JP7232609B2 - fluid control valve - Google Patents

Description

The present invention is a fluid device comprising an input port for inputting a fluid and an output port for outputting the fluid, wherein the fluid device comprises a main body in which a channel is formed for communicating from the input port to the output port. It is about.

2. Description of the Related Art In a semiconductor manufacturing process, various chemical solutions are used, such as a cleaning solution used for cleaning wafers and a developing solution used for developing circuit patterns. Fluid devices such as valves and regulators are used to control the flow rate of chemical solutions, and members that make up the fluid devices and have wetted parts (for example, valve bodies that form flow paths inside) ) is made of a chemical-resistant fluorine resin material (eg, PFA, PTFE). For example, in the fluid control device of Patent Document 1, it is disclosed that the valve body is made of PTFE.

JP 2018-021643 A

However, the above prior art has the following problems.
When the fluid passes through the channel, either positive or negative charge is adsorbed on the inner surface of the channel at the contact interface between the fluid and the inner surface of the channel. A charge remains. As the fluid flows, the fluid and the inner surface of the channel that have been in contact are separated from each other, so that an electric field appears outside, and the inner surface of the channel and the fluid are charged. That is, static electricity is generated.
The generation of static electricity may cause the following problems.
For example, when the inside of a fluid device is partitioned into a wetted portion and a non-wetted portion by an insulating diaphragm, the electrification of the fluid causes the wetted portion and the non-wetted portion inside the fluid device to increases the potential difference between As the potential difference increases, the thickness of the diaphragm is so thin that dielectric breakdown can occur. When a dielectric breakdown occurs, heat is generated due to the sudden movement of charges inside the diaphragm, and the generated heat causes minute cracks at the location where the dielectric breakdown occurs. If cracks occur, fluid leakage may occur. In addition, since the diaphragm repeats elastic deformation due to contact with and separation from the valve seat, stress concentrates on the location where the crack occurs, and the crack develops, which may cause fatigue fracture.
Also, if the charged fluid comes into contact with the wafer during development of the circuit pattern, for example, there is a risk of developing a defective circuit pattern.

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems, and prevents electrification of fluid passing through a fluid device, and also prevents dielectric breakdown between the wetted part and the non-wetted part inside the fluid device. An object of the present invention is to provide a fluid device capable of

In order to solve the above problems, the fluid control valve of the present invention has the following configuration.
(1) A fluid control valve comprising an input port for inputting a fluid and an output port for outputting the fluid, the fluid control valve comprising a main body portion in which a flow path for communicating from the input port to the output port is formed. In the fluid control valve in which the interior of the main body is divided into a wetted part and a non-wetted part by a thin film member, the main body is made of a conductive fluororesin material in which carbon nanotubes are dispersed in the fluororesin material. and the volume resistivity of the conductive fluororesin material is 1.0×10 ⁴ Ω·cm or more and less than 1.0×10 ⁵ Ω·cm.

(2) A fluid control valve comprising an input port for inputting a fluid and an output port for outputting the fluid, the fluid control valve comprising a main body portion in which a flow path for communicating from the input port to the output port is formed , In a fluid control valve in which the interior of a body is partitioned into a wetted part and a non-wetted part by a thin film member, the body is made of a conductive fluororesin material in which carbon nanotubes are dispersed in the fluororesin material. The content of carbon nanotubes in the conductive fluororesin material is 0.04% by weight or more and 0.06% by weight or less.

(3) In the fluid control valve described in (1) or (2), the body portion has a valve seat in the flow path, the fluid device has a valve body having a thin film portion, and the thin film portion is elastically deformed. The valve body controls the flow rate of the fluid by coming into contact with or separating from the valve seat.
(4) In the fluid control valve described in (3), the valve body is made of a conductive fluororesin material.
(5) In the fluid control valve according to any one of (1) to (4), the fluororesin material is PFA or PTFE.

The fluid control valve of the present invention has the following functions and effects due to the above configuration.
(1) A fluid device comprising an input port for inputting a fluid and an output port for outputting the fluid, wherein the fluid comprises a main body in which a channel is formed for communicating from the input port to the output port. In the device, the main body is made of a conductive fluororesin material in which carbon nanotubes are dispersed in a fluororesin material, and the volume resistivity of the conductive fluororesin material is 1.0×10 ⁴ Ω·cm or more. and less than 1.0×10 ⁵ Ω·cm, the fluid passing through the fluid device is prevented from being charged, and the wetted part and the non-liquid-contacted part inside the fluid device can prevent dielectric breakdown during
That is, a general fluororesin material has high insulation and is easily charged, but a conductive fluororesin material has conductivity because carbon nanotubes are dispersed in the fluororesin material. Since the main body of the fluid device is made of a conductive fluororesin material, the static electricity generated by the passage of the fluid through the flow path is discharged, and the main body and the fluid can be prevented from being charged.

By preventing charging of the fluid, for example, even if the inside of the fluid device is divided into a wetted portion and a non-wetted portion by a diaphragm that is an insulator, the wetted portion and the non-wetted portion inside the fluid device can be separated. A potential difference between the wetted parts is less likely to occur. Since a potential difference is less likely to occur between the wetted portion and the non-wetted portion, the risk of dielectric breakdown is reduced even with a very thin diaphragm. If the risk of dielectric breakdown is reduced, it is possible to prevent minute cracks in the diaphragm from being generated by the heat generated by the charge moving rapidly inside the diaphragm. By preventing the generation of minute cracks, the risk of fluid leakage and fatigue failure due to repeated elastic deformation of the diaphragm is reduced.
In addition, since charging of the fluid can be prevented, the risk of developing defective circuit patterns due to contact of the charged fluid with the wafer is reduced.

It should be noted that the lower the volume resistivity of the conductive fluororesin material, the higher the conductivity, and the more quickly the charge moves, the faster the static electricity is discharged. In that case, it seems desirable to form the main body of the fluid device from a conductive fluororesin material with a volume resistivity as low as possible.
However, if the volume resistivity is too low, for example, when a charged worker or an object approaches the main body during maintenance, there is a risk that intense static electricity discharge will occur due to the high conductivity. Therefore, the body is made of a conductive fluororesin material that has a volume resistivity that allows gentle discharge so that static electricity does not suddenly discharge when a charged worker or the like approaches, while preventing the body from being charged. It is necessary to form a department.
Therefore, the applicant found through experiments that it is optimal to set the volume resistivity of the conductive fluororesin material to 1.0×10 ⁴ Ω·cm or more and less than 1.0×10 ⁵ Ω·cm. derived. When the volume resistivity is less than 1.0×10 ⁴ Ω·cm, there is a risk of rapid static discharge, whereas when the volume resistivity is 1.0×10 ⁴ Ω·cm or more, the Static electricity is discharged, and the risk of sudden static electricity discharge is reduced. Further, if the volume resistivity is 1.0×10 ⁵ Ω·cm or more, discharge becomes too slow, so it is desirable that the volume resistivity is less than 1.0×10 ⁵ Ω·cm.

(2) A fluid device comprising an input port for inputting a fluid and an output port for outputting the fluid, wherein the fluid device comprises a main body in which a channel is formed for communicating from the input port to the output port. , the main body is made of a conductive fluororesin material in which carbon nanotubes are dispersed in a fluororesin material, the content of carbon nanotubes in the conductive fluororesin material is 0.04% by weight or more, and 0.06% by weight or less, so that the content of carbon nanotubes is 0.04% by weight or more and 0.06% by weight or less, so that the conductive fluororesin material can obtain an appropriate volume resistivity for antistatic, and by forming the main body of a fluid device from the conductive fluororesin material, it is possible to prevent the main body and the fluid from being charged.
In addition, by containing carbon nanotubes, there is concern about contamination of the fluid due to contact between the flow path and the fluid, but the content is as small as 0.06% by weight or less, so the applicant believes that contamination can be suppressed. was confirmed by experiments.

(3) In the fluid device described in (1) or (2), the main body portion includes a valve seat in the flow path, the fluid device includes a valve body having a thin film portion, and elastic deformation of the thin film portion The valve body is characterized by being a fluid control valve that controls the flow rate of the fluid by contacting or separating from the valve seat. and a non-wetted portion. However, since the main body constituting the fluid device is made of the conductive fluororesin material, the main body is not charged, and the fluid passing through the flow path formed in the main body is also not charged. Therefore, no potential difference occurs between the wetted portion and the non-wetted portion inside the fluid device, and the risk of dielectric breakdown occurring in the thin film portion is reduced. If the risk of dielectric breakdown in the thin film portion is reduced, the risk of fluid leakage or fatigue breakdown of the thin film portion due to minute cracks caused by the dielectric breakdown is reduced.

(4) The fluid device described in (3) is characterized in that the valve body is made of a conductive fluororesin material. It is possible to more reliably prevent electrification of the fluid passing through the fluid device.
The valve body has a thin film portion (for example, a diaphragm), and the thin film portion is particularly prone to dielectric breakdown. However, by forming the valve body from a conductive fluororesin material, the risk of dielectric breakdown occurring in the thin film portion is reduced.
In IEC61340-5-1, 5-2, the antistatic material is a material having a surface resistivity of 1.0×10 ⁵ Ω or more and less than 1.0×10 ¹¹ Ω. Recommended.
When a conductive fluororesin material with a volume resistivity of 1.0×10 ⁴ Ω·cm or more and less than 1.0×10 ⁵ Ω·cm is applied to a thin film portion having a general thickness, the surface Since the resistivity is about 5.0×10 ⁵ to 5.0×10 ⁶ Ω, it falls within the recommended surface resistivity range mentioned above. If a material with a volume resistivity of less than 1.0×10 ⁴ Ω·cm is used, the surface resistivity may fall outside the recommended range.
(5) In the fluid device according to any one of (1) to (4), the fluororesin material is PFA or PTFE. In addition, the main body can have excellent chemical resistance.

1 is a cross-sectional view showing a closed state of a fluid control valve 1 according to an embodiment of the present invention; FIG.

An embodiment of a fluid device of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1 , a fluid control valve 1 (an example of a fluid device) includes a valve portion 2 that controls fluid and a drive portion 3 that applies a driving force to the valve portion 2 . A fluid control valve 1 is attached to, for example, a semiconductor manufacturing apparatus, and controls the flow rate of a chemical liquid supplied to a wafer.

A cylinder body 33 of the drive unit 3 is composed of a cylinder body 31 and a cylinder cover 32 . A piston body 35a of the piston 35 is slidably mounted in a piston chamber 34 formed in the cylinder body 33, and divides the piston chamber 34 into a first chamber 34a and a second chamber 34b. An annular seal member 37 maintains airtightness between the first chamber 34a and the second chamber 34b. A shaft 35b is provided integrally with the piston body 35a. A lower end portion of the shaft 35 b protrudes from the cylinder body 33 toward the valve portion 2 side and is connected to the diaphragm valve element 4 of the valve portion 2 . The compression spring 36 is compressed in the first chamber 34a and always urges the piston 35 toward the valve seat 24 side of the valve portion 2, and the diaphragm valve body 4 connected to the shaft 35b of the piston 35 is sealed. giving a load. The cylinder body 33 is formed with an intake/exhaust port 33a communicating with the first chamber 34a for intake and exhaust, and an operation port 33b communicating with the second chamber 34b for supplying operation air.

The drive unit 3 linearly reciprocates the piston 35 along the axis by the balance between the spring force of the compression spring 36 and the internal pressure of the second chamber 34b, thereby moving the diaphragm valve body 4 by a predetermined stroke. Except for the compression spring 36 and the annular seal member 37, the components of the drive unit 3 are made of fluororesin, so that they can be used even in highly corrosive atmospheres.

The valve portion 2 controls the fluid by contacting or separating the annular seal projection 414 of the diaphragm valve body 4 built in the valve body 21 from the valve seat surface 24 a of the valve seat 24 .
A columnar valve body 41 of the diaphragm valve body 4 is connected to the driving portion 3 and contacts or separates from the valve seat 24 . A thin film portion 42 is connected to the outer peripheral surface of the valve body 41 , and a thick outer edge portion 43 is provided on the outer edge portion of the thin film portion 42 .

The valve main body 21 has a rectangular parallelepiped shape, and has an input port 21a and an output port 21b on opposite sides. The input port 21a is connected to a chemical supply source and receives fluid. Also, the output port 21b is connected to the reaction chamber of the semiconductor manufacturing apparatus, outputs the fluid input from the input port 21a, and supplies it to the reaction chamber.
A cylindrical opening 21e is formed in the upper surface of the valve body 21, and an annular mounting hole 21f is formed outside the opening 21e.
The diaphragm valve body 4 is fixed by press-fitting the outer edge portion 43 into the mounting hole 21f and being sandwiched between the valve body 21 and the cylinder body 33 . The thin film portion 42 of the diaphragm valve body 4 divides the chamber into a diaphragm chamber 22 that is a liquid contacting portion and a non-liquid contacting chamber 23 that is a non-contacting portion. A valve body 41 of the diaphragm valve body 4 is connected to the shaft 35b and moves vertically in the drawing within the diaphragm chamber 22. As shown in FIG. The non-liquid contact chamber 23 communicates with a breathing hole 33c formed in the cylinder body 33, and air in the non-liquid chamber 23 can enter and exit through the breathing hole 33c as the valve body 41 moves. Smooth elastic deformation is possible according to the movement of the main body 41 .

The input-side flow path 21c is formed in a substantially L-shape in the valve body 21 so as to allow the input port 21a and the diaphragm chamber 22 to communicate with each other, and opens at the center of the bottom surface of the diaphragm chamber 22 . A valve seat 24 is provided on the bottom surface of the diaphragm chamber 22 along the outer periphery of the opening where the input-side flow path 21c opens. The valve seat 24 has a valve seat surface 24 a processed to be a flat surface perpendicular to the axis of the diaphragm chamber 22 . 21 d of output side flow paths are formed in substantially L shape so that the output port 21b may be connected with the diaphragm chamber 22, and open outside the valve seat 24. As shown in FIG.

(Overview of operation of fluid control valve)
When the fluid control valve 1 is in a standby state in which the chemical liquid is not supplied to the wafer, the operating air is not supplied to the operating port 33b. In this case, the biasing force of the compression spring 36 acts on the diaphragm valve body 4 via the piston 35, and the annular seal projection 414 of the diaphragm valve body 4 is brought into close contact with the valve seat surface 24a of the valve seat 24 for sealing. Therefore, the fluid input from the input port 21a cannot advance from the opening at the center of the bottom surface of the diaphragm chamber 22 of the input side channel 21c, and the chemical solution is not supplied from the output port 21b to the reaction chamber.

When supplying the chemical solution to the wafer, the fluid control valve 1 supplies operation air to the second chamber 34b through the operation port 33b. As the operation air is supplied, the internal pressure of the second chamber 34b rises, and when the internal pressure of the second chamber 34b becomes larger than the biasing force of the compression spring 36, the piston 35 resists the compression spring 36 and moves toward the valve seat. move to the side. The diaphragm valve body 4 rises integrally with the piston 35 to separate the annular seal projection 414 from the valve seat surface 24a. As a result, the fluid control valve 1 allows the chemical solution to flow from the input port 21a to the output port 21b according to the stroke of the valve body 41, and supplies the chemical solution to the reaction chamber.
The valve body 21 and the fluid are likely to generate static electricity when the fluid passes through the input side channel 21c and the output side channel 21d. That is, at the contact interface between the fluid and the inner surface of the input-side channel 21c or the output-side channel 21d, either positive or negative charges are attracted to the inner surface of the input-side channel 21c or the output-side channel 21d. Charges having a polarity opposite to the charges adsorbed on the inner surface of the side channel 21c or the output side channel 21d remain. When the fluid flows, the fluid that is in contact with the inner surface of the input-side channel 21c or the output-side channel 21d is pulled away, so an electric field appears outside the fluid and the input-side channel 21c or the output-side channel 21d. It becomes an electrically charged state. In particular, the gap between the annular seal projection 414 of the diaphragm valve element 4 and the valve seat surface 24a of the valve seat 24 is smaller than the cross-sectional area of the input side flow path 21c, and the speed of the passing fluid increases. Therefore, due to the friction between the valve body 21 and the fluid, the valve body 21 and the fluid are easily electrified.
However, as will be described later, since the valve body 21 is made of a conductive fluororesin material in which carbon nanotubes are dispersed in the fluororesin material, it is possible to prevent charging of the valve body 21 and the fluid.

When stopping the supply of the chemical solution to the wafer, the fluid control valve 1 exhausts the operating fluid from the operating port 33b. Then, the biasing force of the compression spring 36 causes the piston 35 to move toward the valve seat, and the diaphragm valve body 4 moves toward the valve seat as the piston 35 moves toward the valve seat. Then, the annular seal projection 414 is in close contact with the valve seat surface 24a of the valve seat 24 for sealing. As a result, the fluid control valve 1 enters a standby state.

Next, the material of the valve body 21 will be described.
The valve body 21 of this embodiment is made of a conductive fluororesin material in which carbon nanotubes are dispersed in the fluororesin material.
The content of carbon nanotubes is set in the range of 0.045 to 0.055% by weight within the range of 0.04% by weight or more and 0.06% by weight or less, and the volume resistivity is 1.0×10 ⁴ Ω·cm or more and less than 1.0×10 ⁵ Ω·cm, in the range of 4.5×10 ⁴ to 5.5×10 ⁴ Ω·cm inside. Sufficient performance can be obtained even if the volume resistivity is in the range of 4×10 ⁴ to 6× ^{10 4 Ω} ·cm ^. Range is the more preferred range.
Also, based on the value of one point within the range of 0.045 to 0.055% by weight of the content and the range of 4.5×10 ⁴ to 5.5×10 ⁴ Ω·cm of the volume resistivity may vary, and variations may occur within the range.
Furthermore, the fluorine resin material is PTFE (polytetrafluoroethylene) having chemical resistance. By forming the valve main body 21 from a conductive fluororesin material in which carbon nanotubes are added to PTFE, the valve main body 21 can be made excellent in chemical resistance while preventing electrification. Note that PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) may be applied to the fluororesin material.

The applicant has found that the content of carbon nanotubes is 0.04% by weight or more and 0.06% by weight or less by a method based on ASTM D257, so that the conductive fluororesin material It was confirmed that the volume resistivity was in the range of 1.0×10 ⁴ Ω·cm or more and less than 1.0×10 ⁵ Ω·cm.
Since the characteristics of the carbon nanotubes to be contained differ depending on the material manufacturer, the relationship between the content and the volume resistivity varies depending on the manufacturer.

The valve body 21 and the fluid are likely to generate static electricity when the fluid passes through the input side channel 21c and the output side channel 21d. That is, at the contact interface between the fluid and the inner surface of the input-side channel 21c or the output-side channel 21d, either positive or negative charges are attracted to the inner surface of the input-side channel 21c or the output-side channel 21d. Charges having a polarity opposite to the charges adsorbed on the inner surface of the side channel 21c or the output side channel 21d remain. When the fluid flows, the fluid that is in contact with the inner surface of the input-side channel 21c or the output-side channel 21d is separated, so that an electric field appears outside the fluid and the input-side channel 21c or the output-side channel 21d. It becomes an electrically charged state. In particular, since the gap between the annular seal projection 414 of the diaphragm valve body 4 and the valve seat surface 24a of the valve seat 24 is smaller than the cross-sectional area of the input side flow path 21c, the speed of the passing fluid increases. Friction between the valve body 21 and the fluid causes the valve body 21 and the fluid to be easily electrified.
However, since the valve body 21 is made of a conductive fluororesin material having electrical conductivity, static electricity generated by fluid passing through the input side flow path 21c and the output side flow path 21d is discharged. Charging of the fluid can be prevented. Therefore, the risk of developing defective circuit patterns due to charged fluid coming into contact with the wafer is reduced.

The inside of the fluid control valve 1 is partitioned by the thin film portion 42 of the diaphragm valve element 4 into a diaphragm chamber 22 that is a liquid contacting portion and a non-liquid contacting chamber 23 that is a non-contacting portion. If the fluid is charged, the potential difference between the diaphragm chamber 22 and the non-wetted chamber 23 increases. If the potential difference increases, the thickness of the thin film portion 42 is very thin, so dielectric breakdown may occur.
However, as described above, since the valve body 21 is made of a conductive fluororesin material and the fluid is prevented from being charged, a potential difference occurs between the diaphragm chamber 22 and the non-wetted chamber 23. Therefore, the thin film portion 42 is less likely to cause dielectric breakdown. If the risk of dielectric breakdown occurring in the thin film portion 42 is reduced, the risk of fluid leakage due to minute cracks caused by the dielectric breakdown is reduced.
In addition, the thin film portion 42 repeats elastic deformation each time the annular seal projection 414 of the valve body 41 contacts and separates from the valve seat surface 24a of the valve seat 24. Although there is a risk that stress will concentrate and cause fatigue failure, the risk of dielectric breakdown is reduced, and cracks are also suppressed, so the risk of fatigue failure of the diaphragm is also reduced.

It should be noted that the lower the volume resistivity of the conductive fluororesin material, the higher the conductivity, and the more quickly the charge moves, the faster the static electricity is discharged. In that case, it seems desirable to form the valve body 21 of the fluid control valve 1 from a conductive fluororesin material having a volume resistivity as low as possible.
However, if the volume resistivity is too low, when a charged worker or an object approaches the valve body 21 during maintenance, for example, there is a risk that intense static electricity discharge will occur due to the high conductivity. Therefore, while preventing the valve body 21 from being charged, a conductive fluororesin material with a volume resistivity that allows gentle discharge is used to prevent sudden static discharge even when a charged worker or the like approaches. A valve body 21 needs to be formed.
Therefore, the applicant found through experiments that it is optimal to set the volume resistivity of the conductive fluororesin material to 1.0×10 ⁴ Ω·cm or more and less than 1.0×10 ⁵ Ω·cm. derived. When the volume resistivity is less than 1.0×10 ⁴ Ω·cm, there is a risk of rapid static discharge, whereas when the volume resistivity is 1.0×10 ⁴ Ω·cm or more, the Static electricity is discharged, and the risk of sudden static electricity discharge is reduced. Further, if the volume resistivity is 1.0×10 ⁵ Ω·cm or more, discharge becomes too slow, so it is desirable that the volume resistivity is less than 1.0×10 ⁵ Ω·cm.

The applicant used a fluid control valve 1 in which the valve body 21 was formed of a conductive fluororesin material in which the amount of carbon nanotubes added was a certain value within the range of 0.045 to 0.055% by weight, and the input side flow When the charging voltage generated in the passage 21c and the output side passage 21d was measured, a 70% reduction effect was observed compared to the case where the valve main body 21 was made of general PTFE.

In addition, since the inclusion of carbon nanotubes may cause contamination of the fluid due to contact between the flow path and the fluid, the applicant has decided that the amount of carbon nanotubes added should be within the range of 0.045 to 0.055% by weight. Using the fluid control valve 1 in which the valve body 21 is made of a conductive fluororesin material having a certain numerical value, the number of particles contained in the fluid passing through the input side flow path 21c and the output side flow path 21d was measured. The number of particles refers to the number of particles with a size of 20 nm or more contained in 1 ml of pure water. As a result of measurement, the number of particles was maintained at less than ten.
In the valve body 21 of the present embodiment, the ratio of carbon nanotubes contained in the conductive fluororesin material is as small as 0.06% by weight or less. It is possible to suppress contamination of the fluid due to contact with the

Furthermore, in this embodiment, the diaphragm valve body 4 is also made of a conductive fluororesin material, like the valve body 21 . By also forming the diaphragm valve body 4 from a conductive fluororesin material, not only the valve body 21 of the fluid control valve 1 but also the diaphragm valve body 4 can be prevented from being charged, and the fluid can pass through the fluid control valve 1 more reliably. It is possible to prevent electrification of the fluid to be applied.
The diaphragm valve body 4 has a thin film portion 42, and the thin film portion 42 is particularly susceptible to dielectric breakdown. However, by forming the diaphragm valve body 4 from a conductive fluororesin material, the risk of dielectric breakdown occurring in the thin film portion 42 is reduced.
In IEC61340-5-1, 5-2, the antistatic material is a material having a surface resistivity of 1.0×10 ⁵ Ω or more and less than 1.0×10 ¹¹ Ω. Recommended.
When a conductive fluororesin material having a volume resistivity of 1.0×10 ⁴ Ω·cm or more and less than 1.0×10 ⁵ Ω·cm is applied to the thin film portion 42 having a general thickness, Since the surface resistivity is about 5.0×10 ⁵ to 5.0×10 ⁶ Ω, it falls within the recommended surface resistivity range mentioned above. If a material with a volume resistivity of less than 1.0×10 ⁴ Ω·cm is used, the surface resistivity may fall outside the recommended range.
Incidentally, the surface resistivity is obtained by the following Equation 1.

(Number 1)
Surface resistivity [Ω/sq] = volume resistivity [Ω cm]/thickness [cm]

As described above, according to the fluid control valve 1 of this embodiment,
(1) A fluid device comprising an input port 21a for inputting a fluid and an output port 21b for outputting the fluid, wherein the input-side channel 21c and the diaphragm chamber 22 communicate between the input port 21a and the output port 21b. In the fluid control valve 1 including the valve body 21 in which the output side flow path 21d is formed, the valve body 21 is made of a conductive fluororesin material in which carbon nanotubes are dispersed in the fluororesin material; The volume resistivity of the conductive fluororesin material is 1.0×10 ⁴ Ω·cm or more and less than 1.0×10 ⁵ Ω·cm. It is possible to prevent electrification of the passing fluid and prevent dielectric breakdown between the wetted part and the non-wetted part inside the fluid control valve 1 .
That is, a general fluororesin material has high insulation and is easily charged, but a conductive fluororesin material has conductivity because carbon nanotubes are dispersed in the fluororesin material. Since the valve body 21 of the fluid control valve 1 is made of a conductive fluororesin material having conductivity, static electricity generated when the fluid passes through the input side flow path 21c, the diaphragm chamber 22, and the output side flow path 21d is eliminated. It is discharged and can prevent charging of the valve body 21 and the fluid.

By preventing charging of the fluid, for example, even when the inside of the fluid control valve 1 is divided into a wetted part and a non-wetted part by a diaphragm that is an insulator, the wetted part inside the fluid device and non-wetted parts are unlikely to generate a potential difference. Since a potential difference is less likely to occur between the wetted portion and the non-wetted portion, the risk of dielectric breakdown is reduced even with a very thin diaphragm. If the risk of dielectric breakdown is reduced, it is possible to prevent minute cracks in the diaphragm from being generated by the heat generated by the charge moving rapidly inside the diaphragm. By preventing the generation of minute cracks, the risk of fluid leakage and fatigue failure due to repeated elastic deformation of the diaphragm is reduced.
In addition, since charging of the fluid can be prevented, the risk of developing defective circuit patterns due to contact of the charged fluid with the wafer is reduced.

It should be noted that the lower the volume resistivity of the conductive fluororesin material, the higher the conductivity, and the more quickly the charge moves, the faster the static electricity is discharged. In that case, it seems desirable to form the valve body 21 of the fluid control valve 1 from a conductive fluororesin material having a volume resistivity as low as possible.
However, if the volume resistivity is too low, when a charged worker or an object approaches the valve body 21 during maintenance, for example, there is a risk that intense static electricity discharge will occur due to the high conductivity. Therefore, while preventing the valve body 21 from being charged, a conductive fluororesin material with a volume resistivity that allows gentle discharge is used to prevent sudden static discharge even when a charged worker or the like approaches. A valve body 21 needs to be formed.
Therefore, the applicant found through experiments that it is optimal to set the volume resistivity of the conductive fluororesin material to 1.0×10 ⁴ Ω·cm or more and less than 1.0×10 ⁵ Ω·cm. derived. When the volume resistivity is less than 1.0×10 ⁴ Ω·cm, there is a risk of rapid static discharge, whereas when the volume resistivity is 1.0×10 ⁴ Ω·cm or more, the Static electricity is discharged, and the risk of sudden static electricity discharge is reduced. Further, if the volume resistivity is 1.0×10 ⁵ Ω·cm or more, discharge becomes too slow, so it is desirable that the volume resistivity is less than 1.0×10 ⁵ Ω·cm.
The volume resistivity is in the range of 1.0×10 ⁴ Ω·cm or more and less than 1.0×10 ⁵ Ω·cm, preferably in the range of 4×10 ⁴ to 6×10 ⁴ Ω·cm. , more preferably within the range of 4.5×10 ⁴ to 5.5×10 ⁴ Ω·cm.

(2) A fluid device having an input port 21a for inputting a fluid and an output port 21b for outputting the fluid, wherein the input side flow path 21c and the diaphragm chamber 22 communicate between the input port 21a and the output port 21b. In the fluid control valve 1 including the valve body 21 in which the output side flow path 21d is formed, the valve body 21 is made of a conductive fluororesin material in which carbon nanotubes are dispersed in the fluororesin material; The carbon nanotube content of the conductive fluororesin material is 0.04% by weight or more and 0.06% by weight or less. % by weight or more and 0.06% by weight or less, the conductive fluororesin material can obtain an appropriate volume resistivity for antistatic, and the conductive fluororesin material can be used as a fluid control valve. By forming one valve body 21, the valve body 21 and the fluid can be prevented from being charged.
In addition, the smaller the content of carbon nanotubes, the more it is possible to suppress the contamination of the fluid due to the contact of the fluid with the input side channel 21c and the output side channel 21d. Therefore, the applicant has confirmed through experiments that contamination can be suppressed.
The content of carbon nanotubes is preferably 0.045 to 0.055% by weight within the range of 0.04% by weight or more and 0.06% by weight or less.

(3) In the fluid control valve 1 described in (1) or (2), the valve body 21 includes a valve seat 24 in the diaphragm chamber 22, and the fluid control valve 1 includes a diaphragm valve body 4 having a thin film portion 42. and the diaphragm valve body 4 is brought into contact with or separated from the valve seat 24 due to the elastic deformation of the thin film portion 42, thereby controlling the flow rate of the fluid. 1 is partitioned into a wetted portion and a non-wetted portion by a diaphragm valve element 4 having a thin film portion 42 . However, since the valve main body 21 constituting the fluid control valve 1 is made of a conductive fluororesin material, the valve main body 21 is not charged, and the input side flow path 21c, the diaphragm chamber 22, and the output side formed in the valve main body 21 are charged. The fluid passing through the channel 21d is also not charged. Therefore, no potential difference occurs between the wetted portion and the non-wetted portion inside the fluid control valve 1, and the risk of dielectric breakdown of the thin film portion 42 is reduced. If the risk of dielectric breakdown occurring in the thin film portion 42 is reduced, the risk of fluid leakage and fatigue failure of the thin film portion due to minute cracks caused by the dielectric breakdown is reduced.

(4) The fluid control valve 1 described in (3) is characterized in that the diaphragm valve body 4 is made of a conductive fluororesin material. , charging of the diaphragm valve body 4 can also be prevented, and charging of the fluid passing through the fluid control valve 1 can be prevented more reliably.
The diaphragm valve body 4 has a thin film portion 42, and the thin film portion 42 is particularly susceptible to dielectric breakdown. However, by forming the diaphragm valve body 4 from a conductive fluororesin material, the risk of dielectric breakdown occurring in the thin film portion 42 is reduced.
In IEC61340-5-1, 5-2, the antistatic material is a material having a surface resistivity of 1.0×10 ⁵ Ω or more and less than 1.0×10 ¹¹ Ω. Recommended.
When a conductive fluororesin material having a volume resistivity of 1.0×10 ⁴ Ω·cm or more and less than 1.0×10 ⁵ Ω·cm is applied to the thin film portion 42 having a general thickness, Since the surface resistivity is about 5.0×10 ⁵ to 5.0×10 ⁶ Ω, it falls within the recommended surface resistivity range mentioned above. If a material with a volume resistivity of less than 1.0×10 ⁴ Ω·cm is used, the surface resistivity may fall outside the recommended range.
(5) In the fluid control valve 1 according to any one of (1) to (4), the fluororesin material is PFA or PTFE. While preventing electrification, the main body can have excellent chemical resistance.

It should be noted that this embodiment is merely an example, and does not limit the present invention in any way. Therefore, the present invention can naturally be improved and modified in various ways without departing from the scope of the invention.
For example, in this embodiment, the fluid control valve 1 controls the flow rate of the fluid by bringing the annular seal projection 414 provided on the valve body 41 into contact with or separating from the valve seat surface 24a of the valve seat 24. It is possible to control the flow rate by contacting or separating them.
Moreover, the present invention is applicable not only to fluid equipment used in semiconductor manufacturing processes, but also to fluid equipment used in the chemical industry and the food industry.

1 Fluid control valve (an example of fluid equipment)
4 Diaphragm valve body (an example of valve body)
21 valve body (an example of a body part)
21a input port 21b output port 21c input side flow path 21d output side flow path 22 diaphragm chamber 24 valve seat 42 thin film portion

Claims (5)

A fluid control valve comprising an input port for inputting a fluid and an output port for outputting the fluid, the fluid control valve comprising a main body in which a flow path for communicating from the input port to the output port is formed , In a fluid control valve in which the inside of the main body is divided into a wetted portion and a non-wetted portion by a thin film member ,
The main body is made of a conductive fluororesin material in which carbon nanotubes are dispersed in a fluororesin material;
The conductive fluororesin material has a volume resistivity of 1.0×10 ⁴ Ω·cm or more and less than 1.0×10 ⁵ Ω·cm;
A fluid control valve characterized by: A fluid control valve comprising an input port for inputting a fluid and an output port for outputting the fluid, the fluid control valve comprising a main body having a flow path formed therein for communicating from the input port to the output port , the main body In a fluid control valve in which the inside of a part is divided into a wetted part and a non-wetted part by a thin film member ,
The main body is made of a conductive fluororesin material in which carbon nanotubes are dispersed in a fluororesin material;
The content of the carbon nanotubes in the conductive fluororesin material is 0.04% by weight or more and 0.06% by weight or less;
A fluid control valve characterized by: 3. The fluid control valve according to claim 1 or 2,
the main body includes a valve seat in the flow path;
The fluid device includes a valve body having a thin film portion, and the valve body is brought into contact with or separates from the valve seat due to elastic deformation of the thin film portion , thereby controlling the flow rate of the fluid.
A fluid control valve characterized by: 4. The fluid control valve of claim 3, wherein
wherein the valve body is made of the conductive fluororesin material;
A fluid control valve characterized by: The fluid control valve according to any one of claims 1 to 4,
A fluid control valve , wherein the fluororesin material is PFA or PTFE.

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