Diaphragm and chemical flow control device
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.
1 . 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.
2 . The diaphragm according to claim 1 , wherein the permeation reduction layer is attached to the membrane portion with a double-sided tape.
3 . The diaphragm according to claim 2 , wherein the membrane portion and the double-sided tape are surface-treated to activate the surface of the membrane portion.
4 . The diaphragm according to claim 1 , wherein the permeation reduction layer has a thickness in a range of 10 to 40 μm.
5 . The diaphragm according to claim 1 , wherein
the permeation reduction layer includes a surface that is apart from the membrane portion and on which no layer is stacked, and
the membrane portion includes a surface that contacts the chemical and on which no layer is stacked.
6 . The diaphragm according to claim 1 , wherein the permeation reduction layer has a permeability coefficient in a range of 2.3×10{circumflex over ( )}−10 to 18.7×10{circumflex over ( )}−9.
7 . A chemical flow control device comprising the diaphragm according to claim 1 , wherein the chemical flow control device is used as a pump for suction and discharge of the chemical according to deformation of the diaphragm.
8 . The chemical flow control device according to claim 7 , wherein the pressure of the working gas applied to the diaphragm is in a range of 150 to 300 kPa.
9 . The chemical flow control device according to claim 7 , wherein the permeation reduction layer has a permeability coefficient in a range of 2.3×10{circumflex over ( )}−10 to 18.7×10{circumflex over ( )}− 9 .
10 . The diaphragm according to claim 2 , wherein the permeation reduction layer has a thickness in a range of 10 to 40 μm.
11 . The diaphragm according to claim 2 , wherein
the permeation reduction layer includes a surface that is apart from the membrane portion and on which no layer is stacked, and
the membrane portion includes a surface that contacts the chemical and on which no layer is stacked.
12 . The diaphragm according to claim 2 , wherein the permeation reduction layer has a permeability coefficient in a range of 2.3×10{circumflex over ( )}−10 to 18.7×10{circumflex over ( )}−9.
13 . A chemical flow control device comprising the diaphragm according to claim 2 , wherein the chemical flow control device is used as a pump for suction and discharge of the chemical according to deformation of the diaphragm.
14 . The chemical flow control device according to claim 13 , wherein the pressure of the working gas applied to the diaphragm is in a range of 150 to 300 kPa.
15 . The chemical flow control device according to claim 13 , wherein the permeation reduction layer has a permeability coefficient in a range of 2.3×10{circumflex over ( )}−10 to 18.7×10{circumflex over ( )}−9.
16 . The diaphragm according to claim 3 , wherein the permeation reduction layer has a thickness in a range of 10 to 40 μm.
17 . The diaphragm according to claim 3 , wherein
the permeation reduction layer includes a surface that is apart from the membrane portion and on which no layer is stacked, and
the membrane portion includes a surface that contacts the chemical and on which no layer is stacked.
18 . 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.