JP2023170492A - Fluid controller and manufacturing method thereof - Google Patents

Abstract

To provide a fluid controller which can prevent adhesion of components of control fluid to a liquid contact surface of a diaphragm member, and a manufacturing method thereof.SOLUTION: A fluid controller comprises: an input flow passage 121a into which a control fluid is input; an output flow passage 121b which is in communication with the input flow passage 121a and from which control fluid (for example, medical liquid) is output; and a diaphragm member 122 composed of a fluorine resin. The diaphragm member 122 comprises a thin film part 124 having flexibility, and the control fluid is controlled by elastic deformation of the thin film part 124. The thin film part 124 comprises a liquid contact surface which makes contact with control fluid, and at least a part of the liquid contact surface is a mold-transferred surface 127.SELECTED DRAWING: Figure 2

Description

The present invention includes an input flow path into which a control fluid is input, an output flow path communicating with the input flow path through which the control fluid is output, and a diaphragm member made of a fluororesin, and the diaphragm member is flexible. The present invention relates to a fluid control device that includes a thin film portion having elastic properties and controls a control fluid by elastically deforming the thin film portion, and a method for manufacturing the fluid control device.

Conventionally, in order to control the flow of a control fluid such as a chemical solution (for example, flow rate control, pressure control, etc.), an input flow path into which the control fluid is input, an output flow path through which the control fluid is output, and a flexible A fluid control device is used that includes a diaphragm member having a thin film portion. A fluid control device controls the flow of control fluid input and output through an input flow path and an output flow path by elastically deforming a thin film portion.

Here, known examples of fluid control devices include diaphragm valves, suckback valves, needle valves, regulators, and diaphragm pumps. Further, as a diaphragm member used particularly in a diaphragm valve, a diaphragm 15 disclosed in Patent Document 1 (the reference numeral is based on Patent Document 1) is known.

JP2021-67363A

A diaphragm member used in a fluid control device such as the one described above has a thin film portion provided with a liquid contact surface that comes into contact with a control fluid. Depending on the surface roughness of the liquid-contacted surface, there is a possibility that the control fluid (for example, a chemical solution) may remain on the liquid-contacted surface, and components of the deteriorated control fluid may adhere to the liquid-contacted surface. As the thin film portion repeatedly undergoes elastic deformation, components of the control fluid adhering to the liquid contact surface may fall off, and the dropped components of the control fluid may mix into the control fluid as particles.

In order to prevent adhesion of components of the control fluid as much as possible, it is necessary to reduce the surface roughness of the liquid contact surface as much as possible, and the thin film portion (film portion 35b) of the diaphragm 15 described in Patent Document 1 is cut. It is said that it is formed by processing (see paragraph [0039] of Patent Document 1). Forming the liquid contact surface by cutting is not preferable from the viewpoint of preventing the components of the chemical solution from adhering, since it is difficult to reduce the surface roughness, such as leaving cutting marks on the liquid contact surface.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a fluid control device and a method for manufacturing the same that can prevent components of a control fluid from adhering to the liquid contact surface of a diaphragm member. do.

In order to solve the above problems, the fluid control device of the present invention has the following configuration.

(1) An input flow path into which a control fluid is input, an output flow path for outputting the control fluid input from the input flow path, and a diaphragm member made of fluororesin, the diaphragm member being flexible. In a fluid control device that includes a thin film portion having flexibility and controls the control fluid by elastically deforming the thin film portion, the thin film portion includes a liquid contact surface that comes into contact with the control fluid; At least a part of the surface is a mold transfer surface. Note that the fluid control device refers to a device that uses a diaphragm member including a thin film portion, such as a diaphragm valve, a suckback valve, a regulator, a needle valve, and a diaphragm pump. The mold transfer surface is a surface onto which the cavity surface of an injection mold, the compression mold, or the transfer mold is transferred.

According to the fluid control device described in (1), since at least a part of the liquid contact surface provided in the thin film part is a mold transfer surface, the liquid contact surface is formed by cutting the liquid contact surface. It is possible to reduce the surface roughness of Therefore, it is possible to reduce the occurrence of stagnation of the control fluid (for example, a chemical solution) on the liquid contact surface, and to reduce the possibility that components of the control fluid will adhere to the liquid contact surface. If the risk of the control fluid components adhering can be reduced, the risk of the control fluid components falling off from the liquid contact surface and being mixed into the control fluid as particles can also be reduced.

Note that it does not matter whether a part of the liquid contact surface of the thin film part is used as the mold transfer surface, or whether all of the liquid contact surface of the thin film part is used as the mold transfer surface. When part of the liquid contact surface of the thin film part is used as the mold transfer surface, for example, when the thin film part is elastically deformed, the mold transfer surface should be a part that is largely deformed or a part where stress tends to concentrate. is possible. This is because areas with large deformation or areas where stress tends to concentrate are likely to fall off when components of the control fluid adhere to them, and by forming the mold transfer surface, the components of the control fluid will prevent the components from adhering. It is.

(2) The fluid control device according to (1) is characterized in that a surface of the thin film portion opposite to the liquid contact surface is a machined surface.

Since the surface of the thin film portion opposite to the liquid contact surface does not come into contact with the control fluid, it is not necessary to make the surface roughness as low as the liquid contact surface. Furthermore, since the thin film portion has a thickness of about 0.1 to 0.5 mm, it is difficult to mold it with a mold. Therefore, by making the surface of the thin film part opposite to the liquid contact surface a machined surface, it is possible to prevent the components of the control fluid from adhering to the liquid contact surface of the diaphragm member and to reduce manufacturing costs. can.

(3) The fluid control device according to (1) or (2) is characterized in that the mold transfer surface has a surface roughness of Ra of 0.05 μm or less.

For example, in fluid control equipment used in semiconductor manufacturing equipment, the requirement to prevent particles from being mixed into the control fluid is becoming stricter year by year in order to improve the yield of semiconductors. According to the fluid control device described in (3), since the surface roughness of the mold transfer surface is Ra 0.05 μm or less, it is possible to more reliably prevent the occurrence of stagnation of the control fluid (for example, chemical solution) on the liquid contact surface. It is possible to reduce the risk of components of the control fluid adhering to the liquid-contacted surface, and to withstand the above-mentioned requirements that are becoming stricter year by year. Note that although the fluid control device used in semiconductor manufacturing equipment is mentioned above, the fluid control device according to the present invention is not limited to being used in semiconductor manufacturing equipment.

(4) In the fluid control device according to any one of (1) to (3), the fluororesin is a perfluoroalkoxyalkane having a melt flow rate of 2.2 g/10 min or more and 2.8 g/10 min or less. It is characterized by:

(5) In the fluid control device according to any one of (1) to (4), the fluororesin has a specific gravity in a range of 2.08 or more and 2.16 or less.

Conventionally, there has been concern that repeated elastic deformation of the thin film portion may cause cracks to occur in the thin film portion. When a crack occurs, the control fluid may remain in the crack, and components of the deteriorated control fluid may adhere to the crack. The adhesion of components of the control fluid causes particles to be mixed into the control fluid.

According to the fluid control device described in (4) or (5), the bending durability of the thin film portion can be improved. Therefore, it is possible to prevent cracks from forming in the thin film portion, and it is also possible to prevent the control fluid from stagnation and the generation of particles. Note that the melt flow rate (MFR) here means the MFR of the fluororesin, which is the raw material, after molding. MFR after molding is measured by melting and molding the raw material fluororesin and then melting it again. This measurement is based on ASTM D1238, at a resin temperature of 372 degrees Celsius, a load of 5 kg, and an orifice. The test was carried out under the conditions that the inner diameter was 2.1 mm and the orifice height was 8.0 mm.

(6) In the fluid control device according to any one of (1) to (5), the mold transfer surface is a mirror-finished surface of a mold used for compression molding or transfer molding. characterized by something.

When molding a diaphragm member by injection molding, flow marks may be formed on the surface of the thin film part due to the flow of resin during molding, which may adversely affect the surface roughness of the surface in contact with the liquid (mold transfer surface). . However, according to the fluid control device described in (6), the mold transfer surface is a mirror-finished surface of a mold used for compression molding or transfer molding. It becomes possible to reliably reduce the roughness to Ra 0.05 μm or less. As in compression molding or transfer molding, by applying pressure to the molten resin in the mold, it is possible to press the molten resin in the mold against the mold cavity surface, thereby creating a mold transfer surface. This is because it is possible to form it smoothly.

(7) The fluid control device according to (6) is characterized in that the liquid contact surface is a curved surface.

When forming the thin film part by cutting as in the diaphragm described in Patent Document 1, it is difficult to form the thin film part as a curved surface, so it is generally formed as a flat surface. In this case, when the thin film portion undergoes elastic deformation, stress concentration is likely to occur, and there is a concern that the bending durability may deteriorate.

According to the fluid control device described in (7), the liquid contact surface can be formed as a curved surface having a mold transfer surface by compression molding or transfer molding. Therefore, while preventing components of the control fluid from adhering to the liquid contact surface of the diaphragm member, it is possible to improve bending durability by alleviating stress concentration.

(8) In the fluid control device according to any one of (1) to (7), the diaphragm member includes a valve body that opens and closes a flow path through which the control fluid flows; The present invention is characterized in that the valve body includes a valve seat that abuts and separates from the valve body, and that at least a portion of the valve body that comes into contact with the valve seat is a second mold transfer surface.

According to the fluid control device described in (8), the diaphragm member includes a valve body that opens and closes a flow path through which the control fluid flows, and the fluid control device includes a valve seat on which the valve body abuts and separates. For example, diaphragm valves, needle valves, etc. fall under this category. In this case, it is desirable that at least the portion of the valve body that comes into contact with the valve seat is the second mold transfer surface. Conventionally, the portion of the valve body that comes into contact with the valve seat tends to wear out during repeated opening and closing operations, and there is a risk that wear powder generated by the wear may mix into the control fluid as particles. By using the portion of the valve body that contacts the valve seat as a mold transfer surface and reducing the surface roughness, it is possible to suppress the occurrence of wear. The "second mold transfer surface" may be a continuous surface or a separate surface from the liquid contact surface of the thin film section.

Furthermore, in order to solve the above problems, the method for manufacturing a fluid control device of the present invention has the following configuration.

(9) An input channel into which a control fluid is input, an output channel for outputting the control fluid input from the input channel, and a diaphragm member made of fluororesin, the diaphragm member being In a method for manufacturing a fluid control device that includes a flexible thin film portion and controls the control fluid by elastically deforming the thin film portion, the thin film portion has a contact portion that comes into contact with the control fluid. a liquid surface; at least a portion of the liquid contact surface is a mold transfer surface; a first step of molding a semi-finished product of the diaphragm member having the mold transfer surface; and a second step of obtaining the shape of the diaphragm member by cutting while leaving the mold transfer surface. Note that the fluid control device refers to a device that uses a diaphragm member including a thin film portion, such as a diaphragm valve, a suckback valve, a regulator, a needle valve, and a diaphragm pump. The mold transfer surface is a surface onto which the cavity surface of an injection mold, the compression mold, or the transfer mold is transferred.

According to the method for manufacturing a fluid control device described in (9), at least a part of the liquid contact surface provided in the thin film portion becomes a mold transfer surface, so that rather than forming the liquid contact surface by cutting, It is possible to reduce the surface roughness of the liquid contact surface. Therefore, it is possible to reduce the occurrence of stagnation of the control fluid (for example, a chemical solution) on the liquid contact surface, and to reduce the possibility that components of the control fluid will adhere to the liquid contact surface. If the risk of the control fluid components adhering can be reduced, the risk of the control fluid components falling off from the liquid contact surface and being mixed into the control fluid as particles can also be reduced.

Note that it does not matter whether a part of the liquid contact surface of the thin film part is used as the mold transfer surface, or whether all of the liquid contact surface of the thin film part is used as the mold transfer surface. When using a part of the liquid contact surface as the mold transfer surface, for example, when the thin film part is elastically deformed, it is possible to use the part where the deformation is large or the part where stress is likely to concentrate as the mold transfer surface. . This is because areas with large deformation or areas where stress tends to concentrate are likely to fall off when components of the control fluid adhere to them, and by forming the mold transfer surface, the components of the control fluid will prevent the components from adhering. It is.

(10) In the method for manufacturing a fluid control device according to (9), a surface of the thin film portion opposite to the liquid contact surface is a cut surface.

Since the surface of the thin film portion opposite to the liquid contact surface does not come into contact with the control fluid, it is not necessary to make the surface roughness as low as the liquid contact surface. Furthermore, since the thin film portion has a thickness of about 0.1 to 0.5 mm, it is difficult to mold it with a mold. Therefore, by making the surface of the thin film part opposite to the liquid contact surface a machined surface, it is possible to prevent the components of the control fluid from adhering to the liquid contact surface of the diaphragm member and to reduce manufacturing costs. can.

(11) In the method for manufacturing a fluid control device according to (9) or (10), the mold transfer surface has a surface roughness of Ra of 0.05 μm or less.

For example, in fluid control equipment used in semiconductor manufacturing equipment, the requirement to prevent particles from being mixed into the control fluid is becoming stricter year by year in order to improve the yield of semiconductors. According to the method for manufacturing a fluid control device described in (11), since the surface roughness of the mold transfer surface is Ra 0.05 μm or less, the control fluid (e.g., chemical solution) can be retained more reliably on the liquid contact surface. This can reduce the possibility that components of the control fluid will adhere to the liquid-contacted surface, and can withstand the above-mentioned requirements that are becoming stricter year by year. Note that although the fluid control device used in semiconductor manufacturing equipment is mentioned above, the fluid control device according to the present invention is not limited to being used in semiconductor manufacturing equipment.

(12) In the method for manufacturing a fluid control device according to any one of (9) to (11), the fluororesin has a melt flow rate of 2.2 g/10 min or more and 2.8 g/10 min or less. It is characterized by being a fluoroalkoxyalkane.

(13) In the method for manufacturing a fluid control device according to any one of (9) to (12), the fluororesin has a specific gravity in a range of 2.08 or more and 2.16 or less. shall be.

Conventionally, there has been concern that repeated elastic deformation of the thin film portion may cause cracks to occur in the thin film portion. When a crack occurs, the control fluid may remain in the crack, and components of the deteriorated control fluid may adhere to the crack. The adhesion of components of the control fluid causes particles to be mixed into the control fluid.

According to the method for manufacturing a fluid control device described in (12) or (13), the bending durability of the thin film portion can be improved. Therefore, it is possible to prevent cracks from forming in the thin film portion, and it is also possible to prevent the control fluid from stagnation and the generation of particles. Note that the melt flow rate (MFR) here means the MFR of the fluororesin, which is the raw material, after molding. MFR after molding is measured by melting and molding the raw material fluororesin and then melting it again. This measurement is based on ASTM D1238, at a resin temperature of 372 degrees Celsius, a load of 5 kg, and an orifice. The test was carried out under the conditions that the inner diameter was 2.1 mm and the orifice height was 8.0 mm.

(14) In the method for manufacturing a fluid control device according to any one of (9) to (13), the mold transfer surface is a mirror-finished surface of a mold used for compression molding or transfer molding. It is characterized by the fact that it is

When molding a diaphragm member by injection molding, flow marks may be formed on the surface of the thin film part due to the flow of resin during molding, which may adversely affect the surface roughness of the surface in contact with the liquid (mold transfer surface). . However, according to the method for manufacturing a fluid control device described in (14), the mold transfer surface is a mirror-finished surface of a mold used for compression molding or transfer molding. It becomes possible to reliably reduce the surface roughness of the surface to Ra 0.05 μm or less. As in compression molding or transfer molding, by applying pressure to the molten resin in the mold, it is possible to press the molten resin in the mold against the mold cavity surface, thereby creating a mold transfer surface. This is because it is possible to form it smoothly.

(15) In the method of manufacturing a fluid control device according to (14), the liquid contact surface is a curved surface.

When forming the thin film part by cutting as in the diaphragm 15 described in Patent Document 1, it is difficult to form the thin film part as a curved surface, so it is generally formed as a flat surface. In this case, when the thin film portion undergoes elastic deformation, stress concentration is likely to occur, and there is a concern that the bending durability may deteriorate.

According to the method for manufacturing a fluid control device described in (15), the liquid contact surface can be formed as a curved surface having a mold transfer surface by compression molding or transfer molding. Therefore, while preventing components of the control fluid from adhering to the liquid contact surface of the diaphragm member, it is possible to improve bending durability by alleviating stress concentration.

(16) In the method of manufacturing a fluid control device according to any one of (9) to (15), the diaphragm member includes a valve body that opens and closes a flow path through which the control fluid flows, and the fluid control device The valve body includes a valve seat that comes into contact with and separates from the valve body, and the valve body has at least a portion that comes into contact with the valve seat as a second mold transfer surface. obtaining the semi-finished product having a second mold transfer surface; and obtaining the shape of the diaphragm member by cutting the semi-finished product with the second mold transfer surface remaining in the second step; It is characterized by.

According to the method for manufacturing a fluid control device according to (16), the diaphragm member includes a valve body that opens and closes a flow path through which the control fluid flows, and the fluid control device includes a valve seat on which the valve body abuts and separates. . For example, a diaphragm valve, a needle valve, etc. correspond to the above-mentioned fluid control equipment. In this case, it is desirable that at least the portion of the valve body that comes into contact with the valve seat is the second mold transfer surface. Conventionally, the portion of the valve body that comes into contact with the valve seat tends to wear out during repeated opening and closing operations, and there is a risk that wear powder generated by the wear may mix into the control fluid as particles. By using the portion of the valve body that contacts the valve seat as a mold transfer surface and reducing the surface roughness, it is possible to suppress the occurrence of wear. Note that the second mold transfer surface may be a continuous surface or a separate surface from the liquid contact surface of the thin film portion.

According to the fluid control device and the manufacturing method thereof of the present invention, it is possible to prevent components of the control fluid from adhering to the liquid contact surface of the diaphragm member.

FIG. 3 is a cross-sectional view of a diaphragm valve. It is a partial sectional view of a diaphragm member. It is a figure explaining the 1st process of the manufacturing method of a fluid control device. It is a figure explaining the 1st process of the manufacturing method of a fluid control device. It is a figure explaining the 1st process of the manufacturing method of a fluid control device. It is a partial sectional view of a semi-finished product of a diaphragm member. It is a figure explaining the 2nd process of the manufacturing method of a fluid control device. It is a figure which shows the female mold used for the 1st process of the manufacturing method of a fluid control device. It is a figure explaining the 1st process in the 2nd form of the manufacturing method of a fluid control device. It is a partial sectional view showing a modification of a diaphragm member. 11 is a diagram showing a female mold corresponding to the diaphragm member shown in FIG. 10. FIG. FIG. 3 is a cross-sectional view of a suckback valve. It is a sectional view of a needle valve. FIG. 3 is a cross-sectional view of the regulator. FIG. 2 is a cross-sectional view of a diaphragm pump.

A diaphragm valve 1, which is an embodiment of a fluid control device according to the present invention, will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a diaphragm valve 1. FIG. FIG. 2 is a partial cross-sectional view of diaphragm member 122.

The diaphragm valve 1 is, for example, an air-operated chemical liquid valve that controls the flow rate of a chemical liquid used in semiconductor manufacturing equipment. As shown in FIG. 1, the diaphragm valve 1 includes a driving section 11 and a valve section 12 that are stacked one above the other.

The drive unit 11 is formed by a first housing 111 and a second housing 112 stacked one on top of the other in the vertical direction in FIG. 1, and includes a piston 113 therein.

The first housing 111 is closed at the end opposite to the second housing 112 (the upper end in FIG. 1), while the end on the second housing 112 side (the lower end in FIG. 1) is closed. It has an open hollow cylindrical shape, and a first supply/exhaust port 111a is formed on the outer peripheral surface. The open end of the first housing 111 is hermetically fitted to the upper end of the second housing 112 in FIG. 1 via an O-ring 115.

The second housing 112 has a hollow cylindrical shape with an open end on the first housing 111 side (upper end in FIG. 1) and an open end on the valve part 12 side (lower end in FIG. 1). A second air supply/exhaust port 112a is formed on the outer peripheral surface.

The first housing 111 and the second housing 112 are coaxially arranged, and the hollow portion of the first housing 111 and the hollow portion of the second housing 112 form a piston chamber 116.

A piston 113 is loaded into the piston chamber 116 so as to be slidable in the vertical direction in FIG. Here, the upward direction in FIG. 1 is the valve opening direction, and the downward direction in FIG. 1 is the valve closing direction. The piston 113 includes a disk-shaped piston portion 113a, and the piston chamber 116 is divided into an upper chamber 116a and a lower chamber 116b by the piston portion 113a. An O-ring 117 is disposed between the outer peripheral surface of the piston portion 113a and the inner wall surface of the piston chamber 116, and maintains airtightness between the upper chamber 116a and the lower chamber 116b.

The upper chamber 116a communicates with the first air supply/exhaust port 111a through a first communication path 111b, and the lower chamber 116b communicates with the second air supply/exhaust port 112a through a second communication path 112b. Further, a coil spring 114 is disposed in the upper chamber 116a, and the lower end of the coil spring 114 in FIG. is in contact with the upper surface of the upper chamber 116a. The coil spring 114 biases the piston 113 in the valve closing direction by its elastic force. Therefore, when operating air is supplied to the lower chamber 116b from the second supply/exhaust port 112a, the pressure in the lower chamber 116b increases, and the piston 113 moves in the valve opening direction against the elastic force of the coil spring 114. It is about to be moved. At this time, the air in the upper chamber 116a is exhausted from the first air supply/exhaust port 111a. Then, when the operation air to the lower chamber 116b is stopped, the elastic force of the coil spring 114 causes the piston 113 to move in the valve closing direction.

The piston 113 also includes a piston rod 113c extending toward the lower end of the piston portion 113a. This piston rod 113c is inserted into a through hole 112c that passes through the lower end surface of the second housing 112 and the lower chamber 116b. An O-ring 118 is disposed between the outer peripheral surface of the piston rod 113c and the inner peripheral surface of the through hole 112c to keep the lower chamber 116b airtight. A diaphragm member 122 constituting the valve portion 12 is screwed onto the tip of the piston rod 113c.

The valve portion 12 is connected to the lower side of the drive portion 11 in FIG.

The valve main body 121 includes an input flow path 121a for inputting a control fluid such as a chemical solution, and an output flow path 121b for outputting the input control fluid. Further, a valve chamber 121c is bored in the center of the upper end surface of the valve main body 121 in FIG. The input flow path 121a and the output flow path 121b communicate with each other via this valve chamber 121c. The input flow path 121a and the output flow path 121b communicate with each other, thereby forming a series of flow paths through which the control fluid flows. Furthermore, an annular valve seat 121d (an example of a valve seat) is formed on the bottom surface of the valve chamber 121c, and the diaphragm member 122 comes into contact with and separates from the annular valve seat 121d.

The diaphragm member 122 includes a valve body 123, a thin film portion 124, and a support portion 125, as shown in FIGS. 1 and 2.

As shown in FIG. 2, the valve body 123 includes a small diameter portion 123a and a large diameter portion 123c arranged coaxially, and is formed in a substantially cylindrical shape. A coupling portion 123e is provided upright at the end of the narrow diameter portion 123a on the piston 113 side (the upper end in FIG. 1). The diaphragm member 122 is connected to the piston 113 as shown in FIG. 1 by connecting the connecting portion 123e to the lower end of the piston rod 113c of the piston 113. This allows the valve body 123 to move up and down as the piston 113 slides up and down. Further, a large diameter portion 123c having a larger diameter than the small diameter portion 123a is connected to an end of the small diameter portion 123a on the opposite side from the coupling portion 123e. The lower surface of the large diameter portion 123c facing the annular valve seat 121d is a sealing surface 123d that comes into contact with and separates from the annular valve seat 121d as the valve body 123 moves up and down to control the control fluid.

As shown in FIG. 2, the thin film portion 124 extends diagonally upward in the radial direction from the outer circumferential surface of the valve body 123 near the boundary between the small diameter portion 123a and the large diameter portion 123c, and bulges upward. It is formed in a curved manner. As shown in FIG. 2, the support portion 125 is provided thickly at the outer edge of the thin film portion 124. As shown in FIG. As shown in FIG. 1, the support portion 125 is held between the drive portion 11 and the valve portion 12, so that the diaphragm member 122 is fixed, and the thin film portion 124 is held in place within the valve chamber 121c. The body 123 is supported. Therefore, as the valve body 123 moves up and down, the thin film portion 124 that supports the valve body 123 repeatedly bends.

The lower surface of the thin film portion 124 of the diaphragm member 122 (the surface on the annular valve seat 121d side in FIG. 1), the outer peripheral surface of the large diameter portion 123c, and the sealing surface 123d are liquid contact surfaces that come into contact with the control fluid. The lower surface of the thin film portion 124, the outer circumferential surface of the large diameter portion 123c, and the sealing surface 123d are all a mold transfer surface 127 (the range indicated by the thick dashed line in FIG. 2). In other words, the liquid contact surface of the diaphragm member 122 is entirely formed by the mold transfer surface 127. This mold transfer surface 127 may be formed by injection molding, compression molding, or transfer molding, but it is most desirable to form it by compression molding or transfer molding. Details regarding compression molding or transfer molding will be described later.

The surface roughness of the mold transfer surface 127 forming the liquid contact surface is preferably Ra 0.1 μm or less, more preferably Ra 0.05 μm or less. This is to prevent the control fluid (for example, a chemical solution) from stagnation on the liquid contact surface and the components of the deteriorated control fluid from adhering to the liquid contact surface.

In addition, in the diaphragm member 122 in this embodiment, the entire liquid contact surface is the mold transfer surface 127, but a part of the liquid contact surface may be used as the mold transfer surface. For example, it is conceivable to use a part of the liquid contact surface of the thin film part 124 that undergoes large deformation or a part where stress tends to concentrate when the thin film part is elastically deformed as the mold transfer surface. This is because areas with large deformation or areas where stress tends to concentrate are likely to fall off when components of the control fluid adhere to them, and by forming the mold transfer surface, the components of the control fluid will prevent the components from adhering. It is. In addition to this, it is conceivable that the part of the sealing surface 123d that contacts the annular valve seat 121d is used as a mold transfer surface. The portion that comes into contact with the annular valve seat 121d is likely to wear out as the opening and closing operations are repeated, and there is a risk that abrasion powder generated by the wear may mix into the control fluid as particles. By using the portion of the sealing surface 123d that contacts the annular valve seat 121d as a mold transfer surface and reducing the surface roughness, it is possible to suppress the occurrence of wear.

In addition, the upper surface of the thin film portion 124 of the diaphragm member 122 (the surface opposite to the annular valve seat 121d side in FIG. 1), the outer peripheral surface of the narrow diameter portion 123a, and the outer peripheral surface of the joint portion 123e are cut. This is the machined surface 128 (the area indicated by the thick two-dot chain line in FIG. 2) obtained by.

Next, the material of the diaphragm member 122 will be explained. In order to prevent the thin film portion 124 from being destroyed due to repeated bending of the thin film portion 124, the thin film portion 124 is required to have bending durability. Therefore, as the material of the diaphragm member 122, the specific gravity is in the range of 2.08 or more and 2.16 or less, and the melt flow rate (MFR) of the semi-finished product 50 (see FIG. 6) obtained by the first step described below. A PFA (perfluoroalkoxyalkane) with a value of 1.1 g/10 min or more and 2.8 g/10 min or less is selected. Furthermore, considering the variation in the physical properties of PFA, the MFR of PFA is within the range of 1.1 g/10 min or more and 2.8 g/10 min or less, and within the range of 1.5 g/10 min or more and 2.6 g/10 min or less. is more preferable, and a range of 2.2 g/10 min or more and 2.6 g/10 min or less is even more preferable. Note that the MFR of the semi-finished product 50 means the MFR of PFA, which is a raw material, after molding. The MFR after molding is measured by remelting the semi-finished product 50 obtained by molding the raw material PFA, and this measurement is based on ASTM D1238, at a resin temperature of 372 degrees Celsius and a load of 5 kg. , the inner diameter of the orifice was 2.1 mm, and the height of the orifice was 8.0 mm. The MFR after molding increases by about 5 to 15% compared to the MFR of the raw material (ie, the MFR before molding). This is because the material is heated during molding, causing thermal deterioration of the material. Therefore, in order to make the MFR of the semi-finished product 50 be 1.1 g/10 min or more and 2.8 g/10 min or less, select PFA whose MFR before molding is 1 g/10 min or more and 2.5 g/10 min or less. It's good.

PFA has a molecular structure with excellent low dust generation compared to commonly used PTFE (polytetrafluoroethylene). Therefore, if the diaphragm member 122 is made of PFA, dust generation due to repeated contact and separation between the valve body and the valve seat can be prevented. On the other hand, PFA generally has lower flexibility and inferior bending durability than PTFE. If the diaphragm member 122 was formed of such PFA, there was a risk that the thin film portion 124 would be easily broken due to repeated bending. Under these circumstances, in recent years, PFA with a highly flexible molecular structure has been developed and has come into circulation, as described in, for example, Japanese Patent Application Publication No. 2017-119750. It is expected that the lower the crystallinity and the higher the molecular weight of PFA, the higher the strength and durability. In other words, the higher the molecular weight, the lower the specific gravity, so it is expected that the lower the specific gravity, the higher the bending durability of PFA. However, the inventor confirmed through tests that the lower the specific gravity, the higher the bending durability.

Therefore, the inventor focused on the MFR of PFA, and created a diaphragm member 122 made of PFA with a specific gravity of about 2.11 and an MFR of 2.5 g/10 min, and a diaphragm member 122 made of PFA with a specific gravity of about 2.17 and an MFR of 14 g/10 min. Using the diaphragm member 122 formed of PFA and a diaphragm member of the same shape (comparison sample), a bending durability test was conducted by repeated opening and closing operations. The test conditions are as follows. The diaphragm valve 1 that incorporates the diaphragm member 122 and the diaphragm valve that incorporates comparative data are filled with fluid at room temperature at a fluid pressure of 0.2 to 0.5 MPa in an atmosphere at room temperature, and the diaphragm member is Open and close with a stroke of .5 to 2.5 mm and a cycle of 0.5 to 10 seconds for the valve close time and the valve open time, respectively. As a result of this bending durability test, the thin film portion 124 of the diaphragm member 122 was able to withstand approximately 1 million opening/closing operations, whereas the comparative sample could endure an opening/closing operation of 100,000 times or less.

The diaphragm members of fluid control equipment, which are generally used in semiconductor manufacturing equipment, are not frequently opened and closed and require bending durability that can withstand at least 1 million opening and closing operations, and the MFR is 2.8 g/10 min. If it exceeds this, the flexural durability of the diaphragm member decreases, and there is a possibility that the diaphragm member will not be able to withstand the opening/closing operation of 1 million times. Moreover, if the MFR is less than 1.1 g/10 min, it is thought that the entanglement between molecules becomes stronger and the bending durability increases, but it becomes difficult to mold, which is not preferable from the viewpoint of productivity.

(First form of method for manufacturing fluid control equipment)
Next, a method for manufacturing a fluid control device that manufactures the diaphragm valve 1 including the above-described diaphragm member 122 will be described using FIGS. 3 to 8. FIG. 3-5 is a diagram illustrating the first step of the method for manufacturing a fluid control device. FIG. 6 is a partial cross-sectional view of a semi-finished product 50 of the diaphragm member 122. FIG. 7 is a diagram illustrating the second step of the method for manufacturing a fluid control device. FIG. 8 is a diagram showing a female mold 60 used in the first step of the method for manufacturing a fluid control device.

(1st step)
The first step is a step for molding the semi-finished product 50 of the diaphragm member 122 by compression molding. Compression molding is performed using a female mold 60, a male mold 70, and a firing furnace 80.

As shown in FIG. 8, the female mold 60 includes a cavity 60a for molding the semi-finished product 50 therein. The bottom surface of the cavity 60a is a mirror-finished surface 60b that is mirror-finished to form a mold transfer surface 127 of the semi-finished product 50 (diaphragm member 122). As shown in FIGS. 4 and 5, the male mold 70 can be fitted into the female mold 60, and by fitting into the female mold 60, pressure can be applied to the material filled into the cavity 60a. It is possible. The firing furnace 80 is a firing furnace used for general compression molding.

First, as shown in FIG. 3, PFA pellets 90, which are the raw material for the diaphragm member 122, are filled into the cavity 60a of the female mold 60 for compression molding. Note that the method for filling the pellets 90 into the cavity 60a may be manual or automated.

Next, as shown in FIG. 4, a male mold 70 is fitted into the female mold 60, and the male mold 70 pressurizes the pellets 90 filled in the cavity 60a. This eliminates the gap between the filled pellets 90 and the cavity 60a as much as possible. At this time, the pressure applied by the male die 70 is set to be between about 1 and 3 MPa.

Next, the female mold 60 is heated to a predetermined temperature in a firing furnace 80, as shown in FIG. 5, while the pressure applied by the male mold 70 remains constant. This predetermined temperature is not particularly limited, but is set to at least the melting point of PFA (for example, about 300 to 400° C.). This heating melts the pellets 90 (the pellets after melting are used as molten material 91).

When the female mold 60 reaches a predetermined temperature, the molten material 91 is further pressurized by the male mold 70 to integrate the molten pellet particles and spread the molten material 91 throughout the cavity 60a. At this time, the pressure applied by the male mold 70 is preferably higher in order to integrate the molten pellet particles, but since the clearance between the male mold 70 and the female mold 60 for gas venting is Since there is a possibility that leakage may occur, the pressure is appropriately set between approximately 5 and 15 MPa. Moreover, it is most desirable that the direction in which pressure is applied by the male mold 70 is substantially perpendicular to the mirror-finished surface 60b for forming the mold transfer surface 127 as the liquid contact surface. This is to more reliably transfer the mirror finished surface 60b to the semi-finished product 50 and to reduce the surface roughness of the mold transfer surface 127 as much as possible.

After the molten material 91 is spread throughout the inside of the cavity 60a by pressurization, the door of the firing furnace 80 is opened while keeping the pressurized state, and the material is gradually cooled by outside air. As a result, the temperature of the female mold 60 is lowered to about 80 to 200° C., and the molten material 91 is hardened. The molten material 91 becomes the semi-finished product 50 of the diaphragm member 122 by hardening. The semi-finished product 50 is taken out from the female mold 60, and the first step is completed.

The semi-finished product 50 obtained in the first step is formed into a substantially cylindrical shape, as shown in FIG. 6, and the axis A12 of the semi-finished product 50 is the same as the axis A11 of the diaphragm member 122. Further, the mold transfer surface 127 of the diaphragm member 122, that is, the lower surface of the thin film portion 124 (the surface on the annular valve seat 121d side in FIG. 1) which is the liquid contact surface, the outer circumferential surface of the large diameter portion 123c, and the sealing surface 123d are as follows. It is formed in a semi-finished product 50.

If the diaphragm member 122 is molded by injection molding, flow marks may be formed on the surface of the thin film portion 124 due to the flow of the resin during molding, which may adversely affect the surface roughness of the mold transfer surface 127. According to this embodiment, since the mold transfer surface 127 is a mirror-finished surface 60b of the female mold 60, the surface roughness of the mold transfer surface 127 can be ensured to be Ra0.05 μm or less. (Specifically, Ra of approximately 0.02 to 0.03 μm). As in compression molding, by applying pressure to the molten resin in the female mold 60, it is possible to press the molten resin in the female mold 60 against the mirror-finished surface 60b of the mold, thereby causing mold transfer. This is because it is possible to form the surface 127 smooth. Note that in the above description of the first step, heating is performed in the firing furnace 80 after the pressure application by the male die 70 is started, but heating is started in the firing furnace 80. Pressurization by the male die 70 may be started.

(Second process)
Next, the shape of the diaphragm member 122 is obtained by cutting the semi-finished product 50. For example, a lathe is used for cutting. The semi-finished product 50 is fixed to the chuck 101 of the lathe so that the rotation axis A13 of the lathe is coaxial with the axial center of the semi-finished product 50 (that is, the axial center A11 of the diaphragm member 122). Then, the semi-finished product 50 is rotated around the rotation axis A13, and the cutting blade 100 cuts the semi-finished product 50 from the side opposite to the mold transfer surface 127, forming a cut surface 128 (see FIG. 2). do. Thereby, the diaphragm member 122 is completed.

(Second form of method for manufacturing fluid control equipment)
A second form of the method for manufacturing a fluid control device will be described using FIG. 9. FIG. 9 is a diagram illustrating the first step in the second embodiment of the method for manufacturing a fluid control device (diaphragm valve 1).

In the second embodiment of the method for manufacturing a fluid control device (diaphragm valve 1), a semi-finished product 50 is molded by transfer molding. Transfer molding is performed using an extrusion molding machine 102, a pot 103, a female mold 104, a male mold 105, and firing furnaces 106 and 107. Note that the female mold 104 has the same configuration as the female mold 60 used for compression molding, and the male mold 105 has the same configuration as the male mold 70 used for compression molding, but each is designed for transfer molding. .

The extrusion molding machine 102 includes a heating cylinder 102a, a hopper 102b into which material can be placed, and a screw 102c rotated by a drive mechanism 102e.

PFA pellets 90 thrown into the heating cylinder 102a from the hopper 102b are heated within the heating cylinder 102a and rotated by the screw 102c. Thereby, the pellet 90 is melted while being sent to the tip side of the screw 102c. Note that the molten pellets 90 are referred to as a molten material 92.

The molten material 92 is pushed out into the firing furnace 106 from a discharge port 102d provided at the tip of the heating cylinder 102a by a rotating screw 102c. Inside the firing furnace 106, a female mold 104 and a pot 103 are arranged in a stacked manner, and the molten material 92 extruded from the discharge port 102d is first stored in the pot 103. The molten material 92 stored in the pot 103 is then filled into the cavity 104a of the female mold 104 through a sprue 103a provided at the bottom of the pot 103. At this time, since the pot 103 and the female mold 104 are in the firing furnace 106, the molten material 92 is in a heated state in the cavity 104a. The heating temperature is not particularly limited, but it is heated to a temperature higher than the melting point (for example, about 300 to 400°C).

The female mold 104 filled with molten material is sent to a pressurizing process. The pressurizing process is performed in a firing furnace 107, as shown in FIG. A male die 105 is fitted into the female die 104, and the male die 105 pressurizes the molten material 92 filled in the cavity 104a. Note that the pressurization speed and pressure value when pressurizing the molten material 92 are adjusted as appropriate. This pressurization spreads the molten material 92 throughout the cavity 104a. At this time, the temperature of the firing furnace 107 is set to, for example, approximately 80 to 200° C. in order to slowly cool the molten material 92, although it is not particularly limited. This slow cooling is performed while applying pressure using the male die 105. By performing slow cooling, the molten material 91 is hardened and becomes the semi-finished product 50. The semi-finished product 50 is taken out from the female mold 104, and the first step of transfer molding is completed. The second step for obtaining the diaphragm member 122 from the semi-finished product 50 obtained by transfer molding is the same as the second step in the first embodiment described above.

If the diaphragm member 122 is molded by injection molding, flow marks may be formed on the surface of the thin film portion 124 due to the flow of the resin during molding, which may adversely affect the surface roughness of the mold transfer surface 127. According to this embodiment, since the mold transfer surface 127 is a mirror-finished surface 104b of the female mold 104 transferred thereto, the surface roughness of the mold transfer surface 127 must be surely Ra0.05 μm or less. becomes possible. As in transfer molding, by applying pressure to the molten resin in the female mold 60, it is possible to press the molten resin in the female mold 104 against the mirror-finished surface 104b of the mold, thereby causing mold transfer. This is because it is possible to form the surface 127 smooth.

(About modified examples of diaphragm members)
In addition to molding a semi-finished product using the female molds 60 and 104 described above, it is also conceivable to mold a semi-finished product using a female mold using a slide core.

For example, a diaphragm member 222 shown in FIG. 10 includes a valve body 223, a thin film portion 224, and a support portion 225. The valve body 223 includes a narrow diameter portion 223a, an enlarged diameter portion 223b, and a large diameter portion 223c arranged coaxially, and is formed in a so-called bell shape. A coupling portion 223e is provided upright at the upper end of the narrow diameter portion 223a in FIG. This coupling portion 223e, like the diaphragm member 122, is coupled to the piston. This couples the diaphragm member 222 to the piston. Further, a large diameter portion 223c having a larger diameter than the small diameter portion 223a is connected to the lower end of the small diameter portion 223a via an enlarged diameter portion 223b. The lower surface of the large diameter portion 123c is a sealing surface 223d for controlling the control fluid by contacting and separating from the annular valve seat 121d.

The thin film portion 224 extends obliquely upward in the radial direction from the outer peripheral surface of the valve body 223 near the boundary between the narrow diameter portion 223a and the enlarged diameter portion 223b, and is curved to bulge upward. There is. The support portion 225 is provided thickly at the outer edge of the thin film portion 224 . The support portion 225, like the support portion 125 of the diaphragm member 122, is held between the drive portion 11 and the valve portion 12, thereby fixing the diaphragm member 222.

The lower surface of the thin film portion 224, the outer circumferential surface of the enlarged diameter portion 223b, the outer circumferential surface of the large diameter portion 223c, and the sealing surface 223d of the diaphragm member 222 are liquid contact surfaces that come into contact with the control fluid. The lower surface of the thin film portion 224, the outer circumferential surface of the enlarged diameter portion 223b, the outer circumferential surface of the large diameter portion 223c, and the sealing surface 223d are all mold transfer surfaces 227 (the range indicated by the thick dashed line in FIG. 10). It is. In other words, the liquid contact surface of the diaphragm member 222 is entirely formed by the mold transfer surface 227. The surface roughness of this mold transfer surface 227 is preferably Ra of 0.1 μm or less, more preferably Ra of 0.05 μm or less. Further, the range of the diaphragm member 222 indicated by the thick two-dot chain line in FIG. 10 is a cut surface 128 obtained by cutting.

When attempting to mold the diaphragm member 222 having the above-described configuration, the mold is formed into a reverse taper at the enlarged diameter portion 223b, making it impossible to release the mold. Therefore, a mold using a slide core, such as a female mold 160 shown in FIG. 11, is used. The female mold 160 includes a cavity 160a therein for molding a semi-finished product of the diaphragm member 222. Slide cores 161 and 162 included in the female mold 160 constitute a part of the cavity 160a. The bottom surface of the female mold 160 and the surfaces of the slide cores 161 and 162 are mirror-finished surfaces 160b (range shown by the dashed line in FIG. 11) for forming the mold transfer surface 227 of the diaphragm member 222. . Note that since the slide core 161 is a cylindrical component, although it appears to be located on the left and right sides in FIG. 11, these are one integrated component. Furthermore, the slide core 162 is made up of two parts divided into left and right parts in FIG. 11, and is formed into a cylindrical shape by combining the two parts. When releasing the mold, first, the bottom portion 163 is removed in the direction shown by the arrow Y11, and then the slide core 161 is removed in the direction shown by the arrow Y12 (the same direction as the arrow Y11). Finally, the slide core 162 is divided into left and right parts, and each is removed diagonally downward and outward as shown by arrow Y13. In this manner, by using the female die 160 using the slide cores 161 and 162, it is possible to form the enlarged diameter portion 223b having a reverse tapered shape.

As explained above, according to the fluid control device (for example, diaphragm valve 1) of the present embodiment, (1) the input flow path 121a into which the control fluid (for example, chemical liquid) is input; The diaphragm member 122 includes an output flow path 121b for outputting a control fluid and a diaphragm member 122 made of fluororesin, and the diaphragm member 122 includes a thin film portion 124 having flexibility, and control is performed by elastically deforming the thin film portion 124. In a fluid control device that controls fluid, the thin film portion 124 is characterized in that it includes a liquid contact surface that comes into contact with the control fluid, and that at least a portion of the liquid contact surface is a mold transfer surface 127. The mold transfer surface 127 is a surface onto which the cavity surface of an injection molding mold, the cavity surface of a compression molding mold, or the cavity surface of a transfer molding mold is transferred.

According to the fluid control device (diaphragm valve 1) described in (1), at least a part of the liquid contact surface of the thin film portion 124 is the mold transfer surface 127, so the liquid contact surface is formed by cutting. It is possible to lower the surface roughness of the surface in contact with the liquid. Therefore, it is possible to reduce the occurrence of stagnation of the control fluid on the liquid contact surface, and to reduce the possibility that components of the control fluid will adhere to the liquid contact surface. If the risk of the control fluid components adhering can be reduced, the risk of the control fluid components falling off from the liquid contact surface and being mixed into the control fluid as particles can also be reduced.

Note that it does not matter whether a part of the liquid contact surface of the thin film portion 124 is used as the mold transfer surface, or whether all of the liquid contact surface of the thin film portion 124 is used as the mold transfer surface. When using a part of the liquid contact surface as a mold transfer surface, for example, when the thin film portion 124 is elastically deformed, it is possible to use a part that is largely deformed or a part where stress tends to concentrate as the mold transfer surface. It will be done. This is because areas with large deformation or areas where stress tends to concentrate are likely to fall off when components of the control fluid adhere to them, and by forming the mold transfer surface, the components of the control fluid will prevent the components from adhering. It is.

(2) The fluid control device (diaphragm valve 1) described in (1) is characterized in that the surface of the thin film portion 124 opposite to the liquid contact surface is a cut surface 128.

Since the surface of the thin film portion 124 opposite to the liquid-contacted surface does not come into contact with the control fluid, it is not necessary to make the surface roughness as low as that of the liquid-contacted surface. Furthermore, since the thin film portion 124 has a thickness of about 0.1 to 0.5 mm, it is difficult to mold it with a mold. Therefore, by making the surface of the thin film part opposite to the liquid contact surface the cutting surface 128, it is possible to prevent the components of the control fluid from adhering to the liquid contact surface of the diaphragm member and to reduce manufacturing costs. Can be done.

(3) The fluid control device (diaphragm valve 1) described in (1) or (2) is characterized in that the surface roughness of the mold transfer surface 127 is Ra0.05 μm or less.

For example, in fluid control equipment used in semiconductor manufacturing equipment, the requirement to prevent particles from being mixed into the control fluid is becoming stricter year by year in order to improve the yield of semiconductors. According to the fluid control device (diaphragm valve 1) described in (3), since the surface roughness of the mold transfer surface 127 is Ra 0.05 μm or less, it is possible to more reliably prevent the control fluid from stagnation on the wetted surface. It is possible to reduce the risk of components of the control fluid adhering to the liquid-contacted surface, and to withstand the above-mentioned requirements that are becoming stricter year by year. Note that although the fluid control device used in semiconductor manufacturing equipment is mentioned above, the fluid control device according to the present invention is not limited to being used in semiconductor manufacturing equipment.

(4) In the fluid control device (diaphragm valve 1) according to any one of (1) to (3), the fluororesin has a melt flow rate of 2.2 g/10 min or more and 2.8 g/10 min or less. It is characterized by being a perfluoroalkoxyalkane.

(5) In the fluid control device (diaphragm valve 1) according to any one of (1) to (4), the fluororesin has a specific gravity in the range of 2.08 or more and 2.16 or less. Features.

Conventionally, there has been concern that repeated elastic deformation of the thin film portion may cause cracks to occur in the thin film portion. When a crack occurs, the control fluid may remain in the crack, and components of the deteriorated control fluid may adhere to the crack. The adhesion of components of the control fluid causes particles to be mixed into the control fluid.

According to the fluid control device (diaphragm valve 1) described in (4) or (5), the bending durability of the thin film portion 124 can be improved. Therefore, it is possible to prevent cracks from occurring in the thin film portion 124, and it is possible to prevent the control fluid from stagnation and the generation of particles. Note that the melt flow rate (MFR) here means the MFR of the fluororesin, which is the raw material, after molding. MFR after molding is measured by melting and molding the raw material fluororesin and then melting it again. This measurement is based on ASTM D1238, at a resin temperature of 372 degrees Celsius, a load of 5 kg, and an orifice. The test was carried out under the conditions that the inner diameter was 2.1 mm and the orifice height was 8.0 mm.

(6) In the fluid control device (diaphragm valve 1) according to any one of (1) to (5), the mold transfer surface 127 is a mold used for compression molding or transfer molding (for example, a female mold 60). , 104), the mirror-finished surfaces 60b, 104b are transferred.

When the diaphragm member 122 is molded by injection molding, flow marks are formed on the surface of the thin film portion 124 due to the flow of resin during molding, which adversely affects the surface roughness of the liquid contact surface (mold transfer surface 127). There is a risk. However, according to the fluid control device (diaphragm valve 1) described in (6), the mold transfer surface 127 is the mirror-finished surface 60b of the mold (for example, female mold 60, 104) used for compression molding or transfer molding. , 104b are transferred, it is possible to ensure that the surface roughness of the mold transfer surface 127 is Ra 0.05 μm or less. As in compression molding or transfer molding, if pressure is applied to the molten resins 91, 92 in the molds (female molds 60, 104), the molten resins 91, 92 in the molds (female molds 60, 104) are This is because it can be pressed against the surfaces of the cavities 60a and 104a (mirror-finished surfaces 60b and 104b) of the mold, thereby making it possible to form the mold transfer surface 127 smoothly.

(7) The fluid control device (diaphragm valve 1) described in (6) is characterized in that the liquid contact surface is a curved surface.

When forming the thin film part by cutting as in the diaphragm described in Patent Document 1, it is difficult to form the thin film part as a curved surface, so it is generally formed as a flat surface. In this case, when the thin film portion undergoes elastic deformation, stress concentration is likely to occur, and there is a concern that the bending durability may deteriorate.

According to the fluid control device (diaphragm valve 1) described in (7), the liquid contact surface can be formed as a curved surface having the mold transfer surface 127 by compression molding or transfer molding. . Therefore, while preventing components of the control fluid from adhering to the liquid contact surface of the diaphragm member 122, it is possible to improve bending durability by alleviating stress concentration.

(8) In the fluid control device (diaphragm valve 1) according to any one of (1) to (7), the diaphragm member 122 has a flow path (input flow path 121a and output flow path 121b) through which the control fluid flows. The fluid control device (diaphragm valve 1) includes a valve seat (for example, an annular valve seat 121d) on which the valve body 123 comes into contact and separates. In particular, the valve body 123 is characterized in that at least the portion that contacts the valve seat (annular valve seat 121d) is a second mold transfer surface (mold transfer surface 127).

According to the fluid control device (diaphragm valve 1) described in (8), the diaphragm member 122 includes the valve body 123 that opens and closes the channels (input channel 121a, output channel 121b) through which the control fluid flows, and The control device includes a valve seat (annular valve seat 121d) against which the valve body 123 comes into contact and separates. For example, in addition to the diaphragm valve 1, this applies to needle valves and the like. In this case, it is desirable that at least the portion of the valve body 123 that comes into contact with the valve seat (annular valve seat 121d) is the second mold transfer surface (mold transfer surface 127). Conventionally, the portion of the valve body that comes into contact with the valve seat tends to wear out during repeated opening and closing operations, and there is a risk that wear particles generated by the wear may mix into the control fluid as particles. By using the portion of the valve body 123 that comes into contact with the valve seat (annular valve seat 121d) as a mold transfer surface 127 and reducing the surface roughness, it is possible to suppress the occurrence of wear. Note that the "second mold transfer surface" may be a continuous surface or a separate surface from the liquid contact surface mold transfer surface 127 of the thin film portion 124. In this embodiment, the mold transfer surface 127 (second mold transfer surface) of the liquid contact surface of the sealing surface 123d is continuous with the mold transfer surface 127 of the liquid contact surface of the thin film portion 124. However, for example, instead of using the large diameter portion 123c of the valve body 123 as the mold transfer surface, the mold transfer surface of the thin film portion 124 and the mold transfer surface of the sealing surface 123d may be formed as separate mold transfer surfaces that are not continuous. Good as a mask.

Furthermore, in order to solve the above problems, the method for manufacturing a fluid control device of the present invention has the following configuration.

(9) An input flow path 121a into which a control fluid is input, an output flow path 121b for outputting the control fluid input from the input flow path 121a, and a diaphragm member 122 made of fluororesin. 122 includes a thin film portion 124 having flexibility, and in a method for manufacturing a fluid control device (for example, a diaphragm valve 1) that controls a control fluid by elastically deforming the thin film portion 124, the thin film portion 124 includes a liquid contact surface that comes into contact with the control fluid, at least a part of the liquid contact surface is a mold transfer surface 127, and molds a semi-finished product 50 of the diaphragm member 122 provided with the mold transfer surface 127. The present invention is characterized by comprising a first step of performing a cutting process, and a second step of obtaining the shape of the diaphragm member 122 by cutting the semi-finished product 50 while leaving the mold transfer surface 127. The mold transfer surface 127 is a surface onto which the cavity surface of an injection molding mold, the cavity surface of a compression molding mold, or the cavity surface of a transfer molding mold is transferred.

According to the method for manufacturing a fluid control device described in (9), at least a part of the liquid contact surface provided in the thin film portion 124 becomes the mold transfer surface 127, so that it is better to form the liquid contact surface by cutting. It is also possible to reduce the surface roughness of the liquid contact surface. Therefore, it is possible to reduce the occurrence of stagnation of the control fluid (for example, a chemical solution) on the liquid contact surface, and to reduce the possibility that components of the control fluid will adhere to the liquid contact surface. If the risk of the control fluid components adhering can be reduced, the risk of the control fluid components falling off from the liquid contact surface and being mixed into the control fluid as particles can also be reduced.

Note that it does not matter whether a part of the liquid contact surface of the thin film portion 124 is used as the mold transfer surface, or whether all of the liquid contact surface of the thin film portion 124 is used as the mold transfer surface. When using a part of the liquid contact surface as a mold transfer surface, for example, when the thin film portion 124 is elastically deformed, it is possible to use a part that is largely deformed or a part where stress tends to concentrate as the mold transfer surface. It will be done. This is because areas with large deformation or areas where stress tends to concentrate are likely to fall off when components of the control fluid adhere to them, and by forming the mold transfer surface, the components of the control fluid will prevent the components from adhering. It is.

(10) The method for manufacturing a fluid control device according to (9) is characterized in that the surface of the thin film portion 124 opposite to the liquid contact surface is a cut surface 128.

Since the surface of the thin film portion 124 opposite to the liquid-contacted surface does not come into contact with the control fluid, it is not necessary to make the surface roughness as low as that of the liquid-contacted surface. Furthermore, since the thin film portion 124 has a thickness of about 0.1 to 0.5 mm, it is difficult to mold it with a mold. Therefore, by making the surface of the thin film part opposite to the liquid contact surface the cutting surface 128, it is possible to prevent the components of the control fluid from adhering to the liquid contact surface of the diaphragm member and to reduce manufacturing costs. Can be done.

(11) The method for manufacturing a fluid control device according to (9) or (10) is characterized in that the mold transfer surface 127 has a surface roughness of Ra of 0.05 μm or less.

For example, in fluid control equipment used in semiconductor manufacturing equipment, the requirement to prevent particles from being mixed into the control fluid is becoming stricter year by year in order to improve the yield of semiconductors. According to the method for manufacturing a fluid control device described in (11), since the surface roughness of the mold transfer surface 127 is Ra 0.05 μm or less, the occurrence of stagnation of the control fluid on the liquid contact surface can be more reliably prevented. It is possible to reduce the risk of components of the control fluid adhering to the liquid-contacted surface, and to withstand the above-mentioned requirements that are becoming stricter year by year. Note that although the fluid control device used in semiconductor manufacturing equipment is mentioned above, the fluid control device according to the present invention is not limited to being used in semiconductor manufacturing equipment.

(12) In the method for manufacturing a fluid control device according to any one of (9) to (11), the fluororesin is a perfluorinated resin having a melt flow rate of 2.2 g/10 min or more and 2.8 g/10 min or less. It is characterized by being an alkoxyalkane.

(13) In the method for manufacturing a fluid control device according to any one of (9) to (12), the fluororesin has a specific gravity in a range of 2.08 or more and 2.16 or less. do.

Conventionally, there has been concern that repeated elastic deformation of the thin film portion may cause cracks to occur in the thin film portion. When a crack occurs, the control fluid may remain in the crack, and components of the deteriorated control fluid may adhere to the crack. The adhesion of components of the control fluid causes particles to be mixed into the control fluid.

According to the method for manufacturing a fluid control device described in (12) or (13), the bending durability of the thin film portion 124 can be improved. Therefore, it is possible to prevent cracks from occurring in the thin film portion 124, and it is possible to prevent the control fluid from stagnation and the generation of particles. Note that the melt flow rate (MFR) here means the MFR of the fluororesin, which is the raw material, after molding. MFR after molding is measured by melting and molding the raw material fluororesin and then melting it again. This measurement is based on ASTM D1238, at a resin temperature of 372 degrees Celsius, a load of 5 kg, and an orifice. The test was carried out under the conditions that the inner diameter was 2.1 mm and the orifice height was 8.0 mm.

(14) In the method for manufacturing a fluid control device according to any one of (9) to (13), the mold transfer surface 127 includes a mold (for example, a female mold 60, 104) used for compression molding or transfer molding. ) is characterized in that the mirror-finished surfaces 60b, 104b are transferred.

When the diaphragm member 122 is molded by injection molding, flow marks are formed on the surface of the thin film portion 124 due to the flow of resin during molding, which adversely affects the surface roughness of the liquid contact surface (mold transfer surface 127). There is a risk. However, according to the method for manufacturing a fluid control device described in (14), the mold transfer surface 127 is the mirror-finished surface 60b, 104b of the mold (for example, female mold 60, 104) used for compression molding or transfer molding. is transferred, it is possible to reliably set the surface roughness of the mold transfer surface 127 to Ra 0.05 μm or less. As in compression molding or transfer molding, if pressure is applied to the molten resins 91, 92 in the molds (female molds 60, 104), the molten resins 91, 92 in the molds (female molds 60, 104) are This is because it can be pressed against the surfaces of the cavities 60a and 104a (mirror-finished surfaces 60b and 104b) of the mold, thereby making it possible to form the mold transfer surface 127 smoothly.

(15) In the method for manufacturing a fluid control device according to (14), the liquid contact surface is a curved surface.

When forming the thin film part by cutting as in the diaphragm described in Patent Document 1, it is difficult to form the thin film part as a curved surface, so it is generally formed as a flat surface. In this case, when the thin film portion undergoes elastic deformation, stress concentration is likely to occur, and there is a concern that the bending durability may deteriorate.

According to the method for manufacturing a fluid control device described in (15), the liquid contact surface can be formed as a curved surface having the mold transfer surface 127 by compression molding or transfer molding. Therefore, while preventing components of the control fluid from adhering to the liquid contact surface of the diaphragm member 122, it is possible to improve bending durability by alleviating stress concentration.

(16) In the method for manufacturing a fluid control device according to any one of (9) to (15), the diaphragm member 122 has a channel through which the control fluid flows (the input channel 121a and the output channel 121b communicate with each other). The fluid control device (diaphragm valve 1) includes a valve seat (for example, an annular valve seat 121d) that the valve body 123 comes into contact with and separates from the fluid control device (diaphragm valve 1). At least the portion of the valve body 123 that contacts the valve seat (annular valve seat 121d) is a second mold transfer surface (mold transfer surface 127), and the second mold transfer surface is formed in the first step. In a second step, the semi-finished product 50 is cut while leaving the second mold transfer surface (mold transfer surface 127), thereby forming a diaphragm. The feature is that the shape of the member 122 is obtained.

According to the method for manufacturing a fluid control device described in (16), the diaphragm member 122 includes the valve body 123 that opens and closes the flow path (input flow path 121a, output flow path 121b) through which the control fluid flows, and includes a valve seat (annular valve seat 121d) against which the valve body 123 comes into contact and separates. For example, in addition to the diaphragm valve 1, needle valves and the like correspond to the above-mentioned fluid control equipment. In this case, it is desirable that at least the portion of the valve body 123 that contacts the valve seat (annular valve seat 121d) be the second mold transfer surface (mold transfer surface 127). Conventionally, the portion of the valve body that comes into contact with the valve seat tends to wear out during repeated opening and closing operations, and there is a risk that wear powder generated by the wear may mix into the control fluid as particles. By using the portion of the valve body 123 that comes into contact with the valve seat (annular valve seat 121d) as a mold transfer surface 127 and reducing the surface roughness, it is possible to suppress the occurrence of wear. Note that the "second mold transfer surface" may be a continuous surface or a separate surface from the liquid contact surface mold transfer surface 127 of the thin film portion 124. In this embodiment, the mold transfer surface 127 (second mold transfer surface) of the liquid contact surface of the sealing surface 123d is continuous with the mold transfer surface 127 of the liquid contact surface of the thin film portion 124. However, for example, instead of using the large diameter portion 123c of the valve body 123 as the mold transfer surface, the mold transfer surface of the thin film portion 124 and the mold transfer surface of the sealing surface 123d may be made into separate mold transfer surfaces that are not continuous. Good as a mask.

Note that the above embodiments are merely illustrative and do not limit the present invention in any way. Therefore, it goes without saying that various improvements and modifications can be made to the present invention without departing from the spirit thereof. For example, although the driving method of the diaphragm valve 1 is described as an air operated type, the driving method is not limited to this.

Further, the fluid control device is not limited to the diaphragm valve 1 described above, and may be, for example, a suckback valve, a needle valve, a regulator, or a diaphragm pump described below.

(About suck back valve)
The suckback valve 3, which is an example of a fluid control device, includes a drive section 31 and a valve section 32, as shown in FIG. 12, for example. The valve portion 32 includes an input flow path 321a for inputting a control fluid (for example, a chemical solution), and an output flow path 321b for outputting the control fluid input from the input flow path 321a. The input flow path 321a and the output flow path 321b communicate with each other, thereby forming a series of flow paths through which the control fluid flows.

The valve portion 32 further includes a diaphragm member 322 made of fluororesin. This diaphragm member 322 includes a thin film portion 324 having flexibility. When the diaphragm member 322 is moved in the vertical direction in FIG. 12 by the drive unit 31, the thin film portion 324 is elastically deformed in accordance with this movement. This elastic deformation of the thin film portion 324 changes the volume of the flow path, making it possible to suck back the control fluid flowing through the flow path. The surface of the thin film portion 324 of the diaphragm member 322 facing the flow path is a liquid contact surface that contacts the control fluid. The entire surface in contact with the liquid is formed by a mold transfer surface 327 (range indicated by a thick dashed line in FIG. 12). Note that a part of the liquid contact surface may be used as a mold transfer surface.

The surface roughness of the mold transfer surface 327 is preferably Ra of 0.1 μm or less, and more preferably Ra of 0.05 μm or less. Further, the mold transfer surface 327 may be formed by injection molding, compression molding, or transfer molding, but it is most desirable to form it by the above-described compression molding or transfer molding.

(About the needle valve)
The needle valve 4, which is an example of a fluid control device, includes a drive section 41 and a valve section 42, as shown in FIG. 13, for example. The valve portion 42 includes an input flow path 421a for inputting a control fluid (for example, a chemical solution), and an output flow path 421b for outputting the control fluid input from the input flow path 421a. Further, the valve portion 42 includes a valve chamber 421c, and the input flow path 421a and the output flow path 421b communicate with each other via the valve chamber 421c. The input flow path 421a and the output flow path 421b communicate with each other, thereby forming a series of flow paths through which the control fluid flows. Further, an annular valve seat 421d is provided on the bottom surface of the valve chamber 421c.

The valve portion 42 further includes a diaphragm member 422 made of fluororesin. This diaphragm member 422 includes a substantially conical valve body 423 and a flexible thin film portion 424 surrounding the valve body 423. A portion of the outer peripheral surface of the valve body 423 that faces the annular valve seat 421d is a sealing surface 423d, and when the valve body 423 is moved in the vertical direction in FIG. The flow of control fluid is controlled by contacting and separating from the seat 421d. Further, as the valve body 423 moves up and down, the thin film portion 424 is elastically deformed. The surface of the thin film portion 424 facing the flow path and the outer peripheral surface of the valve body 423 are liquid contact surfaces that come into contact with the control fluid. The entire surface in contact with the liquid is formed by a mold transfer surface 427 (range indicated by a thick dashed line in FIG. 13). Note that a part of the liquid contact surface may be used as a mold transfer surface.

The surface roughness of the mold transfer surface 427 is preferably Ra of 0.1 μm or less, and more preferably Ra of 0.05 μm or less. Further, the mold transfer surface 427 may be formed by injection molding, compression molding, or transfer molding, but it is most desirable to form it by the above-described compression molding or transfer molding.

(About the regulator)
For example, as shown in FIG. 14, the regulator 5, which is an example of a fluid control device, has an input flow path 521a for inputting a control fluid (for example, a chemical solution), and outputs the control fluid input from the input flow path 521a. It is provided with an output flow path 521b for. Further, the regulator 5 includes a first fluid chamber 521c and a second fluid chamber 521d that communicate with each other, and connects to an input flow path 521a via the first fluid chamber 521c and the second fluid chamber 521d. It is in communication with the output flow path 521b. The input flow path 521a and the output flow path 521b communicate with each other, thereby forming a series of flow paths through which the control fluid flows. Furthermore, an annular valve seat 521d is provided on the upper surface of the first fluid chamber 521c on the second fluid chamber 521d side.

The regulator 5 further includes a first diaphragm member 522A and a second diaphragm member 522B made of fluororesin.

The first diaphragm member 522A includes a valve body 523 and a flexible thin film portion 524A around the lower end side of the valve body 523. The surface of the valve body 523 that faces the annular valve seat 521d is a sealing surface 523d, and when the valve body 423 is moved in the vertical direction in FIG. Controls fluid pressure. Further, as the valve body 523 moves up and down, the thin film portion 524 is elastically deformed. The surface of the thin film portion 524A facing the flow path and the outer peripheral surface of the valve body 523 are liquid contact surfaces that come into contact with the control fluid. The entire liquid contact surface is formed by a mold transfer surface 527A (range indicated by a thick dashed line in FIG. 14). Note that a part of the liquid contact surface may be used as a mold transfer surface.

The second diaphragm member 522B is connected to the upper end of the first diaphragm member 522A at the center thereof, and has a flexible thin film portion 524B on its outer periphery. This thin film portion 524B is elastically deformed as the valve body 523 moves up and down. The surface of the thin film portion 524B facing the flow path is a liquid contact surface that comes into contact with the control fluid. The entire liquid contact surface is formed by a mold transfer surface 527B (the range indicated by the thick two-dot chain line in FIG. 14). Note that a part of the liquid contact surface may be used as a mold transfer surface.

The surface roughness of the mold transfer surfaces 527A and 527B is preferably Ra of 0.1 μm or less, more preferably Ra of 0.05 μm or less. Further, the mold transfer surfaces 527A and 527B may be formed by injection molding, compression molding, or transfer molding, but it is most desirable to form them by the above-described compression molding or transfer molding.

(About diaphragm pump)
For example, as shown in FIG. 15, the diaphragm pump 6, which is an example of a fluid control device, has an input channel 621a for inputting a control fluid (for example, a chemical solution), and an output channel 621a for outputting the control fluid input from the input channel 621a. An output flow path 621b is provided for this purpose.

The diaphragm pump 6 has an internal space partitioned into a drive chamber 62 and a fluid chamber 63 by a thin film portion 624, which will be described later. An air supply path 61 is in communication with the drive chamber 62 . Operation air can be supplied to the drive chamber 62 from this air supply path 61 . The fluid chamber 63 communicates the input flow path 621a and the output flow path 621b. The input flow path 621a and the output flow path 621b communicate with each other, thereby forming a series of flow paths through which the control fluid flows.

The diaphragm pump 6 further includes a diaphragm member 622 made of fluororesin. This diaphragm member 622 includes a thin film portion 624 having flexibility. By inputting and outputting operating air to and from the drive chamber 62 through the air supply path 61, the thin film portion 624 is elastically deformed in the vertical direction in FIG. The volume of the fluid chamber 63 is varied by elastic deformation of the thin film portion 624, allowing input and output of control fluid. The surface of the thin film portion 624 facing the fluid chamber 63 is a liquid contact surface that comes into contact with the control fluid. The entire surface in contact with the liquid is formed by a mold transfer surface 627 (range indicated by a thick dashed line in FIG. 15). Note that a part of the liquid contact surface may be used as a mold transfer surface.

The surface roughness of the mold transfer surface 627 is preferably Ra of 0.1 μm or less, and more preferably Ra of 0.05 μm or less. Further, the mold transfer surface 627 may be formed by injection molding, compression molding, or transfer molding, but it is most desirable to form it by the above-described compression molding or transfer molding.

1 Diaphragm valve 121a Input flow path 121b Output flow path 121d Annular valve seat (an example of a valve seat)
122 Diaphragm member 123 Valve body 124 Thin film portion 127 Mold transfer surface

Claims (16)

An input channel into which a control fluid is input, an output channel for outputting the control fluid input from the input channel, and a diaphragm member made of fluororesin, the diaphragm member having flexibility. A fluid control device comprising a thin film portion having a thin film portion and controlling the control fluid by elastically deforming the thin film portion,
The thin film portion includes a liquid contact surface that comes into contact with the control fluid;
at least a portion of the liquid contact surface is a mold transfer surface;
Fluid control equipment featuring: The fluid control device according to claim 1,
The surface of the thin film portion opposite to the liquid contact surface is a machined surface;
Fluid control equipment featuring: The fluid control device according to claim 1 or 2,
The surface roughness of the mold transfer surface is Ra 0.05 μm or less;
Fluid control equipment featuring: The fluid control device according to claim 1 or 2,
The fluororesin is a perfluoroalkoxyalkane with a melt flow rate of 2.2 g/10 min or more and 2.8 g/10 min or less;
Fluid control equipment featuring: The fluid control device according to claim 1 or 2,
The fluororesin has a specific gravity of 2.08 or more and 2.16 or less,
Fluid control equipment featuring: The fluid control device according to claim 1 or 2,
The mold transfer surface is a mirror-finished surface of a mold used for compression molding or transfer molding;
Fluid control equipment featuring: The fluid control device according to claim 6,
the liquid contact surface is a curved surface;
Fluid control equipment featuring: The fluid control device according to claim 1 or 2,
The diaphragm member includes a valve body that opens and closes a flow path through which the control fluid flows;
The fluid control device includes a valve seat on which the valve body abuts and separates;
At least a portion of the valve body that comes into contact with the valve seat is a second mold transfer surface;
Fluid control equipment featuring: An input channel into which a control fluid is input, an output channel for outputting the control fluid input from the input channel, and a diaphragm member made of fluororesin, the diaphragm member having flexibility. In a method for manufacturing a fluid control device, the method includes:
The thin film portion includes a liquid contact surface that comes into contact with the control fluid;
at least a portion of the liquid contact surface is a mold transfer surface;
a first step of molding a semi-finished product of the diaphragm member including the mold transfer surface;
a second step of obtaining the shape of the diaphragm member by cutting the semi-finished product while leaving the mold transfer surface;
to have
A method of manufacturing a fluid control device characterized by: The method for manufacturing a fluid control device according to claim 9,
The surface of the thin film portion opposite to the liquid contact surface is a machined surface;
A method of manufacturing a fluid control device characterized by: The method for manufacturing a fluid control device according to claim 9 or 10,
The surface roughness of the mold transfer surface is Ra 0.05 μm or less;
A method of manufacturing a fluid control device characterized by: The method for manufacturing a fluid control device according to claim 9 or 10,
The fluororesin is a perfluoroalkoxyalkane with a melt flow rate of 2.2 g/10 min or more and 2.8 g/10 min or less;
A method of manufacturing a fluid control device characterized by: The method for manufacturing a fluid control device according to claim 9 or 10,
The fluororesin has a specific gravity of 2.08 or more and 2.16 or less,
A method of manufacturing a fluid control device characterized by: The method for manufacturing a fluid control device according to claim 9 or 10,
The mold transfer surface is a mirror-finished surface of a mold used for compression molding or transfer molding;
A method of manufacturing a fluid control device characterized by: The method for manufacturing a fluid control device according to claim 14,
the liquid contact surface is a curved surface;
A method of manufacturing a fluid control device characterized by: The method for manufacturing a fluid control device according to claim 9 or 10,
The diaphragm member includes a valve body that opens and closes a flow path through which the control fluid flows;
The fluid control device includes a valve seat on which the valve body abuts and separates;
At least a portion of the valve body that comes into contact with the valve seat is a second mold transfer surface;
obtaining the semi-finished product including the second mold transfer surface through the first step;
obtaining the shape of the diaphragm member by cutting the semi-finished product while leaving the second mold transfer surface in the second step;
A method of manufacturing a fluid control device characterized by:

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