Pressure sensor

Abstract

To reduce sensor diaphragm deformation due to heat transfer from measured fluid and reduce the size of a support structure of a sensor element.SOLUTION: A sensor element 40 of a pressure sensor comprises a sensor diaphragm 41 that is deformed by pressure of measured fluid flowing into an inflow space R2, and an annular support part 42 supporting the sensor diaphragm 41. A support structure 70 supporting the sensor element 40 comprises a plate-like member 72 covering the sensor diaphragm 41 from inflow space R2 side, and a spacer 73 arranged between the sensor element 40 and the plate-like member 72. The plate-like member 72 comprises an introduction hole 72A for introducing the measured fluid toward the sensor diaphragm 41. The spacer 73 comprises an annular part 73A fixed on the support part 42, an opposing part 73B protruding from the annular part 73A and opposing the introduction hole 72A, and an open hole 73C overlapping in plan view the sensor diaphragm inside the annular part 73A.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a pressure sensor.

Background Art

[0002] A pressure sensor that measures the pressure of a fluid to be measured using a sensor diaphragm is known. As disclosed in Patent Document 1 (particularly, FIG. 14 of Patent Document 1), such a pressure sensor includes a sensor package, a sensor diaphragm type sensor element disposed within the sensor package, and a pedestal member (plate-like member) that covers the sensor diaphragm and has a through-hole at the center. In the pressure sensor disclosed in Patent Document 1, a spacer that surrounds the sensor diaphragm in a plan view is provided between the sensor element and the pedestal member. The pedestal member and the spacer are part of a support structure that supports the sensor element.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the pressure sensor disclosed in Patent Document 1, in order to prevent deformation of the sensor diaphragm due to heat transfer from the fluid to be measured, the spacer is thickened and the distance between the sensor diaphragm and the pedestal member is increased. However, as the spacer is thickened, the support structure of the sensor element including the spacer becomes larger.

[0005] The present invention has been made in view of the above points, and an object thereof is to reduce deformation of the sensor diaphragm due to heat transfer from the fluid to be measured while miniaturizing the support structure of the sensor element.

Means for Solving the Problems

[0006] The pressure sensor according to the present invention for solving the above problems includes a package forming an inflow space into which a fluid to be measured flows, a sensor element disposed in the package, a sensor diaphragm that is deformed by the pressure of the fluid to be measured flowing into the inflow space, and a sensor element including an annular support portion that surrounds and supports the sensor diaphragm, and a support structure that supports the sensor element with the sensor diaphragm facing the inflow space side. The support structure includes a plate-like member that covers the sensor diaphragm from the inflow space side, and a spacer disposed between the sensor element and the plate-like member. The plate-like member is provided with an introduction hole for introducing the fluid to be measured to the sensor diaphragm side at a position overlapping the sensor diaphragm in a plan view. The spacer includes an annular portion fixed to the support portion, an opposing portion that protrudes from the annular portion and faces the introduction hole, and against which the fluid to be measured from the introduction hole hits, and a through hole that overlaps the sensor diaphragm inside the annular portion in a plan view and guides the fluid to be measured that has hit the opposing portion to the sensor diaphragm.

[0007] The support structure may include a support diaphragm fixed to the package and supporting the sensor element via the spacer. The support diaphragm includes an opening, a first surface facing the inflow space side and fixed with the plate-like member covering the opening, and a second surface opposite to the first surface to which the annular portion of the spacer is fixed.

[0008] The plate-like member may include a plurality of introduction holes provided at positions overlapping the outer edge portion of the sensor diaphragm in a plan view as the introduction holes. The spacer may include a plurality of opposing portions that protrude from the annular portion and respectively face the plurality of introduction holes as the opposing portions. The through hole may extend between each of the plurality of opposing portions from the center of the region inside the annular portion.

[0009] The opposing portion includes a central portion and a plurality of connecting portions extending from the central portion and connected to the annular portion. The spacer may include, as the through holes, a plurality of through holes that overlap the sensor diaphragm inside the annular portion in a plan view, and the plurality of through holes may be arranged between each of the plurality of connecting portions.

[0010] The introduction hole may face the central portion.

[0011] The introduction hole may face the connecting portion.

[0012] The thermal expansion coefficient of the spacer and the thermal expansion coefficient of the sensor element may be the same.

Advantages of the Invention

[0013] According to the present invention, it is possible to reduce the deformation of the sensor diaphragm caused by heat transfer from the fluid to be measured while miniaturizing the support structure of the sensor element.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Best Mode for Carrying Out the Invention

[0015] <First Embodiment> The pressure sensor 10 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4. In FIG. 1, the thicknesses of the sensor diaphragm 41, the support portion 42, the movable electrode 45, and the fixed electrode 46 that constitute the sensor element 40 described later, and the thicknesses of the support diaphragm 71 of the support structure 70 described later, are drawn exaggeratedly compared to FIG. 2. The plan view described later refers to the state of viewing the pressure sensor 10 (particularly, the sensor diaphragm 41 described later) along its central axis direction, and here it refers to the state of viewing from above FIG. 1. In FIG. 2, the cross-section is represented by dots instead of hatching as in FIG. 1 (the same applies to FIGS. 5 and 7). Also, for a plurality of elements having the same function, etc., only a part of them may be labeled. The vertical direction shown in each figure is for convenience and does not indicate the actual use state of the pressure sensor 10. The pressure sensor 10 may be arranged with the upper side in FIG. 1 as the ground side.

[0016] As shown in FIG. 1, the pressure sensor 10 includes a package 20, a baffle 30, a sensor element 40, a contact pad 50, an electrode member 60, and a support structure 70. The pressure sensor 10 is configured as a vacuum gauge for measuring the pressure of the fluid to be measured L including residual gas and process gas in a vacuum chamber.

[0017] The package 20 includes a first package member 21, a second package member 22, and a third package member 23, and houses the sensor element 40, the contact pad 50, the support structure 70, etc. The package 20 forms an introduction path R1 for introducing the fluid to be measured L, an inflow space R2 into which the fluid to be measured L flows from the introduction path R1, and a vacuum chamber R3 in which the vacuum pressure compared with the atmospheric pressure in the inflow space R2, that is, the atmospheric pressure of the fluid to be measured L, is enclosed. The package 20 is formed of a metal such as Inconel.

[0018] The first package member 21 has a funnel shape that demarcates the introduction path R1 by a cylindrical small-diameter portion and demarcates the inflow space R2 together with the support structure 70 by a cup-shaped large-diameter portion. At the lower end of the first package member 21, a cylindrical second package member 22 is joined by welding or the like, sandwiching the peripheral edge of a support diaphragm 71 (described later) of the support structure 70. At the lower end of the second package member 22, a disk-shaped third package member 23 is joined by welding or the like. The third package member 23 demarcates a vacuum chamber R3 together with the second package member 22, the sensor element 40, and the support structure 70.

[0019] The baffle 30 is fixed to the first package member 21 by a fixing member or the like (not shown). The baffle 30 changes the flow of the fluid L to be measured flowing into the inflow space R2 through the introduction path R1 in the outer peripheral direction of the package 20.

[0020] The sensor element 40 detects the pressure of the fluid L to be measured by converting the pressure of the fluid L to be measured into an electrical signal. The sensor element 40 is disposed within the package 20 and is supported by the support structure 70. As shown in FIGS. 1 and 2, the sensor element 40 includes a circular sensor diaphragm 41 and an annular support portion 42 that surrounds the sensor diaphragm 41 and supports the sensor diaphragm 41. The upper surface of the sensor diaphragm 41 facing the inflow space R2 side is a pressure-receiving surface that receives the pressure of the fluid L to be measured. The fluid L to be measured flowing into the inflow space R2 passes through the support structure 70 as described later, and deforms the sensor diaphragm 41 by pressing the pressure-receiving surface of the sensor diaphragm 41 with its pressure.

[0021] The sensor diaphragm 41 and the support portion 42 are integrally formed as one member. The sensor element 40 also has a plate member 43 fixed to the support portion 42 by welding or the like. The plate member 43 forms a capacitance chamber C together with the sensor diaphragm 41 and the support portion 42. The capacitance chamber C is evacuated by communicating with the vacuum chamber R3 through a through hole (not shown) formed in the plate member 43. The sensor diaphragm 41, the support portion 42, and the plate member 43 are made of sapphire or the like.

[0022] The sensor element 40 includes a movable electrode 45 formed on the measurement surface opposite to the pressure receiving surface of the sensor diaphragm 41, and a fixed electrode 46 formed on the plate material 43. The movable electrode 45 and the fixed electrode 46 face each other. The shapes and numbers of the movable electrode 45 and the fixed electrode 46 are arbitrary.

[0023] When the sensor diaphragm 41 deforms, the movable electrode 45 is displaced, and the distance between the movable electrode 45 and the fixed electrode 46 changes. That is, the capacitance of the capacitor formed by the movable electrode 45 and the fixed electrode 46 changes. The sensor element 40 outputs an electrical signal indicating this change in capacitance. In this way, the sensor element 40 converts the deformation of the sensor diaphragm 41, that is, the pressure of the fluid L to be measured, into an electrical signal. The electrical signal is, for example, a voltage signal having a voltage value corresponding to the pressure of the fluid L to be measured.

[0024] As shown in FIG. 1, a plurality of contact pads 50 are formed on the surface of the plate material 43 opposite to the surface on which the fixed electrode 46 is formed. The plurality of contact pads 50 are electrically connected to the movable electrode 45 or the fixed electrode 46 by various wirings (not shown). The plurality of contact pads 50 are used to extract the electrical signal indicating the pressure of the fluid L to be measured output from the sensor element 40.

[0025] A plurality of electrode members 60 for extracting an electrical signal indicating the pressure of the fluid L to be measured to the outside of the package 20 are respectively connected to the plurality of contact pads 50. Each electrode member 60 penetrates the third package member 23 in the package 20 and is fixed to the third package member 23 by a hermetic seal (not shown). Each electrode member 60 includes a conductive pin 61 for transmitting the above electrical signal, a cylindrical shield 62 surrounding the conductive pin 61, and a contact spring 63 connecting the conductive pin 61 and the contact pad 50. The conductive pin 61 is fixed to the shield 62 by a hermetic seal or the like while passing through the shield 62. The above electrical signal is transmitted by the contact pad 50, the contact spring 63, and the conductive pin 61, and as a result, it is output to the outside of the pressure sensor 10.

[0026] As shown in FIGS. 1 and 2, the support structure 70 supports the sensor element 40 in the package 20 with the sensor diaphragm 41 facing the inflow space R2 side. As shown in FIGS. 1 to 4, the support structure 70 includes a support diaphragm 71, a plate-like member 72, and a spacer 73. The support diaphragm 71, the plate-like member 72, and the spacer 73 are formed of sapphire or the like. The central axes of the support diaphragm 71, the plate-like member 72, the spacer 73, the sensor element 40, and the pressure sensor 10 coincide.

[0027] The support diaphragm 71 supports the sensor element 40 via the spacer 73. As shown in FIG. 1, the support diaphragm 71 is fixed to the package 20 by having its peripheral portion sandwiched between the first package member 21 and the second package member 22 of the package 20.

[0028] As shown in FIGS. 1 to 4, a plate-like member 72 is fixed to a first surface 71A of the support diaphragm 71 facing the inflow space R2 side by welding or the like. A spacer 73 is fixed to a second surface 71B of the support diaphragm 71 opposite to the first surface 71A by welding or the like. A sensor element 40 is fixed to the spacer 73 by welding or the like. The spacer 73 is disposed between the plate-like member 72 and the sensor element 40, and more specifically, between the support diaphragm 71 and the sensor element 40. An opening 71C is provided at the center of the support diaphragm 71. In plan view, the opening 71C overlaps the sensor diaphragm 41 so as to be larger than the sensor diaphragm 41 and include the entire sensor diaphragm 41 inside. The opening 71C may have a shape that coincides with the sensor diaphragm 41 in plan view.

[0029] The plate-like member 72 is formed in a flat plate shape and faces the inflow space R2. By fixing the outer edge portion of the plate-like member 72 to the peripheral portion of the opening 71C of the support diaphragm 71, the plate-like member 72 covers the opening 71C of the support diaphragm 71.

[0030] The plate-like member 72 includes four introduction holes 72A that communicate the opening 71C with the inflow space R2 and introduce the fluid L to be measured flowing into the inflow space R2 to the sensor diaphragm 41 side. The four introduction holes 72A are through holes extending in the thickness direction of the plate-like member 72. As shown in FIG. 2, the introduction holes 72A are provided at positions overlapping the outer edge portion of the sensor diaphragm 41 in plan view.

[0031] As shown in FIGS. 1 to 4, the spacer 73 secures the distance between the plate-like member 72 and the sensor element 40. The spacer 73 includes an annular portion 73A having an annular shape fixed to the sensor element 40, and a plurality (here, four) of opposing portions 73B respectively facing a plurality of introduction holes 72A. Each of the plurality of opposing portions 73B projects from the inner peripheral wall of the annular portion 73A to the inside of the annular portion 73A. The spacer 73 also includes a through hole 73C provided inside the annular portion 73A and adjacent to the opposing portion 73B. The through hole 73C is formed in a substantially cross shape and has a shape extending from the center of the region inside the annular portion 73A, that is, the region surrounded by the annular portion 73A, to between each of the plurality of opposing portions 73B.

[0032] The end face (upper end face) of the annular portion 73A on the support diaphragm 71 side is fixed to the peripheral portion of the opening 71C of the support diaphragm 71. The end face (lower end face) of the annular portion 73A on the sensor element 40 side is fixed to the support portion 42 of the sensor element 40. The spacer 73 and the plate-like member 72 also function as a support pedestal that sandwiches the support diaphragm 71 and supports the sensor element 40. The spacer 73, together with the sensor element 40, covers the opening 71C from the vacuum chamber R3 side.

[0033] In a plan view, the opposing portion 73B and the through hole 73C overlap the sensor diaphragm 41 of the sensor element 40. The through hole 73C, together with the opening 71C, exposes a part of the sensor diaphragm 41, that is, the portion of the sensor diaphragm 41 not covered by the opposing portion 73B of the spacer 73, to the inflow space R2 side. The plate-like member 72 covering the opening 71C covers the opposing portion 73B, the through hole 73C, and the sensor diaphragm 41 from the inflow space R2 side.

[0034] The fluid under measurement L flowing into the inflow space R2 passes through the introduction hole 72A of the plate-shaped member 72 as shown by the thick-line arrow in FIG. 2, and then passes through the opening 71C of the support diaphragm 71 and hits the opposing portion 73B of the spacer 73. The opposing portion 73B guides the fluid under measurement L hitting the opposing portion 73B to the through-hole 73C adjacent thereto. The through-hole 73C guides this fluid under measurement L to the sensor diaphragm 41 of the sensor element 40. The sensor diaphragm 41 is deformed by the pressure of the guided fluid under measurement L.

[0035] In this embodiment, when the fluid under measurement L passing through the introduction hole 72A of the plate-shaped member 72 hits the opposing portion 73B, heat exchange occurs between the fluid under measurement L and the opposing portion 73B. As a result, the temperature of the fluid under measurement L is lowered (when the fluid under measurement L is at a high temperature) or raised (when the fluid under measurement L is at a low temperature), and the deformation of the sensor diaphragm 41 due to heat transfer from the fluid under measurement L is reduced. Thereby, the occurrence of an error in the output signal due to hysteresis or shift of the sensor diaphragm 41 is reduced. Further, if the spacer 73 does not include the opposing portion 73B, it is necessary to increase the thickness of the spacer 73 so that the temperature of the fluid under measurement L sufficiently decreases when it reaches the sensor diaphragm 41. In this embodiment, since the fluid under measurement L hits the opposing portion 73B, the thickness of the spacer 73 can be made thinner than when the opposing portion 73B is not provided. Thereby, the entire support structure 70 to the pressure sensor 10 is miniaturized. As described above, according to the present embodiment, the deformation of the sensor diaphragm 41 due to heat transfer from the fluid under measurement L is reduced, and the support structure 70 that supports the sensor element 40 is miniaturized.

[0036] Also, in this embodiment, the through-hole 73C has a shape extending from the center of the region inside the annular portion 73A across between each of the plurality of opposing portions 73B and is formed relatively large. Therefore, in cleaning in the manufacturing process of the pressure sensor 10 or the like, the cleaning liquid easily passes through the support structure 70. The number of the introduction holes 72A and the opposing portions 73B is arbitrary and may be one.

[0037] In this embodiment, the through hole 73C of the spacer 73 overlaps with the sensor diaphragm 41 in a plan view. On the other hand, separately from this, it is also conceivable to make the through hole 73C smaller and provide it at a position outside the sensor diaphragm 41 of the spacer 73. In this case, it is necessary to provide a guide hole for guiding the fluid L to be measured from the through hole 73C to the sensor diaphragm 41 in the support portion 42 of the sensor element 40. However, when joining the sensor element 40 and the spacer 73, it becomes difficult to align this guide hole and the through hole 73C. In this embodiment, since the through hole 73C overlaps with the sensor diaphragm 41 in a plan view, it is not necessary to provide a guide hole or the like in the support portion 42, and the labor for the above alignment is eliminated, and accordingly, the manufacturing cost of the pressure sensor 10 can be suppressed. Further, in a plan view, the facing portion 73B of the spacer 73 is larger than the introduction hole 72A of the plate-like member 72, and the introduction hole 72A is located within the facing portion 73B, so that any slight misalignment between the spacer 73 and the plate-like member 72 is absorbed.

[0038] Also, in this embodiment, the end face 72B (see FIG. 4) of the plate-like member 72 fixed to the support diaphragm 71 protrudes more than the other surface of the plate-like member 72, particularly the surface around the lower end of the introduction hole 72A. Further, the end face 73D (see FIG. 3) of the annular portion 73A of the spacer 73 fixed to the support diaphragm 71 protrudes more than the surface (upper end face) of the facing portion 73B on the support diaphragm 71 side. Therefore, even if the support diaphragm 71 is made thinner, the interval between the introduction hole 72A and the facing portion 73B can be ensured. Thereby, the flow rate when the fluid L to be measured that hits the facing portion 73B of the spacer 73 from the introduction hole 72A of the plate-like member 72 and flows into the through hole 73C flows between the plate-like member 72 and the facing portion 73B is ensured. Note that it is sufficient if either the end face of the plate-like member 72 or the spacer 73 protrudes.

[0039] The materials of the sensor element 40 (particularly, the sensor diaphragm 41, the support portion 42, and the plate material 43), the support diaphragm 71, the plate-like member 72, and the spacer 73 are arbitrary, but it is preferable to make the coefficient of thermal expansion of each member substantially equal, for example, by adopting the same material. This is to prevent the sensor diaphragm 41 from being distorted due to different degrees of expansion of each member during self-heating when the pressure sensor 10 is in use because the coefficients of thermal expansion are different. In particular, by making the coefficients of thermal expansion of the sensor element 40 and the spacer 73 to which the sensor element 40 is directly fixed substantially equal, the distortion of the sensor diaphragm 41 is reduced.

[0040] <Second Embodiment> In the second embodiment, as shown in FIGS. 5 and 6, the support structure 70 is changed to a support structure 170. More specifically, the plate-like member 72 is changed to a plate-like member 172, and the spacer 73 is changed to a spacer 173. Since the other parts are the same as those in the first embodiment, the same reference numerals are given and the detailed description is omitted.

[0041] The plate-like member 172 includes one introduction hole 172A for introducing the fluid L to be measured that has flowed into the inflow space R2 toward the sensor diaphragm 41 instead of the plurality of introduction holes 72A. The introduction hole 172A is formed at the center of the plate-like member 72.

[0042] The spacer 173 includes an annular portion 173A having the same function and shape as the annular portion 73A of the first embodiment, and an opposing portion 173B having the same function as the opposing portion 73B of the first embodiment but a different shape. The opposing portion 173B includes a central portion 173BA located at the center of the region inside the annular portion 173A in a plan view, and a plurality of connection portions 173BB that extend radially from the central portion 173BA and are connected to the annular portion 173A. In this embodiment, four connection portions 173BB are provided, and the opposing portion 173B is formed in a substantially cross shape, but the number of the connection portions 173BB is arbitrary. The central portion 173BA faces the introduction hole 172A of the plate-like member 172.

[0043] The spacer 173 includes a plurality of through holes 173C having the same function as the through hole 73C of the first embodiment. The plurality of through holes 173C overlap with the sensor diaphragm 41 inside the annular portion 173A in a plan view, and guide the fluid to be measured L hitting the opposing portion 173B, more specifically, the central portion 173BA, to the sensor diaphragm 41. The plurality of through holes 173C are arranged between each of the plurality of connection portions 173BB. In other words, along the circumferential direction of the spacer, the through holes 173C and the connection portions 173BB are alternately arranged.

[0044] Also in this embodiment, when the fluid to be measured L passing through the introduction hole 172A of the plate-like member 172 hits the central portion 173BA of the opposing portion 173B, heat exchange is performed between the fluid to be measured L and the opposing portion 173B. Therefore, also in this embodiment, similar to the first embodiment, the deformation of the sensor diaphragm 41 due to heat transfer from the fluid to be measured L is reduced, and the support structure 170 that supports the sensor element 40 is miniaturized.

[0045] Further, in this embodiment, the opposing portion 173B includes a central portion 173BA and a plurality of connection portions 173BB extending from the central portion 173BA and connected to the annular portion 173A. For this reason, the opening area of the spacer 173 due to the through holes 173C is smaller than that of the first embodiment, and accordingly, rigidity is added to the spacer 173. The shape of the opposing portion 173B, that is, the shape, position, and number of the through holes 173C can be derived by topology analysis or the like. By topology analysis or the like, the optimum shape of the opposing portion 173B that can ensure the rigidity of the spacer 173 is derived.

[0046] <Third Embodiment> In the third embodiment, as shown in FIGS. 7 and 8, the support structure 70 is changed to a support structure 270. The support structure 270 is a structure in which the spacer 73 of the support structure 70 in the first embodiment is changed to the spacer 173 in the second embodiment. In this embodiment, the four introduction holes 72A of the plate-like member 72 face the four connection portions 173BB of the opposing portion 173B of the spacer 173, respectively. The fluid to be measured L hits the connection portion 173BB to perform heat exchange, and reaches the sensor diaphragm 41 of the sensor element 40 through the through hole 173C of the spacer 173. Even in this embodiment, the same effects as those in the first and second embodiments can be obtained as appropriate.

[0047] <Modification> Regarding each of the above embodiments, various modifications can be made. For example, the shape of each member, particularly the shape of the spacer, can be changed as appropriate. For example, the number of connection portions of the opposing portion of the spacer is arbitrary. Introduction holes may be provided in the plate-like member for at least a part of the plurality of connection portions. The position of the introduction hole is also arbitrary as long as it faces the opposing portion. Introduction holes may be provided facing the central portion and the connection portion, respectively. The sensing method of the pressure sensor in the above embodiment is a capacitance type, but the present invention is not limited to the sensing method. The present invention can be applied to a pressure sensor using, for example, a strain gauge obtained by attaching a resistance gauge or forming a film by sputtering or the like, or a semiconductor piezoresistor. That is, the present invention can be applied to all pressure sensors having a sensing method for converting the deformation of the sensor diaphragm into an electrical signal. The place where the pressure sensor is used can also be various devices other than the film forming apparatus.

[0048] <Scope of the Invention> As described above, the present invention has been described with reference to the embodiments and modifications. However, the present invention is not limited to the above embodiments and modifications. For example, the present invention includes various modifications to the above embodiments and modifications that can be understood by those skilled in the art within the scope of the technical idea of the present invention. Each configuration described in the above embodiments and modifications can be appropriately combined within a non-contradictory range.

Explanation of Reference Numerals

[0049] 10…Pressure sensor, 20…Package, 21…First package member, 22…Second package member, 23…Third package member, 30…Baffle, 40…Sensor element, 41…Sensor diaphragm, 42…Support part, 43…Sheet material, 45…Movable electrode, 46…Fixed electrode, 50…Contact pad, 60…Electrode member, 61…Conductive pin, 62…Shield, 63…Contact spring, 70…Support structure, 71…Support diaphragm, 71A…First surface, 71B…Second surface, 71C…Opening, 72…Plate-like member, 72A…Introduction hole, 72B…End face, 73…Spacer, 73A…Annular part, 73B…Opposing part, 73C…Through hole, 73D…End face, 170…Support structure, 172…Plate-like member, 172A…Introduction hole, 173…Spacer, 173A…Annular part, 173B…Opposing part, 173BA…Central part, 173BB…Connection part, 173C…Through hole, 270…Support structure, C…Capacity chamber, L…Fluid to be measured, R1…Introduction path, R2…Inflow space, R3…Vacuum chamber.

Claims

1. A package forming an inflow space into which a fluid to be measured flows, a sensor element disposed within the package, the sensor element including a sensor diaphragm that deforms due to the pressure of the fluid to be measured flowing into the inflow space, and an annular support portion surrounding and supporting the sensor diaphragm, and a support structure that supports the sensor element with the sensor diaphragm facing the inflow space side, wherein the support structure includes a plate-like member that covers the sensor diaphragm from the inflow space side, and a spacer disposed between the sensor element and the plate-like member, the plate-like member includes an introduction hole provided at a position overlapping the sensor diaphragm in plan view, for introducing the fluid to be measured to the sensor diaphragm side, the spacer includes an annular portion fixed to the support portion, an opposing portion projecting from the annular portion and facing the introduction hole, against which the fluid to be measured from the introduction hole impinges, and a through hole that overlaps the sensor diaphragm inside the annular portion in plan view and guides the fluid to be measured that has impinged on the opposing portion to the sensor diaphragm, a pressure sensor.

2. The support structure includes a support diaphragm fixed to the package and supporting the sensor element via the spacer, the support diaphragm including an opening, a first surface facing the inflow space side and to which the plate-like member is fixed in a state of covering the opening, and a second surface opposite the first surface to which the annular portion of the spacer is fixed, The pressure sensor according to claim 1.

3. The plate-like member includes a plurality of introduction holes provided at positions overlapping the outer edge portion of the sensor diaphragm in plan view as the introduction holes, the spacer includes a plurality of opposing portions projecting from the annular portion and respectively facing the plurality of introduction holes as the opposing portions, the through hole extends from the center of the region inside the annular portion across between each of the plurality of opposing portions, The pressure sensor according to claim 1 or 2.

4. The opposing portion includes a central portion and a plurality of connecting portions extending from the central portion and connected to the annular portion, the spacer includes a plurality of through holes that overlap the sensor diaphragm inside the annular portion in plan view as the through holes, the plurality of through holes are disposed between each of the plurality of connecting portions, The pressure sensor according to claim 1 or 2.

5. The introduction hole faces the central portion. The pressure sensor according to claim 4. **Claim 6** The introduction hole faces the connection portion. The pressure sensor according to claim 4. **Claim 7** In the pressure sensor according to any one of claims 1 to 6, the thermal expansion coefficient of the spacer is the same as that of the sensor element. Pressure sensor.

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