Flow Rate Control Valve Sealing With Localized Cross-Linked PTFE
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Solution Overview
Problem
Existing flow rate control valves in semiconductor manufacturing processes face issues with dust generation due to low flex resistance of cross-linked PTFE, leading to contamination and reduced product lifetime, and existing solutions do not effectively reduce dust generation or provide sufficient joining strength.
Innovation Solution
A flow rate control valve design utilizing annular or circular seal members made of cross-linked PTFE, joined to specific abutting portions of the valve body and valve seat using PFA or PTFE, with a laminated PFA film and cross-linked PTFE sheet, and a heating block for resistive heating to achieve strong joining and reduced dust generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If cross-linked PTFE is used for valve body and valve seat to reduce dust generation, then abrasion resistance is improved, but flex resistance becomes low causing diaphragm cracks and dust generation
Solution Approach 1:
The patent applies different materials to different parts of the valve: cross-linked PTFE is used specifically for the valve seat and seal portions where abrasion resistance is critical, while the diaphragm is made of PFA or PTFE with sufficient flex resistance. This localized material selection allows each component to have optimal properties for its specific function, resolving the contradiction between reducing dust from contact surfaces and maintaining diaphragm reliability.
2Object-generated harmful factors
If cross-linked PTFE is used to reduce dust generation, then abrasion resistance is improved, but liquidity is lowered preventing production of large-sized components
Solution Approach 1:
The patent uses cross-linked PTFE only for the valve seat and seal portions that require high abrasion resistance, while the main valve body is made of PFA or PTFE that can be easily molded into large sizes. This selective material application allows large-scale production of the valve body while maintaining dust-reducing properties at the critical contact surfaces.
3Object-generated harmful factors
If cross-linked PTFE is used for seal members to reduce dust generation, then abrasion resistance is improved, but joining strength becomes insufficient due to poor adhesion
Solution Approach 1:
The patent uses composite construction for seal members, combining cross-linked PTFE (for abrasion resistance and dust reduction) with PFA or PTFE (for joining capability). The cross-linked PTFE layer is applied on the contact surfaces where dust reduction is critical, while the base material provides sufficient adhesion and joining strength. This composite approach allows both dust reduction and strong joining to be achieved simultaneously.
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 solution effectively reduces dust generation by using cross-linked PTFE only on contact portions, enhancing abrasion resistance and joining strength, while maintaining the shape and uniformity of the seal members, thus improving the longevity and cleanliness of semiconductor manufacturing processes.
Implementation Method 1
a heating block for resistive heating to achieve strong joining
Data Source
AI summary
[Object] The present invention provides a flaw rate control valve and a producing method of the flow rate control valve in which cross-linked PTFE having excellent abrasion resistance and capable of reducing a dust-generating amount is used only on a contact portion between a valve body and a valve seat.[Solving Means] According to a flow rate control valve 1 of the invention, a flow path-side body 10 and a valve body 40 are made of fluorine-based resin composed of PFA or PTFE, and an annular or circular seal member 81 made of cross-linked PTFE is joined to a valve body-side abutting portion 40a having a valve seat 13 against which the valve body 40 abuts and to a valve seat-side abutting portion 13a of the valve seat 13 against which the valve body 40 abuts.