Pressure Sensors

Abstract

The present invention provides a pressure sensor capable of suppressing shock waves from the outside from reaching a sensing part. The pressure sensor (1) of the present invention comprises: a base part (10); a sensing part (20) arranged relative to the base part (10) with a space therebetween in the height direction (4), sensing the pressure applied to a sensing surface (23) on the side opposite to the side where the base part (10) is located in the height direction (4); a peripheral part (30) erected from the base part (10) along the height direction (4), arranged to surround the sensing part (20) in a manner of separating a groove (70) formed around the sensing part (20); a connecting part (40) connecting the sensing part (20) and the peripheral part (30); and a beam member (50) arranged in the groove (70) to act as a resistance to the peripheral part (30) moving toward the sensing part (20).

Description

Technical Field

[0001] The present invention relates to a pressure sensor that senses pressure from the outside. Background Art

[0002] The component that senses minute pressure in the pressure sensor may be formed of MEMS (Micro Electro Mechanical Systems).

[0003] A pressure sensor made of MEMS includes a sensing part having a membrane that deforms according to external pressure and a peripheral part provided around the sensing part. In this case, the sensing part may be damaged due to the shock wave from the outside of the pressure sensor acting on the peripheral part.

[0004] In the pressure sensor disclosed in Patent Document 1, most of the sensing part and the surrounding part are separated by a groove, and only a part of the sensing part and the surrounding part are connected by an arm, thereby reducing the impact of the shock wave applied to the surrounding part on the sensing part.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: U.S. Patent Application Publication No. 2017 / 0253477 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] However, even if the sensing portion and the peripheral portion are separated by the groove, when a large impact acts on the peripheral portion during a fall, the peripheral portion may move and come into contact with the sensing portion, thereby damaging the sensing portion.

[0010] Furthermore, if liquid such as water enters the groove of the pressure sensor disclosed in Patent Document 1 and the groove is occupied by the liquid, the impact acting on the surrounding part is transmitted to the sensing part through the liquid, and the sensing part may be damaged.

[0011] Therefore, an object of the present invention is to solve the above-mentioned problem and to provide a pressure sensor capable of suppressing a shock wave from the outside from reaching a sensing part.

[0012] Solutions for solving problems

[0013] In order to achieve the above object, the present invention is constructed as follows.

[0014] A pressure sensor according to a technical solution of the present invention comprises:

[0015] Base part;

[0016] a sensing portion disposed opposite to the base portion in a height direction with a space therebetween, and sensing a pressure applied to a sensing surface on a side opposite to a side where the base portion is located in the height direction;

[0017] a peripheral portion which is erected from the base portion in the height direction and is configured to surround the sensing portion via a groove formed around the sensing portion;

[0018] a connecting portion connecting the sensing portion and the surrounding portion; and

[0019] The damping part is provided in the groove and applies resistance to the peripheral part moving toward the sensing part.

[0020] Effects of the Invention

[0021] According to the present invention, it is possible to suppress the impact wave from the outside from reaching the sensing part. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a perspective view of the pressure sensor according to the first embodiment of the present invention.

[0023] Figure 2 yes Figure 1 Top view of the pressure sensor.

[0024] Figure 3 It is along Figure 2 Cross-sectional view along line A-A in FIG.

[0025] Figure 4 It is along Figure 2 Cross-sectional view of line B-B in .

[0026] Figure 5 The pressure sensor according to the second embodiment of the present invention is Figure 3 Same cross-section view.

[0027] Figure 6 It is a top view of a pressure sensor according to a third embodiment of the present invention.

[0028] Figure 7 It is a top view of a pressure sensor according to a fourth embodiment of the present invention.

[0029] Figure 8 It is a top view of a pressure sensor according to a fifth embodiment of the present invention.

[0030] Fig. 9 It is a plan view of a pressure sensor according to a modified example of each embodiment of the present invention.

[0031] Fig.10It is a plan view of a pressure sensor according to a modified example of each embodiment of the present invention.

[0032] Fig.11 A pressure sensor according to a sixth embodiment of the present invention Figure 3 Same cross-section view. DETAILED DESCRIPTION

[0033] A pressure sensor according to one aspect of the present invention comprises:

[0034] Base part;

[0035] a sensing portion disposed opposite to the base portion in a height direction with a space therebetween, and sensing a pressure applied to a sensing surface on a side opposite to a side where the base portion is located in the height direction;

[0036] a peripheral portion which is erected from the base portion in the height direction and is configured to surround the sensing portion via a groove formed around the sensing portion;

[0037] a connecting portion connecting the sensing portion and the surrounding portion; and

[0038] The damping part is provided in the groove and applies resistance to the peripheral part moving toward the sensing part.

[0039] According to this structure, when an impact is applied to the peripheral part from the outside of the pressure sensor, the damping part provided in the groove is used to mitigate the transmission of the impact from the peripheral part to the sensing part. Thus, it is possible to suppress the impact from the outside from reaching the sensing part. As a result, the possibility of damage to the sensing part can be reduced.

[0040] It may also be that the sensing portion includes an outer peripheral surface opposite to the surrounding portion, the surrounding portion includes an inner peripheral surface opposite to the outer peripheral surface, the groove is formed between the outer peripheral surface and the inner peripheral surface, and the damping portion includes a beam member supported by the base portion, having a gap between the outer peripheral surface and at least one of the inner peripheral surface and extending along the groove.

[0041] According to this configuration, when an impact acts on the surrounding part from outside the pressure sensor, the beam member functions as a buffer, thereby preventing the impact from outside from reaching the sensing part.

[0042] Furthermore, according to this structure, the gap between the peripheral part and the sensing part is shortened in accordance with the case where the beam member is arranged in the groove. Therefore, when an impact acts on the peripheral part from the outside of the pressure sensor, a resistance to the movement of the peripheral part toward the sensing part is generated due to the squeeze film damping effect, thereby reducing the transmission of the impact to the sensing part.

[0043] Furthermore, according to this configuration, the gap between the peripheral portion and the sensing portion is shortened in accordance with the arrangement of the beam member in the groove, thereby making it possible to suppress the intrusion of liquid such as water into the groove by utilizing the surface tension of the liquid.

[0044] A pressure sensor according to one form of the present invention may further include a cover portion, which is arranged opposite to the sensing surface with a space therebetween, the cover portion is supported by the surrounding portion, a through hole is formed at a position opposite to the sensing surface, and the width of the longer gap between the gap between the damping portion and the outer peripheral surface and the gap between the damping portion and the inner peripheral surface is shorter than the diameter of the through hole.

[0045] The pressure sensor disclosed in Patent Document 1 includes a cover that covers the sensing part from above to prevent liquids such as water from entering the interior of the pressure sensor. However, since the pressure sensor disclosed in Patent Document 1 is an air pressure sensor, it is impossible to completely block the external atmosphere from the sensing part. Therefore, in the pressure sensor disclosed in Patent Document 1, a through hole is formed in the cover for connecting the sensing part with the atmosphere. Therefore, the liquid will enter the groove inside the pressure sensor through the through hole. In this regard, according to this structure, the width of the longer gap between the gap between the damping part and the outer peripheral surface and the gap between the damping part and the inner peripheral surface is shorter than the diameter of the through hole. Therefore, even if the liquid enters the space between the cover and the sensing surface through the through hole, the surface tension of the liquid can be used to suppress the liquid from entering the groove.

[0046] In the pressure sensor disclosed in Patent Document 1, the intrusion of liquid into the interior of the pressure sensor can be reduced by shortening the diameter of the through hole. However, if the diameter of the through hole is shortened, the flow of gas inside and outside the pressure sensor will change drastically, which will cause the time delay from the air pressure outside the pressure sensor to the membrane inside the pressure sensor to increase. According to this structure, as described above, even if liquid enters the space between the cover and the sensing surface through the through hole, it is possible to suppress the liquid from entering the groove, so there is no need to shorten the diameter of the through hole more than required. Therefore, the situation where the time delay increases as described above can be suppressed.

[0047] Alternatively, the beam side surface of the beam member facing the groove may have a beam convex portion. Alternatively, the outer peripheral surface may have an outer peripheral convex portion. Alternatively, the connecting side surface of the connecting portion facing the groove may have a connecting convex portion.

[0048] If liquid such as water enters the groove and causes the liquid to adhere to the beam member, the sensing part, the surrounding part, and the connecting part, the surface tension of the liquid may cause the beam member to stick to the outer peripheral surface of the sensing part, the inner peripheral surface of the surrounding part, and the connecting side surface of the connecting part, and the beam member and the like may still stick after drying. In this case, the beam member may not be able to fully play the function of the damping part. In this regard, according to this structure, a convex portion is provided on the beam side surface of the beam member, the outer peripheral surface of the sensing part, and the connecting side surface of the connecting part. Thus, even when the beam member is in contact with the sensing part, the surrounding part, and the connecting part, the contact area can be reduced. As a result, the above-mentioned sticking can be suppressed and the sticking condition can be maintained.

[0049] Alternatively, the beam side surface of the beam member facing the groove may have a first convex portion and a first concave portion, and the outer peripheral surface may have a second concave portion at a position opposite to the first convex portion, and a second convex portion at a position opposite to the first concave portion. In addition, the connecting side surface of the connecting portion facing the groove may have a third concave portion at a position opposite to the first convex portion, and a third convex portion at a position opposite to the first concave portion. According to this structure, the width of the groove can be set to be constant or approximately constant. Therefore, the squeeze film damping effect in the case where an impact acts on the peripheral portion from the outside of the pressure sensor can be kept constant at each position of the groove.

[0050] Alternatively, the damping portion includes a gel-like member occupying at least a portion of the groove. According to this structure, when an impact is applied to the peripheral portion from the outside of the pressure sensor, the gel-like member can be used to mitigate the impact from the peripheral portion to the sensing portion. In addition, according to this structure, liquid such as water can be prevented from entering the portion of the groove occupied by the gel-like member.

[0051] <First embodiment>

[0052] Figure 1 It is a perspective view of the pressure sensor according to the first embodiment of the present invention. Figure 2 yes Figure 1 Top view of the pressure sensor. Figure 3 It is along Figure 2 Cross-sectional view along line A-A in FIG. Figure 4 It is along Figure 2 Cross-sectional view of line B-B in .

[0053] like Figure 1As shown, the outer shape of the pressure sensor 1 of the first embodiment of the present invention is a rectangular parallelepiped. In the first embodiment, each side of the rectangular parallelepiped of the pressure sensor 1 is several hundred μm (for example, about 700 μm). The pressure sensor 1 senses tiny pressures and is a device composed of MEMS (Micro Electro Mechanical Systems). In addition, the pressure sensor 1 may also be a shape other than a rectangular parallelepiped, such as a cylindrical shape.

[0054] like Figure 1 to Figure 3 As shown in FIG. 1 , the pressure sensor 1 includes a base portion 10, a sensing portion 20, a peripheral portion 30, a connecting portion 40, and a beam member 50. The base portion 10, the sensing portion 20, the peripheral portion 30, the connecting portion 40, and the beam member 50 are integrally formed. The pressure sensor 1 is manufactured using a well-known semiconductor manufacturing process. Figure 1 to Figure 3 The base portion 10, the sensing portion 20, the peripheral portion 30, the connecting portion 40 and the beam member 50 are made of semiconductor materials such as silicon.

[0055] In the following description of each part of the pressure sensor 1, the directions of the sides of the rectangular parallelepiped of the pressure sensor 1 are defined as the length direction 2, the width direction 3, and the height direction 4. In the height direction 4, the base portion 10 side is defined as the bottom, and the sensing film 21 side of the sensing portion 20 is defined as the top.

[0056] like Figure 1 and Figure 3 As shown, the base portion 10 is in the shape of a rectangular parallelepiped plate. The lengths of the base portion 10 in the longitudinal direction 2 and the width direction 3 are longer than the length of the base portion 10 in the height direction 4 .

[0057] like Figure 3 As shown in FIG. 1 , the sensing unit 20 is formed above the base unit 10 and is spaced apart from the base unit 10. The sensing unit 20 and the base unit 10 are arranged opposite to each other with a space 60 therebetween in the height direction 4. Figure 2 As shown, the base portion 10 is supported by a peripheral portion 30 to be described later via a connecting portion 40 to be described later.

[0058] like Figure 1 and Figure 3 As shown, the sensing unit 20 is in the shape of a quadrangular prism. Figure 1 and Figure 2 As shown, the sensing portion 20 is located in the center of the pressure sensor 1 when viewed from above. The sensing portion 20 is a square when viewed from above. In the first embodiment, the length of each side of the square (the length in the length direction 2 and the width direction 3) is about 350 μm. In addition, the shape of the sensing portion 20 may be a shape other than a quadrangular prism, such as a cylindrical shape, and the size of the sensing portion 20 is not limited to the aforementioned size.

[0059] like Figure 3 As shown, the sensing portion 20 has a cavity 22 in its upper portion. The portion of the sensing portion 20 above the cavity 22 is a thinner sensing film 21. In the first embodiment, the thickness (length in the height direction 4) of the sensing film 21 is about 10 μm, but the thickness is not limited thereto. The lower surface of the sensing film 21 faces the cavity 22. The sensing surface 23, which is the upper surface of the sensing film 21, faces the outside of the pressure sensor 1. The sensing surface 23 is a surface located on the side opposite to the side where the base portion 10 is located in the height direction 4.

[0060] The sensing film 21 is deformed by the pressure applied to the sensing surface 23 from outside the pressure sensor 1, that is, from above. Thus, the sensing film 21 senses the pressure applied to the sensing surface 23. The physical quantity of the deformation of the sensing film 21 is converted into an electrical signal by an electrode or a strain gauge (not shown) built into the pressure sensor 1 or externally connected to the pressure sensor 1. An external device in which the pressure sensor 1 is installed or connected to the pressure sensor 1 detects pressure based on the electrical signal. Examples of the external device are smart watches, pedometers, altimeters, and the like.

[0061] like Figure 3 As shown, the peripheral portion 30 is erected upward from the base portion 10. The lower end of the peripheral portion 30 is connected to the upper end of the base portion 10. In the first embodiment, in the height direction 4, the upper end of the peripheral portion 30 is at the same or substantially the same position as the upper end of the sensing portion 20.

[0062] like Figure 1 and Figure 2 As shown, the peripheral portion 30 is formed on both sides of the sensing portion 20 in the length direction 2 and on both sides of the sensing portion 20 in the width direction 3. In a plan view, the peripheral portion 30 is formed to surround the sensing portion 20. The peripheral portion 30 is formed to leave a space between it and the sensing portion 20. The groove 70 is formed using this space.

[0063] like Figure 2 As shown in FIG. 1 , the groove 70 is formed around the sensing portion 20 in a top view. Figure 3 As shown, the lower end of the groove 70 is connected to the space 60. The groove 70 is located at a position closer to the inner side (sensing unit 20 side) than the outer edge of the space 60. In the first embodiment, the width of the groove 70, that is, the length of the groove 70 in the width direction orthogonal to both the height direction 4 and the direction in which the groove 70 extends, is preferably 15 μm or more and 20 μm or less. However, the width of the groove 70 is not limited to the above range.

[0064] like Figure 1 and Figure 2As shown, the connecting portion 40 extends in a manner of crossing the groove 70. One end of the connecting portion 40 is connected to the sensing portion 20. The other end of the connecting portion 40 is connected to the surrounding portion 30. The connecting portion 40 connects the sensing portion 20 and the surrounding portion 30. In the first embodiment, the connecting portion 40 extends from the sensing portion 20 along the longitudinal direction 2, and is bent at the front end portion in the longitudinal direction 2 and extends along the width direction 3 toward the surrounding portion 30. In addition, the shape of the connecting portion 40 is not limited to the curved shape as described above. For example, the connecting portion 40 may extend only in the width direction 3 in a manner of crossing the groove 70 extending in the longitudinal direction 2 along the width direction 3, or may extend only in the length direction 2 in a manner of crossing the groove 70 extending in the width direction 3 along the longitudinal direction 2.

[0065] like Figure 1 to Figure 3 As shown in FIG. 1 , the beam member 50 is provided in the groove 70. The beam member 50 is an example of a damping part. Figure 1 and Figure 2 As shown, the beam member 50 extends along the groove 70. One end 58 of the beam member 50 in the direction along the groove 70 is connected to a surface constituting one end of the groove 70 in the inner peripheral surface 31 of the peripheral portion 30.

[0066] In the first embodiment, the beam member 50 includes a column 51 and an elastic membrane 52 .

[0067] like Figure 1 and Figure 2 As shown, the post 51 is located at the curved portion of the slot 70. Figure 3 As shown, the column 51 is erected upward from the base 10. That is, the lower end of the column 51 is connected to the upper end of the base 10 and supported by the base 10. In the first embodiment, the upper end of the column 51 is at the same or substantially the same position as the upper ends of the sensing portion 20 and the surrounding portion 30 in the height direction 4. In the first embodiment, the column 51 is in the shape of a quadrangular prism. Figure 1 and Figure 2 As shown, the length of one side of the quadrilateral of the column 51, which is a quadrangular column, is shorter than the width of the groove 70. That is, there is a gap between the column 51 and the sensing portion 20 and the surrounding portion 30. In addition, the shape of the column 51 is not limited to a quadrangular column, and may be a cylindrical column, for example.

[0068] like Figure 1 and Figure 2 As shown, the elastic membrane 52 extends along the groove 70. Both ends of the elastic membrane 52 along the groove 70 are connected to the column 51. However, the portion of the end portion of the elastic membrane 52 along the groove 70 corresponding to the one end 58 of the beam member 50 is connected to the inner peripheral surface 31 of the peripheral portion 30 instead of being connected to the column 51.

[0069] like Figure 2 and Figure 3As shown, the width of the elastic membrane 52 is shorter than the width of the groove 70 and shorter than the length of one side of the quadrilateral of the column 51 which is a quadrangular prism. In the first embodiment, the elastic membrane 52 extends while maintaining gaps 55 and 56 between the elastic membrane 52 and the two side surfaces of the groove 70. The two side surfaces of the groove 70 are surfaces constituting both ends of the groove 70 in the width direction. The inner peripheral surface 31 of the peripheral portion 30 and the side surface 41 of the connecting portion 40 constitute the outer end of the groove 70. The outer peripheral surface 26 of the sensing portion 20 and the side surface 42 of the connecting portion 40 constitute the inner end of the groove 70. The gap 55 is the width of the groove 70 between the elastic membrane 52 and the inner end of the groove 70 (the outer peripheral surface 26 and the side surface 42). The gap 56 is the width of the groove 70 between the elastic membrane 52 and the outer end of the groove 70 (the inner peripheral surface 31 and the side surface 41). The outer peripheral surface 26 and the inner peripheral surface 31 face each other with the beam member 50 interposed therebetween. The side surface 41 and the outer peripheral surface 26 are opposed to each other via the beam member 50. The side surface 42 and the inner peripheral surface 31 are opposed to each other via the beam member 50.

[0070] The gaps 55 and 56 are longer than the gaps between the column 51 and the sensing portion 20 and the surrounding portion 30. The gaps 55 and 56 are preferably 10 μm or less. In the first embodiment, the gaps 55 and 56 are about 5 μm. In addition, the gaps 55 and 56 are not limited to the aforementioned lengths. In the first embodiment, the gaps 55 and 56 are equal in length, but may be different in length.

[0071] By arranging the beam member 50 in the groove 70, the space constituting the groove 70 is constituted by two spaces having two widths of about 5 μm. On the other hand, assuming that the beam member 50 is not arranged in the groove 70, the space constituting the groove 70 is constituted by one space having a width of 15 μm to 20 μm. That is, by arranging the beam member 50 in the groove 70, the width of one space constituting the groove 70 becomes smaller.

[0072] In the first embodiment, Figure 3 and Figure 4 As shown in FIG. 1 , the upper end of the elastic membrane 52 is at the same or substantially the same position as the upper end of the column 51 in the height direction 4. The lower end of the elastic membrane 52 is located above the lower end of the column 51 in the height direction 4. That is, the elastic membrane 52 is arranged with a gap between it and the base portion 10 in the height direction 4. Thus, the elastic membrane 52 is easily flexed in the width direction.

[0073] When an impact acts inward on the peripheral portion 30 from the outside of the pressure sensor 1, the peripheral portion 30 bends or deforms inward toward the sensing portion 20. At this time, in the above-mentioned space (gaps 55, 56) having a width of 5 μm, resistance to the inward movement of the peripheral portion 30 is generated due to the squeeze film damping effect. In addition, when the peripheral portion 30 that has moved inward contacts the elastic film 52, the elastic film 52 is pushed by the peripheral portion 30 and bends inward. At this time, an elastic force toward the outside is generated in the elastic film 52. This elastic force acts as resistance to the inward movement of the peripheral portion 30.

[0074] According to the first embodiment, when an impact acts on the peripheral portion 30 from the outside of the pressure sensor 1, the beam member 50 provided in the groove 70 mitigates the transmission of the impact from the peripheral portion 30 to the sensing portion 20. This can suppress the impact from the outside from reaching the sensing portion 20. As a result, the possibility of damage to the sensing portion 20 can be reduced.

[0075] According to the first embodiment, when an impact acts on the peripheral portion 30 from outside the pressure sensor 1 , the beam member 50 functions as a buffer. This can prevent the impact from the outside from reaching the sensing portion 20 .

[0076] According to the first embodiment, the gap between the peripheral portion 30 and the sensing portion 20 is shortened in accordance with the arrangement of the beam member 50 in the groove 70. Thus, when an impact acts on the peripheral portion 30 from the outside of the pressure sensor 1, resistance to the movement of the peripheral portion 30 toward the sensing portion 20 is generated due to the squeeze film damping effect, and thus the transmission of the impact to the sensing portion 20 can be reduced.

[0077] According to the first embodiment, the gap between the peripheral portion 30 and the sensing portion 20 is shortened in accordance with the arrangement of the beam member 50 in the groove 70. Thus, it is possible to suppress the intrusion of liquid such as water into the groove 70 by utilizing the surface tension of the liquid.

[0078] In the first embodiment, the elastic film 52 extends while maintaining gaps 55 and 56 between the elastic film 52 and the two side surfaces of the groove 70. However, the elastic film 52 may extend while maintaining a gap between the elastic film 52 and only one of the two side surfaces of the groove 70. In other words, the elastic film 52 may contact the inner end (outer peripheral surface 26 and side surface 42) of the groove 70. In this case, there is no gap 55 and only the gap 56 exists. In addition, the elastic film 52 may contact the outer end (inner peripheral surface 31 and side surface 41) of the groove 70. In this case, there is no gap 56 and only the gap 55 exists.

[0079] In the first embodiment, Figure 2As shown, the column 51 of the beam member 50 is located in the curved portion of the slot 70. However, the column 51 may also be located in the uncurved portion of the slot 70.

[0080] In the first embodiment, Figure 3 and Figure 4 As shown, the lower end of the elastic membrane 52 of the beam member 50 is located at the same position as the lower end of the sensing portion 20 and the upper end of the space 60 in the height direction 4. However, the lower end of the elastic membrane 52 may be located below the lower end of the sensing portion 20 and the upper end of the space 60, or may be located above the lower end of the sensing portion 20 and the upper end of the space 60.

[0081] In the first embodiment, the lower end of the elastic membrane 52 is located above the lower end of the column 51, but it may be located at the same position as the lower end of the column 51. In other words, the elastic membrane 52 may be connected to the upper end of the base 10 and supported by the base 10 like the column 51.

[0082] In the first embodiment, the beam member 50 includes the column 51 and the elastic membrane 52 , but the beam member 50 may not include the column 51 . In this case, at least a part of the elastic membrane 52 is supported by the base portion 10 .

[0083] <Second embodiment>

[0084] Figure 5 The pressure sensor according to the second embodiment of the present invention is Figure 3 Same cross-section view.

[0085] The pressure sensor of the second embodiment is different from the pressure sensor of the first embodiment in that Figure 5 The cover portion 80 is shown.

[0086] The cover 80 is in the shape of a rectangular plate. The lengths of the cover 80 in the longitudinal direction 2 and the width direction 3 are longer than the length of the cover 80 in the height direction 4. In the second embodiment, the cover 80 is made of a semiconductor material such as silicon, similarly to the base 10 and the like.

[0087] The cover 80 faces the sensing unit 20 and the peripheral unit 30 in the height direction 4 . The cover 80 is disposed above the sensing unit 20 with a gap therebetween. The cover 80 faces the sensing unit 20 with a space 90 therebetween in the height direction 4 .

[0088] The cover 80 is supported by the peripheral portion 30 around the sensing portion 20. In the second embodiment, a coupling portion 110 is arranged between the cover 80 and the peripheral portion 30 in the height direction 4. The coupling portion 110 is made of a metal material such as copper, a polymer material, or a glass material. The lower surface of the coupling portion 110 contacts the upper surface of the peripheral portion 30 from above. Thus, the coupling portion 110 is supported by the peripheral portion 30. The lower surface of the cover 80 contacts the upper surface of the coupling portion 110 from above. Thus, the cover 80 is supported by the peripheral portion 30 via the coupling portion 110.

[0089] In the second embodiment, the connecting portion 110 is a member independent of the cover portion 80 and the surrounding portion 30 , but the connecting portion 110 may be formed integrally with the cover portion 80 and the surrounding portion 30 .

[0090] The cover 80 has a through hole 81 that penetrates the cover 80 in the height direction 4. The through hole 81 is formed at a position facing the sensing surface 23 of the sensing film 21 of the sensing unit 20 in the height direction 4. The diameter 82 of the through hole 81 is longer than the width of the gaps 55 and 56 (5 μm in the second embodiment as in the first embodiment).

[0091] Furthermore, when the gaps 55 and 56 have different lengths, the diameter 82 of the through hole 81 is longer than the longer gap between the gaps 55 and 56 .

[0092] The pressure sensor disclosed in Patent Document 1 includes a cover that covers the sensing portion from above to prevent liquids such as water from entering the interior of the pressure sensor. However, since the pressure sensor disclosed in Patent Document 1 is an air pressure sensor, the external atmosphere and the sensing portion cannot be completely blocked. Therefore, in the pressure sensor disclosed in Patent Document 1, a through hole is formed in the cover for connecting the sensing portion with the atmosphere. Therefore, liquid enters the groove inside the pressure sensor through the through hole. In response to this, according to the second embodiment, the width of the gaps 55 and 56 is configured to be shorter than the diameter of the through hole 81. Therefore, even if the liquid enters the space 90 between the cover 80 and the sensing surface 23 through the through hole 81, the surface tension of the liquid can be used to suppress the liquid from entering the groove 70.

[0093] In the pressure sensor disclosed in Patent Document 1, the intrusion of liquid into the interior of the pressure sensor can be reduced by shortening the diameter of the through hole. However, if the diameter of the through hole is shortened, the flow of gas inside and outside the pressure sensor will change drastically, which will cause the time delay for the air pressure outside the pressure sensor to reach the membrane inside the pressure sensor to increase. According to the second embodiment, as described above, even if liquid enters the space 90 between the cover 80 and the sensing surface 23 through the through hole 81, it is possible to suppress the liquid from entering the groove 70, so there is no need to shorten the diameter of the through hole 81 more than required. Therefore, the situation where the time delay increases as described above can be suppressed.

[0094] <Third embodiment>

[0095] Figure 6 It is a top view of a pressure sensor according to a third embodiment of the present invention.

[0096] The pressure sensor of the third embodiment is different from the pressure sensor of the first embodiment in that Figure 6 The beam member 50 shown has a convex portion.

[0097] like Figure 6 As shown, the beam member 50 has a convex portion 53 on the side surface 54 of the elastic membrane 52. The side surface 54 of the elastic membrane 52 faces the groove 70 and is a surface opposite to both side surfaces (inner peripheral surface 31, outer peripheral surface 26, side surface 41, and side surface 42) of the groove 70. The side surface 54 of the elastic membrane 52 is an example of a beam side surface. The convex portion 53 is an example of a beam convex portion.

[0098] In the third embodiment, a plurality of protrusions 53 are formed at regular intervals in the direction in which the groove 70 extends. Each protrusion 53 extends from the upper end of the elastic membrane 52 to the lower end of the elastic membrane 52 along the height direction 4. The cross section of each protrusion 53 is a rectangle. In other words, each protrusion 53 is in the shape of a quadrangular prism.

[0099] If liquid such as water enters the groove 70 and causes the liquid to adhere to the beam member 50, the sensing part 20, the surrounding part 30, and the connecting part 40, the surface tension of the liquid may cause the beam member 50 to adhere to the outer peripheral surface 26 of the sensing part 20, the inner peripheral surface 31 of the surrounding part 30, and the side surfaces 41 and 42 of the connecting part 40, and the beam member 50 and the like are still adhered after drying. In this case, the beam member 50 may not be able to fully play the function as a damping part. In this regard, according to the third embodiment, the beam member 50 has a convex portion 53 on the side surface 54. Thus, even when the beam member 50 contacts the sensing part 20, the surrounding part 30, and the connecting part 40, the contact area can be reduced. As a result, the above-mentioned adhesion can be suppressed and the adhesion can be maintained.

[0100] In the third embodiment, the projections 53 are formed at constant intervals in the direction in which the grooves 70 extend, but the intervals may not be constant.

[0101] In the third embodiment, Figure 6 As shown, the shapes and sizes of the plurality of protrusions 53 are the same, but the shapes and sizes of the protrusions 53 may be different.

[0102] In the third embodiment, Figure 6 As shown, the convex portion 53 is formed on substantially the entire area of ​​the elastic film 52 of the beam member 50, but the convex portion 53 may be formed only on a part of the elastic film 52. For example, the convex portion 53 may be located only near the curved portion of the groove 70.

[0103] The number of protrusions 53 can be Figure 6 The number shown is less, but can also be Figure 6 For example, the elastic membrane 52 between two pillars 51 may be provided with only one protrusion 53 .

[0104] In the third embodiment, each convex portion 53 is in the shape of a quadrangular prism, but the shape is not limited to a quadrangular prism. For example, each convex portion 53 may be in the shape of a triangular prism (see Fig. 9 ), or a semi-cylindrical shape.

[0105] In the third embodiment, the convex portion 53 extends from the upper end to the lower end of the elastic film 52, but the present invention is not limited thereto and may be provided only in a portion of the region between the upper end and the lower end of the elastic film 52. For example, the convex portion 53 may be a hemispherical protrusion.

[0106] In the third embodiment, the convex portion 53 extends along the height direction 4 , but the convex portion 53 may extend along a direction other than the height direction 4 .

[0107] The shape of the beam member 50 is not limited to Figure 6 and Fig. 9 For example, it is also possible to Fig.10 As shown in FIG. 1 , the elastic film 52 is in a wave shape in a plan view. In this case, the portion of the wave shape that is curved so as to shorten the distance between the two side surfaces of the groove 70 corresponds to the convex portion 53 .

[0108] <Fourth embodiment>

[0109] Figure 7 It is a top view of a pressure sensor according to a fourth embodiment of the present invention.

[0110] The pressure sensor of the fourth embodiment is different from the pressure sensor of the first embodiment in that Figure 7The sensing portion 20 and the connecting portion 40 shown have convex portions.

[0111] like Figure 7 As shown, the sensing part 20 has a convex part 24 on the outer peripheral surface 26, and the connecting part 40 has a convex part 44 on the side surfaces 41 and 42. The outer peripheral surface 26 and the side surfaces 41 and 42 face the groove 70 and are surfaces opposite to the two side surfaces 54 of the beam member 50. The side surfaces 41 and 42 are examples of connecting side surfaces. The convex part 24 is an example of an outer peripheral convex part. The convex part 44 is an example of a connecting convex part.

[0112] In the fourth embodiment, a plurality of convex portions 24 are formed at regular intervals in the direction in which the groove 70 extends. Each convex portion 24 extends from the upper end of the sensing portion 20 to the lower end of the sensing portion 20 along the height direction 4. The cross section of each convex portion 24 is a rectangle. In other words, each convex portion 24 is in the shape of a quadrangular prism.

[0113] In the fourth embodiment, a plurality of convex portions 44 are formed at regular intervals in the direction in which the groove 70 extends. Each convex portion 44 extends from the upper end of the connecting portion 40 to the lower end of the connecting portion 40 along the height direction 4. The cross section of each convex portion 44 is a rectangle. In other words, each convex portion 44 is in the shape of a quadrangular prism.

[0114] If liquid such as water enters the groove 70 and causes the liquid to adhere to the beam member 50, the sensing part 20, the surrounding part 30, and the connecting part 40 arranged in the groove 70, the beam member 50 may be attached to the outer peripheral surface 26 of the sensing part 20, the inner peripheral surface 31 of the surrounding part 30, and the side surfaces 41 and 42 of the connecting part 40 due to the surface tension of the liquid, and the beam member 50 and the like may still be attached after drying. In this case, the beam member 50 may not fully function as a damping part. In this regard, according to the fourth embodiment, the sensing part 20 has a convex portion 24 on the outer peripheral surface 26, and the connecting part 40 has a convex portion 44 on the side surfaces 41 and 42. Thus, even when the beam member 50 contacts the sensing part 20, the surrounding part 30, and the connecting part 40, the contact area can be reduced. As a result, the above-mentioned sticking can be suppressed and the sticking can be maintained.

[0115] In the fourth embodiment, the projections 24 and 44 are formed at a constant interval in the direction in which the groove 70 extends, but the intervals may not be constant.

[0116] In the fourth embodiment, Figure 7 As shown, the plurality of protrusions 24 and 44 have the same shape and size, but the shapes and sizes of the protrusions 24 and 44 may be different.

[0117] In the fourth embodiment, Figure 7As shown in the figure, the convex portion 24 is formed in the range of substantially the entire area of ​​the outer peripheral surface 26, but the convex portion 24 may be formed only in a partial area of ​​the outer peripheral surface 26. For example, the convex portion 24 may be formed only in both ends of the length direction 2 or the width direction 3 of the outer peripheral surface 26. Similarly, in the fourth embodiment, the convex portion 44 is formed in the range of substantially the entire area of ​​the side surfaces 41 and 42, but the convex portion 44 may be formed only in a partial area of ​​the side surfaces 41 and 42.

[0118] The number of protrusions 24 can be Figure 7 The number shown is less, but can also be Figure 7 For example, only one convex portion 24 may be provided on each peripheral surface 26. Similarly, the number of convex portions 44 may be greater than Figure 7 The number shown is less, but can also be Figure 7 Quantities shown are large.

[0119] In the fourth embodiment, each convex portion 24, 44 is in a quadrangular prism shape, but the shape is not limited to a quadrangular prism shape. For example, each convex portion 24, 44 may be in a triangular prism shape or a semi-cylindrical shape.

[0120] In the fourth embodiment, the convex portion 24 extends from the upper end of the sensing portion 20 to the lower end of the sensing portion 20, but the present invention is not limited thereto, and the convex portion 24 may be provided only in a portion of the region between the upper end and the lower end of the sensing portion 20. Similarly, the convex portion 44 extends from the upper end of the connecting portion 40 to the lower end of the connecting portion 40, but the present invention is not limited thereto, and the convex portion 44 may be provided only in a portion of the region between the upper end and the lower end of the connecting portion 40. For example, the convex portions 24 and 44 may be hemispherical protrusions.

[0121] In the fourth embodiment, the convex portions 24 and 44 extend along the height direction 4 , but the convex portions 24 and 44 may extend along a direction other than the height direction 4 .

[0122] The outer peripheral surface 26 and the side surfaces 41 and 42 are not limited to Figure 7 The plane shown can also be, for example Fig.10 In this case, the portion of the corrugated surface that protrudes toward the beam member 50 corresponds to the convex portions 24 and 44.

[0123] <Fifth embodiment>

[0124] Figure 8 It is a top view of a pressure sensor according to a fifth embodiment of the present invention.

[0125] The pressure sensor of the fifth embodiment is different from the pressure sensor of the first embodiment in that Figure 8The beam member 50 has a convex portion, and the sensing portion 20 and the connecting portion 40 have convex portions. That is, the pressure sensor according to the fifth embodiment is an embodiment in which the third embodiment and the fourth embodiment described above are combined.

[0126] like Figure 8 As shown, the beam member 50 has the same convex portion 53 as in the third embodiment on the side surface 54 of the elastic film 52. The sensing portion 20 has the same convex portion 24 as in the fourth embodiment on the outer peripheral surface 26, and the connecting portion 40 has the same convex portion 44 as in the fourth embodiment on the side surfaces 41 and 42.

[0127] In the fifth embodiment, the convex portions formed on the two opposing surfaces do not face each other.

[0128] To explain in detail, in the direction in which the groove 70 extends, the convex portion 53 (an example of the first convex portion) of the beam member 50 that faces the outer peripheral surface 26 of the sensing portion 20 faces the concave portion 25 (an example of the second concave portion) formed between two adjacent convex portions 24 in the outer peripheral surface 26. In addition, in the direction in which the groove 70 extends, the convex portion 53 of the beam member 50 that faces the side surface 41 of the connecting portion 40 faces the concave portion 45 (an example of the third concave portion) formed between two adjacent convex portions 44 in the side surface 41. In addition, in the direction in which the groove 70 extends, the convex portion 53 of the beam member 50 that faces the side surface 42 of the connecting portion 40 faces the concave portion 45 (an example of the third concave portion) formed between two adjacent convex portions 44 in the side surface 42.

[0129] Furthermore, in the direction in which the groove 70 extends, the convex portion 24 (an example of a second convex portion) of the sensing portion 20 that faces the side surface 54 of the beam member 50 faces the concave portion 57 (an example of a first concave portion) formed between two adjacent convex portions 53 in the side surface 54 of the beam member 50. Furthermore, in the direction in which the groove 70 extends, the convex portion 44 (an example of a third convex portion) of the connecting portion 40 that faces the side surface 54 of the beam member 50 faces the concave portion 57 formed between two adjacent convex portions 53 in the side surface 54 of the beam member 50.

[0130] That is, in the fifth embodiment, the side surface 54 of the beam member 50 facing the groove 70 has the convex portion 53 and the concave portion 57. In addition, the outer peripheral surface 26 of the sensing portion 20 has the convex portion 24 and the concave portion 25. In addition, the side surfaces 41 and 42 of the connecting portion 40 have the convex portion 44 and the concave portion 45, respectively. The convex portion 24 is located opposite to the concave portion 57. The concave portion 25 is located opposite to the convex portion 53. The convex portion 44 is located opposite to the concave portion 57. The concave portion 45 is located opposite to the convex portion 53.

[0131] According to the fifth embodiment, the width of the groove 70 can be made constant or substantially constant. Therefore, the squeeze film damping effect when an impact acts on the peripheral portion 30 from the outside of the pressure sensor 1 can be kept constant at each position of the groove 70 .

[0132] In the fifth embodiment, convex parts 24 and 44 are respectively located opposite to concave part 57, and concave parts 25 and 45 are respectively located opposite to convex part 53. However, convex parts 24 and 44 may not be opposite to concave part 57, and concave parts 25 and 45 may not be opposite to convex part 53.

[0133] The convex parts 53 of the fifth embodiment may have various shapes, positions, and numbers as in the third embodiment. The convex parts 24 and 44 of the fifth embodiment may have various shapes, positions, and numbers as in the fourth embodiment.

[0134] In the fifth embodiment, the elastic film 52 may be in a corrugated shape as in the third embodiment, and the outer peripheral surface 26 and the side surfaces 41 and 42 may be corrugated surfaces as in the fourth embodiment. In this case, it is preferred that the side surface 54 of the corrugated elastic film 52 is parallel to the corrugated surface. In other words, it is preferred that the convex portion (an example of the first convex portion) of the side surface 54 of the corrugated elastic film 52 is opposite to the concave portion (an example of the second concave portion and the third concave portion) of the corrugated surface, and the concave portion (an example of the first concave portion) of the corrugated elastic film 52 is opposite to the convex portion (an example of the second convex portion and the third convex portion) of the corrugated surface.

[0135] <Sixth embodiment>

[0136] Fig.11 A pressure sensor according to a sixth embodiment of the present invention Figure 3 Same cross-section view.

[0137] The pressure sensor of the sixth embodiment is different from the pressure sensor of the first embodiment in that Fig.11 The groove 70 is filled with a gel-like member 100 instead of the beam member 50 provided in the groove 70. The gel-like member 100 is an example of a damping portion.

[0138] like Fig.11 As shown, the gel-like member 100 occupies the entire space 60 and the groove 70. The liquid surface of the gel-like member 100 is in the same plane or substantially in the same plane as the sensing surface 23. In addition, the gel-like member 100 may occupy only a portion of the space 60 and the groove 70. For example, the liquid surface of the gel-like member 100 may be located between the upper end and the lower end of the groove 70 in the height direction 4. That is, the gel-like member 100 occupies at least a portion of the groove 70.

[0139] The minimum value of the elastic modulus of the gel-like member 100 is 0.5 kPa according to the complex elastic modulus at room temperature. Preferably, the minimum value of the elastic modulus of the gel-like member 100 is 1 kPa according to the complex elastic modulus at room temperature. More preferably, the minimum value of the elastic modulus of the gel-like member 100 is 2 kPa according to the complex elastic modulus at room temperature. The maximum value of the elastic modulus of the gel-like member 100 is 30 kPa according to the complex elastic modulus at room temperature. Preferably, the maximum value of the elastic modulus of the gel-like member 100 is 10 kPa according to the complex elastic modulus at room temperature. More preferably, the maximum value of the elastic modulus of the gel-like member 100 is 5 kPa according to the complex elastic modulus at room temperature. In addition, the normal temperature is a range of above 0°C and below 45°C.

[0140] The gel-like member 100 is preferably made of a material having fluorine or silicon as a base material, but is not limited thereto as long as the material satisfies the above-mentioned elastic modulus.

[0141] According to the sixth embodiment, when an impact acts on the peripheral portion 30 from the outside of the pressure sensor 1 , the gel-like member 100 can mitigate the transmission of the impact from the peripheral portion 30 to the sensing portion 20 .

[0142] According to the sixth embodiment, since the interior of the groove 70 is occupied by the gel-like member 100 , it is possible to prevent liquid such as water from entering the groove 70 .

[0143] In addition, any of the various embodiments described above can be appropriately combined to achieve the effects possessed by each. For example, the first embodiment described above and the sixth embodiment can be combined. In this case, the beam member 50 is provided in the groove 70 and the groove 70 is filled with the gel-like member 100.

[0144] Although the present invention has been fully described in connection with the preferred embodiments with appropriate reference to the accompanying drawings, various modifications and variations will be apparent to those skilled in the art, and such modifications and variations are to be understood as being included therein as long as they do not depart from the scope of the present invention as defined by the appended claims.

[0145] Description of Reference Numerals

[0146] 1. Pressure sensor; 4. Height direction; 10. Base; 20. Sensing part; 23. Sensing surface; 24. Protrusion (outer convex part, second convex part); 25. Concave part (second concave part); 26. Outer circumferential surface; 30. Peripheral part; 31. Inner circumferential surface; 40. Connecting part; 44. Protrusion (connecting convex part, third convex part); 45. Concave part (third concave part); 50. Beam member (damping part); 53. Protrusion (beam convex part, first convex part); 55. Gap; 56. Gap; 57. Concave part (first concave part); 60. Space; 70. Groove; 80. Cover; 81. Through hole; 90. Space; 100. Gel-like member (damping part).

Claims

1. A pressure sensor, wherein: The pressure sensor includes: Base part; a sensing portion disposed opposite to the base portion in a height direction with a space therebetween, and sensing a pressure applied to a sensing surface on a side opposite to a side where the base portion is located in the height direction; a peripheral portion which is erected from the base portion in the height direction and is configured to surround the sensing portion via a groove formed around the sensing portion; a connecting portion connecting the sensing portion and the surrounding portion; and The damping part is provided in the groove and applies resistance to the peripheral part moving toward the sensing part.

2. The pressure sensor according to claim 1, wherein: The sensing portion includes an outer peripheral surface opposite to the surrounding portion, The peripheral portion includes an inner peripheral surface opposite to the outer peripheral surface, The groove is formed between the outer peripheral surface and the inner peripheral surface, The damper portion includes a beam member supported by the base portion, having a gap between the beam member and at least one of the outer peripheral surface and the inner peripheral surface and extending along the groove.

3. The pressure sensor according to claim 2, wherein: The pressure sensor further includes a cover portion, the cover portion is arranged opposite to the sensing surface with a space therebetween, the cover portion is supported by the peripheral portion, and a through hole is formed at a position opposite to the sensing surface. A width of a longer gap among the gap between the damper portion and the outer peripheral surface and the gap between the damper portion and the inner peripheral surface is shorter than a diameter of the through hole.

4. The pressure sensor according to claim 2 or 3, wherein: The beam member has a beam protrusion on a beam side surface facing the groove.

5. The pressure sensor according to any one of claims 2 to 4, wherein: The outer peripheral surface has an outer peripheral convex portion.

6. The pressure sensor according to any one of claims 2 to 5, wherein: The connecting portion has a connecting protrusion on a connecting side surface facing the groove.

7. The pressure sensor according to claim 2 or 3, wherein: The beam side surface of the beam member facing the groove has a first convex portion and a first concave portion, The outer peripheral surface has a second recessed portion at a position facing the first recessed portion, and has a second recessed portion at a position facing the first recessed portion.

8. The pressure sensor according to claim 7, wherein: The connecting portion has a connecting side surface facing the groove having a third recessed portion at a position facing the first recessed portion, and has a third recessed portion at a position facing the first recessed portion.

9. The pressure sensor according to any one of claims 1 to 8, wherein: The damping portion includes a gel-like member occupying at least a portion of the groove.

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