Flow control device, vaporization supply device, and method for manufacturing a flow control device

Abstract

To provide a pressure-type flow rate control device capable of accurately controlling the flow rate in a wide pressure range without causing leakage even in high-temperature gas.SOLUTION: A flow rate control device 20 includes a control valve 22, a first pressure sensor 24 on the downstream side of the control valve, a throttle section 28 on the downstream side of the first pressure sensor, a second pressure sensor 26 on the downstream side of the throttle section, a first flow path block BL1 carrying the control valve and the first pressure sensor, and a second flow path block BL2 carrying the second pressure sensor. A gasket member is sandwiched between the first flow path block and the second flow path block. A connection hole H includes a first hole portion H1 facing the first flow path block and a second hole portion H2 having a larger cross-sectional area and extending outward, and is formed in the second flow path block. The length La of the first hole portion H1 is shorter than the distance Lb from a connection surface BLS of the first and second flow path blocks to a sealed end of the second pressure sensor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a flow control device, a vaporization supply device including the same, and a method for manufacturing the flow control device.

Background Art

[0002] In semiconductor manufacturing equipment, chemical plants, etc., it is required to supply raw material gases and etching gases to a process chamber at a desired flow rate. As a gas flow rate control device, a mass flow controller (thermal mass flow controller) and a pressure type flow control device are known.

[0003] The pressure type flow control device is widely used because it can control the mass flow rate of various fluids with high accuracy by a relatively simple configuration combining a control valve and a throttle part (for example, an orifice plate or a critical nozzle). The pressure type flow control device has excellent flow control characteristics such that it can stably perform flow control even when the supply pressure on the primary side fluctuates greatly.

[0004] Some pressure type flow control devices adjust the flow rate of the fluid flowing to the downstream side of the throttle part by controlling the fluid pressure (hereinafter sometimes referred to as the upstream pressure P1) between the control valve and the throttle part. The upstream pressure P1 is measured by a pressure sensor provided in the flow path, and by adjusting the opening degree of the control valve based on the output of the pressure sensor, the upstream pressure P1 and thus the mass flow rate can be controlled to a desired value.

[0005] Also, as a pressure type flow control device, there is known one that can control the flow rate based on the upstream pressure P1 and the downstream pressure P2 (the fluid pressure on the downstream side of the throttle part) (for example, Patent Document 1). In this type of flow control device, even when the upstream pressure P1 is not greater than the critical ratio compared to the downstream pressure P2 and does not satisfy the critical expansion condition, the flow control can be performed accurately.

[0006] On the other hand, Patent Document 2 discloses a vaporization supply device that heats a liquid material introduced into a vaporizer and supplies the generated gas with controlled flow rate. In the vaporizer, liquid or solid raw materials can be heated by a heater to generate a desired process gas used in semiconductor device manufacturing. The generated gas is supplied to the process chamber after its flow rate is controlled by a flow control device located downstream of the vaporizer. Such a vaporization supply device is used, for example, when forming films by metal-organic vapor deposition (MOCVD).

[0007] The flow rate of the gas produced by the vaporizer can also be controlled using the pressure-type flow control device described above. Patent documents 2 and 3 disclose an integrated vaporization supply system in which a pressure-type flow control device is located adjacent to the downstream side of the vaporizer.

[0008] The gas produced in a vaporizer is often relatively hot (e.g., 150°C or higher). Therefore, it is preferable that the flow control device is also capable of handling high-temperature gases. In the flow control device described in Patent Document 2, the piezoelectric actuator is positioned away from the gas flow path via a heat dissipation spacer so that the control valve (typically a piezoelectric element-driven valve) is not damaged by high-temperature gases. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] International Publication No. 03 / 058363 [Patent Document 2] International Publication No. 2016 / 174832 [Patent Document 3] International Publication No. 2019 / 021948 [Patent Document 4] International Publication No. 2022 / 137812 [Overview of the project] [Problems that the invention aims to solve]

[0010] The flow rate of the high-temperature gas generated using a vaporizer can be controlled based on measurements of both the upstream pressure P1 and the downstream pressure P2. However, if the downstream pressure P2 is also measured, a pressure sensor must be placed not only on the upstream side of the throttling section but also on the downstream side of the throttling section.

[0011] However, it was found that in flow control devices equipped with a pressure sensor downstream of the throttle, gas leaks can occur from the location of the sensor. In particular, in pressure-type flow control devices positioned downstream of the vaporizer as described above, it was found that the likelihood of gas leaks occurring around the downstream pressure sensor increases when controlling the flow rate of high-temperature gas.

[0012] The present invention was made to solve the above problems, and its main objective is to provide a flow control device that can prevent leakage even when controlling the flow rate of high-temperature gas over a wide range, a vaporization supply device equipped with the same, and a method for manufacturing such a flow control device. [Means for solving the problem]

[0013] A flow control device according to an embodiment of the present invention comprises a control valve, a first pressure sensor provided in the flow path downstream of the control valve, a throttling portion provided in the flow path downstream of the first pressure sensor, a second pressure sensor provided in the flow path downstream of the throttling portion, a first flow path block supporting the control valve and the first pressure sensor, and a second flow path block provided adjacent to the first flow path block and supporting the second pressure sensor, wherein a gasket member is sandwiched at the connection portion between the first flow path block and the second flow path block, and the second flow path block extends toward the first flow path block. The device has a connection hole, the connection hole includes a first hole portion having a first cross-sectional area and facing the first flow path block, and a second hole portion having a second cross-sectional area larger than the first cross-sectional area and extending outward from the first hole portion, a stepped surface formed at the boundary between the first hole portion and the second hole portion, the second flow path block is fixed to the first flow path block by the enlarged diameter portion of the block fixing member placed in the connection hole pressing against the stepped surface of the connection hole, and the length of the first hole portion of the connection hole is shorter than the distance from the connection surface between the first flow path block and the second flow path block to the seal end of the second pressure sensor.

[0014] In one embodiment, the sealing end of the second pressure sensor is defined by the outer circumferential surface of an annular gasket arranged to seal the second pressure sensor.

[0015] In one embodiment, the gasket member has a structure that includes the constricted portion.

[0016] In one embodiment, the gasket member is a gasket-type orifice member.

[0017] In one embodiment, the second flow channel block is provided with four connection holes, and the block fixing member is placed in each connection hole.

[0018] In one embodiment, the four connection holes include two connection holes provided on the side closer to the second pressure sensor mounting surface of the second flow path block and two connection holes provided on the farther side, and a flow path formed inside the second flow path block and extending from the gasket member passes through a position between the two connection holes on the side closer to the second pressure sensor mounting surface and the two connection holes on the side farther from the second pressure sensor mounting surface.

[0019] In one embodiment, the first hole portion of the connection hole is closed with respect to the side surface of the second flow path block, and the second hole portion is open with respect to the side surface of the second flow path block.

[0020] The vaporization supply device according to an embodiment of the present invention includes a vaporizer and the above-described flow rate control device connected adjacent to the downstream side of the vaporizer.

[0021] The method for manufacturing a flow rate control device according to an embodiment of the present invention is the above-described method for manufacturing a flow rate control device, and includes a step of preparing the first flow path block, the second flow path block, the block fixing member, and the second pressure sensor, and using the block fixing member disposed in the connection hole formed in the second flow path block, a step of fixing the second flow path block to the first flow path block, and a step of fixing the second pressure sensor to the second flow path block after the step of fixing the second flow path block to the first flow path block.

Advantages of the Invention

[0022] According to an embodiment of the present invention The flow According to the flow rate control device and the vaporization supply device, it is possible to appropriately control the flow rate of a gas used in a semiconductor manufacturing apparatus or the like and supply it over a wide control flow rate range, and it is also possible to suppress the occurrence of leaks even when supplying a high-temperature gas.

Brief Description of the Drawings

[0023] [Figure 1]This is a schematic diagram showing a gas supply system including a vaporization supply device equipped with a flow rate control device according to an embodiment of the present invention. [Figure 2] This figure shows a specific configuration example of a vaporization supply device equipped with a flow control device according to an embodiment of the present invention. [Figure 3] This is a perspective view showing an example of a flow path block for fixing a second pressure sensor used in a flow control device. [Figure 4] This diagram shows how the flow path block for fixing the second pressure sensor is fixed to the adjacent flow path block. [Modes for carrying out the invention]

[0024] Embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments.

[0025] Figure 1 shows a gas supply system 100 including a flow rate control device 20 according to an embodiment of the present invention and a vaporization supply device 50 equipped with the flow rate control device 20 downstream of the vaporizer 10. Figure 2 shows a specific configuration example of the vaporization supply device 50.

[0026] As shown in Figure 1, the gas supply system 100 comprises a liquid material source 2, a vaporization supply device 50 connected to the liquid material source 2, and a process chamber 6 connected to the vaporization supply device 50 via a shut-off valve 4. The vaporization supply device 50 comprises a vaporizer 10 and a flow rate control device 20 located downstream of the vaporizer 10. In the vaporization supply device 50 shown in Figure 2, the vaporizer 10 and the flow rate control device 20 are installed adjacently and integrally, and the shut-off valve 4 is also installed integrally downstream of the flow rate control device 20.

[0027] The gas supply system 100 is configured to vaporize the liquid material L from the liquid material source 2 in the vaporizer 10, and to supply the resulting material gas G to the process chamber 6 by controlling the flow rate with the flow rate control device 20. In Figure 1, the supply path for the liquid material L is shown by a thick solid line, and the supply path for the material gas G is shown by a thick dashed line.

[0028] A vacuum pump 8 is connected to the process chamber 6, which can reduce the pressure inside the chamber and in the flow paths connected to the chamber. Although only one gas supply line is shown in Figure 1, it goes without saying that multiple gas supply lines may be connected to the process chamber 6 to supply various gases.

[0029] Examples of liquid materials L used include HCDS (Si2Cl6), or organometallic materials such as TEOS (tetraethyl orthosilicate), TMGa (trimethylgallium), and TMAl (trimethylaluminum). These materials are liquid at room temperature and can be vaporized by heating them to, for example, 150°C to 200°C. The generated material gas G is then used in the process chamber 6 to create a silicon nitride film (SiN). x It is used to form insulating films such as silicon oxide films (SiO2 films).

[0030] The vaporization supply device 50 is equipped with multiple heaters, which can independently heat the vaporizer 10 and the flow rate control device 20 to a desired temperature. As heaters, jacket heaters or heaters that heat a metal block from the outside can be used, such as heaters formed by inserting a cartridge heater as a heating element into an aluminum plate as a heat transfer member. Such heaters are disclosed, for example, in Patent Document 3 (International Publication No. 2019 / 021948).

[0031] The vaporizer 10 is configured to heat the liquid material L, which has been pumped from the liquid material source 2, in the vaporization chamber of the vaporization unit 16 using a heater to generate a material gas G. Furthermore, the material gas G generated in the vaporizer 10 needs to be supplied to the process chamber 6 while being kept at a relatively high temperature to prevent reliquefaction. In contrast, as shown in Figure 2, by using a vaporization supply device 50 in which the vaporizer 10 and the flow control device 20 are arranged adjacently and integrally, the area that needs to be kept at a high temperature can be compactly arranged by placing it near the process chamber 6.

[0032] As shown in Figure 2, the vaporizer 10 of this embodiment includes a preheating section 14, a vaporization section 16, and a liquid replenishment valve 18 provided in the flow path between them. By preheating the liquid material L in the preheating section 14 to a temperature that does not cause vaporization, vaporization in the vaporization section 16 can be facilitated. This suppresses the decrease in liquid temperature due to the latent heat of vaporization, making it easier to maintain a high supply pressure P0 of the material gas G and stably supply the gas.

[0033] To facilitate maintaining the preheating section 14 and the vaporization section 16 at different temperatures, an insulating member 30 may be provided between the preheating section 14 and the vaporization section 16. The insulating member 30 may be, for example, a resin plate material such as PEEK (Poly Ether Ether Ketone).

[0034] Furthermore, in the vaporization supply device 50, the supply pressure P0 of the material gas G generated in the vaporizer 10 is measured by the supply pressure sensor 12. As shown in Figure 2, the supply pressure sensor 12 may be installed upstream of the control valve 22 in the first flow path block BL1, to which the control valve 22 and the first pressure sensor 24 that constitute the flow control device 20 are attached.

[0035] By measuring the supply pressure P0 using the supply pressure sensor 12, it is possible to determine whether the amount of liquid material L in the vaporization chamber is sufficient. When the supply pressure P0 falls below a threshold, the liquid replenishment valve 18 can be opened to replenish the liquid material, enabling stable gas generation in the vaporization section 16. The vaporizer 10 may also be equipped with a liquid detection unit (not shown) that can detect when more than a predetermined amount of liquid material L has been supplied to the vaporization section 16. By providing a liquid detection unit, it is possible to prevent oversupply of liquid material L to the vaporization section 16. The liquid detection unit may consist of, for example, a thermometer (platinum resistance thermometer, thermocouple, thermistor, etc.), a liquid level gauge, a load cell, etc., placed in the vaporization chamber.

[0036] The following describes the detailed configuration of the flow rate control device 20 for controlling the flow rate of the material gas G generated in the vaporizer 10.

[0037] As shown in Figures 1 and 2, the flow control device 20 of this embodiment includes a control valve 22, a first pressure sensor 24 provided downstream of the control valve 22, a throttling section 28 provided in the flow path downstream of the control valve 22 and the first pressure sensor 24, and a second pressure sensor 26 provided downstream of the throttling section 28. As will be described later, in this embodiment, the throttling section 28 is configured to be included in a gasket member, and corresponds to a structure in which a gasket member sandwiched between flow path blocks has a throttling function.

[0038] The first pressure sensor (or upstream pressure sensor) 24 can measure the upstream pressure P1 between the control valve 22 and the throttling section 28, and the second pressure sensor (or downstream pressure sensor) 26 can measure the downstream pressure P2 on the downstream side of the throttling section 28. The control valve 22, the first pressure sensor 24, and the second pressure sensor 26 are electrically connected to a control circuit (not shown).

[0039] The flow rate control device 20 is a pressure-type flow rate control device that can control the flow rate of gas flowing downstream of the throttling section 28 by controlling the opening degree of the control valve 22 based on the output of the first pressure sensor 24 (upstream pressure P1), or based on both the output of the first pressure sensor 24 (upstream pressure P1) and the output of the second pressure sensor 26 (downstream pressure P2). The flow rate control device 20 may also be equipped with a temperature sensor (not shown) for measuring the temperature of the gas downstream of the control valve 22. By additionally referring to the output of the temperature sensor when controlling the opening degree of the control valve 22, the gas flow rate can be controlled more accurately.

[0040] As shown in Figure 2, in this embodiment, the control valve 22 and the first pressure sensor 24 are fixed to the upstream first flow path block BL1, which has a flow path inside. On the other hand, the second pressure sensor 26 is fixed to the downstream second flow path block BL2, which also has a flow path inside. Here, a flow path block is typically a metal block body in which a flow path and a fluid containment space are formed, and is also called a main body block. The vaporization supply device 50 of this embodiment is manufactured by arranging a plurality of flow path blocks adjacent to each other to form a flow path, and by attaching the necessary sensors and valves to the flow path blocks (main body blocks).

[0041] Furthermore, a throttling portion 28 (or gasket member) is positioned in a recess formed at the connection (or boundary) between the first flow path block BL1 and the second flow path block BL2 (in this case, a main recess formed in the first flow path block BL1 and a secondary recess formed in the second flow path block BL2). The first flow path block BL1 and the second flow path block BL2 are fixed to each other by sandwiching the throttling portion 28 at their connection surfaces. The first flow path block BL1 and the second flow path block BL2 are metal blocks made of stainless steel such as SUS316L, and gas flow paths are formed inside them by drilling holes.

[0042] As the control valve 22, for example, a piezoelectric element-driven valve can be used. A piezoelectric element-driven valve is a valve with adjustable opening or proportional valve whose opening degree can be arbitrarily adjusted by controlling the amount of movement of the diaphragm valve body by controlling the voltage applied to one or more stacked piezoelectric elements built into a piezoelectric actuator.

[0043] As shown in Figure 2, the control valve 22 may have a configuration in which a piezo actuator 22D and a rod-shaped heat dissipation spacer 22E are arranged in a line to counter high temperatures. The heat dissipation spacer 22E is made of, for example, Invar material, and by moving it in conjunction with the piezo actuator 22D, the opening and closing of the diaphragm valve 22V (see Figure 4) can be controlled.

[0044] In this configuration, the high-temperature gas flowing through the internal flow path of the first flow path block BL1 and the heat from the external heater that heats the first flow path block BL1 prevent the piezo actuator 22D from being heated to a high temperature. Therefore, it is possible to properly control the flow rate while preventing the piezo element from exceeding its heat resistance temperature and preventing damage or malfunction of the piezo actuator 22D.

[0045] Furthermore, in this embodiment, the throttling section 28 is constructed using a gasket-type orifice member. The gasket-type orifice member has a configuration in which an orifice plate is incorporated inside a gasket member that is configured to be fitted into a recess in a metal block to provide a seal. The outer gasket member is made of, for example, SUS316L or PCTFE (polychlorotrifluoroethylene), and the orifice plate held inside is made of, for example, SUS316L. The orifice diameter of the throttling section 28 is set to, for example, 40 μm to 2500 μm. However, a critical nozzle or a sonic nozzle can also be used as the throttling section 28.

[0046] In this embodiment, a gasket-type orifice member is used as the throttling portion 28, and this gasket-type orifice member has both the function of a throttling portion 28 and the function of a gasket member. However, in other embodiments, the throttling portion 28 and the gasket member may be installed as separate members in the first flow path block BL1 or the second flow path block BL2, respectively. In either case, the gasket member needs to be sandwiched at the connection between the first flow path block BL1 and the second flow path block BL2, and is used to ensure the sealing performance of the connection.

[0047] By using a gasket-type orifice member as the throttling portion 28, the sealing performance of the gas flow path can be improved at the boundary between the first flow path block BL1 and the second flow path block BL2. Therefore, gas leakage from this connection can be prevented.

[0048] However, in a configuration in which a gasket-type orifice member is placed at the connection between the first flow path block BL1 and the second flow path block BL2, it is desirable to firmly fix the first flow path block BL1 and the second flow path block BL2 to each other in order to prevent gas leakage at the connection. For this reason, as will be described later, the second flow path block BL2 is firmly fixed to the first flow path block BL1 by being pressed against by a block fixing member (such as a socket head cap screw) inserted into the connection hole H.

[0049] As the first pressure sensor 24 and the second pressure sensor 26, for example, a silicon single crystal pressure sensor having a pressure-sensitive diaphragm equipped with strain gauges, or a capacitance manometer can be used. As the first pressure sensor 24 and the second pressure sensor 26, for example, the pressure sensor described in Patent Document 4 (International Publication No. 2022 / 137812) can also be used. As the temperature sensor, for example, a thermocouple, thermistor, or platinum resistance thermometer can be used.

[0050] Furthermore, in this embodiment, the shut-off valve 4 is configured using an AOV (air-operated valve). The liquid replenishment valve 18 of the vaporizer 10 is also configured using an AOV. A solenoid valve that controls the supply of compressed air is connected to the AOV, and by controlling the solenoid valve, the shut-off valve 4 and the liquid replenishment valve 18 can be opened and closed quickly. However, this is not limited to this configuration, and the shut-off valve 4 or the liquid replenishment valve 18 may be configured as an on / off valve such as a solenoid valve or an electric valve.

[0051] As shown in Figure 2, the shut-off valve 4 may be positioned to straddle the second flow path block BL2 and the downstream block. Between the blocks (below the shut-off valve 4), an insulating member 32, for example, made of PEEK plate material, may be provided. This allows for more efficient heat retention of the upstream gas even when the gas supply is stopped by closing the shut-off valve 4, and prevents gas reliquefaction in the flow control device 20.

[0052] The flow rate control device 20 configured as described above can perform flow rate control by utilizing the principle that when the critical expansion condition P1 / P2 ≥ approximately 2 (where P1 is the upstream pressure, P2 is the downstream pressure, and approximately 2 is the case for nitrogen gas), the flow rate Q is determined by the upstream pressure P1 and not by the downstream pressure P2. When the critical expansion condition is met, the flow rate Q is calculated from Q = K1·P1 (where K1 is a constant that depends on the opening area of ​​the throttling section, the type of fluid, and the fluid temperature).

[0053] Furthermore, since the flow rate control device 20 is equipped with a second pressure sensor 26, even if the critical expansion condition is not satisfied, the flow rate Q is calculated as Q = K²·P² m (P1-P2) n (Here, K2 is a constant that depends on the opening area of ​​the throttling section, the type of fluid, and the fluid temperature, and m and n are indices derived from the actual flow rate.)

[0054] To perform flow control, a set flow rate Qs is input to the control circuit. The control circuit calculates a calculated flow rate Qc according to the above formula based on the outputs of the first pressure sensor 24 and the second pressure sensor 26, and then feedback controls the control valve 22 so that this calculated flow rate Qc approaches the input set flow rate Qs. The calculated flow rate Qc may be displayed on an external monitor as a flow rate output value.

[0055] However, as described above, when the second pressure sensor 26 is fixed to the second flow path block BL2, the inventors have confirmed that gas leaks may occur from the fixing point of the second pressure sensor 26, especially in applications involving the flow of high-temperature gases. According to the inventors' experiments, when the second flow path block BL2 is firmly attached to the first flow path block BL1, stress is generated in the second flow path block BL2, which is typically made of metal such as stainless steel, resulting in slight deformation of the block. As a result, the sealing performance of the fixing point of the second pressure sensor 26 is reduced.

[0056] Therefore, in the flow control device 20 of this embodiment, even when the second flow path block BL2 is fixed to the first flow path block BL1 by a block fixing member, stress is less likely to occur in the fixing portion of the second pressure sensor 26, thereby ensuring high sealing performance. The specific method for achieving this will be described below.

[0057] Figure 3 is a perspective view of the second flow channel block BL2, illustrating the difference between the configuration of the comparative example and the configuration of the embodiment. Figure 4 shows the fixing configuration of the first flow channel block BL1 and the second flow channel block BL2 in this embodiment.

[0058] As shown in Figure 3, the upper surface of the second flow path block BL2 is provided with a recess 26H and an outlet 4H for fixing the second pressure sensor 26. The recess 26H and outlet 4H communicate with the flow path formed within the block. The outlet 4H is connected to the upstream flow path of the shut-off valve 4.

[0059] Furthermore, the second flow channel block BL2 has a connection hole H formed therein for connecting to the first flow channel block BL1. The connection hole H extends horizontally (in the block connection direction) toward the first flow channel block BL1. The connection hole H is composed of a first hole portion H1 having a first cross-sectional area facing the first flow channel block BL1, and a second hole portion H2 having a larger diameter (a larger second cross-sectional area) that extends outward as an extension of the first hole portion H1. A stepped surface (the bottom surface of the second hole portion H2) is formed at the boundary between the first hole portion H1 and the second hole portion H2.

[0060] For convenience, the direction in which the blocks are arranged may be described as the horizontal direction, and the direction perpendicular to this on the paper of Figure 2 may be described as the vertical direction or up-down direction. However, it goes without saying that the actual horizontal and vertical directions may differ depending on the orientation and mounting direction of the vaporization supply device 50. Also for convenience, the surface corresponding to the block connection surface may be described as the end face of the block, the surface to which elements etc. are attached may be described as the top and bottom surfaces of the block, and the side surface between the top and bottom surfaces (the surface perpendicular to the end face) may be described as the side surface of the block.

[0061] In the embodiment shown in Figure 3, the second flow channel block BL2 is provided with four connection holes H. The four connection holes H are formed in pairs on each side of the second flow channel block BL2, spaced apart vertically and parallel to each other. This makes it possible to firmly fix the second flow channel block BL2 to the first flow channel block BL1 at four points. Furthermore, it is possible to fix it with relatively equal force in the vertical, horizontal, and vertical directions without bias.

[0062] Furthermore, the first hole portion H1 of each connection hole H is closed to the side surface of the second flow channel block BL2, that is, it is a through hole extending into the interior of the block. On the other hand, the larger diameter second hole portion H2 is open to the side surface of the second flow channel block BL2, and the second hole portion H2 can be accessed from the side surface of the block. Therefore, fastening members such as bolts inserted into the first hole portion H1 can be tightened securely and firmly, and the tightening operation of fastening members in the second hole portion H2 can be performed more easily. However, this is not limited to this, and the second hole portion H2 may also be a hole closed to the side surface of the block.

[0063] Here, as shown in Figure 3, the horizontal length La of the first hole portion H1 in the upper connection hole H of the embodiment is smaller than the horizontal length La' of the first hole portion H1 in the lower connection hole H of the comparative example. In other words, the counterbore depth of the connection hole H of the embodiment is deeper than the counterbore depth of the second hole portion H2 in the connection hole H of the comparative example. A counterbore is a hole in an enlarged diameter portion, which is a part that has been enlarged and dug out so that the heads of fixing members such as screws and bolts do not protrude.

[0064] By drilling the counterbore deeper than in the comparative example, the stress generated in the second flow channel block BL2 when it is fixed to the first flow channel block BL1 with bolts or the like can be concentrated in the vicinity of the first flow channel block BL1. This suppresses the generation of stress and strain near the recess 26H for fixing the second pressure sensor 26, thereby preventing gas leakage from the mounting portion of the second pressure sensor 26.

[0065] Figure 4 shows the manner in which the second flow channel block BL2 is fixed to the first flow channel block BL1 using the block fixing member 29 in this embodiment. As shown in Figure 4, the block fixing member 29 is inserted into a connecting hole H in the second flow channel block BL2, which is composed of a small-diameter first hole portion H1 and a larger-diameter second hole portion H2. In this embodiment, the block fixing member 29 is a hexagon socket head bolt having an enlarged diameter portion (or head) 29H, and its tip is inserted into a receiving hole formed in the first flow channel block BL1.

[0066] In this embodiment, the insertion portion of the block fixing member 29 has a screw thread, and the receiving hole also has a screw thread. Therefore, by rotating the enlarged diameter portion 29H, the block fixing member 29 can be advanced in the direction of the first flow path block BL1. Although not shown in the figures, a washer may be placed between the enlarged diameter portion 29H and the stepped surface HS of the connection hole H (the bottom surface of the second hole portion H2).

[0067] Furthermore, after the enlarged diameter portion 29H contacts the stepped surface HS, further rotation of the enlarged diameter portion 29H presses against the stepped surface HS, thereby firmly and securely fixing the second flow path block BL2 to the first flow path block BL1. This prevents gas leakage from the connection surface BLS, even in a configuration where the constricted portion 28 is placed at the block boundary.

[0068] However, the strong tightening by the block fixing member 29 generates relatively large stresses in the second flow path block BL2. In response to this, the flow control device 20 of this embodiment sets the length La of the first hole portion H1 to be shorter than the distance Lb from the connection surface BLS between the first flow path block BL1 and the second flow path block BL2 to the seal end of the second pressure sensor 26, thereby making it difficult for stresses to be transmitted to the seal end of the second pressure sensor 26. This maintains the sealing performance of the second pressure sensor 26 and makes gas leaks less likely to occur.

[0069] In this embodiment, the second pressure sensor 26 used is fixed to the mounting surface of the sensor body 26S to the second flow path block BL2 with an annular gasket 26G sandwiched between them to ensure sealing. In this embodiment, the outer circumferential surface of this gasket 26G is defined as the sealing end of the second pressure sensor 26. However, in cases where a gasket is not used, the sealing end of the second pressure sensor 26 may be the outer circumferential surface of the sealing portion closest to the flow path, which is the part of the second pressure sensor 26 that comes into contact with the second flow path block BL2 when fitted into a recess formed in the second flow path block BL2 to form a seal.

[0070] As described above, since the length La of the first hole portion H1 is set to be relatively short (i.e., the counterbore is relatively deep), a stress buffer portion with a distance Lc is provided between the stepped surface HS, which directly receives the force from the enlarged diameter portion 29H of the block fixing member 29, and the outer circumferential surface of the gasket 26G. This prevents slight distortion of the second flow path block BL2 near the gasket 26G when the block fixing member 29 is tightened, and maintains sealing performance.

[0071] As shown in Figure 4, a gasket guide ring 26R may be provided around the gasket 26G, and the sensor body 26S may be held by a sensor bonnet 26B that covers the sensor body 26S via an anti-rotation washer. By engaging the threads formed on the outer circumference of the sensor bonnet 26B with the threads formed on the inner circumference of the recess 26H (see Figure 3) of the second flow path block BL2 and rotating the sensor bonnet 26B, the sensor body 26S can be securely fixed to the second flow path block BL2 with high sealing performance while pressing the gasket 26G.

[0072] Furthermore, as shown in Figure 3, the connection holes H may include two connection holes on the side closer to the mounting surface of the second pressure sensor and two connection holes on the side further away. In this case, as shown in Figure 4, the flow path extending from the throttling portion 28 may pass through the central portion of the block between the connection holes on the side closer to the mounting surface and the connection holes on the side further away. This allows the four connection holes and the inserted block fixing members to be evenly distributed around the flow path when viewed from the end face direction, enabling the second flow path block BL2 to be pressed and fixed to the first flow path block BL1 with a uniform force across the surface without unnecessarily increasing the size of the second flow path block BL2. In this case as well, since the length La of the first hole portion H1 (or the distance between the connection surface BLS and the stepped surface HS) is smaller than the distance Lb to the seal end of the second pressure sensor 26, the stress due to the tightening of each block fixing member is less likely to be transmitted to the seal end of the second pressure sensor 26, and therefore, the sealing performance of the second pressure sensor 26 can be maintained at a high level. Furthermore, if there are no problems with the fixing, the number of connection holes H may be one or more.

[0073] Next, a method for manufacturing the flow control device 20 described above that can further reduce the occurrence of gas leaks from the fixing point of the second pressure sensor 26 will be explained.

[0074] In connecting flow path blocks, pressure sensors, control valves, and other components are usually fixed to the flow path block beforehand before connecting the flow path blocks. However, in the manufacturing method of the flow control device 20 according to this embodiment, the second pressure sensor 26 is fixed to the second flow path block BL2 after the second flow path block BL2 is fixed to the first flow path block BL1.

[0075] To explain in more detail, first, a first flow path block BL1 is prepared, to which the control valve 22, supply pressure sensor 12, and first pressure sensor are attached. Next, a second flow path block BL2 is prepared, with the second pressure sensor 26 not yet fixed. After interposing a gasket member (in this case, a throttling portion 28), this is firmly fixed to the first flow path block BL1 using a block fixing member 29 via a connection hole H. At this time, stress may be generated in the second flow path block BL2 due to the fixing by the block fixing member 29, but since the stepped surface HS is formed close to the first flow path block BL1 as described above, the occurrence of distortion at the fixing point of the second pressure sensor 26 can be reduced.

[0076] Then, the second flow path block BL2 is fixed to the first flow path block BL1, and then the second pressure sensor 26 is fixed to the second flow path block BL2. As described above, this fixing of the second pressure sensor 26 can be done by placing the sensor body 26S in the recess of the second flow path block BL2 via the gasket 26G, and then covering it with the sensor bonnet 26B from above and rotating it.

[0077] Thus, it was found that by fixing the second pressure sensor 26 to the second flow path block BL2, which had been previously fixed to the first flow path block BL1, the occurrence of gas leaks from the mounting location of the second pressure sensor 26 can be further suppressed. The reason for this is thought to be that even if some distortion occurs in the second flow path block BL2 before the installation of the second pressure sensor 26, the sealing performance is restored by the gasket 26G deforming appropriately during the process of fixing the second pressure sensor 26. Therefore, by using a manufacturing method in which the second pressure sensor 26 is installed afterward, the occurrence of gas leaks can be prevented even more effectively.

[0078] Although embodiments of the present invention have been described above, various modifications are possible. For example, the above description describes a connecting hole H composed of a first hole portion H1 having a first diameter and a second hole portion H2 having a larger second diameter, but the invention is not limited to this. The second hole portion H2 does not necessarily have to have an elongated hole shape, and may be, for example, a groove or recess formed on the side surface of the second flow channel block BL2. The formed groove or recess does not have to reach the downstream end face of the second flow channel block BL2. As long as the cross-sectional area of ​​the second hole portion H2 is larger than the cross-sectional area of ​​the first hole portion H1, and a stepped surface HS is formed at their boundary, the shape of the first hole portion H1 can be arbitrary. [Industrial applicability]

[0079] The flow rate control device and vaporization supply device according to embodiments of the present invention are appropriately used to perform flow rate control over a wide control range when incorporated into gas supply systems such as semiconductor manufacturing equipment. [Explanation of Symbols]

[0080] 2 Liquid material source 4. Shut-off valve 6 Process Chambers 8. Vacuum pump 10. Vaporizer 12. Supply pressure sensor 20 Flow control device 22 Control valve 24. First pressure sensor 26. Second pressure sensor 28 Restricted section (gasket component) 29 Block fixing member 29H Enlarged diameter portion (head) of block fixing member 50 Vaporization supply device 100 Gas supply systems BL1 First channel block BL2 Second channel block H connection hole H1 1st hole part H2 2nd hole part HS step surface P0 Supply pressure P1 Upstream pressure P2 Downstream pressure

Claims

1. Control valve and A first pressure sensor is provided in the flow path downstream of the control valve, A throttling section is provided in the flow path downstream of the first pressure sensor, A second pressure sensor is provided in the flow path downstream of the aforementioned throttling section, A first flow path block supporting the control valve and the first pressure sensor, A second flow channel block is provided adjacent to the first flow channel block and supports the second pressure sensor. A flow control device comprising a gasket member being sandwiched at the connection between the first flow path block and the second flow path block, The second flow channel block has a connecting hole extending toward the first flow channel block, the connecting hole includes a first hole portion having a first cross-sectional area and facing the first flow channel block, and a second hole portion having a second cross-sectional area larger than the first cross-sectional area and extending outward from the first hole portion, and a stepped surface is formed at the boundary between the first hole portion and the second hole portion. The second flow path block is fixed to the first flow path block by the enlarged diameter portion of the block fixing member positioned in the connection hole pressing against the stepped surface of the connection hole. A flow control device wherein the length of the first hole portion of the connection hole is shorter than the distance from the connection surface between the first flow path block and the second flow path block to the seal end of the second pressure sensor.

2. The flow control device according to claim 1, wherein the sealing end of the second pressure sensor is defined by the outer circumferential surface of an annular gasket disposed to seal the second pressure sensor.

3. The flow control device according to claim 1, wherein the gasket member has a structure including the throttling portion.

4. The flow control device according to claim 3, wherein the gasket member is a gasket-type orifice member.

5. The flow control device according to any one of claims 1 to 4, wherein the second flow path block is provided with four connection holes, and the block fixing member is arranged in each connection hole.

6. The flow control device according to claim 5, wherein the four connection holes include two connection holes provided on the side of the second flow path block closer to the second pressure sensor mounting surface and two connection holes provided on the side further away, and the flow path formed inside the second flow path block and extending from the gasket member passes through the position between the two connection holes on the side closer to the second pressure sensor mounting surface and the two connection holes on the side further away from the second pressure sensor mounting surface.

7. The flow control device according to any one of claims 1 to 4, wherein the first hole portion of the connection hole is closed to the side surface of the second flow path block, and the second hole portion is open to the side surface of the second flow path block.

8. Vaporizer and, A flow control device according to any one of claims 1 to 4 is connected adjacent to the downstream side of the vaporizer. A vaporization supply device equipped with the following features.

9. A method for manufacturing a flow control device according to any one of claims 1 to 4, The steps include preparing the first flow path block, the second flow path block, the block fixing member, and the second pressure sensor, A step of fixing the second flow channel block to the first flow channel block using the block fixing member placed in the connection hole formed in the second flow channel block, After the step of fixing the second flow channel block to the first flow channel block, the step of fixing the second pressure sensor to the second flow channel block and A method for manufacturing a flow control device, including the method described above.

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