Patent Publication Number: US-2022213972-A1

Title: Flow-path forming block and fluid control device provided with flow-path forming block

Description:
TECHNICAL FIELD 
     The present invention relates to a flow-path forming block and to a fluid control device provided with the flow-path forming block. 
     BACKGROUND ART 
     JP2014-152874A discloses a process-gas diverted-flow supply device that is configured such that fluid control apparatuses are communicated with each other through a V-shaped flow path formed in a lower body. 
     SUMMARY OF INVENTION 
     In a fluid control device (the process-gas diverted-flow supply device) such as that disclosed in JP2014-152874A, if a distance between two flow paths of the V-shaped flow path is reduced in order to reduce a size of a fluid control device and/or a flow-path forming block (the lower body), an angle formed by these two flow paths is made smaller. As the angle between the flow paths is made smaller as described above, the effective cross section of a portion where the flow path is turned is reduced, causing the pressure loss to increase, which in turn results in a higher resistance to a flow of fluid. 
     The present invention is made in view of such a technique problem, and an object thereof is to provide a flow-path forming block that is capable of ensuring the effective cross section of flow paths even if a size of a flow-path forming block and/or a fluid control device is reduced. 
     A flow-path forming block according to an aspect of the present invention is provided with: a first block; a second block attached to the first block, the second block having a first flow path and a second flow path; and a gasket provided between the first block and the second block, the gasket being configured to seal between the first block and the second block, wherein the second block has a communication portion formed on a surface facing the gasket, the communication portion being configured such that the first flow path and the second flow path are communicated, and the gasket has a recessed portion formed at a position facing the communication portion. 
     According to this aspect, it is possible to allow the first flow path and the second flow path to be communicated with each other through the recessed portion in addition to the communication portion. With such a configuration, even if the angle formed between the first flow path and the second flow path becomes smaller, it is possible to ensure the effective cross section of the flow path at a portion where the first flow path and the second flow path are connected. With such a configuration, it is possible to reduce the size of the flow-path forming block and/or the fluid control device. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an exploded perspective view of a fluid control device according to an embodiment of the present invention. 
         FIG. 2  is a perspective view of a first block according to the embodiment of the present invention. 
         FIG. 3  is a top view of the fluid control device according to the embodiment of the present invention. 
         FIG. 4  is a side view of the fluid control device according to the embodiment of the present invention. 
         FIG. 5  is a sectional view taken along a line V-V in  FIG. 3 . 
         FIG. 6  is a partial sectional view of main relevant parts of a flow-path forming block according to the embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     An embodiment of the present invention will be described below with reference to the attached drawings. 
     A fluid control device  100  in this embodiment is used for means for supplying a process gas and a purge gas in a semiconductor manufacturing equipment (a CVD equipment, a sputtering equipment, an etching equipment, and so forth). 
     As shown in  FIGS. 1, 3, and 4 , the fluid control device  100  is provided with a flow-path forming block  1  and a plurality of valve devices  2 ,  3 ,  4 ,  5 , and  6  attached to the flow-path forming block  1 . The valve devices  2 ,  3 ,  4 ,  5 , and  6  are air-operated valves that are operated by supplying operating pressure. Note that the valve devices  2 ,  3 ,  4 ,  5 , and  6  may be of a normally closed type or of a normally open type. In addition, the valve devices  2 ,  3 ,  4 ,  5 , and  6  each has a metallic diaphragm serving as a valve body. 
     The flow-path forming block  1  is provided with a block  10  serving as a first block, a block  20  that is attached to the block  10 , a block  30  serving as a second block that is attached to the block  10 , a block  40  serving as the second block that is attached to the block  10 , and a plurality of gaskets  50  and  51  that are provided between the block  10  and the blocks  20 ,  30 , and  40  so as to seal between the block  10  and the blocks  20 ,  30 , and  40 . The blocks  20 ,  30 , and  40  are attached to the block  10  with bolts  60 . In the above configuration, because the block  30  and the block  40  have the same configuration, only the block  30  will be specifically described below, and the description of the block  40  will be omitted. 
     The block  10  is made of stainless steel (for example, SUS316L). The block  10  is provided with a first attachment surface  11  to which the blocks  20 ,  30 , and  40  are attached, a second attachment surface  12  located on the opposite side from the first attachment surface  11 , a flow path  13  (see  FIG. 2 ) that is formed in the block  10  so as to penetrate through in the longitudinal direction of the block  10 , accommodating concave portions  11   a  to  11   l  that are formed in the first attachment surface  11  and that respectively accommodate the gaskets  50  and  51 , and accommodating concave portions  12   a  to  12   c  (see  FIG. 2 ) that are formed in the second attachment surface  12  and that respectively accommodate gaskets (not shown). 
     The accommodating concave portions  11   a  to  11   l  are formed so as to be cylindrically recessed from the first attachment surface  11 . Annular protrusions  14 , which are each formed to have an annular shape, are respectively of provided on bottom surfaces of the accommodating concave portions  11   a  to  11   l . The accommodating concave portions  11   a  to  11   l  are all formed to have the same shape. With such a configuration, it is possible to improve the working efficiency of processing of the accommodating concave portions  11   a  to  11   l.    
     As shown in  FIG. 2 , the block  10  is further provided with a flow path  13   a  that opens in an inner circumferential side of the annular protrusion  14  of the accommodating concave portion  11   a  so as to communicate with the flow path  13 , a flow path  13   b  that opens in an inner circumferential side of the annular protrusion  14  of the accommodating concave portion  11   b  so as to communicate with the accommodating concave portion  12   a , a flow path  13   c  that opens in an inner circumferential side of the annular protrusion  14  of the accommodating concave portion  11   c  so as to communicate with the flow path  13 , a flow path  13   d  that opens in an inner circumferential side of the annular protrusion  14  of the accommodating concave portion  11   d  so as to communicate with the accommodating concave portion  12   b , a flow path  13   f  that opens in an inner circumferential side of the annular protrusion  14  of the accommodating concave portion  11   f  so as to communicate with the flow path  13 , a flow path  13   g  that opens in an inner circumferential side of the annular protrusion  14  of the accommodating concave portion  11   g  so as to communicate with the flow path  13 , a flow path  13   h  that opens in an inner circumferential side of the annular protrusion  14  of the accommodating concave portion  11   h  so as to communicate with the flow path  13 , a flow path  13   i  that opens in an inner circumferential side of the annular protrusion  14  of the accommodating concave portion  11   i  so as to communicate with the flow path  13 , a flow path  13   k  that opens in an inner circumferential side of the annular protrusion  14  of the accommodating concave portion  11   k  so as to communicate with the accommodating concave portion  12   c , and a flow path  13   l  that opens in an inner circumferential side of the annular protrusion  14  of the accommodating concave portion  11   l  so as to communicate with the flow path  13 . In the above, the flow paths  13   a ,  13   g ,  13   h , and  13   l  are in communication with a fluid apparatus (not shown), etc. that is to be attached to the first attachment surface  11 . In addition, the flow paths  13   b ,  13   d , and  13   k  are in communication with other flow-path forming block (not shown), etc. that is to be attached to the second attachment surface  12 . 
     The block  20  is made of the stainless steel (for example, SUS316L). As shown in  FIG. 5 , the block  20  is provided with a third attachment surface  21  that is attached to the block  10 , a fourth attachment surface  22  located on the opposite side from the third attachment surface  21  and to which the valve device  2  is attached, accommodating concave portions  21   a  and  21   b  that are formed in the third attachment surface  21  and that respectively accommodate the gaskets  50 , and a valve-accommodating portion  22   a  that is formed in the fourth attachment surface  22  and that partially accommodates the valve device  2 . 
     The accommodating concave portions  21   a  and  21   b  are formed so as to be cylindrically recessed from the third attachment surface  21 . The annular protrusions  14  are respectively provided on bottom surfaces of the accommodating concave portions  21   a  and  21   b . In the above, the accommodating concave portions  21   a  and  21   b  are formed to have the same shape as the accommodating concave portions  11   a  to  11   l . With such a configuration, it is possible to improve the working efficiency of the processing of the accommodating concave portions  21   a  and  21   b.    
     On a bottom surface of the valve-accommodating portion  22   a , an annular valve sheet  23 , on/from which a diaphragm  2   a  serving as the valve body of the valve device  2  is seated/separated, is provided. The valve-accommodating portion  22   a  is formed with an internal thread that is threaded to an external thread that is formed on an outer circumference portion of the valve device  2 . The valve device  2  is fixed to the block  20  by threading the external thread formed on the outer circumference portion of the valve device  2  to the internal thread formed in the valve-accommodating portion  22   a.    
     The block  20  is further provided with a flow path  24   a  that opens in an inner circumferential side of the valve sheet  23  in the valve-accommodating portion  22   a  and that is in communication with the accommodating concave portion  21   a  and a flow path  24   b  that opens at an outer circumferential side of the valve sheet  23  in the valve-accommodating portion  22   b  and that is in communication with the accommodating concave portion  21   b . The flow path  24   a  communicates with the flow path  13   b  through a through hole  50   a  formed in the gasket  50 . The flow path  24   b  communicates with the flow path  13   c  through the through hole  50   a  formed in the gasket  50 . 
     The block  30  is made of the stainless steel (for example, SUS316L). As shown in  FIG. 5 , the block  30  is provided with a fifth attachment surface  31  attached to the block  10 , a sixth attachment surface  32  located on the opposite side from the fifth attachment surface  31  and to which the valve devices  3  and  4  are attached, accommodating concave portions  31   a  to  31   c  that are formed in the fifth attachment surface  31  and that respectively accommodate the gaskets  50  and  51 , and valve-accommodating portions  32   a  and  32   b  that are formed in the sixth attachment surface  32  and that respectively accommodate the valve devices  3  and  4  partially. 
     The accommodating concave portions  31   a  to  31   c  are formed so as to be cylindrically recessed from the fifth attachment surface  31 . The annular protrusions  14  are respectively provided on bottom surfaces of the accommodating concave portions  31   a  to  31   c . In the above, the accommodating concave portions  31   a  to  31   c  are formed to have the same configuration as the accommodating concave portions  11   a  to  11   l . With such a configuration, it is possible to improve the working efficiency of the processing of the accommodating concave portions  31   a  to  31   c.    
     As shown in  FIGS. 5 and 6 , annular valve sheets  33 , on/from which diaphragms  3   a  and  4   a  serving as the valve bodies of the valve devices  3  and  4  are respectively seated/separated, are respectively provided on bottom surfaces of the valve-accommodating portions  32   a  and  32   b . The valve-accommodating portions  32   a  and  32   b  are each formed with an internal thread that is threaded to an external thread that is formed on each of outer circumference portions of the valve devices  3  and  4 . The valve devices  3  and  4  are each fixed to the block  30  by threading the external thread formed on the outer circumference portion thereof to each of the internal threads formed in the valve-accommodating portions  32   a  and  32   b.    
     The block  30  is further provided with a flow path  34   a  that opens at an outer circumferential side of the valve sheet  33  in the valve-accommodating portion  32   a  so as to communicate with the accommodating concave portion  31   b , a flow path  34   b  that opens at the outer circumferential side of the valve sheet  33  in the valve-accommodating portion  32   b  so as to communicate with the accommodating concave portion  21   b , a flow path  34   c  that opens at an inner circumferential side of the valve sheet  33  in the valve-accommodating portion  32   a  so as to communicate with the accommodating concave portion  31   a , a flow path  34   d  that opens at the inner circumferential side of the valve sheet  33  in the valve-accommodating portion  32   b  so as to communicate with the accommodating concave portion  31   c , and a communication portion  36  through which the flow path  34   a  is communicated with the flow path  34   b.    
     The flow path  34   a  and the flow path  34   b  are provided so as to approach with each other towards the communication portion  36 , in other words, so as to form a substantially V-shape. 
     The flow path  34   c  communicates with the flow path  13   d  through the through hole  50   a  formed in the gasket  50 . The flow path  34   d  communicates with the flow path  13   f  through the through hole  50   a  formed in the gasket  50 . 
     As shown in  FIG. 6 , the communication portion  36  is formed on a bottom surface  35  facing the gasket  51  of the accommodating concave portion  31   b . Specifically, the communication portion  36  is formed so as to open at an inner circumferential side of the annular protrusion  14  in the accommodating concave portion  31   b . For example, the communication portion  36  is formed to have a conical shape. The shape of the communication portion  36  is not limited thereto, and the communication portion  36  may have a hemispherical shape, for example. 
     Next, the gasket  50  and the gasket  51  will be described. The gaskets  50  and  51  are disc-shaped metal gaskets and are made of stainless steel (for example, SUS316L), for example. The gasket  50  and the gasket  51  are formed to have the same diameter and the same thickness. The gaskets  50  and  51  are respectively provided in spaces that are respectively formed by the accommodating concave portions  11   b  to  11   f  and  11   i  to  11   k  and the accommodating concave portions  21   a ,  21   b , and  31   a  to  31   c . As the annular protrusions  14  formed in the accommodating concave portions  11   b  to  11   f  and  11   i  to  11   k  and the annular protrusions  14  formed in the accommodating concave portions  21   a ,  21   b , and  31   a  to  31   c  bite into the gaskets  50  and  51 , the gaskets  50  and  51  are respectively clamped between the block  10  and the blocks  20 ,  30 , and  40  and a leakage of the gas from between the block  10  and the blocks  20 ,  30 , and  40  is prevented. 
     The gasket  50  is formed with the center through hole  50   a  that penetrates through between both surfaces thereof. The gasket  50  seals between the block  10  and the blocks  20 ,  30 , and  40  and ensures the communication between the flow path formed in the block  10  and each of the flow paths formed in the blocks  20 ,  30 , and  40  through the through hole  50   a.    
     The gasket  51  is a gasket of a blind type having no through hole. The gasket  51  closes an opening of the communication portion  36  and has a recessed portion  51   a  that is formed at a position facing the communication portion  36 . The recessed portion  51   a  is formed to have the hemispherical shape having a radius that is substantially the same as that of an opening portion of the communication portion  36 . A curved surface portion  51   b  (see  FIG. 6 ) forming the recessed portion  51   a  is formed such that the fluid flowing from the flow path  34   a  is guided so as to be turned to the flow path  34   b.    
     Next, an operation of the fluid control device  100  will be described. The fluid control device  100  controls flows of the process gas and the purge gas. In the following, although an example of a method of using the fluid control device  100  is shown, the invention is not limited to this method. 
     First and second process gases are, for example, gases used when a thin film is to be formed on a wafer, and they are supplied into a chamber (not shown) via the fluid control device  100 . The first process gas is supplied from the other flow-path forming block (not shown) that is attached at a position facing the accommodating concave portion  12   b  in the second attachment surface  12 . The first process gas that has been supplied from the accommodating concave portion  12   b  is guided to the valve device  3  through the flow path  13   d , the through hole  50   a , and the flow path  34   c  (see  FIGS. 5 and 6 ). As the diaphragm  3   a  of the valve device  3  is separated from the valve sheet  33 , the first process gas is guided to the valve device  4  through the flow path  34   a , the communication portion  36 , the recessed portion  51   a , and the flow path  34   b . Furthermore, as the diaphragm  4   a  of the valve device  4  is separated from the valve sheet  33 , the first process gas is guided to the flow path  13  through the flow path  34   d , the through hole  50   a , and the flow path  13   f . The first process gas that has been guided to the flow path  13  is then guided to other fluid apparatus, etc. through the flow paths  13   a ,  13   g ,  13   h , and  13   l  and is supplied to the chamber (not shown). 
     As described above, in the fluid control device  100 , the valve device  3  and the valve device  4  are provided in series in the flow path formed by the flow paths  34   a  to  34   d . Therefore, even in the event of failure of one of the valve device  3  and the valve device  4 , it is possible to surely shut off the flow of the first process gas flowing through the flow paths  34   a  to  34   d.    
     Similarly to the first process gas, the second process gas is supplied from other flow-path forming block (not shown) that is attached at a position facing the accommodating concave portion  12   c  of the second attachment surface  12  and is guided to the flow path  13  through the valve devices  5  and  6  and the flow path  13   i  (see  FIGS. 1 and 2 ). Although detailed description is omitted because the block  30  and the block  40  have the same configuration, the valve device  5  and the valve device  6  are also provided in series with respect to the flow path. Thus, even in the event of failure of one of the valve device  5  and the valve device  6 , it is possible to surely shut off the flow of the second process gas. In addition, the above-described advantage is also afforded with the gasket  51  provided between the block  40  and the block  10 . 
     The purge gas is an inert gas (for example, nitrogen gas). For example, the purge gas is supplied into the fluid control device  100  in order to purge an interior of the fluid control device  100  when the supply of the first process gas is switched to the supply of the second process gas. The purge gas is supplied from other flow-path forming block (not shown) that is attached at the position facing the accommodating concave portion  12   a  of the second attachment surface  12 . The purge gas that has been supplied from the accommodating concave portion  12   a  is guided to the valve device  2  through the flow path  13   b , the through hole  50   a , and the flow path  24   a . As the diaphragm  2   a  of the valve device  2  is separated from the valve sheet  23 , the purge gas is guided to the flow path  13  through the flow path  24   b , the through hole  50   a , and the flow path  13   c . The interior of the flow path  13  is purged with the purge gas that has been guided to the flow path  13  as described above. 
     For example, if the distance between the valve device  3  and the valve device  4  is reduced in order to reduce the size of the fluid control device  100 , the distance between the flow path  34   a  and the flow path  34   b  is reduced, and as a result, the angle formed between the flow path  34   a  and the flow path  34   b  becomes smaller. As described above, as the angle formed between the flow path  34   a  and the flow path  34   b  becomes smaller, a pressure loss (a flow path resistance) for the flow from the flow path  34   a  to the flow path  34   b  is increased. However, because the fluid control device  100  is provided with the recessed portion  51   a  formed in the gasket  51 , it is possible to allow the flow path  34   a  to be communicated with the flow path  34   b  not only through the communication portion  36  but also through the recessed portion  51   a . With such a configuration, it is possible to ensure the required effective cross section at a portion where the flow path  34   a  and the flow path  34   b  are connected. Thus, it is possible to reduce the size of the fluid control device  100  without disturbing the flow of the fluid. 
     Especially, in a case in which the angle formed between the flow path  34   a  and the flow path  34   b  is 45° or smaller, it is difficult to ensure the required effective cross section only with the communication portion  36 . Therefore, the provision of the recessed portion  51   a  is useful because the required effective cross section can be ensured at the portion where the flow path  34   a  and the flow path  34   b  are connected. 
     Furthermore, in the fluid control device  100 , because the recessed portion  51   a  is formed with the curved surface portion  51   b  such that the fluid flowing from the flow path  34   a  is guided so as to be turned to the flow path  34   b , it is possible to guide the fluid from the flow path  34   a  to the flow path  34   b  smoothly. 
     The configurations, operations, and effects of the embodiment of the present invention configured as described above will be collectively described. 
     The flow-path forming block  1  has: the first block (the block  10 ); the second block (the block  30 ,  40 ) attached to the first block (the block  10 ), the second block (the block  30 ,  40 ) having a first flow path (the flow path  34   a ) and a second flow path (the flow path  34   b ); and the gasket  51  provided between the first block (the block  10 ) and the second block (the block  30 ,  40 ), the gasket  51  being configured to seal between the first block (the block  10 ) and the second block (the block  30 ,  40 ), wherein the second block (the block  30 ,  40 ) has the communication portion  36  formed on the bottom surface  35  facing the gasket  51 , the communication portion  36  being configured such that the first flow path (the flow path  34   a ) and the second flow path (the flow path  34   b ) are communicated, and the gasket  51  has the recessed portion  51   a  formed at the position facing the communication portion  36 . 
     In this configuration, because the recessed portion  51   a  is formed at the position facing the communication portion  36 , it is possible to allow the first flow path (the flow path  34   a ) and the second flow path (the flow path  34   b ) to be communicated with each other through the recessed portion  51   a  in addition to the communication portion  36 . With such a configuration, it is possible to ensure the effective cross section of the flow path at the portion where the first flow path (the flow path  34   a ) and the second flow path (the flow path  34   b ) are connected. Thus, it is possible to reduce the size of the flow-path forming block  1  without disturbing the flow of the fluid. 
     In addition, in the flow-path forming block  1 , the first flow path (the flow path  34   a ) and the second flow path (the flow path  34   b ) are formed so as to approach each other towards the recessed portion  51   a , and the recessed portion  51   a  has the curved surface portion  51   b  configured such that the fluid flowing from the first flow path (the flow path  34   a ) is guided so as to be turned to the second flow path (the flow path  34   b ). 
     In this configuration, even if the angle formed between the first flow path (the flow path  34   a ) and the second flow path (the flow path  34   b ) becomes smaller, because the recessed portion  51   a  has the curved surface portion  51   b  that is configured such that the fluid flowing from the first flow path (the flow path  34   a ) is guided so as to be turned to the second flow path (the flow path  34   b ), it is possible to guide the fluid flowing from the first flow path (the flow path  34   a ) to the second flow path (the flow path  34   b ) smoothly by the curved surface portion  51   b . With such a configuration, it is possible to further reduce the pressure loss at the portion where the first flow path (the flow path  34   a ) and the second flow path (the flow path  34   b ) are connected. 
     The fluid control device  100  is provided with: the flow-path forming block  1 ; and a first valve device (the valve device  3 ,  6 ) and a second valve device (the valve device  4 ,  5 ) attached to the second block (the block  30 ,  40 ), wherein the second block (the block  30 ,  40 ) further has: a third flow path (the flow path  34   c ) communicated with and shut off from the first flow path (the flow path  34   a ) by the first valve device (the valve device  3 ,  6 ); and a fourth flow path (the flow path  34   d ) communicated with and shut off from the second flow path (the flow path  34   b ) by the second valve device (the valve device  4 ,  5 ). 
     In a case in which the size of the fluid control device  100  is to be reduced, as the distance between the first valve device (the valve device  3 ,  6 ) and the second valve device (the valve device  4 ,  5 ) is reduced, the distance between the first flow path (the flow path  34   a ) and the second flow path (the flow path  34   b ) is also reduced, and as a result, the angle formed between the first flow path (the flow path  34   a ) and the second flow path (the flow path  34   b ) becomes smaller even further. As described above, as the angle formed between the first flow path (the flow path  34   a ) and the second flow path (the flow path  34   b ) becomes smaller, the pressure loss (the flow path resistance) for the flow flowing from the first flow path (the flow path  34   a ) to the second flow path (the flow path  34   b ) is increased. However, in the fluid control device  100 , because the recessed portion  51   a  is formed, it is possible to ensure the effective cross section of the flow path for connecting the first flow path (the flow path  34   a ) and the second flow path (the flow path  34   b ). Thus, it is possible to reduce the size of the fluid control device  100  without disturbing the flow of the fluid. 
     In the fluid control device  100 , the first flow path (the flow path  34   a ) is an outlet flow path of the first valve device (the valve device  3 ,  6 ), the second flow path (the flow path  34   b ) is an inlet flow path of the second valve device (the valve device  4 ,  5 ), the third flow path (the flow path  34   c ) is an inlet flow path of the first valve device (the valve device  3 ,  6 ), and the fourth flow path (the flow path  34   d ) is an outlet flow path of the second valve device (the valve device  4 ,  5 ). 
     In this configuration, because the first valve device (the valve device  3 ,  6 ) and the second valve device (the valve device  4 ,  5 ) are provided in series in the flow paths  34   a  to  34   d , even in the event of failure of one of the first valve device (the valve device  3 ,  6 ) and the second valve device (the valve device  4 ,  5 ), it is possible to surely shut off the flow of the fluid flowing through the flow paths  34   a  to  34   d.    
     The above describes an embodiment of the present invention, however the above embodiment merely illustrates one portion of an application example of the present invention, and does not intend to limit the technical range of the present invention to the specific configurations in the above embodiment. 
     For example, the valve devices  2 ,  3 ,  4 ,  5 , and  6  may be a valve device that is operated by manually operating a driving unit. In addition, the valve devices  2 ,  3 ,  4 ,  5 , and  6  may also be a valve device driven by a solenoid. In addition, a description has been given, as an example, of the valve device having the metal diaphragm as the valve body, however, the valve body may be of any type, and for example, the valve body may be a lift valve having a metal bellow, etc. 
     In addition, in the above-mentioned embodiment, a description has been given of the example in which the flow path  34   b  is provided as the inlet flow path and the flow path  34   d  is provided as the outlet flow path, however, the flow path  34   d  may be provided as the inlet flow path and the flow path  34   b  may be provided as the outlet flow path. 
     In the above-mentioned embodiment, a description has been given of the example in which the valve devices  3  and  4  are attached to the block  30 , however, the present invention is not limited thereto, and the present invention may be applied to a device to which the other fluid apparatus such as a pressure sensor, a three-way valve, and so forth is attached. 
     In addition, in the above-mentioned embodiment, a description has been given of the example in which the flow path  34   a  and the flow path  34   b  are formed so as to approach each other towards the recessed portion  51   a , however, the present invention is not limited thereto, and the flow path  34   a  and the flow path  34   b  may extend in parallel. 
     This application claims priority based on Japanese Patent Application No. 2019-086395 filed with the Japan Patent Office on Apr. 26, 2019, the entire contents of which are incorporated into this specification.