Proportional Valve Fluid Control for Rapid Pressure Adjustment
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Solution Overview
Problem
Conventional vacuum control systems for semiconductor manufacturing, particularly in ALD processes, face challenges with long pressure control times due to the use of mass flow controllers, leading to increased production costs and frequent maintenance needs.
Innovation Solution
A fluid control system that replaces the mass flow controller with a proportional valve and flowmeter, allowing for rapid adjustment of gas flow rates and pressures, controlled by a pressure sensor and flow controller, respectively, to shorten pressure control times and reduce manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a mass flow controller is used to control gas flow rate, then the flow rate can be controlled accurately, but the pressure control time becomes long
Solution Approach 1:
The patent removes the mass flow controller from the gas supply path and extracts its flow control function, replacing it with a proportional valve that responds faster to control signals, thereby eliminating the time delay associated with mass flow controllers while maintaining flow control capability
Solution Approach 2:
The patent replaces the mechanical mass flow controller with an electronically controlled proportional valve system that uses feedback from a flow sensor and pressure sensor to achieve both accurate flow control and rapid response, substituting slow mechanical adjustment with faster electronic control
2Ease of operation
If a mass flow controller is used, then flow rate control is achieved, but the system becomes expensive and requires frequent maintenance
Solution Approach 1:
The patent replaces the expensive mass flow controller with a combination of a relatively inexpensive proportional valve and a flow sensor, creating a more cost-effective system that maintains flow control functionality without the high cost and maintenance burden of mass flow controllers
Solution Approach 2:
The proportional valve serves multiple functions: it controls gas flow rate, responds to pressure changes, and works with the flow sensor to provide both flow control and pressure regulation, eliminating the need for separate mass flow controller hardware
3Productivity
If the pressure control time is reduced, then manufacturing efficiency improves, but flow rate control accuracy may be compromised
Solution Approach 1:
The patent implements a feedback control system where a flow sensor continuously monitors the actual gas flow rate and a pressure sensor monitors chamber pressure, feeding this information back to the controller which adjusts the proportional valve to maintain both accurate flow control and rapid pressure response, achieving both speed and precision simultaneously
Data Source
AI summary
A fluid control system includes a vacuum chamber, a gas supply source to supply gas as a fluid, an exhaust pipe to discharge the fluid from the vacuum chamber, a gas supply pipe to connect the vacuum chamber to the gas supply source, and a pressure sensor to detect an internal pressure of the vacuum chamber. This system further includes a flowmeter placed between the gas supply source and the vacuum chamber, a proportional valve placed between the flowmeter and the vacuum chamber, a pressure controller to control the proportional valve based on output of the pressure sensor, a metering valve placed on the exhaust pipe, and a flow controller to control the metering valve based on an output of the flowmeter.