Pressure sensor element

Abstract

Provides is a pressure sensor element with which it is possible to suppress a reduction in the sensitivity of pressure detection. This pressure sensor element includes: a membrane layer having a diaphragm part; and a plurality of electrode parts facing the membrane layer in the thickness direction. The diaphragm part includes a first conductive layer and a second conductive layer electrically insulated from the first conductive layer. The plurality of electrode parts are separated from each other. Each electrode part includes: a support part supported by the first conductive layer; and a movable part that is supported by the first conductive layer via the support part, is spaced apart from and faces the second conductive layer in the thickness direction, and moves due to deflection of the diaphragm part. When viewed along the thickness direction, each support part is located at a position outside both the center of the diaphragm part in the longitudinal direction and the center of the diaphragm part in the lateral direction, and has an elongated shape in the longitudinal direction of the diaphragm part.

Description

pressure sensor element

[0001] The present disclosure relates to a pressure sensor element for detecting pressure.

[0002] A pressure sensor element is known that detects pressure acting on a diaphragm based on the amount of displacement of the diaphragm (see, for example, Patent Document 1).

[0003] The pressure sensor element disclosed in Patent Document 1 includes a diaphragm that is square in plan view, a support portion provided at the center of the square diaphragm, and a movable plate supported by the support portion. As will be described in detail below, pressure changes are detected by changes in the electrostatic capacitance between the movable plate and the diaphragm.

[0004] When pressure acts on the surface of the diaphragm opposite to the surface where the support portion is provided, the diaphragm bends toward the support portion, displacing the movable plate via the support portion. Here, when pressure acts on the diaphragm, the diaphragm bends more the closer it is to the center. Therefore, when pressure acts on the diaphragm, the gap between the movable plate, which is supported via the support portion at the center of the diaphragm, and the portion of the diaphragm other than the center increases. As a result, the capacitance between the movable plate and the diaphragm decreases. The pressure acting on the diaphragm is detected based on the amount of decrease in capacitance.

[0005] Japanese Patent Application Publication No. 11-201848

[0006] In the pressure sensor element disclosed in Patent Document 1, the square support portion is provided only in the center of the square diaphragm in plan view. This may result in a decrease in the support strength of the movable plate provided by the support portion. Therefore, it is conceivable to lengthen one side of the support portion to make it rectangular in plan view. This increases the area of ​​the support portion that is bonded to the diaphragm, thereby increasing the support strength of the movable plate provided by the support portion.

[0007] However, increasing the area of ​​the support portion bonded to the diaphragm may hinder the diaphragm's deflection, which may reduce the amount of change in the gap between the movable plate and the diaphragm when pressure is applied to the diaphragm, thereby reducing the amount of change in capacitance, and thus reducing the pressure detection sensitivity of the pressure sensor element.

[0008] Therefore, an object of the present disclosure is to solve the above-mentioned problems by providing a pressure sensor element that can suppress a decrease in pressure detection sensitivity.

[0009] A pressure sensor element according to one embodiment of the present disclosure comprises: a membrane layer having a diaphragm portion; and a plurality of electrode portions facing the diaphragm portion in a thickness direction; the diaphragm portion comprises: a first conductive layer; and a second conductive layer spaced apart from the first conductive layer; the plurality of electrode portions are spaced apart from one another; and each of the plurality of electrode portions comprises: a support portion supported by the first conductive layer; and a movable portion supported by the first conductive layer via the support portion, facing the second conductive layer at a distance in the thickness direction, and displacing when the diaphragm portion flexes; and when viewed along the thickness direction, each of the support portions is located away from both a longitudinal center position, which is the center of the diaphragm portion in the longitudinal direction, and a lateral center position, which is the center of the diaphragm portion in the lateral direction, and has an elongated shape in the longitudinal direction of the diaphragm portion.

[0010] According to the present disclosure, it is possible to provide a pressure sensor element that can suppress a decrease in pressure detection sensitivity.

[0011] 6 is a schematic plan view of a pressure sensor element according to a first embodiment of the present disclosure. FIG. 7 is a schematic plan view of a portion of the pressure sensor element according to the first embodiment of the present disclosure, from which the membrane layer has been removed. FIG. 8 is a schematic end view showing the A-A end face of FIG. 1. FIG. 9 is a schematic end view of a portion corresponding to the B-B end face of FIG. 1. FIG. 10 is a schematic cross-sectional view showing the B-B cross section of FIG. 1, with pressure acting on the diaphragm portion. FIG. 11 is a schematic plan view of a portion of a pressure sensor element according to a comparative example, from which the membrane layer has been removed. FIG. 6 is a schematic end view showing the C-C end face of FIG. 6, with pressure acting on the diaphragm portion. FIG. 7 is a schematic end view showing the D-D end face of FIG. 1, with pressure acting on the diaphragm portion. FIG. 8 is a schematic plan view of a portion of a pressure sensor element according to a second embodiment of the present disclosure, from which the membrane layer has been removed. FIG. 9 is a schematic plan view of a portion of a pressure sensor element according to a modified example of the second embodiment of the present disclosure, from which the membrane layer has been removed. FIG. 11 is a schematic plan view of a portion of a pressure sensor element according to a third embodiment of the present disclosure, from which the membrane layer has been removed. Fig. 1 is a schematic plan view of a pressure sensor element according to a fourth embodiment of the present disclosure; Fig. 2 is a schematic plan view of a pressure sensor element according to a modified example of the fourth embodiment of the present disclosure; Fig. 3 is a graph showing deformation of a diaphragm portion and displacement of a movable portion along the short side direction in the first embodiment and a comparative example; Fig. 4 is a graph showing deformation of a diaphragm portion along the long side direction in each embodiment and a comparative example; Fig. 5 is a graph showing deformation of a diaphragm portion along the long side direction when the length of a support portion is changed;

[0012] An example of the present disclosure will now be described with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure, its applications, or its uses. The drawings are schematic, and the ratios of dimensions and the like do not necessarily correspond to reality. In the following description, terms indicating specific directions or positions (e.g., terms including "upper," "lower," "right," "left," "front," and "rear") may be used as necessary. However, the use of terms indicating specific directions or positions is intended to facilitate understanding of the present disclosure with reference to the drawings, and the meanings of these terms do not limit the technical scope of the present disclosure.

[0013] <First embodiment> Fig. 1 is a schematic plan view of a pressure sensor element according to a first embodiment of the present disclosure. Fig. 2 is a schematic plan view of a portion of the pressure sensor element according to the first embodiment of the present disclosure excluding a membrane layer. Fig. 3 is a schematic end view showing the A-A end face in Fig. 1. Fig. 4 is a schematic end view of a portion corresponding to the B-B end face in Fig. 1.

[0014] The pressure sensor element 10 shown in Figures 1 to 4 is for detecting pressure. The pressure sensor element 10 is a capacitance type element. In the first embodiment, the pressure sensor element 10 is a MEMS (Micro Electro Mechanical Systems) element. The pressure sensor element 10 is mounted on, for example, a mobile object such as an automobile, or a consumer device such as a smartphone or a smartwatch.

[0015] The pressure sensor element 10 has a rectangular parallelepiped shape. However, the shape of the pressure sensor element 10 is not limited to a rectangular parallelepiped shape (a quadrilateral shape when viewed from the thickness direction 101). For example, the pressure sensor element 10 may have a polygonal shape other than a quadrilateral when viewed from the thickness direction 101, or may have a cylindrical shape.

[0016] 1 to 4, the pressure sensor element 10 includes a membrane layer 20, an intermediate layer 30, and a substrate layer 60. The intermediate layer 30 includes a plurality of electrode portions 40 and a sidewall portion 50.

[0017] As shown in Figures 3 and 4, the membrane layer 20 includes a membrane plate 21, an insulating layer 22, and a conductive layer 23. The insulating layer 22 is laminated on the membrane plate 21 in the thickness direction 101. The conductive layer 23 is laminated on the insulating layer 22 on the opposite side of the membrane plate 21 in the thickness direction 101. The layer configuration of the membrane layer 20 is not limited to the configuration shown in Figures 3 and 4. For example, the membrane layer 20 may have a protective film (not shown) that covers one main surface 20B and a side surface 20C of the membrane layer 20. The protective film may be made of, for example, silicon dioxide (SiO ２ ) and silicon nitride (SiN).

[0018] The membrane plate 21 is conductive and made of silicon (Si). The insulating layer 22 is insulating and made of silicon dioxide (SiO ２ ). The conductive layer 23 is conductive and is made of polysilicon (Poly-Si). Note that the materials constituting the membrane plate 21, the insulating layer 22, and the conductive layer 23 are not limited to the above-mentioned materials. For example, the membrane plate 21 may be made of polysilicon (Poly-Si).

[0019] In the first embodiment, the thickness of the membrane layer 20 is 3 to 5 μm, but is not limited to this. The thickness is the length in the thickness direction 101 of the pressure sensor element 10.

[0020] As shown in FIGS. 1, 3, and 4, the membrane layer 20 has a diaphragm portion 20A.

[0021] In Fig. 1, the diaphragm portion 20A is indicated by a two-dot chain line. The diaphragm portion 20A is the region of the membrane layer 20 inside the two-dot chain line. As shown in Fig. 1, in a plan view taken along the thickness direction 101, the diaphragm portion 20A is a rectangle extending in a longitudinal direction 102 and a lateral direction 103. The longitudinal direction 102 and the lateral direction 103 are directions perpendicular to each other. Both the longitudinal direction 102 and the lateral direction 103 are directions perpendicular to the thickness direction 101.

[0022] Note that the diaphragm portion 20A may have a shape other than a rectangle, such as a square, when viewed along the thickness direction 101. When the diaphragm portion 20A is a square when viewed along the thickness direction 101, the length of the diaphragm portion 20A in the longitudinal direction 102 is equal to the length of the diaphragm portion 20A in the lateral direction 103.

[0023] 3 and 4, the diaphragm portion 20A is a portion of the membrane layer 20 sandwiched between two dashed lines in the short-side direction 103. As shown in Figures 3 and 4, the diaphragm portion 20A is a portion of the membrane layer 20 facing an internal space 30A (described later). The diaphragm portion 20A is made up of the regions of the membrane plate 21 and the insulating layer 22 sandwiched between the two dashed lines in the short-side direction 103, and a first conductive layer 231 and a second conductive layer 232 (described later) of the conductive layer 23.

[0024] The diaphragm portion 20A is capable of bending. For example, the diaphragm portion 20A bends toward the substrate layer 60 when pressure acts on one main surface 20B of the membrane layer 20.

[0025] The insulating layer 22 is located between the membrane plate 21 and the conductive layer 23 in the thickness direction 101. As a result, the membrane plate 21 and the conductive layer 23 are electrically insulated from each other.

[0026] The conductive layer 23 includes a first conductive layer 231 , a second conductive layer 232 , and a third conductive layer 233 .

[0027] The first conductive layer 231, the second conductive layer 232, and the third conductive layer 233 are provided apart from one another and are electrically insulated from one another.

[0028] As described above, the first conductive layer 231 and the second conductive layer 232 are part of the diaphragm portion 20A of the membrane layer 20. The first conductive layer 231 and the second conductive layer 232 are laminated on the portion of the insulating layer 22 that constitutes the diaphragm portion 20A. The first conductive layer 231 and the second conductive layer 232 face the internal space 30A.

[0029] The third conductive layer 233 is laminated on a portion of the insulating layer 22 that is different from the diaphragm portion 20A. When viewed along the thickness direction 101, the third conductive layer 233 surrounds the first conductive layer 231 and the second conductive layer 232.

[0030] 3 and 4 , the substrate layer 60 faces the membrane layer 20 at a distance in the thickness direction 101. The substrate layer 60 includes a conductive conductive layer 61, an insulating insulating layer 62, and a conductive substrate 63.

[0031] The conductive layer 61 is laminated on the insulating layer 62. The conductive layer 61 faces the internal space 30A. The insulating layer 62 is laminated on the substrate 63. The insulating layer 62 is sandwiched between the conductive layer 61 and the substrate 63 in the thickness direction 101. In Figures 3 and 4, the conductive layer 61 and the substrate 63 are electrically insulated from each other, but the conductive layer 61 and the substrate 63 may be electrically connected to each other.

[0032] In the first embodiment, the conductive layer 61 is made of polysilicon (Poly-Si), and the insulating layer 62 is made of silicon dioxide (SiO ２ ), and the substrate 63 is made of silicon (Si). In the first embodiment, the thickness of the substrate layer 60 is 100 to 150 μm. The materials constituting the conductive layer 61, the insulating layer 62, and the substrate 63 are not limited to the above-mentioned materials. The thickness of the substrate layer 60 is not limited to 100 to 150 μm.

[0033] The layer configuration of the substrate layer 60 is not limited to the configuration shown in Figures 3 and 4. For example, the substrate layer 60 does not need to have the insulating layer 62.

[0034] 3 and 4, the intermediate layer 30 is located between the membrane layer 20 and the substrate layer 60. As described above, the intermediate layer 30 includes a plurality of electrode portions 40 and a side wall portion 50.

[0035] In the first embodiment, the intermediate layer 30 is conductive and made of silicon (Si). In the first embodiment, the thickness of the sidewall portion 50 is 50 μm. The thickness of the two electrode portions 40A, 40B is thinner than the sidewall portion 50 by the gap G1 between the electrode portions 40A, 40B and the substrate layer 60. The material constituting the intermediate layer 30 is not limited to silicon. The thickness of the sidewall portion 50 is not limited to 50 μm.

[0036] The side wall portion 50 is bonded to the third conductive layer 233, which is a portion of the membrane layer 20 that is different from the diaphragm portion 20A. In the first embodiment, the side wall portion 50 is bonded to the entire surface of the third conductive layer 233 that faces the side wall portion 50. The side wall portion 50 is also bonded to the conductive layer 61 of the substrate layer 60. When viewed along the thickness direction 101, the side wall portion 50 surrounds the first conductive layer 231 and the second conductive layer 232 of the membrane layer 20 and the plurality of electrode portions 40.

[0037] The side wall portion 50, the third conductive layer 233, the diaphragm portion 20A, and the conductive layer 61 define an internal space 30A. The internal space 30A is a space that is sealed from the outside of the pressure sensor element 10. A plurality of electrode portions 40 are provided in the internal space 30A. That is, the plurality of electrode portions 40 are provided between the membrane layer 20 and the substrate layer 60 in the thickness direction 101. In other words, the substrate layer 60 is provided on the opposite side of the membrane layer 20 with respect to the plurality of electrode portions 40 in the thickness direction 101.

[0038] In the first embodiment, the pressure sensor element 10 includes two electrode portions 40A and 40B as the plurality of electrode portions 40.

[0039] Each of the two electrode portions 40A, 40B faces the diaphragm portion 20A in the thickness direction 101. Each of the two electrode portions 40A, 40B is provided away from the substrate layer 60 (more specifically, the conductive layer 61 of the substrate layer 60) and the side wall portion 50.

[0040] As shown in FIGS. 2 to 4, the two electrode portions 40A and 40B are spaced apart from each other.

[0041] As shown in Fig. 2, the two electrode portions 40A, 40B are positioned, shaped, and sized to be point-symmetrical with respect to the center C of the diaphragm portion 20A when viewed along the thickness direction 101. The center C of the diaphragm portion 20A is a position that is a longitudinal center position 102A and a lateral center position 103A. As shown in Fig. 1, the longitudinal center position 102A is the center position of the diaphragm portion 20A in the longitudinal direction 102. The lateral center position 103A is the center position of the diaphragm portion 20A in the lateral direction 103.

[0042] The two electrode portions 40A, 40B do not have to be completely point-symmetrical with respect to the center C of the diaphragm portion 20A when viewed along the thickness direction 101, and may be slightly misaligned. In other words, the two electrode portions 40A, 40B may be approximately point-symmetrical with respect to the center C of the diaphragm portion 20A when viewed along the thickness direction 101.

[0043] As shown in FIGS. 1 to 4, each of the two electrode portions 40A and 40B includes a support portion 41 and a movable portion .

[0044] The support part 41 and the movable part 42 of the electrode part 40A have the same configuration as the support part 41 and the movable part 42 of the electrode part 40B, with some exceptions. Therefore, the configurations of the support part 41 and the movable part 42 of the electrode part 40A will be described below. The description of the configurations of the support part 41 and the movable part 42 of the electrode part 40B will be omitted in principle and will be described only when necessary.

[0045] 3 and 4 , the support portion 41 is bonded to the first conductive layer 231 of the membrane layer 20. As a result, the support portion 41 is supported by the first conductive layer 231. In the first embodiment, the entire surface of the surface of the support portion 41 facing the first conductive layer 231 is bonded to the first conductive layer 231.

[0046] The movable portion 42 is located closer to the substrate layer 60 than the support portion 41 in the thickness direction 101, and is joined to the support portion 41. This allows the movable portion 42 to be supported by the support portion 41. In other words, the movable portion 42 is supported by the first conductive layer 231 of the membrane layer 20 via the support portion 41. In the first embodiment, the movable portion 42 is configured integrally with the support portion 41, and the support portion 41 protrudes from the movable portion 42 toward the first conductive layer 231. However, the movable portion 42 may be a separate member from the support portion 41 and joined to the support portion 41.

[0047] 2 , the support portion 41 has an elongated shape in the longitudinal direction 102. That is, the length of the support portion 41 in the longitudinal direction 102 is longer than the length of the support portion 41 in the short direction 103. In the first embodiment, the support portion 41 has a rectangular shape when viewed along the thickness direction 101. In the first embodiment, the length of the support portion 41 in the longitudinal direction 102 is equal to or greater than ¼ of the length of the diaphragm portion 20A in the longitudinal direction 102.

[0048] Note that the support portion 41 may have a shape other than a rectangle when viewed along the thickness direction 101. For example, the support portion 41 may have a shape that is curved and extends in the longitudinal direction 102. The length of the support portion 41 in the longitudinal direction 102 may be less than ¼ of the length of the diaphragm portion 20A in the longitudinal direction 102.

[0049] When viewed along the thickness direction 101, the support portion 41 of the electrode portion 40A and the support portion 41 of the electrode portion 40B are each located away from both the longitudinal center position 102A and the lateral center position 103A. In the first embodiment, the support portion 41 of the electrode portion 40A and the support portion 41 of the electrode portion 40B are provided on opposite sides of the longitudinal center position 102A in the longitudinal direction 102, and are also provided on opposite sides of the lateral center position 103A in the lateral direction 103.

[0050] The support portion 41 of the electrode portion 40A and the support portion 41 of the electrode portion 40B may be provided on the same side of the longitudinal center position 102A in the longitudinal direction 102. Furthermore, the support portion 41 of the electrode portion 40A and the support portion 41 of the electrode portion 40B may be provided on the same side of the transverse center position 103A in the transverse direction 103.

[0051] When viewed along the thickness direction 101, the movable portion 42 is larger than the support portion 41. As shown in Figures 3 and 4 , the movable portion 42 faces the second conductive layer 232 of the membrane layer 20 at a distance in the thickness direction 101, except for the portion supported by the support portion 41. In the first embodiment, of the surface of the movable portion 42 facing the second conductive layer 232, almost the entire surface, except for the portion joined to and supported by the support portion 41, faces the second conductive layer 232 at a distance.

[0052] 2, the movable part 42 includes a one-side portion 421 located on one side of the short-side central position 103A in the short-side direction 103, and a other-side portion 422 located on the other side of the short-side central position 103A in the short-side direction 103. When viewed along the thickness direction 101, the other-side portion 422 has a larger area than the one-side portion 421.

[0053] In the first embodiment, the one-side portion 421 is provided only on one side of the longitudinal center position 102A in the longitudinal direction 102, while the other-side portion 422 is provided on both sides of the longitudinal center position 102A in the longitudinal direction 102. In the short direction 103, the other-side portion 422 of the electrode portion 40B is provided between the one-side portion 421 of the electrode portion 40A and the side wall portion 50. Similarly, in the short direction 103, the other-side portion 422 of the electrode portion 40A is provided between the one-side portion 421 of the electrode portion 40B and the side wall portion 50.

[0054] The support portion 41 protrudes from the one side portion 421 toward the first conductive layer 231. In other words, the one side portion 421 is supported by the support portion 41.

[0055] The movable portion 42 is electrically connectable to the outside of the pressure sensor element 10 via the support portion 41, the first conductive layer 231, and a first terminal (not shown). The second conductive layer 232 is electrically connectable to the outside of the pressure sensor element 10 via a second terminal (not shown). As a result, in each of the electrode portions 40A, 40B, a capacitor having gaps G2, G3 is formed between the movable portion 42 and the second conductive layer 232, as shown in Figures 3 and 4. In the first embodiment, the gaps G2, G3 have the same length, but they may also have different lengths.

[0056] FIG. 5 is a schematic cross-sectional view showing the cross section BB in FIG. 1, in which pressure is applied to the diaphragm portion.

[0057] As shown in Figure 5, when pressure acts on one main surface 20B of the membrane layer 20, the diaphragm portion 20A of the membrane layer 20 bends in the thickness direction 101 toward the substrate layer 60. As the diaphragm portion 20A bends, the support portions 41 and movable portions 42 of each electrode portion 40A, 40B bonded to the diaphragm portion 20A are displaced in the thickness direction 101 toward the substrate layer 60. This increases the gap between the movable portion 42 and the second conductive layer 232 compared to when no pressure is acting on the one main surface 20B (the state shown in Figures 3 and 4). The capacitance of the capacitor changes based on the amount of change in this gap. The pressure acting on the membrane layer 20 is detected based on this change in capacitance.

[0058] Here, the portion of the diaphragm portion 20A to which the support portion 41 is joined is inclined with respect to an imaginary plane extending in the longitudinal direction 102 and the lateral direction 103. Therefore, the movable portion 42 supported by the support portion 41 is also inclined with respect to the imaginary plane. As a result, the gap between the movable portion 42 and the second conductive layer 232 can be made larger, as shown by gaps G21 and G31 in FIG. 5 , compared to when the movable portion 42 is not inclined with respect to the imaginary plane. This allows the amount of change in the gap to be made larger.

[0059] 6 is a schematic plan view of a portion of a pressure sensor element of a comparative example excluding the membrane layer. The pressure sensor element 90 shown in FIG. 6 differs from the pressure sensor element 10 according to the first embodiment in the following respects. The pressure sensor element 90 of this comparative example includes one electrode portion 40. The support portion 41 extends along the short-side central position 103A when viewed along the thickness direction 101, and overlaps with the center C.

[0060] In the pressure sensor element 90 of the comparative example, the support portion 41 is not located at a position deviating from the longitudinal center position 102A and the lateral center position 103A when viewed along the thickness direction 101. Therefore, when pressure acts on one main surface 20B of the membrane layer 20, the portion of the diaphragm portion 20A to which the support portion 41 is bonded does not tilt, or if tilted, the tilt is small, with respect to an imaginary plane extending in the longitudinal direction 102 and the lateral direction 103. Therefore, the movable portion 42 supported by the support portion 41 also does not tilt, or if tilted, the tilt is small, with respect to the imaginary plane. As a result, the pressure sensor element 90 has a smaller change in the gap than the pressure sensor element 10.

[0061] In both the pressure sensor elements 10 and 90, when pressure acts on one main surface 20B of the membrane layer 20, the apex of the deflection of the diaphragm portion 20A (the position where the deflection is maximum) is at the center C. In both the pressure sensor elements 10 and 90, the deformation of the diaphragm portion 20A is inhibited in the portion where the support portion 41 is provided.

[0062] In the pressure sensor element 90 of the comparative example shown in Fig. 6, the portion of the diaphragm portion 20A to which the support portion 41 is joined includes the apex. Therefore, as shown in Fig. 7, the entire area of ​​the portion of the diaphragm portion 20A to which the support portion 41 is joined becomes the apex of the deflection of the diaphragm portion 20A, and the deflection shape becomes gentle. This reduces the deflection of the diaphragm portion 20A at the apex. Fig. 7 is a schematic end view showing the CC cross section of Fig. 6, showing a state in which pressure is acting on the diaphragm portion.

[0063] On the other hand, in the pressure sensor element 10 according to the first embodiment shown in FIG. 1 , the portion of the diaphragm portion 20A to which the support portion 41 is bonded does not include the center C. That is, in the pressure sensor element 10, the diaphragm portion 20A has a region where the support portion 41 is not bonded and includes the center C, and a region where the support portion 41 is bonded but does not include the center C. Therefore, as shown in FIG. 8 , only the central portion of the diaphragm portion 20A (in other words, the center C and its surrounding region) becomes the apex of the deflection of the diaphragm portion 20A, resulting in a steeper deflection shape. As a result, the deflection of the diaphragm portion 20A at this apex is larger than that of the pressure sensor element 90. FIG. 8 is a schematic end view showing the D-D cross section of FIG. 1 when pressure is applied to the diaphragm portion. The deflection amount D10 of the diaphragm portion 20A shown in FIG. 8 is larger than the deflection amount D90 of the diaphragm portion 20A shown in FIG. 7 .

[0064] The pressure sensor element 10 according to the first embodiment can achieve the following effects.

[0065] On the other hand, when the diaphragm portion 20A is bent by the application of pressure to the main surface 20B, the diaphragm portion 20A at a position other than the short-side center position 103A is tilted relative to the horizontal direction. Here, the horizontal direction is the direction in which the diaphragm portion 20A expands when no pressure is applied. In other words, the horizontal direction is the direction along an imaginary plane that expands in the longitudinal direction 102 and the short-side direction 103.

[0066] According to the first embodiment, the support portion 41 is supported by the diaphragm portion 20A at a position that is off the short-side center position 103A in the short-side direction 103. Therefore, when the diaphragm portion 20A bends, the movable portion 42 that is supported by the diaphragm portion 20A via the support portion 41 is displaced while tilting relative to the horizontal direction in accordance with the tilt of the diaphragm portion 20A.

[0067] At this time, the displacement of the movable portion 42 increases by the amount that the movable portion 42 is tilted relative to the horizontal direction. Therefore, the change in the distance between the movable portion 42 and the second conductive layer 232 of the diaphragm portion 20A is greater than in a configuration in which the movable portion 42 is displaced without tilting relative to the horizontal direction. This increases the amount of change in capacitance between the movable portion 42 and the second conductive layer 232. As a result, it is possible to suppress a decrease in the pressure detection sensitivity of the pressure sensor element 10.

[0068] According to the first embodiment, the support portion 41 has an elongated shape extending along the longitudinal direction 102, and therefore the support strength of the movable portion 42 provided by the support portion 41 can be increased compared to a shape in which the support portion 41 does not extend along the longitudinal direction 102.

[0069] If the elongated support portion is configured to contact the center of the diaphragm portion as described above, when the diaphragm portion bends, the peak of the bending will be not only the center of the diaphragm portion but also the entire area where the support portion is in contact, which will result in a gentler bending shape of the diaphragm portion and a smaller amount of bending.

[0070] In contrast, according to the first embodiment, the support portions 41 are located at positions that are away from both the longitudinal center position 102A and the lateral center position 103A. That is, the support portions 41 are not in contact with the center portion of the diaphragm portion 20A. In this case, when the diaphragm portion 20A bends, the center portion of the diaphragm portion 20A becomes the peak of the bending, while the portion of the diaphragm portion 20A that is in contact with the support portions 41 does not become the peak of the bending. That is, in the first embodiment, the diaphragm portion 20A has a region that is not in contact with the support portions 41 and that includes the center portion, and a region that is in contact with the support portions 41 and that does not include the center portion.

[0071] As a result, in the first embodiment, only the central portion of the diaphragm portion 20A becomes the apex of the deflection, resulting in a steep deflection shape. Therefore, compared to the configuration described above, the amount of deflection of the diaphragm portion 20A is greater. This increases the amount of change in the gap between the movable portion 42 and the second conductive layer 232 that accompanies the deflection of the diaphragm portion 20A, thereby increasing the amount of change in capacitance between the movable portion 42 and the second conductive layer 232. As a result, it is possible to suppress a decrease in the pressure detection sensitivity of the pressure sensor element 10.

[0072] When the movable portion 42 is displaced while tilting due to the deflection of the diaphragm portion 20A, the amount of displacement due to the tilt of the movable portion 42 is greater the farther the movable portion 42 is from the support portion 41. According to the first embodiment, the other-side portion 422 having a large area is located farther from the support portion 41. Therefore, according to the first embodiment, when the movable portion 42 is displaced while tilting due to the deflection of the diaphragm portion 20A, the area where the amount of displacement of the movable portion 42 is large can be increased. As a result, the amount of change in capacitance between the movable portion 42 and the second conductive layer 232 can be increased, thereby suppressing a decrease in the pressure detection sensitivity of the pressure sensor element 10.

[0073] According to the first embodiment, the two electrode portions 40A, 40B are point-symmetric or approximately point-symmetric with respect to the center C of the diaphragm portion 20A when viewed along the thickness direction 101. Therefore, when the diaphragm portion 20A is bent, the amount of displacement of the movable portion 42 of the electrode portion 40A and the amount of displacement of the movable portion 42 of the electrode portion 40B can be made the same or approximately the same. This makes it easy to design the movable portion 42 so that it achieves a target amount of displacement corresponding to the magnitude of pressure acting on the diaphragm portion 20A.

[0074] According to the first embodiment, since the plurality of electrode sections 40 are located in the internal space 30A, adhesion of foreign matter to the plurality of electrode sections 40 can be reduced.

[0075] Second Embodiment The pressure sensor element according to the second embodiment differs from the pressure sensor element 10 according to the first embodiment in that the pressure sensor element according to the second embodiment includes support portions having a plurality of widths instead of the support portion 41 having a constant width. The differences between the pressure sensor element according to the second embodiment and the pressure sensor element 10 according to the first embodiment will be described below. The same reference numerals are used to denote commonalities with the pressure sensor element 10 according to the first embodiment, and explanations thereof will be omitted in principle, and will be provided only when necessary.

[0076] FIG. 9 is a schematic plan view of a portion of the pressure sensor element according to the second embodiment of the present disclosure, excluding the membrane layer.

[0077] As shown in FIG. 9 , the support portion 41A included in the pressure sensor element 11 according to the second embodiment extends in the longitudinal direction 102 and has two different widths as an example of multiple widths. Here, the width of the support portion 41A is the length of the support portion 41A in the short direction 103. The support portion 41A has a wide portion 411 and a narrow portion 412. The wide portion 411 has a first width W1. The narrow portion 412 has a second width W2. The second width W2 is smaller than the first width W1. The wide portion 411 and the narrow portion 412 are continuous in the longitudinal direction 102. The narrow portion 412 is located closer to the longitudinal center position 102A than the wide portion 411.

[0078] In the short side direction 103, the narrow width portion 412 is located farther from the short side central position 103A than the wide width portion 411. Specifically, the central position 412A of the narrow width portion 412 in the short side direction 103 is located further outward in the short side direction 103 than the central position 411A of the wide width portion 411 in the short side direction 103. Note that, conversely to the above, the central position 412A of the narrow width portion 412 in the short side direction 103 may be located further inward in the short side direction 103 than the central position 411A of the wide width portion 411 in the short side direction 103. Furthermore, the central position 412A of the narrow width portion 412 in the short side direction 103 may be located at the same position in the short side direction 103 as the central position 411A of the wide width portion 411 in the short side direction 103.

[0079] FIG. 10 is a schematic plan view of a portion of a pressure sensor element according to a modified example of the second embodiment of the present disclosure, from which the membrane layer is removed.

[0080] As shown in Fig. 10 , the support portion 41B included in the pressure sensor element 12 according to the modified example of the second embodiment has a width that gradually narrows toward the longitudinal center position 102A in the longitudinal direction 102. In this case, the support portion 41B also has a plurality of widths. In the configuration shown in Fig. 10 , if any position of the support portion 41B except the end on the longitudinal center position 102A side in the longitudinal direction 102 corresponds to a wide portion, any position closer to the longitudinal center position 102A than the wide portion corresponds to a narrow portion.

[0081] The pressure sensor elements 11 and 12 according to the second embodiment can achieve the following effects.

[0082] In the portions of the diaphragm portion 20A where the support portions 41A and 41B are joined, deformation of the diaphragm portion 20A is inhibited, making the diaphragm portion 20A less likely to bend. According to the second embodiment, when viewed along the thickness direction 101, the narrow portion 412 is located closer to the longitudinal center position 102A than the wide portion 411. This reduces the area of ​​the support portions 41A and 41B joined to the diaphragm portion 20A at positions closer to the center C of the diaphragm portion 20A. This allows the diaphragm portion 20A to bend more easily at positions closer to the center C of the diaphragm portion 20A, thereby increasing the maximum amount of deflection of the diaphragm portion 20A. As a result, the amount of change in the gap between the movable portion 42 and the second conductive layer 232 due to deflection of the diaphragm portion 20A increases, thereby increasing the amount of change in the electrostatic capacitance between the movable portion 42 and the second conductive layer 232.

[0083] According to the second embodiment, the narrow width portion 412 is provided farther from the lateral center position 103A in the lateral direction 103 than the wide width portion 411. Therefore, compared to a configuration in which the narrow width portion 412 is provided closer to the lateral center position 103A than the wide width portion 411 in the lateral direction 103, the area of ​​the support portion 41 that joins to the diaphragm portion 20A at a position closer to the center C of the diaphragm portion 20A can be made smaller. This makes it easier for the diaphragm portion 20A to bend at a position closer to the center C of the diaphragm portion 20A.

[0084] <Third Embodiment> The pressure sensor element according to the third embodiment differs from the pressure sensor element 10 according to the first embodiment in that, instead of the support portions 41 extending straight along the longitudinal direction 102, the pressure sensor element according to the third embodiment has support portions extending along a direction inclined with respect to the longitudinal direction 102. Differences between the pressure sensor element according to the third embodiment and the pressure sensor element 10 will be described below. Points in common with the pressure sensor element 10 according to the first embodiment are denoted by the same reference numerals, and explanations thereof will be omitted in principle, and will be described only when necessary.

[0085] FIG. 11 is a schematic plan view of a portion of the pressure sensor element according to the third embodiment of the present disclosure, excluding the membrane layer.

[0086] 11 , the support portion 41C included in the pressure sensor element 13 according to the third embodiment is inclined with respect to the longitudinal direction 102 so as to approach a longitudinal center position 102A in the longitudinal direction 102 and to approach a lateral center position 103A in the lateral direction 103. Note that the support portion 41C may be inclined with respect to the longitudinal direction 102 so as to move away from the lateral center position 103A in the lateral direction 103 as it approaches the longitudinal center position 102A in the longitudinal direction 102.

[0087] The pressure sensor element 13 according to the third embodiment can achieve the following effects.

[0088] According to the third embodiment, compared to a configuration in which the support portion 41 extends parallel to the longitudinal direction 102 of the diaphragm portion 20A, the diaphragm portion 20A can be made more flexible at positions closer to the center C of the diaphragm portion 20A. This increases the amount of change in the gap between the movable portion 42 and the second conductive layer 232 that accompanies the bending of the diaphragm portion 20A, thereby increasing the amount of change in the capacitance between the movable portion 42 and the second conductive layer 232.

[0089] <Fourth embodiment> The pressure sensor element according to the fourth embodiment differs from the pressure sensor element 10 according to the first embodiment in that a diaphragm portion having a protrusion is provided instead of the diaphragm portion 20A. Differences between the pressure sensor element according to the fourth embodiment and the pressure sensor element 10 will be described below. Points in common with the pressure sensor element 10 according to the first embodiment are given the same reference numerals, and explanations thereof will be omitted in principle, and will be described only when necessary.

[0090] FIG. 12 is a schematic plan view of a pressure sensor element according to a fourth embodiment of the present disclosure.

[0091] As shown in FIG. 12 , the diaphragm portion 20D of the pressure sensor element 14 according to the fourth embodiment includes a protruding portion 20Da. In FIG. 12 , the diaphragm portion 20D is the region of the membrane layer 20 inside the two-dot chain line. In FIG. 12 , the boundary between the protruding portion 20Da and the remaining portion of the diaphragm portion 20D is indicated by a three-dot chain line. The protruding portion 20Da protrudes in the short-side direction 103 from both ends of the diaphragm portion 20D in the short-side direction 103. The protruding tip 20Db of the protruding portion 20Da is located closer to the longitudinal center position 102A in the longitudinal direction 102 than the support portions 41 of the electrode portions 40A and 40B. In the configuration shown in FIG. 12 , the position of the protruding tip 20Db in the long-side direction 102 is the longitudinal center position 102A, but it does not have to be the longitudinal center position 102A.

[0092] FIG. 13 is a schematic plan view of a pressure sensor element according to a modified example of the fourth embodiment of the present disclosure.

[0093] As shown in Fig. 13, the diaphragm portion 20D of the pressure sensor element 15 according to the modified example of the fourth embodiment includes a protrusion 20Dc. The protrusion 20Da shown in Fig. 12 is provided over the entire area of ​​the diaphragm portion 20D in the longitudinal direction 102. On the other hand, the protrusion 20Dc shown in Fig. 13 is provided over a partial area of ​​the diaphragm portion 20D in the longitudinal direction 102. The diaphragm portion 20D shown in Fig. 13 also includes another protrusion 20Dd in the portions of both ends in the short side direction 103 where the protrusion 20Dc is not provided. In Fig. 13, the boundary between the protrusions 20Dc, 20Dd and the rest of the diaphragm portion 20D is indicated by a three-dot chain line. The presence or absence of the protrusion 20Dd is optional.

[0094] The pressure sensor elements 14 and 15 according to the fourth embodiment can achieve the following effects.

[0095] According to the fourth embodiment, the diaphragm portion 20D has a protrusion 20Da at a position closer to the longitudinal center position 102A in the longitudinal direction 102 than the support portions 41. The protrusion 20Da increases the length of the diaphragm portion 20D in the short direction 103 at the center of the diaphragm portion 20D in the longitudinal direction 102. This increases the amount of deflection of the diaphragm portion 20D at the center of the diaphragm portion 20D in the longitudinal direction 102. As a result, the amount of change in the gap between the movable portion 42 and the second conductive layer 232 due to deflection of the diaphragm portion 20D increases, thereby increasing the amount of change in the electrostatic capacitance between the movable portion 42 and the second conductive layer 232.

[0096] <Evaluation> The deflection amount of the diaphragm portion and the gap between the movable portion and the diaphragm portion were evaluated for the pressure sensor elements 10, 11, 12, 13, 14, and 15 of the first to fourth embodiments described above and the pressure sensor element 90 of the comparative example. The evaluation was performed using finite element method (FEM) analysis. In the following description and in Figures 14 and 15, the pressure sensor elements 10, 11, 12, 13, 14, and 15 are referred to as Examples 1, 2, 3, 4, 5, and 6, respectively, and the pressure sensor element 90 shown in Figures 6 and 7 is referred to as the comparative example.

[0097] The evaluation results are shown in Figures 14 and 15. Figure 14 is a graph showing the deformation of the diaphragm portion and the displacement of the movable portion along the short side direction in the first embodiment and the comparative example. Figure 15 is a graph showing the deformation of the diaphragm portion along the long side direction in each embodiment and the comparative example.

[0098] The "distance" on the horizontal axis in Figure 14 is the distance from one end 20E (see Figure 1) of the diaphragm portion in the short side direction 103. In this evaluation, a diaphragm portion having a length of 200 µm in the short side direction 103 was used. Therefore, in the "distance" on the horizontal axis, "0 µm" indicates the position of one end 20E of the diaphragm portion, "100 µm" indicates the short side center position 103A (see Figure 1), and "200 µm" indicates the position of the other end 20F (see Figure 1) of the diaphragm portion.

[0099] The "position" on the vertical axis in Figure 14 indicates the position in the thickness direction 101 of the diaphragm portion and the position in the thickness direction 101 of the upper surface 42A of the movable portion 42 (see Figure 5). The position in the thickness direction 101 of the diaphragm portion 20A is indicated by a solid line, and the position in the thickness direction 101 of the upper surface 42A of the movable portion 42 is indicated by a dashed line. On the "position" on the vertical axis, "0 μm" indicates the position of one main surface 20B (see Figure 5) of the second conductive layer 232 when no pressure is applied. The larger the "position" on the vertical axis in the negative direction, the greater the amount of movement of the diaphragm portion 20A and the movable portion 42 toward the substrate layer 60.

[0100] 14 , when a set pressure acts on the diaphragm portion 20A, the amount of deflection of the diaphragm portion 20A in Example 1 is greater than the amount of deflection of the diaphragm portion in Comparative Example 1. Also, as described above, in Example 1, the movable portion 42 is tilted. On the other hand, in the Comparative Example, the movable portion 42 is not tilted. Therefore, the gaps G21 and G31 between the movable portion 42 and the diaphragm portion 20A in Example 1 are greater than the gap G9 between the movable portion 42 and the diaphragm portion 20A in Comparative Example 1.

[0101] The "distance" on the horizontal axis in Figure 15 is the distance from one end 20G of the diaphragm portion (see Figure 1) in the longitudinal direction 102. In this evaluation, a diaphragm portion having a length of 640 µm in the longitudinal direction 102 was used. Therefore, in the "distance" on the horizontal axis, "0 µm" indicates the position of one end 20G of the diaphragm portion, "320 µm" indicates the longitudinal center position 102A (see Figure 1), and "640 µm" indicates the position of the other end 20H of the diaphragm portion (see Figure 1).

[0102] The "diaphragm deformation amount" on the vertical axis in Figure 15 indicates the amount of deflection in the thickness direction 101 of the diaphragm portion. On the "diaphragm deformation amount" on the vertical axis, "0 μm" indicates the position of one main surface 20B (see Figure 5) of the second conductive layer 232 when no pressure is applied. The larger the "diaphragm deformation amount" on the vertical axis in the negative direction, the greater the amount of deflection of the diaphragm portion toward the substrate layer 60.

[0103] 15, when a set pressure is applied to the diaphragm portion, the amount of deflection of the diaphragm portion at the longitudinal center position 102A is greater in Examples 1 to 6 than in the comparative example. The amounts of deflection of the diaphragm portion in Examples 1 to 6, from largest to smallest, are Examples 5, 6, 3, 4, 2, and 1. In other words, the amount of deflection of the diaphragm portion in Example 5 is the largest, and the amount of deflection of the diaphragm portion in Example 1 is the smallest. Furthermore, the deflection shape, based on the peak of the deflection of the diaphragm portion, is steeper in the order of Examples 5, 6, 3, 4, 2, and 1.

[0104] In the pressure sensor element 10 according to the first embodiment, the amount of deflection of the diaphragm portion 20A when the length of the support portion 41 in the longitudinal direction 102 is changed is evaluated.

[0105] The evaluation results are shown in Fig. 16. Fig. 16 is a graph showing the deformation of the diaphragm portion along the longitudinal direction when the length of the support portion is changed.

[0106] The definitions of "distance" on the horizontal axis and "diaphragm deformation amount" on the vertical axis in Fig. 16 are the same as in Fig. 15. Examples 11, 12, and 13 in Fig. 16 differ from one another in the length of the support portion 41 in the longitudinal direction 102 in the pressure sensor element 10 according to the first embodiment. The length of the support portion 41 in the longitudinal direction 102 of Example 11 is 1 / 3 of the length of the diaphragm portion 20A in the longitudinal direction 102. The length of the support portion 41 in the longitudinal direction 102 of Example 12 is 1 / 4 of the length of the diaphragm portion 20A in the longitudinal direction 102. The length of the support portion 41 in the longitudinal direction 102 of Example 13 is 1 / 5 of the length of the diaphragm portion 20A in the longitudinal direction 102.

[0107] As shown in FIG. 16, the deflection shape with the apex of the deflection in the diaphragm portion 20A as the reference point becomes steeper in the order of Examples 11, 12, and 13.

[0108] <Modifications> In each of the above-described embodiments, the pressure sensor element includes two electrode portions 40A and 40B. However, the pressure sensor element may include three or more electrode portions 40A and 40B.

[0109] In this case, all of the three or more electrode sections 40 may have the above-described configuration, or only some of them may have the above-described configuration.

[0110] For example, when the pressure sensor element includes four electrode portions 40, two of the electrode portions 40 may be point-symmetrical with each other, while the remaining two electrode portions 40 may not be point-symmetrical with each other. Alternatively, two of the electrode portions 40 may be point-symmetrical with each other, and the remaining two electrode portions 40 may also be point-symmetrical with each other.

[0111] Furthermore, for example, when the pressure sensor element includes three electrode portions 40, only the movable portions 42 of any of the three electrode portions 40 may include the one-side portion 421 and the other-side portion 422. Alternatively, the movable portions 42 of all of the three electrode portions 40 may include the one-side portion 421 and the other-side portion 422.

[0112] In each of the above-described embodiments, the pressure sensor element includes one diaphragm portion. However, the pressure sensor element may include multiple diaphragm portions. In this case, multiple electrode portions 40 having the above-described configuration may be provided corresponding to each of the multiple diaphragm portions. Alternatively, multiple electrode portions 40 having the above-described configuration may be provided corresponding to only some of the multiple diaphragm portions.

[0113] The pressure sensor element described above can also be expressed as follows.

[0114] (1) A pressure sensor element according to one aspect of the present disclosure comprises: a membrane layer having a diaphragm portion; and a plurality of electrode portions facing the diaphragm portion in a thickness direction; the diaphragm portion comprises: a first conductive layer; and a second conductive layer spaced apart from the first conductive layer; the plurality of electrode portions are spaced apart from one another; and each of the plurality of electrode portions comprises: a support portion supported by the first conductive layer; and a movable portion supported by the first conductive layer via the support portion, facing the second conductive layer at a distance in the thickness direction, and displacing when the diaphragm portion flexes; and when viewed along the thickness direction, each of the support portions is located away from both a longitudinal center position, which is the center of the diaphragm portion in the longitudinal direction, and a lateral center position, which is the center of the diaphragm portion in the lateral direction, and has an elongated shape in the longitudinal direction of the diaphragm portion.

[0115] (2) In the pressure sensor element of (1), at least one of the movable parts may have a one-side portion located on one side of the short-side center position in the short-side direction of the diaphragm part, and a other-side portion located on the other side of the short-side center position in the short-side direction of the diaphragm part and having a larger area than the one-side portion when viewed along the thickness direction, and the one-side portion of the movable part may be supported by the support part.

[0116] (3) In the pressure sensor element of (1) or (2), the plurality of electrode portions may include two electrode portions that are point-symmetric or approximately point-symmetric with respect to the center of the diaphragm portion when viewed along the thickness direction.

[0117] (4) In the pressure sensor element of any one of (1) to (3), at least one of the support portions may include a wide portion having a first width and a narrow portion having a second width smaller than the first width and located closer to the longitudinal center position than the wide portion.

[0118] (5) In the pressure sensor element according to any one of (1) to (4), at least one of the support portions may extend in a direction inclined with respect to a longitudinal direction of the diaphragm portion.

[0119] (6) In any one of the pressure sensor elements (1) to (5), the diaphragm portion may have a protrusion that protrudes from a short-side end of the diaphragm portion in the short-side direction of the diaphragm portion, and the protruding tip of the protrusion may be located in a position closer to the longitudinal center position of the diaphragm portion in the longitudinal direction than each of the support portions.

[0120] (7) Any one of the pressure sensor elements (1) to (6) may further include a substrate layer provided on the opposite side of the membrane layer from the plurality of electrode portions in the thickness direction, and a side wall portion joined to the substrate layer and a portion of the membrane layer different from the diaphragm portion and surrounding the plurality of electrode portions when viewed along the thickness direction, and the plurality of electrode portions may be provided apart from the substrate layer and the side wall portion in an internal space partitioned by the diaphragm portion, the substrate layer, and the side wall portion.

[0121] Any of the various embodiments described above may be combined appropriately to achieve the effects of each of them.

[0122] While the present invention has been fully described in connection with preferred embodiments, with appropriate reference to the drawings, various changes and modifications will become apparent to those skilled in the art, and it is to be understood that such changes and modifications are included within the scope of the present invention as defined by the appended claims unless they depart therefrom.

[0123] 10 Pressure sensor element 20 Membrane layer 20A Diaphragm portion 20D Diaphragm portion 20Da Projection portion 231 First conductive layer 232 Second conductive layer 30A Internal space 40 Electrode portion 40A Electrode portion 40B Electrode portion 41 Support portion 411 Wide portion 412 Narrow portion 42 Movable portion 421 One side portion 422 Other side portion 50 Side wall portion 60 Substrate layer 101 Thickness direction 102 Longitudinal direction 102A Longitudinal center position 103 Shortitudinal direction 103A Shortitudinal center position C Center W1 First width W2 Second width

Claims

1. A pressure sensor element comprising: a membrane layer having a diaphragm portion; and a plurality of electrode portions facing the diaphragm portion in a thickness direction, wherein the diaphragm portion comprises: a first conductive layer; and a second conductive layer provided at a distance from the first conductive layer, wherein the plurality of electrode portions are spaced apart from one another, and each of the plurality of electrode portions comprises: a support portion supported by the first conductive layer; and a movable portion supported by the first conductive layer via the support portion, facing the second conductive layer at a distance in the thickness direction, and displacing when the diaphragm portion flexes, wherein, when viewed along the thickness direction, each of the support portions is located at a position that is away from both a longitudinal center position that is the center of the diaphragm portion in the longitudinal direction and a lateral center position that is the center of the diaphragm portion in the lateral direction, and the pressure sensor element has an elongated shape in the longitudinal direction of the diaphragm portion.

2. A pressure sensor element as described in claim 1, wherein at least one of the movable parts comprises a one-side portion located on one side of the lateral center position in the lateral direction of the diaphragm part, and a other-side portion located on the other side of the lateral center position in the lateral direction of the diaphragm part and having a larger area than the one-side portion when viewed along the thickness direction, and the one-side portion of the movable part is supported by the support part.

3. A pressure sensor element according to claim 1 or 2, wherein the plurality of electrode portions include two electrode portions that are point-symmetric or approximately point-symmetric with respect to the center of the diaphragm portion when viewed along the thickness direction.

4. A pressure sensor element as described in any one of claims 1 to 3, wherein at least one of the support portions comprises: a wide portion having a first width; and a narrow portion having a second width smaller than the first width and located closer to the longitudinal center position than the wide portion.

5. A pressure sensor element according to any one of claims 1 to 4, wherein at least one of the support portions extends in a direction inclined with respect to the longitudinal direction of the diaphragm portion.

6. A pressure sensor element according to any one of claims 1 to 5, wherein the diaphragm portion has a protrusion that protrudes in the short direction of the diaphragm portion from an end portion in the short direction of the diaphragm portion, and the protruding tip of the protrusion is located in a position closer to the longitudinal center position of the diaphragm portion in the longitudinal direction than each of the support portions.

7. A pressure sensor element as described in any one of claims 1 to 6, further comprising: a substrate layer provided on the opposite side of the membrane layer from the plurality of electrode portions in the thickness direction; and a side wall portion joined to the substrate layer and a portion of the membrane layer different from the diaphragm portion and surrounding the plurality of electrode portions when viewed along the thickness direction, wherein the plurality of electrode portions are provided apart from the substrate layer and the side wall portion in an internal space partitioned by the diaphragm portion, the substrate layer, and the side wall portion.

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