Mass Flow Controller Sensors for Precise Flow and Bleed-Down Control
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Solution Overview
Problem
Current Mass Flow Controllers (MFCs) and diagnostic systems lack precision, affecting semiconductor wafer manufacturing yield, repeatability, and uniformity due to inadequate control over fluid flow rates and pressure bleed-down during shutdowns.
Innovation Solution
The implementation of high precision sensors, including semiconductor-based pressure and position sensors, combined with upstream and downstream valves, to minimize bleed-down time and optimize flow control, using algorithms that calculate and adjust flow rates based on real-time pressure and position data, ensuring consistent fluid delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current state of the art MFCs are used, then basic flow control is achieved, but precision and consistency are insufficient affecting wafer manufacturing yield
Solution Approach 1:
The patent replaces traditional mechanical sensing systems with semiconductor-based sensors that utilize piezoresistive effects and capacitive measurements. This substitution enables higher precision flow rate measurements and pressure detection, directly resolving the contradiction between measurement precision and manufacturing reliability
Solution Approach 2:
The patent implements comprehensive feedback mechanisms where semiconductor sensors continuously monitor pressure and position, and the control system adjusts valve actuation in real-time based on measured deviations from target flow rates. This closed-loop feedback ensures high precision control while maintaining consistent wafer manufacturing outcomes
2Adaptability or versatility
If MFCs operate at multiple set points with shutdown and restart, then process flexibility is achieved, but flow control precision deteriorates causing delays
Solution Approach 1:
The patent employs preliminary action by pre-positioning the downstream valve using semiconductor-based position sensors before shutdown and implementing pressure bleed-down control through the upstream valve. This ensures that when restart occurs, the system is already prepared to achieve target flow rates quickly and precisely, maintaining manufacturing precision during adaptive operations
Solution Approach 2:
The patent makes the valve positions and pressure control dynamic through real-time adjustment by semiconductor sensors and control algorithms. The system continuously adapts valve opening positions and pressure levels based on current operating conditions, enabling precise flow control across multiple set points while maintaining rapid response during shutdown and restart cycles
3Duration of action of stationary object
If traditional pressure control is used during shutdown, then basic valve closure is achieved, but pressure bleed-down time is excessive affecting response time
Solution Approach 1:
The patent uses semiconductor-based pressure sensors to continuously monitor pressure during shutdown and provides real-time feedback to the control system. The controller adjusts the upstream valve position dynamically based on measured pressure levels, enabling rapid and controlled pressure bleed-down that minimizes both time and response delay
Solution Approach 2:
The patent replaces traditional mechanical pressure relief mechanisms with electronically controlled semiconductor pressure sensors and actuated valves. This substitution enables precise, rapid, and programmable pressure control during shutdown, dramatically reducing bleed-down time while maintaining fast response capability
4Measurement precision
If high precision sensors and advanced diagnostics are implemented, then flow control precision is improved, but device complexity increases
Solution Approach 1:
The patent merges multiple functions into integrated semiconductor-based components that combine pressure sensing, position sensing, and flow control capabilities in unified valve assemblies. This integration reduces the number of separate components and interconnections, managing device complexity while maintaining high measurement precision
Solution Approach 2:
The patent implements multi-functional semiconductor sensors that simultaneously perform pressure measurement, position detection, and diagnostic functions. The upstream and downstream valves serve multiple purposes including flow control, pressure regulation, and shutdown operations, reducing overall system complexity through universal components
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
This solution enhances the precision and consistency of fluid flow control, reducing unwanted flow perturbations and improving wafer manufacturing yield and uniformity by minimizing pressure bleed-down and optimizing response times.
Implementation Method 1
semiconductor-based pressure sensor
Implementation Method 2
semiconductor-based position sensor
Data Source
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AI summary
A mass flow controller for controlling flow rate comprising a controller, a valve assembly, and at least one pressure sensor, valve position sensor, and temperature sensor; wherein, at least one of the sensors is a semiconductor based sensor. The valve assembly is in fluid communication with at least one upstream location and at least one downstream location. The at least one pressure sensor is in in fluid communication with the at least one upstream location and the at least one downstream location. The valve assembly can comprise at least one piezoelectric or solenoid valve. The controller is communicable coupled with the valve assembly and at least one of the sensors. The controller determines at least one of: pressure; position; and temperature. The controller further causes an adjustment to valve stroke based on an actual fluid flow rate and at least one of the pressure, position, temperature, and a predetermined value.