JP4684387B2 - Flow rate detection mechanism and method for manufacturing resistor used in flow rate detection mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mass flow meter that measures a mass flow rate of a fluid, a flow rate detection mechanism that is included in a mass flow controller that measures the mass flow rate of a fluid and controls the fluid flow rate, and a method of manufacturing a resistor used in the flow rate detection mechanism. .
[0002]
[Prior art]
In the flow rate detection mechanism in which the fluid is divided into the sensor flow path and the bypass flow path, and the total amount of the introduced fluid is detected based on the flow split ratio of the fluid and the flow rate detection information of the fluid flowing in the sensor flow path, A resistor, which is a member for obtaining a pressure loss, is inserted into the bypass channel, and the completed product is used as a bypass.
[0003]
And, as the resistor, conventionally, it is made of a stainless steel plate having a substantially circular shape in plan view, and a plurality of etching plates having the same shape having a net-like portion at the center are stacked in the same direction. In some cases, a pin is inserted into a pin insertion hole formed in the plate, the pin is fixed by caulking, and a plurality of etching plates thus fixed are held in a holder.
[0004]
[Problems to be solved by the invention]
However, the conventional resistor having the above-described configuration requires parts such as pins and holders, and has a relatively large number of parts. This increased the cost and increased the number of assembly steps, and made it difficult to make the resistor compact. In addition, since the resistor could not be created mechanically and was done manually, there was a large variation in the stacked state of the etching plate due to differences in the skill level of the worker creating the resistor. There was a problem that occurred.
[0005]
In addition, the conventional flow rate detection mechanism itself using the resistor having the above-described drawbacks is time-consuming and labor-intensive to manufacture and expensive, and it is difficult to achieve compactness. The measurement accuracy was greatly varied.
[0006]
The present invention has been made in consideration of the above-mentioned matters, and its object is to make it easier to manufacture, to achieve cost reduction and compactness, and to hardly cause variations in the state after individual assembly. Thus, it is to provide a flow rate detection mechanism capable of improving the measurement accuracy and a method of manufacturing a resistor used in the flow rate detection mechanism .
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the flow rate detection mechanism of the present invention divides a fluid into a sensor flow path and a bypass flow path, and based on the flow split ratio of the fluid and the flow rate detection information of the fluid flowing through the sensor flow path. And a plurality of etchings in which the resistors inserted in the bypass flow path are joined together by row joining or diffusion joining to form a laminated state. Each etching plate has a through hole in the thickness direction, and all the etching plates are positioned using guide plates connected to each etching plate so that the through holes of all the etching plates communicate with each other. All the through holes provided in each etching plate are used for passing the fluid. It is characterized by that (claim 1).
The resistance material may optionally be one in which the guide plate is continuously provided on each etched plate obtained by being cut after bonding of all etched plate (claim 2).
The resistance material may optionally be one in which the guide plate is continuously provided through the bridge and the etched plate is obtained by being cut along with the bridge after the bonding of all etched plate (claim 3).
In order to achieve the above object, the method of manufacturing a resistor used in the flow rate detection mechanism of the present invention splits a fluid into a sensor flow path and a bypass flow path, and flows through the fluid flow split ratio and the sensor flow path. A method of manufacturing a resistor inserted in the bypass flow path of a flow rate detection mechanism that detects the total amount of introduced fluid based on fluid flow rate detection information, wherein all through holes in the thickness direction are A plurality of etching plates used to allow fluid to pass through are superposed in a state where they are aligned using a guide plate connected to each etching plate so that the through holes of all the etching plates communicate with each other. is characterized by obtaining the resistance material by a laminated state are joined by bonding or diffusion bonding (claim 4).
Alignment when superposing in an aligned state so that the plurality of etching plates through holes between all of the etching plates communicate with each other, using the guide plate provided continuously to each etching plate, all etching The resistor may be obtained by cutting the guide plate after joining the plates (Claim 5).
Alignment when superposing in an aligned state so that the plurality of etching plates through holes between all of the etching plates communicate with each other, using the guide plate that is continuously provided through the bridge and the etched plate The resistor may be obtained by cutting the guide plate together with the bridge after joining all the etching plates (Claim 6).
[0008]
With the above configuration, a flow rate detection mechanism that can be manufactured more easily, can be reduced in cost and can be made compact, is less likely to vary in the state after individual assembly, and can improve measurement accuracy. And it becomes possible to provide the manufacturing method of the resistor used for a flow volume detection mechanism .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a longitudinal end view schematically showing a configuration of a flow rate detection mechanism D according to the first embodiment of the present invention.
The flow rate detection mechanism D includes a sensor flow path 1, a bypass flow path 2, an inlet 3 for introducing a fluid F into the sensor flow path 1 and the bypass flow path 2, and the sensor flow path 1 and the bypass flow path. 2 and the outlet 4 from which the fluid F is led out. The fluid F is divided into the sensor flow path 1 and the bypass flow path 2, and flows through the sensor flow path 1 and the flow ratio of the fluid F. Based on the flow rate detection information of the fluid F, the total amount of the fluid F introduced is detected.
[0010]
The fluid F is, for example, hydrogen fluoride (HF) used for manufacturing a semiconductor.
[0011]
The sensor flow path 1 is provided with a thermal flow sensor comprising a pair of heating resistors 5, 5, and the instantaneous flow rate of the fluid F is detected by the heating resistors 5, 5.
[0012]
A resistor 6 having a circular outer cross-sectional shape is inserted into the bypass channel 2 and is held by a holding member (for example, an O-ring) 7.
[0013]
2A, 2B and 2C are perspective views schematically showing a method for producing the resistor 6, respectively.
The resistor 6 is formed by stacking a plurality of etching plates 8, 8... By row bonding or diffusion bonding.
[0014]
The etching plate 8 is a member made of, for example, stainless steel and having a substantially circular shape in a plan view and a thin plate shape (for example, a thickness of 0.1 mm). The size of the etching plate 8 can be selected in various ways according to the intended use. Further, a net-like portion 9 in which a large number of through holes 10, 10... Are regularly arranged is formed in the central portion of the etching plate 8. For example, as shown in FIG. 3, a honeycomb structure in which the through holes 10 have a regular hexagonal shape can be adopted as the mesh portion 9. The front and back surfaces of the etching plate 8 are formed so that the portions excluding the through holes 10, 10... Are on the same plane, that is, have a constant thickness over the entire surface.
[0015]
When the etching plates 8, 8... Are stacked, all the etching plates 8, 8... Need to be overlapped with each other so that the through holes 10 of all the etching plates 8 communicate with each other. However, a guide plate 11 is connected to each etching plate 8 so that this alignment operation can be easily performed.
[0016]
The guide plate 11 is a frame-shaped member in which the plan view of the inner wall and the outer wall are both formed in a rectangular shape, and the length and width are each set to 2 to 15 mm, for example, depending on the size of the etching plate 8. . The guide plate 11 is connected to the etching plate 8 via four bridges 12, 12... Having one end connected to the inner wall of the guide plate 11 and the other end connected to the peripheral edge of the etching plate 8. It is installed. Here, the guide plate 11 and the bridge 12 are made of the same material as that of the etching plate 8 (that is, stainless steel in this embodiment), and the thickness of each is also the same as the thickness of the etching plate 8. . The number of the bridges 12 is not limited to four.
[0017]
The guide plate 11 having the above-described configuration has four corners on the periphery, and when all the guide plates 11 are overlapped so that the corners overlap each other, all the etching plates 8, 8. The holes are configured to communicate with each other.
[0018]
The guide plate 11 is not limited to a frame shape in which the inner wall and the outer wall are both formed in a rectangular shape in plan view, and is etched so that the through holes of all the etching plates 8, 8. Any shape can be used as long as the operation of aligning the plates 8 can be simplified.
[0019]
Next, a method for producing the resistor 6 will be described.
The resistor 6 is produced by forming a basic plate 13 consisting of an etching plate 8 and a guide plate 11 connected to the etching plate 8 via a bridge 12 into a laminated state by row bonding or diffusion bonding. This is performed by cutting away portions other than the etching plate 8, that is, the guide plate 11 and the bridge 12. The method will be described in detail below.
[0020]
First, the basic plate 13 (see FIG. 2A) is overlapped by a desired number (for example, 50 to 100). At the time of this overlap, at least one of the front and back of each etching plate 8 is overlapped. One surface is coated with a bonding material used for brazing. It is desirable to apply the bonding material not only to one side of the etching plate 8 but also to one side of the bridge 12. The means used for joining the etching plates 8, 8... Is not limited to the wax joining, but may be, for example, diffusion joining that joins the etching plates 8, 8,.
[0021]
After the desired number of basic plates 13 are laminated (see FIG. 2B), the bridge 12 is wire-cut, for example, as shown in FIG. Will be created. The method for cutting the bridge 12 is not limited to wire cutting, and other known cutting methods may be used.
[0022]
The width of the bridge 12 only needs to be large enough to prevent the guide plate 11 from holding the etching plate 8 (for example, 1 mm). The length of the bridge 12 does not interfere with the wire cutting. Any size that does not come (for example, 1 mm) is sufficient.
[0023]
The width of the bridge 12 may be constant, but as shown in FIG. 4, it may be formed so as to become thinner toward the etching plate 8 side. When formed in this way, the uncut portion of the bridge 12 formed on the etching plate 8 side after cutting the bridge 12 by wire cutting can be made smaller, and the work can be shortened. It is also possible.
[0024]
Further, in the basic plate 13, four bridges 12, 12... Are connected to the four sides of the etching plate 8. However, the configuration is not limited to this, and for example, three bridges 12, 12, 12 are provided. May be connected to three sides of the etching plate 8, or two bridges 12, 12 may be connected to two sides of the etching plate 8, and only one bridge 12 may be connected to the etching plate 8. In addition, five or more bridges 12, 12... May be connected to the etching plate 8.
[0025]
Since the resistor 6 having the above-described configuration can be mechanically created without manual work, there is almost no variation in the stacked state of the etching plate 8, mass production is possible, and consequently cost reduction is achieved. Can do.
[0026]
Further, since the resistor 6 having the above configuration does not require a pin or a holder, the number of parts and the number of assembling steps can be reduced, and this also makes it possible to further reduce the cost. In particular, since no holder is required, it is possible to obtain a larger flow rate as much as it is blocked by the holder, and it is possible to achieve compactness.
[0027]
Furthermore, in the resistor 6 having the above-described configuration, the peripheral portions of the etching plates 8 are firmly joined to each other, so that the fluid F flows in and out from the side surface (between the etching plates 8, 8...). Can be prevented. That is, if a flow rate leaks between the etching plates 8, 8..., The differential pressure as a bypass changes, but this is not the case with the resistor 6 configured as described above.
[0028]
Therefore, for example, as shown in FIG. 1, even if the junction of the sensor flow path 1 and the bypass flow path 2 comes to the side surface of the resistor 6, the fluid F flows from the side surface of the resistor 6 into the inside thereof. There is no hindrance to flow rate detection. As a result, in order to make the flow rate detection mechanism D more compact, it may be necessary to bring the confluence of the sensor flow path 1 and the bypass flow path 2 to the side surface of the resistor 6. In the resistor 6, it is possible to meet such a request.
[0029]
FIG. 5 is a plan view schematically showing a configuration of a basic plate 14 which is another example of the basic plate 13.
The basic plate 14 shown in FIG. 5 includes the etching plate 8 and a guide plate 15 connected to the etching plate 8 via the bridge 12.
[0030]
The guide plate 15 is different from the guide plate 11 in the plan view used for the basic plate 13 in the shape of a frame. The guide plate 11 has a rectangular shape in the plan view. In contrast, only one etching plate 8 is connected to one guide plate 11, whereas in the guide plate 15, a plurality of etching plates 8, 8. However, they are different in that they are connected to each other via a bridge 12.
[0031]
The procedure for producing the resistor 6 using the etching plates 8, 8... Provided with the guide plate 15 having the above-described configuration is the etching plates 8, 8. Since this is the same as the procedure for creating the resistor 6 using, its description is omitted.
[0032]
The width of the bridge 12 only needs to be large enough to prevent the etching plate 8 from being held by the guide plate 15 (for example, 1 mm), and the length of the bridge 12 does not interfere with the wire cutting. Any size that does not come (for example, 1 mm) is sufficient.
[0033]
In the basic plate 14 configured as described above, the etching plate 8 is connected to the guide plate 15 via only one bridge 12, but the etching plate 8 is connected to the guide plate 15 via two or more bridges 12. 15 may be provided continuously.
[0034]
Further, in the basic plate 14 having the above-described configuration, the plurality of etching plates 8, 8,... Are connected to only one side of the guide plate 15. However, the configuration is not limited to this configuration, and a plurality of etching plates is provided. Plates 8, 8... May be connected to two or more sides of the guide plate 15.
[0035]
When the basic plate 15 shown in FIG. 5 is used, there is an advantage that a plurality of resistors 6, 6,... Can be formed at a time.
[0036]
FIG. 6 is a plan view schematically showing a configuration of a basic plate 17 which is still another example of the basic plate 13.
The basic plate 17 shown in FIG. 6 includes the etching plates 8, 8... And a guide plate 16 connected to the plurality of etching plates 8 via the bridge 12.
[0037]
The guide plate 16 has a shape obtained by enlarging the guide plate 11 having a frame shape in plan view used for the basic plate 13. In contrast, only one etching plate 8 is continuously provided, whereas in the guide plate 16, a plurality of etching plates 8, 8... It is different in that it is connected continuously.
[0038]
That is, the plurality of etching plates 8, 8... In the basic plate 17 are arranged in a matrix (for example, 6 rows × 6 columns), and adjacent etching plates 8 are connected to each other via the bridge 12. Yes. The plurality of etching plates 8, 8... Arranged in this way are connected to the inner wall of the guide plate 16 via the plurality of bridges 12, 12.
[0039]
The procedure for producing the resistor 6 using the etching plates 8, 8... Provided with the guide plate 16 having the above-described configuration is the etching plates 8, 8. Since this is the same as the procedure for creating the resistor 6 using, its description is omitted.
[0040]
The width of the bridge 12 only needs to be large enough to prevent the guide plate 16 from holding the etching plate 8 (for example, 1 mm). The length of the bridge 12 does not interfere with the wire cutting. Any size that does not come (for example, 1 mm) is sufficient.
[0041]
When the basic plate 17 shown in FIG. 6 is used, there is an advantage that a plurality of resistors 6, 6... Can be formed at a time.
[0042]
When the resistor 6 having the above-described configuration and can be produced by the above-described method is used for the flow rate detection mechanism D, the flow rate detection mechanism D can be manufactured more easily, and the cost can be reduced and the size can be reduced. In addition, it is possible to obtain an effect that it is difficult to cause variations in the state after individual assembly, and as a result, measurement accuracy can be improved.
[0043]
【The invention's effect】
According to the present invention having the above-described configuration, it can be manufactured more easily, cost reduction and downsizing can be achieved, and variations after individual assembly are unlikely to occur, thereby improving measurement accuracy. It is possible to provide a flow rate detection mechanism that can be used and a method of manufacturing a resistor used in the flow rate detection mechanism .
[Brief description of the drawings]
FIG. 1 is an explanatory view schematically showing a configuration of a flow rate detection mechanism according to a first embodiment of the present invention.
FIG. 2A is a perspective view schematically showing a configuration of a basic plate in the embodiment, and FIG. 2B is a perspective view schematically showing a configuration when the basic plate is in a laminated state. (C) is a perspective view schematically showing the configuration of the resistor in the above embodiment.
FIG. 3 is an explanatory view schematically showing a configuration of an etching plate in the embodiment.
FIG. 4 is a plan view schematically showing a configuration of another example of the etching plate in the embodiment.
FIG. 5 is an explanatory view schematically showing a configuration of another example of the basic plate in the embodiment.
FIG. 6 is an explanatory view schematically showing a configuration of still another example of the basic plate in the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sensor flow path, 2 ... Bypass flow path, 6 ... Resistor, 8 ... Etching plate, D ... Flow rate detection mechanism, F ... Fluid.

Claims (6)

This is a flow rate detection mechanism that divides a fluid into a sensor flow channel and a bypass flow channel, and detects the total amount of introduced fluid based on the flow split ratio of the fluid and flow rate detection information of the fluid flowing through the sensor flow channel. The resistor inserted into the bypass flow path is composed of a plurality of stacked etching plates joined together by row bonding or diffusion bonding, and each etching plate has a through hole in the thickness direction. All the etching plates are superposed in a state of being aligned using a guide plate connected to each etching plate so that the through holes of all the etching plates communicate with each other. All the through holes are used for allowing the fluid to pass therethrough. The resistance material, the flow rate detection mechanism according to claim 1 wherein the guide plate is provided continuously to each etching plate is obtained by being cut after bonding of all etching plate. The resistance material, the flow rate detection mechanism according to claim 1 in which the guide plate is continuously provided through the bridge and the etched plate is obtained by being cut along with the bridge after the bonding of all the etching plates . The flow rate detection mechanism is configured to divide a fluid into a sensor flow channel and a bypass flow channel, and to detect the total amount of the introduced fluid based on a flow split ratio of the fluid and flow rate detection information of the fluid flowing through the sensor flow channel. A method of manufacturing a resistor inserted into a bypass flow path, wherein a plurality of through holes in the thickness direction are used for passing the fluid, and a plurality of etching plates are connected to each other. A flow rate characterized in that the resistor is obtained by stacking in a state of being aligned using a guide plate connected to each etching plate so as to communicate with each other, and by joining by row joining or diffusion joining to form a laminated state. A method of manufacturing a resistor used in a detection mechanism. Alignment when superposing in an aligned state so that the plurality of etching plates through holes between all of the etching plates communicate with each other, using the guide plate provided continuously to each etching plate, all etching The method of manufacturing a resistor used in the flow rate detection mechanism according to claim 4, wherein the resistor is obtained by cutting the guide plate after joining the plates. Alignment when superposing in an aligned state so that the plurality of etching plates through holes between all of the etching plates communicate with each other, using the guide plate that is continuously provided through the bridge and the etched plate 5. The method of manufacturing a resistor used in the flow rate detection mechanism according to claim 4, wherein the resistor is obtained by cutting the guide plate together with the bridge after joining all the etching plates.

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