Fluid Device Unit Structure Minimizing Stagnation
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Solution Overview
Problem
In fluid device unit structures, chemical solution stagnation occurs between the main fluid flow path valve and the branching point of the return flow path, leading to solidification and clogging, which affects semiconductor manufacturing processes, especially when handling slurry-like chemical solutions.
Innovation Solution
The return flow path is positioned close to the upstream side of the first valve, and the valves are designed with a plug-type mechanism and high back-pressure responsive configuration to minimize stagnation volume and ensure sealing, using pneumatic valves with a smaller base-side diameter and diaphragm to reduce back pressure and prevent solidification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the return flow path is branched from the main fluid flow path far from the valve, then the valve can be positioned optimally for flow control, but a large chemical solution stagnation portion is formed causing solidification and clogging
Solution Approach 1:
The flow path configuration transitions from a linear arrangement to a three-dimensional integrated structure where the return flow path branches from the side surface of the base member. This spatial reconfiguration minimizes the stagnation portion volume while maintaining optimal valve positioning for flow control.
Solution Approach 2:
The invention changes the geometric parameters of the flow path, specifically positioning the branching point of the return flow path close to the upstream side of the first valve. This parameter optimization reduces the stagnation volume to minimize chemical solution solidification while preserving flow control functionality.
2Reliability
If piping is used to connect fluid devices, then flow control is reliable, but the overall apparatus size increases
Solution Approach 1:
Multiple fluid devices (valves, flow paths, connection ports) are merged and integrated into a single base member structure. The first and second flow paths are formed within the same base member, eliminating the need for external piping connections and reducing overall apparatus size while maintaining flow control reliability.
Solution Approach 2:
The base member serves multiple functions simultaneously: it acts as the structural support, contains the flow paths, provides mounting positions for valves, and forms connection ports. This multi-functionality consolidates what would traditionally require separate components and piping into a single integrated unit.
3Ease of operation
If the valve is positioned far from the branching point, then flow switching is more controllable, but the stagnation portion volume increases causing solidification
Solution Approach 1:
The valve and branching point are positioned in three-dimensional space within the base member such that the distance between them is minimized. The flow path routing in multiple dimensions allows the valve to remain close to the branching point while maintaining effective flow switching control.
4Object-affected harmful factors
If the chemical solution flow path is minimized, then solidification is prevented, but valve positioning and flow control capability are compromised
Solution Approach 1:
The flow path parameters (length, cross-section, routing) are optimized to minimize stagnation volume while maintaining adequate flow control capability. The branching point is positioned close to the valve upstream side, and the flow paths are configured to provide sufficient control authority despite the reduced path length.
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 minimizes chemical solution stagnation, preventing clogging and maintaining chemical solution supply, thereby enhancing the reliability of semiconductor manufacturing processes by reducing the likelihood of solidification and maintaining flow path integrity.
Implementation Method 1
the second valve has a diaphragm that receives liquid pressure and opens or closes the return flow path by an open-and-close operation mechanism
Data Source
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AI summary
Provided is a fluid device unit structure in which a chemical solution stagnation portion that is formed between a valve of a main fluid flow path and a branching point of a return flow path is minimized to cause hardly any solidification of a chemical solution. In the fluid device unit structure in which a plurality of fluid devices that are connected via flow paths are integrated on a base member (10) to form a single unit, and the main fluid flow path (11) and the return flow path (12) formed in the base member (10) are respectively provided with a first valve (20) and a second valve (40) for switching the flow paths, the branching inlet (12a) at which the return flow path (12) branches from the main fluid flow path (11) is close to the upstream side of the first valve (20).