Pressure-Type Flow Rate Control Device Fall Response
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Solution Overview
Problem
Pressure-type flow rate control devices in semiconductor manufacturing have poor fall response, taking excessively long times to drop flow rates from 100% to lower levels, which is not suitable for the rapid control required in these applications.
Innovation Solution
The design includes a fluid passage with a control valve, an orifice, and a pressure sensor arranged below the control valve, with vertically extending first and second passage portions connecting the control valve to a pressure detection chamber, and a ring gasket for efficient sealing, reducing the inner capacity of the fluid passage and improving fall response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the fluid passage is designed with conventional routing between control valve and orifice, then the structural layout is simple, but the fall response time is excessively long
Solution Approach 1:
The pressure sensor is positioned below the control valve in a different spatial arrangement, with the fluid passage routing upward through the pressure detection chamber and then to the orifice. This three-dimensional routing reduces the horizontal passage length and internal capacity, thereby improving fall response speed and reducing fall time from several seconds to 1 second or less.
2Device complexity
If the pressure sensor is positioned above the control valve, then the fluid passage routing is simpler, but the fall response is slower
Solution Approach 1:
Instead of positioning the pressure sensor above the control valve with simple vertical routing, the sensor is placed below the valve. The fluid passage routes upward through the pressure detection chamber and then to the orifice, utilizing three-dimensional space to minimize passage volume and improve response speed despite increased routing complexity.
3Stability of the object's composition
If the fluid passage has large internal capacity, then the pressure stabilization is better, but the fall response time increases
Solution Approach 1:
The fluid passage is designed with different characteristics in different sections: the pressure detection chamber has sufficient volume for stable pressure measurement, while the connecting passages are minimized in volume to enable rapid flow rate changes. This local differentiation allows pressure stability where needed while achieving fast fall response overall.
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 configuration significantly reduces the fall time in flow rate control, allowing the flow rate to drop to predetermined levels within 1 second or less, meeting the rapid control requirements of semiconductor manufacturing devices.
Implementation Method 1
a pressure sensor which is fixed to the body to detect the internal pressure of the fluid passage between the control valve for pressure control and the orifice
Data Source
AI summary
A pressure-type flow rate controller includes a body provided with a fluid passage which communicates a fluid inlet and a fluid outlet, a control valve for pressure control fixed to the body to open and close the fluid passage, an orifice arranged in the course of the fluid passage on the downstream side of the control valve, and a pressure sensor fixed to the body to detect the internal pressure of the fluid passage between the control valve and the orifice, wherein the fluid passage comprises a first passage portion communicating the control valve and a pressure detection chamber provided on a pressure detection surface of the pressure sensor, and a second passage portion spaced away from the first passage portion and communicating the pressure detection chamber and the orifice.