Self-Sensing Coolant Valve Using SMA Spring Flow Control
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Solution Overview
Problem
Current servo-controlled valves for modulating process coolant flow in semiconductor manufacturing are costly and complex, requiring external sensors, control logic, and actuators, and involve time-consuming parameter tuning.
Innovation Solution
A self-sensing and self-actuating valve using a shape memory alloy (SMA) spring to variably control coolant flow based on temperature, eliminating the need for external sensors and energy sources, and allowing for both continuous and step adjustments in flow rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If servo-controlled valves are used to modulate coolant flow, then flow rate control is achieved, but device complexity and cost increase due to required sensors, control logic, and actuators
Solution Approach 1:
The valve system uses the coolant itself to actuate the valve mechanism. The thermal expansion of the coolant directly drives the piston and plunger assembly, eliminating the need for external sensors, control logic, and actuators. The system serves itself by using its own operational medium (coolant) to perform the control function.
Solution Approach 2:
The patent replaces the electro-mechanical servo control system with a pure thermal-mechanical system. Instead of using motors, sensors, and electronic control, the invention uses thermal expansion of the coolant to mechanically drive the valve components, substituting complex electro-mechanical systems with simpler thermal-mechanical principles.
2Ease of operation
If servo-controlled valves are used to modulate coolant flow, then flow rate control is achieved, but time-consuming parameter tuning is required
Solution Approach 1:
The valve automatically adjusts to different operating conditions without requiring manual parameter tuning. The thermal expansion characteristics of the coolant naturally adapt the valve opening to match the cooling demand, making the system self-adjusting and eliminating time-consuming tuning procedures.
Solution Approach 2:
The system leverages the inherent thermal expansion parameters of the coolant to automatically adjust valve opening. As coolant temperature changes, its expansion characteristics naturally modify the valve position, providing automatic adaptation to different operating conditions without manual intervention or parameter tuning.
3Device complexity
If traditional valves are used, then structural simplicity is maintained, but flow rate modulation capability is insufficient
Solution Approach 1:
The valve is divided into functional segments: a thermal expansion chamber, a piston section, a plunger with tip, and flow paths. This segmentation allows each component to perform a specific function while maintaining overall structural simplicity. The segmented design enables sophisticated flow modulation through relatively simple individual components.
Solution Approach 2:
The invention merges the coolant flow path with the actuation mechanism. The coolant serves dual purposes: it is both the medium being controlled and the actuator that drives the valve. This merging of functions achieves sophisticated modulation capability within a compact, simple structure without requiring separate control systems.
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
The SMA-enabled valve reduces complexity and costs by mechanically controlling coolant flow, conserving heat energy and functioning in corrosive environments without external energy, while providing efficient flow rate modulation.
Implementation Method 1
a shape memory alloy (SMA) spring positioned on the plunger between the bias spring and the tip, the SMA spring attached to the tip to variably withdraw the tip from the second inlet in response to a rise in temperature of the coolant above a threshold temperature value
Data Source
AI summary
A valve includes a first inline compartment to attach to a first return line exiting a processing chamber and a second inline compartment to attach to a second return line entering a coolant source. A flow compartment is attached between the first inline compartment and the second inline compartment and through which a coolant is to return to the coolant source. A first inlet orifice and a second inlet orifice positioned between the first inline compartment and the flow compartment. A plunger has a tip to variably open and close the second inlet orifice. A shape memory alloy (SMA) spring is positioned on the plunger and attached to the tip, the SMA spring to variably increase or decrease a flow rate of the coolant through the second inlet orifice according to a temperature of the coolant.