Resistor manufacturing method, fluid measurement device, fluid control device, and fluid devices

Abstract

To reduce efforts and steps required for acquiring a correction coefficient or gas data with fluid control devices regardless of the scale of a controlled flow rate range by using resistors with the same flow characteristic.SOLUTION: A method of manufacturing three or more types of resistors to be respectively used for three or more fluid measurement devices with different flow rate measurement ranges is provided, method involving making the flow channel lengths and flow channel diameters substantially the same for internal flow channels of the three or more types of resistors, and making the number of internal flow channels different for the three or more types of resistors.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a resistor, a fluid measuring device, a fluid control device, and a group of fluid devices. [Background technology]

[0002] Conventionally, the resistors used in thermal mass flow controllers have been tapered type resistors as shown in Patent Document 1 for small flow rates controlled in a flow rate range of, for example, 1000 [sccm] or less, and etched plate type resistors as shown in Patent Document 2 for medium flow rates of, for example, 3000 [sccm] or more.

[0003] However, the linearity of the flow characteristics differs between a tapered type resistor (TP bypass) and an etched plate type resistor (EP bypass) as shown in Fig. 7. In addition, for the etched plate type resistor, the flow is designed for each control flow range so that the Reynolds number is as small as possible, and the linearity of the flow characteristics is not unified even for the etched plate type resistor.

[0004] For this reason, it is necessary to obtain a correction coefficient or gas data for correcting the variation in flow rate accuracy for each control flow rate range, which requires time and effort. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2000-171275 A [Patent Document 2] JP 2001-336958 A Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, the present invention has been made to solve the above-mentioned problems, and its main objective is to reduce the effort and labor required to obtain correction coefficients or gas data by making the flow characteristics of resistors the same in fluid control devices with various flow control ranges from low flow rates to high flow rates or fluid measurement devices with various flow measurement ranges. [Means for solving the problem]

[0007] In other words, the manufacturing method of the resistor of the present invention is a manufacturing method of three or more types of resistors to be used in three or more fluid measuring devices each having a different flow measurement range, and is characterized in that the flow path length and flow path diameter of the internal flow path are approximately the same in the three or more types of resistors, and the number of flow paths of the internal flow path formed in each of the three or more types of resistors is different from one another.

[0008] According to this method of manufacturing a resistor, the flow path length and flow path diameter of the internal flow paths are made approximately the same among three or more types of resistors, and the number of flow paths of the internal flow paths formed in each of the resistors is made different, so that the flow characteristics of the resistors can be made the same in fluid measurement devices with a wide range of measurement flow rates, from small flow rates to large flow rates. As a result, in three or more fluid measurement devices having different flow rate measurement ranges, such as a small flow rate, a medium flow rate, and a large flow rate, the effort and man-hours required for acquiring correction coefficients or gas data can be reduced. In addition, if the flow characteristics of the resistor are consistent across the entire flow measurement range, gas data can be obtained using a fluid measuring device that is compatible with small flow ranges. As a result, the amount of expensive gas or greenhouse gas used can be reduced, which is effective in terms of cost and the environment.

[0009] Specifically, by making the flow path length and flow path diameter of the resistors approximately the same, the Reynolds number of each of the three or more types of resistors can be made approximately the same.

[0010] The three or more types of resistors are desirably used in three or more fluid measurement devices each having a flow rate measurement range of 30 to 50,000 [sccm]. Here, possible flow rate measurement ranges include full-scale flow rates of, for example, 30 [sccm], 100 [sccm], 300 [sccm], 1000 [sccm], 3000 [sccm], 10000 [sccm], 30000 [sccm], and 50000 [sccm].

[0011] A fluid measuring device using a resistor manufactured by the above-mentioned manufacturing method is also one aspect of the present invention.

[0012] Furthermore, the fluid control device of the present invention is characterized in that it comprises the above-mentioned fluid measurement device, a fluid control valve provided upstream or downstream of the fluid measurement device, and a valve control unit that controls the fluid control valve based on the flow rate measured by the fluid measurement device.

[0013] In addition, the fluid device group of the present invention consists of three or more fluid measurement devices having different flow rate measurement ranges, or three or more fluid control devices constructed using these fluid measurement devices, and is characterized in that the resistors used in each of the fluid measurement devices have internal flow paths having approximately the same flow path length and flow path diameter, and the internal flow paths have different numbers of flow paths.

[0014] Furthermore, the fluid device group of the present invention consists of three or more fluid measurement devices having different flow rate measurement ranges, or three or more fluid control devices constructed using these fluid measurement devices, and is characterized in that the three or more types of resistors used in each of the fluid measurement devices have approximately the same Reynolds number.

[0015] Here, it is desirable that the three or more types of resistors have internal flow paths with approximately the same flow path length and flow path diameter, and that the internal flow paths have the same number of flow paths, and that at least two or more of the three or more fluid control devices or the three or more fluid measuring devices have a blocking plate attached to the upstream end face of the resistor for blocking some of the flow paths formed in the resistor, and that the three or more fluid control devices have flow rate control ranges that are different from one another due to the blocking plate. Effect of the Invention

[0016] According to the present invention configured in this manner, by making the flow characteristics of the resistor the same in fluid measurement devices with various flow measurement ranges from small flow rates to large flow rates, the effort and labor required to obtain correction coefficients or gas data can be reduced. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic diagram showing a fluid control device according to an embodiment of the present invention; [Diagram 2] 3 is a schematic diagram showing a configuration example of a resistor according to the embodiment; FIG. [Diagram 3] 4A to 4C are diagrams for explaining a method of manufacturing the resistor according to the embodiment. [Figure 4] 4 is a graph showing flow characteristics of the resistor of the embodiment. [Diagram 5] 13 is a cross-sectional view showing the configuration of a resistor and a closure plate in a modified embodiment. FIG. [Figure 6] FIG. 13 is a schematic diagram showing a configuration having a straightening plate according to a modified embodiment. [Figure 7] 1 is a graph showing flow characteristics of a conventional resistor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a fluid control device according to the present invention will be described with reference to the drawings. In addition, in any of the drawings shown below, for the purpose of easy understanding, some parts are omitted or exaggerated in schematic form as appropriate. The same components are denoted by the same reference numerals and the description thereof is omitted as appropriate.

[0019] <Device configuration> The fluid control device 100 of this embodiment is used in a semiconductor manufacturing process, for example by being incorporated into a semiconductor manufacturing apparatus, and is provided, for example, in one or more gas supply lines connected to a semiconductor processing chamber to control the flow rate of process gas flowing through each gas supply line.

[0020] Specifically, the fluid control device 100 is a so-called thermal mass flow controller (thermal MFC), and as shown in FIG. 1, includes a metal (e.g., stainless steel) block body 20 in which a main flow path X, which is an internal flow path, is formed, a flow sensor 30 installed in the block body 20 for measuring the flow rate of fluid flowing through the main flow path X, a fluid control valve 40 installed in the block body 20 for controlling the flow rate of fluid flowing through the main flow path X, and a valve control unit 50 for adjusting the valve opening of the fluid control valve 40 based on the measurement value measured by the flow sensor 30 to control the flow rate of fluid flowing through the main flow path X.

[0021] The flow sensor 30 is a thermal flow sensor. Specifically, the flow sensor 30 includes a sensor flow path L that bypasses the main flow path X, and a pair of heating resistors 32 wound around the upstream and downstream sides of a measuring tube 31 that forms the sensor flow path L. The flow sensor 30 also includes a flow rate calculation unit 33 that calculates the flow rate of the fluid flowing through the sensor flow path L based on the temperature difference between the pair of heating resistors 32 that occurs when the fluid flows through the sensor flow path L.

[0022] Here, a resistor R having constant flow characteristics is provided between the branch point of the sensor flow path L in the main flow path X and the junction point of the sensor flow path L, so that the branch flow ratio of the main flow path X and the sensor flow path L is a predetermined design value. Here, the flow sensor 30, the block body 20, and the resistor R constitute a fluid measurement device 200. Here, in the fluid measurement device 200, the other flow path structures are the same, except for the resistors R in each flow measurement range described later. More specifically, it is sufficient that the sensor flow path L is the same in the fluid measurement device 200.

[0023] Then, the flow rate calculation unit 33 calculates the flow rate through the main flow path X based on the division ratio between the main flow path X and the sensor flow path L. The flow rate calculation unit 33 may be configured using a computer that performs the functions of a valve control unit 50 described later.

[0024] The fluid control valve 40 is provided upstream of the flow sensor 30. Specifically, the fluid control valve 40 controls the flow rate by moving a valve body toward and away from a valve seat using an actuator. This fluid control valve may be a solenoid valve (electromagnetic valve) using a solenoid as an actuator, or a piezo valve using a piezo element as an actuator. In addition, the fluid control valve may be a so-called normally closed type that is in a fully closed state when the valve body is not driven, or may be a so-called normally open type that is in a fully open state when the valve body is not driven.

[0025] The valve control unit 50 controls the fluid control valve 40 based on the flow rate Q and the target flow rate (set value) calculated by the flow rate calculation unit 33 of the flow sensor 30. The valve control unit 50 is composed of a so-called computer equipped with, for example, a CPU, a memory, an A / D-D / A converter, and an input / output means, and functions as the valve control unit 50 are fulfilled by executing a flow rate control program stored in the memory and cooperating with various devices.

[0026] <Detailed configuration of resistor R> The resistor R of this embodiment is configured so that three or more types of resistors R used in three or more fluid control devices 100 each having a different flow control range have substantially the same flow characteristics.

[0027] Specifically, the three or more types of resistors R have internal flow paths Rx with substantially the same flow path length A1 and flow path diameter A2, but the internal flow paths Rx have different numbers of flow paths, as shown in Fig. 2. The internal flow paths formed in one resistor R have substantially the same flow path length A1 and flow path diameter A2.

[0028] Here, the phrase "the flow path length A1 is substantially the same" and the flow path diameter A2 is substantially the same" means that they are the same, allowing for variation within the range of processing accuracy. For example, if the variation in the flow path length A1 is within ±15%, more preferably within ±10%, they are considered to be substantially the same, and if the variation in the flow path diameter A2 is within ±15%, more preferably within ±10%, they are considered to be substantially the same. In terms of design values, the flow path length A1 is the same and the flow path diameter A2 is the same.

[0029] In this way, by making the flow path length A1 and flow path diameter A2 of three or more types of resistors R approximately the same, the flow rate through the resistors R is changed by making the number of flow paths different while making the Reynolds numbers approximately the same. Here, "approximately the same Reynolds number" means that the Reynolds numbers are the same, allowing for variation in the Reynolds numbers calculated by making the flow path length A1 and flow path diameter A2 approximately the same. In other words, the Reynolds numbers of three or more types of resistors R are the same as each other in terms of design values.

[0030] Here, the three or more types of resistors R are used in three or more fluid control devices 100 each having a flow control range (flow measurement range) of 30 to 50,000 [sccm], for example. If the measurable range of the fluid measurement device 200 is within the controllable range of the fluid control valve 40, the flow control range of the fluid control device 100 and the flow measurement range of the fluid measurement device 200 will be the same.

[0031] Specifically, the flow rate control range is: (1) Full-scale flow rate of 30 [sccm], (2) Full-scale flow rate of 100 [sccm] (3) Full-scale flow rate of 300 [sccm] (4) Full-scale flow rate of 1000 [sccm] (5) Full-scale flow rate of 3000 [sccm] (6) Full-scale flow rate of 10,000 [sccm] (7) Full-scale flow rate of 30,000 [sccm] (8) Full-scale flow rate of 50,000 [sccm]. The full-scale flow rate is the maximum value of the flow rate control range.

[0032] The flow path length A1 and flow path diameter A2 of the internal flow paths Rx formed in each of the eight types of resistors R used in the above-mentioned eight types of fluid control devices 100 are the same, and the number of flow paths of the internal flow paths Rx formed in each of the resistors R is different.

[0033] As a detailed design example, the following can be considered.

[0034] [Table 1]

[0035] Here, a method for manufacturing the resistor R will be described. In the following, an example will be described in which the resistor R is manufactured by drilling holes in a metal plate by etching.

[0036] First, as shown in Fig. 3, holes 2 of the same diameter are formed in a metal plate 1 having a thickness of, for example, 0.1 mm by etching. Here, the number of holes 2 to be formed is determined according to the flow rate control range of the device No. as shown in Table 1 above. Note that Fig. 3 shows, as an example, metal plates 1 for manufacturing resistors R in devices No. #3 and No. #4.

[0037] The shape of the holes 2 formed is circular. This is to theoretically obtain the flow characteristics from the Hagen-Poyse equation. Furthermore, it is preferable to arrange the multiple holes 2 evenly on the metal plate 1. If they are concentrated in the center, vortexes will be generated on the periphery, resulting in losses.

[0038] As described above, a plurality of metal plates 1 with holes 2 formed therein are joined together by brazing or diffusion bonding so that the holes 2 are aligned with each other to form an integrated unit. Here, in order to set the flow path length to a [mm], a predetermined number of metal plates 1 with holes 2 formed therein are joined together to form a resistor R. The eight types of resistors R thus manufactured have the same outer size, the same flow path length of the internal flow paths Rx at a [mm], the same flow path diameter of the internal flow paths Rx at b [mm], the same Reynolds number (calculated), and only the number of flow paths differ. The resistor R thus constructed is shaped to fit the shape of the main flow path X. Here, the resistor R is cylindrical.

[0039] The flow characteristics of the eight types of resistors R configured in this manner are shown in Fig. 4. It can be seen that the eight types of resistors R configured according to this embodiment exhibit substantially the same flow characteristics.

[0040] Furthermore, the fluid control devices 100 using the eight types of resistors R manufactured as described above constitute a group of fluid control devices having mutually different control flow rate ranges. That is, in this group of fluid control devices, the resistors R used in each of the fluid control devices 100 have substantially the same flow path length and flow path diameter of the internal flow paths Rx, and the number of flow paths in the internal flow paths is different from each other. In this group of fluid control devices, the three or more types of resistors R used in each of the fluid control devices 100 have substantially the same Reynolds number.

[0041] <Effects of this embodiment> According to the fluid control device 100 of this embodiment configured in this manner, the flow path length and flow path diameter of the internal flow paths Rx formed in each of the three or more types of resistors R are made approximately the same, and the number of flow paths of the internal flow paths Rx formed in each of the resistors R is made different, so that the flow characteristics of the resistors R can be made the same in the fluid control device 100, which has a wide control flow rate range from small flow rates to large flow rates. As a result, in three or more fluid control devices 100 having different flow rate control ranges such as a small flow rate, a medium flow rate, and a large flow rate, the effort and man-hours required for acquiring correction coefficients or gas data can be reduced. In addition, if the flow characteristics of resistor R are consistent across the entire flow control range, gas data can be obtained using a fluid control device that is compatible with the small flow range. As a result, the amount of expensive gas or greenhouse gas used can be reduced, which is effective in terms of cost and the environment.

[0042] <Other embodiments> For example, as shown in FIG. 5, three or more types of resistors R may have the same internal flow paths Rx, the same flow path diameter, and the same number of flow paths, and at least two or more of the three or more fluid control devices 100 may have a blocking plate SP attached to the upstream end face of the resistor R to block some of the flow paths formed in the resistor R. The blocking plate SP may cause the three or more fluid control devices 100 to have different flow rate control ranges. Specifically, in correspondence with the above embodiment, the resistor R is set to have a full-scale flow rate of 50,000 [sccm] (#8), and the number of holes formed in the blocking plate SP provided in the resistor R is changed to make the flow rate control ranges different from each other. Furthermore, a blocking plate may be provided on the downstream side as well as on the upstream side. This is expected to prevent unused flow paths from becoming dead volumes, and to further improve measurement accuracy.

[0043] With this configuration, the resistor R can be common to three or more fluid control devices 100, which not only reduces the manufacturing cost of the resistor R but also further reduces the effort and man-hours required to obtain the correction coefficient or gas data. When the flow rates are made different using the closure plates SP, it is desirable to provide closure plates SP for all types of resistors R and to make the flow path lengths and flow meters of the internal flow paths formed in the closure plates SP approximately the same in order to match the flow characteristics.

[0044] Furthermore, as shown in FIG. 6, a straightening plate TM may be disposed upstream of the resistor R. In particular, the effect is more pronounced when the straightening plate TM is attached to a fluid control device 100 that is compatible with a large flow rate, such as 30,000 sccm or more, among the group of fluid devices. At a small flow rate, the original flow rate is small, so the flow enters the resistor R in a laminar state, but at a large flow rate, the flow enters the resistor R in a state close to turbulence. For this reason, it is desirable to place the straightening plate TM immediately before the resistor R. The straightening plate TM has countless holes smaller than the flow path of the resistor R, and by passing through them, the turbulent state approaches a laminar state, so that the fluid can flow to the resistor R in a laminar state even at a large flow rate.

[0045] Further, in the above embodiment, the fluid control device group is described as having eight types of flow rate control ranges, but the number is not limited to eight, and may be three or more.

[0046] In the resistor of the above embodiment, the holes are formed in the metal plate by etching. However, the holes may be formed by using a laser beam or by drilling.

[0047] Furthermore, the flow rate sensor in the above embodiment is of a thermal type, but it may be of a differential pressure type.

[0048] Moreover, the fluid control valve of the above embodiment may be provided upstream of the flow sensor.

[0049] The resistor R of the embodiment may be used in three or more fluid measurement devices having different flow rate measurement ranges. This fluid measurement device may be configured in such a way that the fluid control device of the embodiment does not have the fluid control valve 40 and the valve control unit 50.

[0050] In addition, various modifications and combinations of the embodiments may be made without departing from the spirit of the present invention. [Explanation of symbols]

[0051] 100... Fluid control device 2. Flow passage block R...Resistor SP...occlusion plate

Claims

1. A method for manufacturing three or more types of resistors used in three or more fluid measurement devices each having a different flow rate measurement range, comprising: A method for manufacturing a resistor, comprising making the flow path lengths and flow path diameters of the internal flow paths of the three or more types of resistors approximately the same, and making the numbers of flow paths of the internal flow paths formed in the three or more types of resistors different from one another.

2. The method for manufacturing a resistor according to claim 1 , wherein the Reynolds numbers of the three or more types of resistors are substantially the same.

3. 3. The method for manufacturing a resistor according to claim 1, wherein the three or more types of resistors are used in three or more fluid measurement devices each having a flow rate measurement range of 30 to 50,000 sccm.

4. 3. A fluid measuring device using a resistor manufactured by the manufacturing method according to claim 1.

5. The fluid measurement device according to claim 4 ; A fluid control valve provided on the upstream side or downstream side of the fluid measurement device; a valve control unit that controls the fluid control valve based on a flow rate measured by the fluid measurement device.

6. A fluid device group including three or more fluid measurement devices having different flow rate measurement ranges, or three or more fluid control devices configured using the fluid measurement devices, A group of fluid devices, wherein the resistors used in each of the fluid measurement devices have internal flow paths having substantially the same flow path length and flow path diameter, and the internal flow paths have different numbers of flow paths.

7. A fluid device group including three or more fluid measurement devices having different flow rate measurement ranges, or three or more fluid control devices configured using the fluid measurement devices, A group of fluid devices, wherein the three or more types of resistors used in each of the fluid measurement devices have substantially the same Reynolds number.

8. The three or more types of resistors have internal flow paths that are substantially the same in length and diameter, and the internal flow paths have the same number of flow paths, At least two or more of the three or more fluid measurement devices have a blocking plate attached to an upstream end surface of the resistor and blocking a part of a flow path formed in the resistor, The group of fluidic devices according to claim 7 , wherein the three or more fluid measurement devices have flow rate measurement ranges different from one another due to the closure plate.

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