JP2022134312A - Pressure measuring device - Google Patents

Abstract

To provide a pressure measuring device that can reduce a size of a body.SOLUTION: A pressure measuring device 1 has a body 2 that is installed, in an internal space 26, with a pressure sensor chip 23 that receives a pressure of a pressure transmission medium 25 charged between pressure receiving diaphragms 12, 13 to detect the pressure, and a sensor case 32 that accommodates the pressure sensor chip 23. The sensor case 32 is formed of an insulating material and has an opening for introducing the pressure of the pressure transmission medium 25 to the pressure sensor chip 23. The body 2 has first and second pressure guide paths 15, 16 communicating from pressure transmission chambers 12, 14 to the internal space 26. The internal space 26 is provided with first and second washers 17, 18 attached to opening ends of the pressure guide paths 15, 16, first and second capillaries 21, 22, and a substrate 36 mounted with an electric circuit generating an electric signal from detection output from the pressure sensor chip 23. The sensor case 32 is mounted on the substrate 36.SELECTED DRAWING: Figure 1

Description

The present invention relates to a pressure measuring device having a sensor chip and a substrate in an internal space of a body.

As a conventional pressure measuring device, there is one described in Patent Document 1, for example. The pressure measuring device disclosed in Japanese Patent Application Laid-Open No. 2002-200001 includes a body having a pressure receiving portion for receiving the pressure of the fluid to be measured, which is connected to the pressure receiving portion via a pipe for introducing pressure, and measures the pressure of the fluid to be measured. It comprises a pressure sensor for detection and a circuit board on which circuits relating to processing of electrical signals from the pressure sensor are provided. The pressure sensor and circuit board are housed inside the body. The pressure sensor is arranged adjacent to the pressure receiving portion, and the circuit board is arranged at the other end of the body so that the pressure sensor is positioned between the pressure receiving portion.

Japanese Patent No. 4955394

In the pressure measuring device disclosed in Patent Literature 1, a space for mounting the pressure sensor and a space for mounting the circuit board are required in the body, so there is a problem that the body becomes large.

SUMMARY OF THE INVENTION An object of the present invention is to provide a pressure measuring device capable of miniaturizing the body.

In order to achieve this object, the pressure measuring device according to the present invention comprises a pressure receiving diaphragm for receiving the pressure of the process fluid to be measured, and receives the pressure of the pressure transmission medium filled between the pressure receiving diaphragm and the pressure receiving diaphragm. A pressure measuring device having a body in which a pressure sensor chip for detecting pressure by means of a pressure sensor and a sensor case for housing the pressure sensor chip are installed in an internal space, the sensor case being made of an insulating material and , an opening for introducing the pressure of the pressure transmission medium to the pressure sensor chip, and the body is formed with the pressure receiving diaphragm as part of a wall to accommodate a portion of the pressure transmission medium. A pressure guide path leading from the transmission chamber to the internal space of the body is provided, and the internal space of the body is provided with a through hole mounted at an open end of the pressure guide path leading to the internal space of the body. a stainless steel washer having one end inserted into the through hole of the washer and joined thereto, and the other end penetrating the opening of the sensor case to communicate with the pressure sensor chip; A thin tube filled with a pressure transmission medium and a circuit board mounted with an electric circuit for generating an electric signal from the detection output of the pressure sensor chip are provided, and the sensor case is mounted on the circuit board. There is.

According to the present invention, in the pressure measuring device, the circuit board has a notch through which the narrow tube passes at an end, and the sensor case is mounted on the circuit board around the notch. good too.

In the pressure measuring device according to the present invention, the circuit board is fixed to the body in a state in which the direction in which the open end of the pressure guide path is oriented is the thickness direction, and the pressure guide path in the circuit board A through hole may be formed at a position facing the open end.

According to the present invention, soldering lands connected to the electric circuit are provided in portions forming three sides surrounding the hole portion of the notch in the circuit board, and the sensor case is mounted on the circuit board of the sensor case. Electrode pads may be provided on the bottom surface, which is the mounting surface on which the device is placed, to be connected to the soldering lands for electrical continuity.

In the present invention, since the sensor case can be mounted on the circuit board, the space occupied by the circuit board and the sensor case can be minimized, and the circuit board and the sensor case can be arranged compactly within the body. can be done. Therefore, it is possible to provide a pressure measuring device whose body can be miniaturized.

FIG. 1 is a cross-sectional view of a pressure measuring device according to the invention. FIG. 2 is a perspective sectional view of the pressure measuring device. FIG. 3 is an exploded perspective view showing the body and resin case of the pressure measuring device in a cutaway manner. FIG. 4 is a perspective cross-sectional view of the pressure sensor assembly. FIG. 5 is an enlarged cross-sectional view showing the junction between the sensor case, the pressure sensor chip, and the thin tube. FIG. 6 is a cross-sectional view showing an enlarged joint between the washer and the thin tube. FIG. 7 is a plan view of the pressure sensor assembly and substrate. FIG. 8 is a perspective view of the pressure sensor assembly and substrate. FIG. 9 is a perspective cross-sectional view for explaining the procedure for welding the washer to the body. FIG. 10 is a plan view of the substrate according to the second embodiment. FIG. 11 is a plan view showing an enlarged main part of the substrate. FIG. 12 is a perspective view of the pressure sensor assembly and substrate. FIG. 13 is a perspective view of the pressure sensor assembly and substrate. FIG. 14 shows a substrate according to the third embodiment. FIG. 15 is a perspective view of the pressure sensor assembly;

(First embodiment)
An embodiment of a pressure measuring device according to the present invention will be described in detail below with reference to FIGS. 1 to 9. FIG.
A pressure measuring device 1 shown in FIG. 1 is constructed by assembling a plurality of functional parts, which will be described later, to a body 2 depicted in the center of FIG. The body 2 has a pressure receiving portion 3 drawn on the lower side in FIG. 1 and a detecting portion 4 drawn on the upper side. The body 2 according to this embodiment is made of stainless steel.

The pressure receiving portion 3 is formed in a plate shape whose thickness direction is the left-right direction in FIG. A second pipe 6 is connected. The inside of the first pipe 5 is filled with a first process fluid 7 to be measured. The interior of the second pipe 6 is filled with a second process fluid 8 to be measured.
A first pressure-receiving diaphragm 11 for receiving the pressure of the first process fluid 7 is provided at one end of the pressure-receiving portion 3 connected to the first pipe 5, and the first pressure-receiving diaphragm 11 is A first pressure transmission chamber 12 is formed as a part of the wall.
A second pressure-receiving diaphragm 13 for receiving the pressure of the second process fluid 8 is provided at the other end of the pressure-receiving portion 3 connected to the second pipe 6 , and the second pressure-receiving diaphragm 13 A second pressure transmission chamber 14 is formed in which is a part of the wall.

The first pressure transmission chamber 12 and the second pressure transmission chamber 14 are, as shown in FIG. It communicates with the pressure chamber 24 (see FIG. 5) of the pressure sensor chip 23 via the first and second washers 17 and 18 and the first and second capillaries 21 and 22 of the detector 4 . A pressure transmission system from the first and second pressure transmission chambers 12, 14 to the pressure chamber 24 is filled with a pressure transmission medium 25 (see FIGS. 1 and 5). The pressure sensor chip 23 receives the pressure of the pressure transmission medium 25 filled between the first and second pressure receiving diaphragms 11 and 13 and detects the pressure.

The detecting portion 4 of the body 2 is formed in a cylindrical shape and opens in the direction opposite to the pressure receiving portion 3 . An internal space 26 of the body 2 is formed within the detection section 4 . A cover 27 (see FIG. 1) is attached to the opening of the detector 4 and closed by the cover 27 .
As shown in FIG. 3, first and second pressure guide paths 15 and 16 are opened at the inner bottom of the detector 4, respectively. The first and second pressure guide paths 15 and 16 are formed inside the body 2 so as to communicate with the internal space 26 of the body 2 from the first and second pressure transmission chambers 12 and 14 .

A first washer 17 is attached to the open end of the first pressure guide path 15 that communicates with the internal space 26, as shown in FIG. A second washer 18 is attached to the open end of the second pressure guide path 16 that communicates with the internal space 26 . The first and second washers 17 and 18 are made of stainless steel and are disc-shaped and welded to the body 2 .

As shown in FIG. 6, projections 17a and 18a facing the inside of the first and second pressure guide paths 15 and 16 are provided at the centers of the first and second washers 17 and 18, respectively. , through holes 28 and 29 are formed. As shown in FIG. 4, one end of a first thin tube 21, which will be described later, is inserted into and joined to a through hole 28 of the first washer 17. As shown in FIG. One end of a later-described second thin tube 22 is inserted and joined to the through hole 29 of the second washer 18 .

The first thin tube 21 and the second thin tube 22 are each made of stainless steel and bent into a predetermined shape. The first and second tubules 21 and 22 are joined to the first and second washers 17 and 18 by fitting the outer circumferences of the tips of the tubules 21 and 22 to the opening edges of through holes 28 and 29 that open to the projections 17a and 18a. It is done by welding the parts. As shown in FIG. 6, this welding is performed so that the weld 30 provides a liquid-tight seal between the first and second washers 17, 18 and the first and second tubules 21, 22. there is
A first capillary tube 21 welded to the first washer 17 and a second capillary tube 22 welded to the second washer 18 form part of the pressure sensor assembly indicated at 31 in FIG. It is.

The pressure sensor assembly 31, as shown in FIG. , 22 and a sensor case 32 and a pressure sensor chip 23 . The first and second capillaries 21, 22 extend from the first and second washers 17, 18 in the direction opposite to the pressure receiving portion 3 of the body 2, and connect the first and second washers 17, 18 and the sensor. The narrow tubes 21 and 22 are bent so that the distance between them and the case 32 is narrowed. The interval between the first and second capillaries 21 and 22 is widened on one end side welded to the first and second washers 17 and 18 and narrowed on the other end side joined to the sensor case 32 .

The sensor case 32 is composed of a case body 33 made of a ceramic material and a lid body 34 made of a ceramic material or a metal material. The pressure sensor chip 23 is formed in a cubic shape by stacking a plurality of plate-like members made of silicon in the thickness direction, and is accommodated in the sensor case 32 .
A case main body 33 of the sensor case 32 is formed in a bottomed square tube shape that opens toward the upper side in FIG. The lid 34 is formed in a plate shape and is fixed to the case body 33 by brazing or seam welding in a state of closing the opening of the case body 33 . The operation of joining the lid 34 to the case main body 33 is performed so that the inside of the case main body 33 is airtightly sealed while being filled with vacuum or _N2 .

On the bottom surface of the sensor case 32, that is, on the outer surface of the bottom wall 33a of the case main body 33, a plurality of electrodes electrically connected to a plurality of terminals (not shown) of the pressure sensor chip 23 are provided as shown in FIG. electrode pads 35 are formed. The electrode pads 35 according to this embodiment are arranged at both ends of the bottom wall 33a in a direction orthogonal to the direction in which the first thin tubes 21 and the second thin tubes 22 are arranged.
These electrode pads 35 are soldered over soldering lands 37 formed on a substrate 36 (see FIG. 3). By performing this soldering, the sensor case 32 is electrically connected (mounted) to the soldering lands 37 while being placed on the substrate 36 . In this embodiment, the board 36 corresponds to the "circuit board" according to the invention.

The substrate 36 is formed in a disc shape, as shown in FIG. The substrate 36 is formed with two circular through-holes 38, 38 through which the first and second washers 17, 18 can pass, and a slit 39 connecting the through-holes 38 with each other. As shown in FIG. 2, the through holes 38 are formed in the substrate 36 at positions facing the open ends of the first and second pressure guide paths 15 and 16 .

The operation of stacking the sensor case 32 on the substrate 36 is performed by passing the first and second washers 17 and 18 through the through holes 38 and 38 and passing the first and second capillaries 21 and 22 through the slits 39 . Further, as shown in FIGS. 7 and 8, the substrate 36 is mounted with an electric circuit 40 for generating an electric signal from the detection output of the pressure sensor chip 23 and a connector terminal 41 for external connection. Although not shown, a wiring pattern for electrically connecting the soldering lands 37 and the electric circuit 40 and a wiring pattern for electrically connecting the electric circuit 40 and the connector terminal 41 are provided on the substrate 36 . and are formed. The positions where the electric circuit 40 and the connector terminals 41 are mounted are not limited to the positions shown in the figure, and can be changed as appropriate.

The substrate 36 according to this embodiment is supported by a resin case 51 (see FIG. 3) and supported by the body 2 via the resin case 51 . The resin case 51 is formed in a bottomed cylindrical shape that can be accommodated in the internal space 26 of the body 2 . The resin case 51 has a mounting surface 52 on which the substrate 36 is mounted, claw pieces 53 for mounting and locking the substrate 36 on the mounting surface 52, and first and second washers 17 and 18. Two through holes 54, 54 are formed for passage.

Around the through hole 54 are two circular projections 55 projecting from the bottom wall 51a of the resin case 51 downward in FIG. Two cylindrical bodies 56, 56 projecting in the direction opposite to the pressure receiving portion 3 from 51a are provided. The circular protrusion 55 fits into a circular recess 57 formed in the body 2 so as to surround the first and second pressure guide paths 15 and 16 . A concave portion 58 for passing the first and second thin tubes 21 and 22 is formed in the cylindrical body 56 .

By welding the first and second washers 17 and 18 to the body 2 while the substrate 36 is attached to the resin case 51, the substrate 36 is mounted in a state in which the thickness direction of the substrate 36 is the vertical direction in FIG. is fixed to the body 2. The vertical direction in FIG. 1 is the direction in which the open ends of the first and second pressure guide paths 15 and 16 are oriented.

As shown in FIG. 5, the bottom wall 33a of the case main body 33 is formed with mounting seats 61 for supporting both sides of the pressure sensor chip 23, and the pressure of the pressure transmission medium 25 is introduced to the pressure sensor chip 23. First and second openings 62 and 63 (see FIG. 4) are formed for this purpose.
As shown in FIG. 4, the pressure sensor chip 23 has a first hole 64 into which the other end of the first thin tube 21 is inserted and a second hole 65 into which the other end of the second thin tube 22 is inserted. is formed and fixed to the mounting seat 61 of the case body 33 by, for example, brazing. The pressure sensor chip 23 is configured to detect the differential pressure between the pressure of the pressure transmission medium 25 transmitted to the first hole 64 and the pressure of the pressure transmission medium 25 transmitted to the second hole 65. there is

The first and second openings 62, 63 of the case main body 33 are formed to be through holes penetrating the bottom wall 33a. The hole diameters of the first and second openings 62, 63 are such that the other ends of the first and second capillaries 21, 22 can pass through. The other end of the first thin tube 21 passes through the first opening 62 and is inserted into the first hole 64 of the pressure sensor chip 23 to communicate with the pressure sensor chip 23 . The other end of the second thin tube 22 passes through the second opening 63 and is inserted into the second hole 65 of the pressure sensor chip 23 to communicate with the pressure sensor chip 23 .

The first and second capillaries 21 and 22 are adhered to the pressure sensor chip 23 with an adhesive 66, as shown in FIG. As this adhesive 66, an epoxy-based adhesive can be used. The inside of the sensor case 32 is in a state where the epoxy-based adhesive does not absorb moisture. This state is a vacuum state or a state filled with an inert gas such as N ₂ gas. In order to keep the interior of the sensor case 32 in such an inert state, the portions of the first and second thin tubes 21 and 22 that penetrate through the first and second openings 62 and 63 of the sensor case 32 are soldered. sealed by the adhesive. Soldering is performed so that the solder 67 wets and spreads over the entire area around the first and second openings 62 and 63 .

The first and second openings 62, 63 of the case main body 33 are metallized so as to enable this soldering. The first and second thin tubes 21 and 22 are plated for soldering at the portions to be soldered to the first and second openings 62 and 63 . This plating for soldering is Au plating with Ni as the base.

Next, a procedure for assembling the pressure measuring device 1 configured as described above will be described. When assembling the pressure measuring device 1, first, the portions to be soldered to the first and second openings 62, 63 of the first and second thin tubes 21, 22 are plated for soldering. In addition, metallization is applied in advance to the portions where the first and second openings 62 and 63 of the case body 33 and the lid 34 are joined.

Then, the first and second washers 17 and 18 are welded to the first and second thin tubes 21 and 22, respectively. After that, the first and second thin tubes 21 and 22 are passed through the first and second openings 62 and 63 of the case body 33 , and the first and second thin tubes 21 and 22 are adhered to the pressure sensor chip 23 . Then, the pressure sensor chip 23 is joined to the case main body 33, and the pressure sensor chip 23 and the conducting portion of the case main body 33 are connected by, for example, bonding wires (not shown).

After the pressure sensor chip 23 is attached to the sensor case 32 in this way, the first and second thin tubes 21, 22 are soldered to the first and second openings 62, 63 of the case body 33, and the thin tubes penetrate through. Seal the part. Then, the case main body 33 and the first and second thin tubes 21 and 22 are loaded into a joining device (not shown), the inside of the case main body 33 is made inactive, and the cover 34 is brazed or seam-welded to the case main body 33 . Install by The pressure sensor assembly 31 is completed by joining the cover 34 to the case body 33 .

Next, pressure sensor assembly 31 is attached to substrate 36 . In this mounting operation, the first and second washers 17 and 18 are passed through the through holes 38 of the board 36, the first and second thin tubes 21 and 22 are passed through the slits 39, and the sensor case 32 is soldered to the board 36. and do. Thereafter, the board 36 is engaged with the resin case 51 and the resin case 51 is inserted into the internal space 26 of the body 2 . When assembling the substrate 36 to the resin case 51 , the first and second washers 17 , 18 pass through the resin case 51 while visually checking the first and second washers 17 , 18 through the through holes 38 of the substrate 36 . Adjust the position of the substrate 36 so that it enters the hole 54 . Then, the circular projection 55 of the resin case 51 is fitted into the circular recess 57 of the body 2, and the projections 17a, 18a of the first and second washers 17, 18 are connected to the first and second pressure guide paths 15, 16. insert into

Next, the first and second washers 17, 18 are welded to the body 2. As shown in FIG. As shown in FIG. 9, this welding is performed by placing the body 2 on the lower electrode 71 and pressing the upper electrode 72 against the first and second washers 17 and 18 by resistance welding. The upper electrode 72 is rod-shaped, passes through the through hole 54 of the resin case 51 and the through hole 38 of the substrate 36 and overlaps the first and second washers 17 and 18 . A slit 73 is formed at the tip of the upper electrode 72 to allow the first and second thin tubes 21 and 22 to pass therethrough.
After the first and second washers 17 and 18 are welded to the body 2, the pressure transmission medium 25 is filled in the pressure transmission path from the first and second pressure transmission chambers 12 and 14 to the pressure sensor chip 23. . This filling is performed using filling holes (not shown) extending from the first and second pressure transmission chambers 12 and 14 to the outside of the body 2 .

The sensor case 32 of the pressure measuring device 1 configured in this way is placed on the substrate 36 . Therefore, since the sensor case 32 can be mounted on the substrate 36, the space occupied by the substrate 36 and the sensor case 32 can be minimized, and the substrate 36 and the sensor case 32 can be arranged compactly within the body 2. can do. Therefore, according to this embodiment, it is possible to provide a pressure measuring device whose body can be miniaturized.

(Second embodiment)
The substrate and pressure sensor assembly may be configured as shown in FIGS. 10-13. In FIGS. 10 to 13, the same reference numerals are assigned to members that are the same as or equivalent to those described with reference to FIGS. 1 to 9, and detailed description thereof will be omitted as appropriate.
A substrate 81 shown in FIG. 10 is formed in a disc shape and has two through holes 38 and a notch 82 positioned at one location on the outer periphery. The two through holes 38, 38 are formed at the same positions as in the first embodiment, that is, at positions facing the open ends of the first and second pressure guide paths 15, 16. As shown in FIG. An electric circuit 40 and connector terminals 41 are mounted on the substrate 81 . The positions where the electric circuit 40 and the connector terminals 41 are mounted are not limited to the positions shown in FIG. 10, and can be changed as appropriate.

The notch 82 is for passing the first and second thin tubes 21 and 22, and is formed at the radial end of the disk-shaped substrate 81. extended. The notch 82 according to this embodiment extends in a direction orthogonal to the imaginary line L connecting the centers of the two through holes 38 . Therefore, the notch 82 extends toward the center between one through hole 38 and the other through hole 38 . The notch 82 extends parallel to the imaginary line L so as to connect first and second sides 82a and 82b extending from the outer peripheral edge 81a of the substrate 81 toward the imaginary line L and one ends of these two sides. The opening is surrounded by the first to third sides 82a to 82c.

As shown in FIG. 11, a plurality of soldering lands 83 are formed in the portion of the substrate 81 forming the first side 82a of the notch 82. As shown in FIG. A plurality of soldering lands 84 are formed in the portion of the substrate 81 that forms the second side 82b of the notch 82 . A plurality of soldering lands 85 are formed in a portion of the substrate 81 forming the third side 82c of the notch 82. As shown in FIG. These soldering lands 83 to 85 are connected to the electric circuit 40 mounted on the substrate 81 by wiring patterns (not shown). The sensor case 32 is mounted on these soldering lands 83-85. That is, the sensor case 32 is placed and fixed on the periphery of the notch 82 on the substrate 81 with the first and second capillaries 21 and 22 passed through the notch 82 .

If the soldering lands 83 to 85 are concentrated in the vicinity of one side of the notch 82, the sensor case 32 may be subjected to an external force during the manufacturing process of the pressure measuring device, or may be damaged by the surrounding environment. Stress concentration occurs when thermal stress is generated in the solder joint due to temperature changes. In addition, since the area of each joint surface of the electrode pads 35 on the sensor case 32 side becomes smaller, the process becomes more difficult and the soldering strength of the electrode pads 35 becomes smaller. In this embodiment, the soldering lands 83 to 85 are dispersedly arranged on the three sides of the notch 82 so as not to cause such a problem.

The plurality of soldering lands 83 provided in the vicinity of the first side 82a and the plurality of soldering lands 84 provided in the vicinity of the second side 82b may be arranged symmetrically in FIG. desirable. Therefore, if the soldering lands 83 and 84 are asymmetrical, a dummy soldering land that is not wired is provided on the substrate 81, and a dummy electrode pad that is not wired is provided on the sensor case 32. to achieve a symmetrical structure. In this embodiment, soldering lands 85 for passing sensor signals are provided along the third side 82c. By adopting this configuration, the efficiency of mounting the sensor case 32 on the substrate 81 is increased.

The first and second tubules 21, 22 according to this embodiment are formed by bending as shown in FIG. 12 or FIG.
The first and second thin tubes 21 and 22 shown in FIG. 12 have two bent portions 21a, 21b and 22b, respectively, and are formed in a V-shape when viewed from a direction perpendicular to the main surface 81b of the substrate 81. It is
The first and second capillaries 21 and 22 shown in FIG. 13 each have three bent portions 21a to 21c and 22a to 22c, and are U-shaped when viewed from a direction perpendicular to the main surface 81b of the substrate 81. are formed in an L-shape so that

As shown in this embodiment, a notch 82 is formed at the edge of the substrate 81, and the sensor case 32 is placed and fixed on the periphery of the notch 82, thereby forming the first and second sensors on the substrate 81. Since the slit 39 for passing the thin tubes 21 and 22 is not required, the central portion of the substrate 81 can be used as a component mounting space 86 (see FIG. 10). Therefore, many electronic components can be mounted on the substrate 81 without enlarging the substrate 81 .

(Third Embodiment)
The substrate and pressure sensor assembly can be constructed as shown in FIGS. 14 and 15, the same or similar members as those explained with reference to FIGS. 1 to 13 are denoted by the same reference numerals, and detailed explanation thereof will be omitted as appropriate. FIG. 14A is a side view of the board viewed from the front side where the sensor case is mounted, and FIG. 14B is a side view of the board viewed from the back side where the sensor case is not mounted. FIGS. 14A and 14B are drawn without attaching the first and second capillaries to the sensor case.

A substrate 91 shown in FIGS. 14A and 14B is formed in a rectangular plate shape and has a notch 82 at one end in the longitudinal direction. Four holes 92 provided in the substrate 91 in FIGS. 14A and 14B are holes for passing mounting bolts (not shown). The mounting bolts fix the board 91 to a support bracket (not shown) on the side of the body 2 . The main surface 91a of the substrate 91 extends parallel to the longitudinal direction of the body 2 (the direction in which the pressure receiving portion 3 and the detecting portion 4 are aligned, which is the vertical direction in FIGS. 14A and 14B). The notch 82 is fixed to the body 2 via the support bracket in such a posture as to approach the pressure receiving portion 3 .

Soldering lands 83 to 85 are provided in a portion of the substrate 91 where the notch 82 is formed, as in the second embodiment, and the sensor case 32 is mounted on these soldering lands 83 to 85. Being placed and fixed.
The first and second capillaries 21, 22 according to this embodiment are attached to the ends 93, 94 connected to the sensor case 32 by the first and second washers 17, 18 as shown in FIG. are bent so that the other ends 95 and 96 connected to are vertical.

As shown in this embodiment, by arranging the substrate 91 so as to extend parallel to the direction in which the pressure receiving portion 3 and the detecting portion 4 of the body 2 are arranged, the detecting portion 4 can be compactly formed so as to reduce the area occupied. can do.

REFERENCE SIGNS LIST 1 pressure measuring device 2 body 7 first process fluid 8 second process fluid 11 first pressure receiving diaphragm 12 first pressure transmission chamber 13 second pressure receiving diaphragm , 14... Second pressure transmission chamber 15... First pressure guide path 16... Second pressure guide path 17... First washer 18... Second washer 21... First narrow tube 22 2nd narrow tube 23 pressure sensor chip 25 pressure transmission medium 26 internal space 28, 29 through hole 32 sensor case 35 electrode pad 36, 81, 91 substrate (circuit board ), 40...Electric circuit 62...First opening 63...Second opening 82...Notch 38...Through hole 82a...First side 82b...Second side 82c...Second side Side 3, 37, 83 to 85, lands for soldering.

Claims (4)

Equipped with a pressure-receiving diaphragm that receives the pressure of the process fluid to be measured,
a pressure sensor chip that receives the pressure of the pressure transmission medium filled between the pressure receiving diaphragm and detects the pressure;
A pressure measuring device having a body in which a sensor case containing the pressure sensor chip is installed in an internal space,
the sensor case is made of an insulating material and has an opening for introducing the pressure of the pressure transmission medium to the pressure sensor chip;
the body has a pressure transmission chamber formed with the pressure receiving diaphragm as a part of a wall and containing a part of the pressure transmission medium, and a pressure transmission path leading to the internal space of the body;
The internal space of the body includes:
a stainless steel washer having a through-hole attached to the open end of the pressure guide path communicating with the internal space of the body;
One end of the washer is inserted into and joined to the through hole of the washer, and the other end of the washer passes through the opening of the sensor case to communicate with the pressure sensor chip, and the interior is filled with the pressure transmission medium. a tubule;
a circuit board mounted with an electric circuit for generating an electric signal from the detection output of the pressure sensor chip;
A pressure measuring device, wherein the sensor case is mounted on the circuit board. The pressure measurement device according to claim 1,
The circuit board has a notch at the end for the thin tube to pass through,
The pressure measuring device, wherein the sensor case is placed on the periphery of the notch on the circuit board. In the pressure measuring device according to claim 2,
the circuit board is fixed to the body in a state in which the direction in which the open end of the pressure guiding path is oriented is the thickness direction;
A pressure measuring device, wherein a through hole is formed in the circuit board at a position facing the open end of the pressure guiding path. In the pressure measuring device according to claim 2 or 3,
Soldering lands connected to the electric circuit are provided in portions forming three sides surrounding the hole portion of the notch in the circuit board, respectively;
A pressure measuring device, wherein electrode pads are provided on a bottom surface of the sensor case, which is a mounting surface to be mounted on the circuit board, and are electrically connected to the soldering lands.

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