficiency is reduced
Solution Approach 1:
The patent introduces a purging gas line that connects upstream of the flow rate controller, allowing purging gas to enter the system before the main gas flow path. This preliminary action enables efficient displacement of gases in dead volumes without requiring changes to the existing gas path configuration, significantly improving purging speed.
Solution Approach 2:
The patent uses a dedicated purging gas line as an intermediary path that bypasses the flow rate controller. This intermediary channel allows purging gas to reach upstream positions and efficiently clear dead volumes without being constrained by the flow rate controller's internal geometry, thereby improving purging efficiency while maintaining simple device configuration.
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 efficient purging without dead volumes, accurate flow rate measurement, and enhanced safety by eliminating manual valves, meeting SEMI safety standards.
Implementation Method 1
The gas flow rate is controlled by using a thermal sensor type mass flow rate controller (MASS FLOW RATE CONTROLLER, hereinafter referred to as MFC)
Implementation Method 2
The gas flow rate is controlled by using a thermal sensor type mass flow rate controller (MASS FLOW RATE CONTROLLER, hereinafter referred to as MFC) or a pressure flow rate controller (PRESSURE FLOW RATE CONTROLLER, hereinafter referred to as PFC)
Data Source
AI summary
A gas supply control device that supplies a gas to a processing chamber in which a workpiece is processed, includes: a first port connected to a gas source of a purge gas; a second port to which a gas source of a processing gas is connected; a collective pipe in which each of the purge gas and the processing gas supplied from the first port and the second port merges, respectively, and flow; a first flow rate controller provided between the first port and the collective pipe; and a second flow rate controller provided between the second port and the collective pipe. A gas flow path through which the purge gas flows is provided from an output side of the first flow rate controller to an input side of the second flow rate controller.