JP7695866B2 - Pressure Sensors - Google Patents

Description

The present invention relates to a pressure sensor.

Patent Document 1 discloses a pressure sensor with multiple measurement ranges. In this pressure sensor, multiple diaphragms are provided within a single differential pressure sensor chip, and the measurement range is changed by switching the diaphragm used for measurement.

JP 2002-13996 A

In the pressure sensor described in Patent Document 1, multiple diaphragms are formed within one differential pressure sensor chip. For example, if it is desired to change a portion of the measurement range during the manufacturing stage of the pressure sensor, the entire differential pressure sensor chip must be redesigned. Here, the measurement range of the pressure measured by the pressure sensor often differs depending on the use of the pressure sensor, and it is desirable for the measurement range of the pressure sensor to be easily changeable depending on the delivery destination of the pressure sensor.

The present invention was made in consideration of the above points, and aims to make it possible to easily change at least one of multiple measurement ranges.

To achieve this objective, the pressure sensor of the present invention comprises a first diaphragm that deforms when it receives a first pressure of the fluid to be measured, a second diaphragm that deforms when it receives a second pressure of the fluid to be measured, a pressure transmission member that includes a plurality of differential pressure sensor chips each configured to detect a pressure difference between the first pressure and the second pressure and having different measurement ranges, a first transmission path filled with a first pressure transmission fluid that transmits the first pressure received by the first diaphragm to each of the plurality of differential pressure sensor chips, and a second transmission path filled with a second pressure transmission fluid that transmits the second pressure received by the second diaphragm to each of the plurality of differential pressure sensor chips.

The first transmission path may include a 1-1 transmission path having a pressure receiving chamber at a first end facing the first diaphragm, and a 1-2 transmission path extending from a second end opposite the first end of the 1-1 transmission path, branching midway, and reaching each of the multiple sensor chips, and the second transmission path may include a 2-1 transmission path having a pressure receiving chamber at a first end facing the second diaphragm, and a 2-2 transmission path extending from a second end opposite the first end of the 2-1 transmission path, branching midway, and reaching each of the multiple sensor chips, and the pressure transmission member may include a first member forming the 1-1 transmission path and the 2-1 transmission path, and a second member connected to the first member and forming the 1-2 transmission path and the 2-2 transmission path.

Each of the multiple differential pressure sensor chips may include a sensor diaphragm that is deformed by the differential pressure and a detection element that detects the deformation of the sensor diaphragm. At least one of the size, shape, thickness, and material of the sensor diaphragm of each of the multiple differential pressure sensor chips is different between the multiple differential pressure sensor chips, so that the measurement ranges of the multiple differential pressure sensor chips are different. The multiple differential pressure sensor chips may include a first differential pressure sensor chip having a measurement range on the highest differential pressure side and one or more second differential pressure sensor chips having a measurement range on the lower differential pressure side than the measurement range of the first differential pressure sensor chip. At least one of the one or more second differential pressure sensor chips may include an overpressure protection mechanism that prevents the sensor diaphragm from further deforming by contacting the sensor diaphragm deformed by the differential pressure.

According to the present invention, the measurement range of the pressure sensor can be changed simply by replacing the differential pressure sensor chip, making it easy to change at least one of the multiple measurement ranges.

1 is a partial cross-sectional view showing a schematic configuration of a pressure sensor according to an embodiment of the present invention. 1 is a cross-sectional view showing a schematic configuration of a differential pressure sensor chip.

The following describes a pressure sensor according to one embodiment of the present invention with reference to the drawings. Note that the up-down direction set in the drawings is set for the convenience of explanation and may differ from the actual up-down direction. For example, the pressure sensor may be installed with the top of FIG. 1 facing the ground in the up-down direction.

The pressure sensor 10 according to this embodiment shown in FIG. 1 detects the differential pressure between a first pressure P1 of the fluid to be measured at a first position of a pipe through which the fluid to be measured flows, and a second pressure P2 of the fluid to be measured at a second position of the pipe. The fluid to be measured may be a liquid or a gas. The pressure sensor 10 transmits the detected differential pressure to the outside. Here, the pressure sensor 10 is configured as a differential pressure transmitter. The transmitted differential pressure is used, for example, to measure the flow rate of the fluid to be measured. The pressure sensor 10 is arranged so that the first pressure P1 is the pressure on the low pressure side, and the second pressure P2 is the pressure on the high pressure side.

As shown in FIG. 1, the pressure sensor 10 comprises a first diaphragm 21, a second diaphragm 22, a pressure transmission member 30, a circuit section 40, a circuit housing member 50, and differential pressure sensor chips 61-63. Note that in FIG. 1, the second member 32 (described below), the pin member 42 (described below), and the differential pressure sensor chips 61-63, which should be depicted as cross-sectional views, are depicted as elevational views seen from the front of the paper of FIG. 1.

The first diaphragm 21 comes into contact with a fluid to be measured having a first pressure P1 drawn in through a specified flow path 91, and is deformed by receiving the first pressure P1. The second diaphragm 22 comes into contact with a fluid to be measured having a second pressure P2 drawn in through a specified flow path 92, and is deformed by receiving the second pressure P2. Each diaphragm 21 and 22 is fixed to a first surface 31A and a second surface 31B facing in opposite directions among the four outer surfaces of the first member 31 of the rectangular prism shape of the pressure transmission member 30, the details of which will be described later.

The pressure transmission member 30 transmits the pressures P1 and P2 received by the diaphragms 21 and 22, respectively, to each of the differential pressure sensor chips 61-63. The pressure transmission member 30 comprises a first member 31 in the shape of a rectangular prism, and a second member 32 including three-pronged pipes 32A and 32B connected to the first member 31. The first member 31 is also called a pressure-receiving body. As described above, the diaphragms 21 and 22 are fixed to the first member 31, and the first pressure P1 and the second pressure P2 are received by the pressure-receiving chambers S1 and S2, which will be described later.

The pressure transmission member 30 has a first transmission path 30A including a 1-1 transmission path 30AA formed by a first member 31 and a 1-2 transmission path 30AB formed by a pipe 32A of a second member 32. A first pressure transmission fluid F1 is sealed in the first transmission path 30A, which transmits the first pressure P1 received by the first diaphragm 21 to each of the differential pressure sensor chips 61 to 63.

The 1-1 transmission path 30AA has a pressure receiving chamber S1 as a first end, which faces the surface of the first diaphragm 21 opposite to the surface that contacts the fluid to be measured. The pressure receiving chamber S1 is a recess that opens into the first surface 31A of the first member 31. The pressure receiving chamber S1 is sealed by the first diaphragm 21. The portion of the 1-1 transmission path 30AA other than the pressure receiving chamber S1 is a hole that passes through the first member 31. The second end of the 1-1 transmission path 30AA, which is opposite to the first end, opens into the upper surface of the first member 31. One end of the pipe 32A of the second member 32 that forms the 1-2 transmission path 30AB is inserted and connected to the second end of the 1-1 transmission path 30AA.

The 1-2 transmission path 30AB consists of a hollow portion of a three-pronged pipe 32A that branches into three midway through the second member 32. The end of the pipe 32A that does not branch is connected to the first member 31 as described above. The other three branched ends of the pipe 32A are connected to the low-pressure side pressure input parts of the differential pressure sensor chips 61 to 63, respectively. With this configuration, the 1-2 transmission path 30AB extends from the second end of the 1-1 transmission path 30AA, branches midway, and reaches each of the differential pressure sensor chips 61 to 63.

The pressure transmission member 30 has a second transmission path 30B including a second-1 transmission path 30BA formed by the first member 31 and a second-2 transmission path 30BB formed by the pipe 32B of the second member 32. A second pressure transmission fluid F2 is sealed in the second transmission path 30B, which transmits the second pressure P2 received by the second diaphragm 22 to each of the differential pressure sensor chips 61 to 63.

The 2-1 transmission path 30BA has a pressure receiving chamber S2 as a first end, which faces the surface of the second diaphragm 22 opposite to the surface that contacts the fluid to be measured. The pressure receiving chamber S2 is a recess that opens into the second surface 31B of the first member 31. The pressure receiving chamber S2 is sealed by the second diaphragm 22. The portion of the 2-1 transmission path 30BA other than the pressure receiving chamber S2 is a hole that passes through the first member 31. The second end of the 2-1 transmission path 30BA, which is opposite to the first end, opens into the upper surface of the first member 31. One end of the pipe 32B of the second member 32 that forms the 2-2 transmission path 30BB is inserted and connected to the second end of the 2-1 transmission path 30BA.

The 2-2 transmission path 30BB is formed by a hollow portion of a three-way pipe 32B that branches into three midway through the second member 32, with one end of the pipe 32B that does not branch being connected to the first member 31 as described above. The other three branched ends of the pipe 32B are connected to the high-pressure side pressure input parts of the differential pressure sensor chips 61 to 63, respectively. With this configuration, the 2-2 transmission path 30BB extends from the second end of the 2-1 transmission path 30BB, branches midway, and reaches each of the differential pressure sensor chips 61 to 63.

The circuit unit 40 controls the operation of the pressure sensor 10. The circuit unit 40 comprises a circuit board 41 on which the differential pressure sensor chips 61-63 are mounted, a pin member 42 for external connection, and wiring 43 that connects the circuit board 41 and the pin member 42. The pin member 42 comprises a number of connection pins 42A connected to the wiring 43, and a support portion 42B in which the connection pins 42A are embedded and which supports the connection pins 42A.

The circuit housing member 50 houses the circuit section 40. The circuit housing member 50 is fixed to the first member 31 of the pressure transmission member 30. The circuit housing member 50 includes a cylindrical member 51 that houses the second member 32, the circuit board 41, and the differential pressure sensor chips 61-63, and a lid 52 that is disposed inside the cylindrical member 51 and covers the circuit board 41 and the differential pressure sensor chips 61-63. The lid 52 supports the pin members 42 of the circuit section 40. The cylindrical member 51 and the lid 52 form a space S11 that receives the connector of the external wiring that is connected to the connection pin 42A.

The differential pressure sensor chips 61 to 63 are arranged on the upper surface of the circuit board 41. The pipes 32A and 32B of the second member 32, which are connected to the differential pressure sensor chips 61 to 63, respectively, are routed from the lower surface to the upper surface of the circuit board 41 through three through holes formed in the circuit board 41.

When the first diaphragm 21 receives the first pressure P1 and deforms so as to bulge to the right side of the drawing, the volume of the pressure-receiving chamber S1 that the first diaphragm 21 faces decreases. This causes the first pressure transmission fluid F1 sealed in the first transmission path 30A including the pressure-receiving chamber S1 to be pushed toward the differential pressure sensor chips 61-63. As a result, the first pressure P1 received by the first diaphragm 21 is transmitted to each of the differential pressure sensor chips 61-63.

When the second diaphragm 22 receives the second pressure P2 and deforms so as to bulge to the left side of the drawing, the volume of the pressure receiving chamber S2 that the second diaphragm 22 faces decreases. This causes the second pressure transmission fluid F2 sealed in the second transmission path 30B including the pressure receiving chamber S2 to be pushed toward the differential pressure sensor chips 61-63. As a result, the second pressure P2 received by the second diaphragm 22 is transmitted to each of the differential pressure sensor chips 61-63.

Each of the differential pressure sensor chips 61 to 63 is configured to detect the differential pressure between a first pressure P1 transmitted via a first pressure transmission fluid F1 and a second pressure P2 transmitted via a second pressure transmission fluid F2. The differential pressure sensor chips 61 to 63 have different measurement ranges.

The differential pressure sensor chip 61 has a low differential pressure measurement range, which is a measurement range of a relatively low differential pressure. In other words, the differential pressure sensor chip 61 is formed as a highly sensitive sensor chip. The differential pressure sensor chip 62 has a medium differential pressure measurement range, which is a measurement range on the high differential pressure side compared to the low differential pressure measurement range of the differential pressure sensor chip 61. The differential pressure sensor chip 63 has a high differential pressure measurement range, which is a measurement range on the high differential pressure side compared to the medium differential pressure measurement range of the differential pressure sensor chip 62. The differential pressure sensor chips 61 to 63 are also collectively referred to as the differential pressure sensor chip 60. The measurement range may be any range in which the reliability of the measured value is guaranteed. A part of the high differential pressure side included in the low differential pressure measurement range may overlap with a part of the low differential pressure side included in the medium differential pressure measurement range. A part of the high differential pressure side included in the low differential pressure measurement range may overlap with a part of the low differential pressure side included in the medium differential pressure measurement range. In this way, the different measurement ranges may overlap in part.

The differential pressure sensor chips 61 to 63 may have any structure. Here, an example of these structures will be described as the structure of the differential pressure sensor chip 60 with reference to FIG. 2. The differential pressure sensor chip 60 has a layered structure made up of a first layer 60A, a second layer 60B, and a third layer 60C, for example, as shown in FIG. 2.

The first layer 60A has a recess 60AA formed on its upper surface, and an introduction path 60AB that communicates with the recess 60AA and the first-2 transmission path 30AB of the first transmission path 30A shown in FIG. 1 and introduces the first pressure transmission fluid F1 into the recess 60AA. The first layer 60A is formed from a material such as silicon, for example.

The second layer 60B is formed on the first layer 60A and covers the recess 60AA of the first layer 60A. The portion of the second layer 60B covering the recess 60AA is the sensor diaphragm SD. The second layer 60B is formed with a detection element D that detects the displacement of the sensor diaphragm SD. The detection element D is made of a strain gauge using a semiconductor piezoresistance element. The second layer 60B has, for example, a main layer made of silicon or the like, an active layer that constitutes the detection element D and is formed by adding impurities to a predetermined region of the main layer, and an insulating protective layer made of silicon oxide or the like that is formed on the main layer so as to cover the active layer (in FIG. 2, the main layer and the insulating protective layer are depicted as one layer).

The third layer 60C is formed on the second layer 60B. The third layer 60C has a recess 60CA covered by the second layer 60B, and an introduction path 60CB that communicates with the recess 60CA and the second-2 transmission path 30BB of the second transmission path 30B and introduces the second pressure transmission fluid F2 into the recess 60CA. The introduction path 60CB penetrates the first layer 60A via the second layer 60B, and is thereby connected to the second-2 transmission path 30BB located on the first layer 60A side. The third layer 60C is formed from a material such as silicon, for example.

A first pressure P1 is applied to the sensor diaphragm SD of the second layer 60B by the first pressure transmission fluid F1 introduced into the recess 60AA of the first layer 60A. A second pressure P2 is applied to the sensor diaphragm SD by the second pressure transmission fluid F2 introduced into the recess 60CA of the third layer 60C. Therefore, the sensor diaphragm SD is deformed by the differential pressure between the first pressure P1 and the second pressure P2. As described above, since the first pressure P1 is lower than the second pressure P2, the sensor diaphragm SD is deformed so as to bulge toward the first layer 60A (the lower side of FIG. 2). The detection element D outputs an electrical signal corresponding to the degree of deformation of the sensor diaphragm SD to the circuit board 41 shown in FIG. 1 through wiring (not shown) or the like. This electrical signal is, for example, a voltage signal having a voltage value corresponding to the degree of deformation of the sensor diaphragm SD. In this way, the detection element D detects the deformation of the sensor diaphragm SD.

Returning to FIG. 2, the inner surface Y of the recess 60AA of the first layer 60A contacts the sensor diaphragm SD so that the deformed sensor diaphragm SD, which bulges toward the recess 60AA, does not deform any further. Therefore, the inner surface Y can mechanically suppress excessive deformation of the sensor diaphragm SD due to an excessive pressure difference. In this way, the inner surface Y functions as an overpressure protection mechanism that prevents the sensor diaphragm SD, which has deformed to the upper limit of the allowable deformation degree, from deforming any further. Hereinafter, this inner surface Y is also referred to as the overpressure protection mechanism Y.

As described above, the differential pressure sensor chips 61 to 63 have different measurement ranges. The different measurement ranges are achieved by making at least one of the size, shape, thickness, and material of the sensor diaphragm SD different among the differential pressure sensor chips 61 to 63. The shape of the sensor diaphragm SD also includes the aspect ratio. The shape of the overpressure protection mechanism Y, i.e., the inner surface Y, is naturally changed as appropriate depending on the shape of the sensor diaphragm SD, etc.

Of the differential pressure sensor chips 61 to 63, the recess 60AA in the first layer 60A of the differential pressure sensor chip 63, which has the highest differential pressure measurement range, may be formed in a shape that prevents the deformed sensor diaphragm SD from contacting the inner surface Y. In other words, the differential pressure sensor chip 63 does not need to be equipped with an excessive pressure protection mechanism Y. This is because the differential pressure sensor chip 63 has the highest differential pressure measurement range, and excessive differential pressure is unlikely to occur for the differential pressure sensor chip 63. For example, the recess 60AA may be cubic in shape, as shown by the dashed line in Figure 2.

When measuring the differential pressure between the first pressure P1 and the second pressure P2, the circuit board 41 in FIG. 1 first determines whether the value of the voltage value or the like of the electrical signal from the detection element D of the differential pressure sensor chip 61 is equal to or greater than a first threshold value. The first threshold value is preset as the value of the electrical signal that corresponds to the upper limit value of the measurement range of the differential pressure sensor chip 61.

If the result of the above determination is positive, the circuit board 41 derives the differential pressure based on the above value. If the result of the above determination is negative, the circuit board 41 determines whether the value of the voltage value or the like of the electrical signal from the detection element D of the differential pressure sensor chip 62 is equal to or greater than the second threshold value. The second threshold value is preset as the value of the electrical signal corresponding to the upper limit value of the measurement range of the differential pressure sensor chip 62. The first threshold value and the second threshold value may be the value of the electrical signal output by the detection element D immediately before the deformed sensor diaphragm SD comes into contact with the inner surface Y of the recess 60AA of the first layer 60A of the differential pressure sensor chip 61 or 62.

If the result of the determination for the differential pressure sensor chip 62 is positive, the circuit board 41 derives the differential pressure based on the above value. If the result of the determination is negative, the circuit board 41 derives the differential pressure based on a value such as the voltage value of the electrical signal from the detection element D of the differential pressure sensor chip 63.

The circuit board 41 outputs the differential pressure derived from any of the above judgment results to an external device, for example, via the wiring 43 and the pin member 42 in the form of a direct current electrical signal of, for example, 4 to 20 mA.

As described above, in this embodiment, multiple measurement ranges are realized by multiple differential pressure sensor chips 61 to 63. Therefore, multiple types of differential pressure sensor chips are prepared in advance, and the measurement range of the pressure sensor 10 to be manufactured can be changed simply by changing the differential pressure sensor chip to be mounted on the pressure sensor 10. Therefore, at least one of the multiple measurement ranges of the pressure sensor can be easily changed. This makes it possible to easily manufacture a pressure sensor having a measurement range required by the shipping destination. In addition, since one pressure sensor 10 is equipped with multiple measurement ranges, it is no longer necessary to prepare multiple pressure sensors for each measurement range, and this also reduces the cost of introducing pressure sensors and saves space.

In addition, in this embodiment, the transmission paths 30A and 30B that transmit the pressures P1 and P2 of the diaphragms 21 and 22, respectively, are branched in correspondence with the multiple differential pressure sensor chips 60. The members that form the 1-1 transmission path 30AA and the 2-1 transmission path 30BA before branching are referred to as the first member 31, and the members that form the 1-2 transmission path 30AB and the 2-2 transmission path 30BB are referred to as the second member 32. In this way, by separating the members that form the 1-1 transmission path 30AA and the 2-1 transmission path 30BA from the members that form the 1-2 transmission path 30AB and the 2-2 transmission path 30BB, the first member 31 that forms the 1-1 transmission path 30AA and the 2-1 transmission path 30BA can use a pressure receiving body or the like that is used in a conventional differential pressure transmitter. This makes it possible to obtain the structure according to this embodiment with only minor changes from the conventional structure.

In the above embodiment, the multiple differential pressure sensor chips 61 to 63 are composed of a first differential pressure sensor chip 63 having a measurement range on the highest differential pressure side, and one or more second differential pressure sensor chips 61 and 62 having a measurement range on the lower differential pressure side than the measurement range of the first differential pressure sensor chip. At least one of the one or more second differential pressure sensor chips is provided with an overpressure protection mechanism (inner surface) Y that prevents the sensor diaphragm SD from being further deformed by contact with the sensor diaphragm SD. There is a trade-off between the measurement range of the sensor diaphragm SD, that is, the measurement sensitivity of the differential pressure, and the pressure resistance. By providing the overpressure protection mechanism Y for the second differential pressure sensor chip having a measurement range of a relatively low differential pressure, the measurement sensitivity of the differential pressure is increased while the pressure resistance is also ensured. Furthermore, excessive deformation of the sensor diaphragm SD is suppressed, and the inconvenience of the sensor diaphragm SD constantly bending due to excessive deformation and the measurement accuracy of the differential pressure being reduced is suppressed. Therefore, the pressure sensor of this embodiment enables accurate differential pressure measurement.

Various modifications are possible to the embodiment described above. For example, the shapes of the components described in the embodiment above are arbitrary. In the embodiment above, the pressure sensor 10 has three differential pressure sensor chips 61 to 63, but the pressure sensor according to the present invention may be one that includes multiple differential pressure sensor chips. The differential pressure sensor chip may be a chip that detects differential pressure in a form other than a diaphragm. The multiple differential pressure sensor chips may be configured as separate parts. The second member 32 may be formed in a cubic shape, similar to the first member 31. The holes formed in the cubic shape may be the first-2 transmission path 30AB and the second-2 transmission path 30BB. Instead of the first member 31 and the second member 32, a combination of a member that forms the entire first transmission path 30A and a member that forms the entire second transmission path 30B, or a member that forms the entire first transmission path 30A and the entire second transmission path 30B may be used. Each diaphragm 21 and 22 may be arranged to face, for example, in the vertical direction. The configuration of the overpressure protection mechanism Y is also arbitrary. The overpressure protection mechanism Y may have any configuration that mechanically suppresses excessive deformation of the sensor diaphragm SD, for example.

10...pressure sensor, 21...first diaphragm, 22...second diaphragm, 30...pressure transmission member, 30A...first transmission path, 30AA...1-1 transmission path, 30AB...1-2 transmission path, 30B...second transmission path, 30BA...2-1 transmission path, 30BB...2-2 transmission path, 31...first member, 31A...first surface, 31B...second surface, 32...second member, 32A, 32B...pipe, 40...circuit portion, 41...circuit board, 42...pin member, 42A...connection pin, 42B...support portion, 43...wiring, 50 ...circuit housing member, 51...cylindrical member, 52...lid, 60...differential pressure sensor chip, 60A...first layer, 60AA...recess, 60AB...inlet passage, 60B...second layer, 60C...third layer, 60CA...recess, 60CB...inlet passage, 61-63...differential pressure sensor chip, 91, 92...flow path, D...detection element, F1...first pressure transmission fluid, F2...second pressure transmission fluid, P1...first pressure, P2...second pressure, S1, S2...pressure receiving chamber, S11...space, SD...sensor diaphragm, Y...inner surface (overpressure protection mechanism).

Claims (2)

a first diaphragm that is deformed by receiving a first pressure of the fluid to be measured;
a second diaphragm that is deformed by receiving a second pressure of the fluid to be measured;
A plurality of differential pressure sensor chips each configured to detect a differential pressure between the first pressure and the second pressure and having different measurement ranges;
a pressure transmitting member including: a first transmission path filled with a first pressure transmitting fluid for transmitting the first pressure received by the first diaphragm to each of the plurality of differential pressure sensor chips; and a second transmission path filled with a second pressure transmitting fluid for transmitting the second pressure received by the second diaphragm to each of the plurality of differential pressure sensor chips;
Equipped with
The first transmission path is
a first-1 transmission path having a pressure receiving chamber at a first end thereof facing the first diaphragm;
a first-second transmission path extending from a second end of the first-first transmission path opposite to the first end, branching midway, and reaching each of the plurality of sensor chips;
The second transmission path is
a second-1 transmission path having a first end including a pressure-receiving chamber facing the second diaphragm;
a second-2 transmission path extending from a second end of the second-1 transmission path opposite to the first end, branching midway, and reaching each of the plurality of sensor chips;
The pressure transmission member is
A first member forming the first-1 transmission path and the second-1 transmission path;
a second member including a first pipe and a second pipe connected to the first member and forming the first-second transmission path and the second-second transmission path, respectively;
the 1-1 transmission path is connected to the 1-2 transmission path by inserting one end of the first pipe on the side of the first member into the second end of the 1-1 transmission path,
The 2-1 transmission path is a pressure sensor that is connected to the 2-2 transmission path by inserting one end of the second pipe on the first member side into the second end of the 2-1 transmission path . Each of the plurality of differential pressure sensor chips includes a sensor diaphragm that is deformed by the differential pressure and a detection element that detects the deformation of the sensor diaphragm,
At least one of the size, shape, thickness, and material of the sensor diaphragm of each of the plurality of differential pressure sensor chips is different among the plurality of differential pressure sensor chips, so that the measurement ranges of each of the plurality of differential pressure sensor chips are different;
the plurality of differential pressure sensor chips include a first differential pressure sensor chip having a measurement range on the highest differential pressure side, and one or more second differential pressure sensor chips having a measurement range on the lower differential pressure side than the measurement range of the first differential pressure sensor chip;
At least one of the one or more second differential pressure sensor chips includes an overpressure protection mechanism that prevents the sensor diaphragm, which has been deformed by the differential pressure, from being further deformed by contacting the overpressure protection mechanism.
The pressure sensor according to claim 1 .

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