Diaphragm and chemical flow control device
AssigneeCkd Corporation
InventorsMasaki Yoshida, Yoshifumi Nishio, Takayuki Kumagai, Shigenobu Nishida
Life of this patent
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Abstract
A diaphragm to be used in a chemical flow control device that controls a flow of a chemical in a semiconductor manufacturing process and to which a pressure of a working gas is applied. The diaphragm includes a membrane portion and a permeation reduction layer. The membrane portion is made of fluoroplastic that is resistant to the chemical. The permeation reduction layer is less likely to pass the working gas in comparison to the membrane portion and disposed on a surface of the membrane portion to which the pressure of the working gas is applied.
Claims18
A diaphragm disposed in a chemical flow control device that controls a flow of a chemical in a semiconductor manufacturing process, the diaphragm comprising:
- a membrane portion that is made of fluoroplastic that is resistant to the chemical;
- and
- a permeation reduction layer that is made of polyvinylidene chloride or ethylene-vinyl alcohol copolymer and that is less likely to pass a working gas in comparison to the membrane portion and disposed on a surface of the membrane portion to which a pressure of the working gas is applied.
A diaphragm disposed in a chemical flow control device that controls a flow of a chemical in a semiconductor manufacturing process, the diaphragm comprising:
- a membrane portion that is made of fluoroplastic that is resistant to the chemical;
- and
- a permeation reduction layer that has a permeability coefficient to pass the working gas in a range of 2.3×10{circumflex over ( )}−10 to 18.7×10{circumflex over ( )}−9 and that is lower than the membrane portion, wherein the permeation reduction layer is disposed on a surface of the membrane portion to which a pressure of a working gas is applied.
Dependencies are inferred from the claim text.