Pressure sensing device

Abstract

The embodiment of the utility model discloses a pressure sensing device. The pressure sensing device comprises a substrate; the shell is arranged on one side of the substrate, a containing cavity is defined by the shell and the substrate, a window is formed in the shell, and the window communicates with the containing cavity; the pressure sensitive assembly is arranged on the base plate and contained in the containing cavity, the pressure sensitive assembly comprises a substrate and a device structure layer which are arranged in a stacked mode, and a cavity is formed between the substrate and the device structure layer; the pressing convex part is accommodated in the window, and the pressing convex part is connected with one side, deviating from the substrate, of the device structure layer through the first dielectric layer; in the thickness direction of the substrate, the orthographic projection of the pressing convex part on the substrate is located in the range of the orthographic projection of the cavity on the substrate; the side, away from the substrate, of the pressing protruding part is arranged on the shell in a protruding mode. According to the utility model, the sensitivity and the reliability are improved, and the production process difficulty and the production cost are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of micro-electromechanical sensors, in particular to a pressure sensing device. Background Art

[0002] At present, consumer electronic products such as toys, mobile phones, tablets, and headphones are increasingly moving towards intelligence, and more and more sensors are added to them to be able to sense more physical quantities. Among them, the demand for measuring stress or pressure generated by human body contact, especially fingers, is also gradually increasing. Some special requirements are put forward for sensors used to detect force or pressure. First, a film that can effectively transmit pressure or force to the pressure sensor chip is required. Secondly, the various parts on the chip must be protected from damage. Furthermore, a small size must be maintained to meet the trend of miniaturization of portable products.

[0003] The existing force sensors based on micro-electro-mechanical system (MEMS) technology are piezoresistive and capacitive. Piezoresistive is usually implemented in three ways: 1) Metal eutectic bonding. For example, a silicon wafer with MEMS graphics and a wafer acting as a silicon cap are metal eutectic bonded, and then wire bonded and encapsulated. However, this eutectic bonding requires expensive equipment and is costly. 2) During the packaging process, the piezoresistive chip forms a rolling stainless steel ball as a pressure-bearing component. The packaging is used to control the position and force limit of the steel ball to solve the problem of membrane rupture caused by overpressure. However, the packaging process is relatively complex, and has high requirements and high costs. 3) During the packaging process of the piezoresistive chip, an additional layer of hard resin is added to the sensitive membrane or the packaging shell. Although the cost is low, the resin material will cause pressure hysteresis, nonlinearity, and reliability problems, affecting the performance of the pressure sensor. Utility Model Content

[0004] The embodiments of the present invention provide a pressure sensing device to improve sensitivity and reliability and reduce production process difficulty and production cost.

[0005] In order to solve the above technical problems, the embodiments of the present utility model disclose the following technical solutions:

[0006] In one aspect, a pressure sensing device is provided, comprising:

[0007] substrate;

[0008] A shell, which is arranged on one side of the substrate, the shell and the substrate together form a receiving cavity, and a window is provided on the shell, and the window is communicated with the receiving cavity;

[0009] A pressure sensitive component, which is arranged on the substrate and accommodated in the accommodating cavity, the pressure sensitive component comprises a substrate and a device structure layer which are stacked, and a cavity is arranged between the substrate and the device structure layer;

[0010] A pressing protrusion is accommodated in the window and connected to the side of the device structure layer away from the substrate through a first dielectric layer; in the thickness direction of the substrate, the orthographic projection of the pressing protrusion on the substrate is located within the range of the orthographic projection of the cavity on the substrate; and the side of the pressing protrusion away from the substrate is convexly arranged on the shell.

[0011] In addition to one or more of the features disclosed above, or as an alternative, the pressure sensitive component also includes a varistor, which is embedded in the surface of the device structure layer on the side facing away from the substrate; in the thickness direction of the substrate, the orthographic projection of the varistor on the substrate is accommodated within the orthographic projection of the cavity on the substrate.

[0012] In addition to one or more of the features disclosed above, or as an alternative, the pressure sensitive component also includes a second dielectric layer, which is sandwiched between the device structure layer and the substrate; the second dielectric layer has the cavity, and the cavity penetrates the second dielectric layer along the thickness direction of the second dielectric layer.

[0013] In addition to or as an alternative to one or more of the features disclosed above, a surface of the substrate facing the device structure layer is provided with a groove sunken along the thickness direction thereof, and the groove is configured to form the cavity.

[0014] In addition to or as an alternative to one or more features disclosed above, the substrate has a back cavity penetrating along its thickness direction, the base plate is provided with a through hole penetrating along its thickness direction, and the cavity is connected to the through hole through the back cavity.

[0015] In addition to or as an alternative to one or more of the features disclosed above, the second dielectric layer has at least one channel, the channel connects the cavity and the accommodating cavity, and an extension direction of the channel is perpendicular to a thickness direction of the substrate.

[0016] In addition to or as an alternative to one or more of the features disclosed above, the second dielectric layer includes a second peripheral portion and a second central portion separated from each other, the second peripheral portion surrounds the outer periphery of the second central portion, and the cavity is formed between the second peripheral portion and the second central portion;

[0017] The first dielectric layer includes a first dielectric layer body and a through region penetrating along the thickness direction of the first dielectric layer body; in the thickness direction of the substrate, the orthographic projection of the first dielectric layer body on the substrate is accommodated within the orthographic projection of the cavity on the substrate.

[0018] In addition to or as an alternative to one or more of the features disclosed above, in a thickness direction of the substrate, the cavity has a height h satisfying 1 μm≤h≤2 μm.

[0019] In addition to or as an alternative to one or more of the features disclosed above, the invention further includes a signal processing chip, wherein the signal processing chip is disposed on the substrate and accommodated in the accommodation cavity.

[0020] In addition to or as an alternative to one or more of the features disclosed above, the pressure sensitive component further comprises:

[0021] a third dielectric layer, the third dielectric layer being arranged on a side of the device structure layer away from the substrate;

[0022] A pad, the pad being arranged on a surface of the third dielectric layer on a side facing away from the substrate;

[0023] A lead is connected between the pad and the varistor.

[0024] In another aspect, another pressure sensing device is provided, comprising:

[0025] substrate;

[0026] A shell is arranged on one side of the substrate, the shell and the substrate are combined to form a receiving cavity, a window is arranged on the shell, and the window is communicated with the receiving cavity; the shell has a first surface on a side away from the substrate;

[0027] A pressure sensitive component, which is arranged on the substrate and accommodated in the accommodating cavity, the pressure sensitive component comprises a substrate and a device structure layer which are stacked, and a cavity is arranged between the substrate and the device structure layer;

[0028] A pressing protrusion is accommodated in the window and connected to the side of the device structure layer away from the substrate through a first dielectric layer; the first dielectric layer includes a first peripheral portion and a first central portion separated from each other, and the first peripheral portion surrounds the outer periphery of the first central portion; in the thickness direction of the substrate, the orthographic projection of the first peripheral portion on the substrate overlaps with the orthographic projection of the second dielectric layer on the substrate, and the orthographic projection of the first central portion on the substrate is accommodated in the orthographic projection of the cavity on the substrate; the side of the pressing protrusion away from the substrate is convexly arranged on the shell.

[0029] In addition to one or more of the features disclosed above, or as an alternative, the pressure sensitive component also includes a varistor, which is embedded in the surface of the device structure layer on the side facing away from the substrate; in the thickness direction of the substrate, the orthographic projection of the varistor on the substrate is accommodated within the orthographic projection of the cavity on the substrate.

[0030] One of the above technical solutions has the following advantages or beneficial effects: the pressure sensing device of the present application installs the pressing protrusion at a position corresponding to the cavity on the pressure sensitive component through the first dielectric layer to serve as a pressure-bearing component, thereby improving sensitivity and reliability, and reducing the difficulty of the production process and production cost. Specifically, compared with the method of forming a pressure-bearing component by metal eutectic bonding in the prior art, the present application has the advantages of low equipment requirements and low production costs. Compared with the method of using stainless steel balls as pressure-bearing components in the prior art, the present application has the advantages of simple manufacturing process. Compared with the method of using hard resin as a pressure-bearing component in the prior art, the present application has the advantages of higher sensitivity and better reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The technical solutions and other beneficial effects of the present invention will be made apparent by describing in detail the specific embodiments of the present invention in conjunction with the accompanying drawings.

[0032] Figure 1 It is a structural schematic diagram of a pressure sensing device provided according to the first embodiment of the utility model;

[0033] Figure 2 It is a structural schematic diagram of a pressure sensing device provided in Embodiment 1 of the present utility model under the action of external pressure;

[0034] Figure 3 It is a structural schematic diagram of a pressure sensing device provided according to the second embodiment of the utility model;

[0035] Figure 4 It is a structural schematic diagram of a pressure sensing device provided according to the third embodiment of the utility model;

[0036] Figure 5 It is a structural schematic diagram of a pressure sensing device provided according to the fourth embodiment of the utility model;

[0037] Figure 6 It is a top view of a second medium layer in a pressure sensing device provided according to the first embodiment of the utility model;

[0038] Figure 7 It is a top view of a second medium layer in a pressure sensing device provided according to the fourth embodiment of the utility model;

[0039] Figure 8 It is a top view of a second medium layer in a pressure sensing device provided according to the fourth embodiment of the utility model;

[0040] Fig. 9 It is a structural schematic diagram of a pressure sensing device provided according to Embodiment 5 of the present utility model;

[0041] Fig.10 It is a perspective view of a second medium layer in a pressure sensing device provided according to Embodiment 5 of the present utility model;

[0042] Fig.11 It is a structural schematic diagram of a pressure sensing device provided according to the sixth embodiment of the utility model;

[0043] Fig.12 is a perspective view of a first medium layer in a pressure sensing device provided according to Embodiment 6 of the present utility model;

[0044] Fig.13 It is a structural schematic diagram of a pressure sensing device provided according to Embodiment 7 of the present utility model;

[0045] In the figure: 110-substrate; 112-groove; 113-back cavity; 120-second dielectric layer; 1201-second peripheral portion; 1202-second central portion; 121-cavity; 122-channel; 130-device structure layer; 150-third dielectric layer; 160-varistor; 170-pad; 171-lead; 180-first wire;

[0046] 210 - pressing convex part; 220 - first dielectric layer; 221 - first peripheral part; 222 - first central part; 223 - annular groove; 2201 - first dielectric layer body; 2202 - through area;

[0047] 300-substrate; 310-through hole;

[0048] 400-housing; 410-gap; 401-accommodating cavity;

[0049] 500 - signal processing chip; 501 - second wire. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and beneficial effects of the utility model clearer, the utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific implementation methods described in this specification are only for explaining the utility model, and are not intended to limit the utility model.

[0051] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present utility model, the meaning of "multiple" refers to two or more, unless otherwise clearly and specifically defined.

[0052] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0053] In the present utility model, unless otherwise clearly stipulated and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0054] See also Figure 1 , Figure 1The schematic diagram of the structure of a pressure sensing device provided according to the first embodiment of the present invention is shown. The pressure sensing device provided in the first embodiment of the present application comprises: a substrate 300, a shell 400, a pressure sensitive component and a pressing protrusion 210. The substrate 300 is a plate-shaped structure. The substrate 300 has a first surface and a second surface relative to each other in the thickness direction. The shell 400 is arranged on the first surface of the substrate 300. The shell 400 is fixedly connected to the substrate 300 to form a receiving cavity 401. A window communicating with the receiving cavity 401 is arranged on the side of the shell 400 away from the substrate 300. The pressure sensitive component is arranged on the first surface of the shell 400 and received in the receiving cavity 401. The pressure sensitive component is used to sense the magnitude of the pressure. In the thickness direction of the substrate 300, the orthographic projection of the window on the substrate 300 is located within the range of the orthographic projection of the pressure sensitive component on the substrate 300. The pressing protrusion 210 is arranged on the side of the pressure sensitive component away from the substrate 300. The pressing protrusion 210 is connected to the pressure sensitive component through the first dielectric layer 220. The pressing protrusion 210 is at least partially exposed from the above-mentioned window. The side of the pressing protrusion 210 facing away from the substrate 300 is protruded from the housing 400 so that the outside can transmit pressure to the pressure sensitive component through the pressing protrusion 210 .

[0055] Specifically, the pressure sensitive component includes a substrate 110, a second dielectric layer 120, a device structure layer 130, a piezoresistor 160 and a third dielectric layer 150 which are sequentially arranged in a stacked manner along the thickness direction of the substrate 300. The material of the substrate 110 is usually silicon, and the second dielectric layer 120 is sandwiched between the substrate 110 and the device structure layer 130. A cavity 121 is provided in the second dielectric layer 120, and the cavity 121 penetrates the second dielectric layer 120 along the thickness direction of the second dielectric layer 120. Therefore, the height of the cavity 121 is determined by the thickness of the second dielectric layer 120. The cavity 121 provides a deformation space for the deformation of the device structure layer 130, and can also limit the deformation area to avoid damage caused by excessive deformation of the device structure layer 130. The part of the device structure layer 130 facing the cavity 121 is a pressure sensitive area, so the length and width of the cavity 121 determine the length and width of the pressure sensitive area. Four varistors 160 are embedded on the surface of the device structure layer 130 facing away from the substrate 110. In the thickness direction of the substrate 110, the orthographic projection of the varistor 160 on the substrate 110 is located within the range of the orthographic projection of the cavity 121 on the substrate 110. The varistor 160 is arranged in the pressure sensitive area of ​​the device structure layer 130. The four varistors 160 form a Wheatstone bridge. When the pressure sensitive area of ​​the device structure layer 130 is deformed, the varistor 160 outputs a signal about the pressure value of the device structure layer 130. The third dielectric layer 150 is arranged on the surface of the device structure layer 130 facing away from the substrate 110 and covers the varistor 160. The third dielectric layer 150 protects the varistor 160 and the second dielectric layer 120. The third dielectric layer 150 can be a single dielectric layer, or a silicon oxide layer or a silicon nitride layer, or a composite dielectric layer, such as a silicon oxide-silicon nitride composite layer, or a silicon oxide-silicon nitride-silicon oxide composite layer.

[0056] Furthermore, the depth h of the cavity 121 and the thickness t of the second dielectric layer 120 satisfy h=t, 1 μm≤h≤2 μm.

[0057] In this embodiment, the pressure sensitive component further includes a lead 171 and a pad 170, the pad 170 is disposed on a surface of the third dielectric layer 150 on a side away from the substrate 110, the pad 170 is electrically connected to the varistor 160 through the lead 171, and the lead 171 is buried in the device structure layer 130 and the third dielectric layer 150. The material of the lead 171 includes one or more of aluminum, copper, gold or platinum.

[0058] Specifically, the varistor 160 is formed by lightly doping at least a portion of the device structure layer 130 with boron, and the lead 171 is formed by heavily doping at least a portion of the device structure layer 130 .

[0059] In this embodiment, the pressure sensing device further includes a first wire 180 , and the pad 170 is electrically connected to the substrate 300 via the first wire 180 , so as to realize signal output from the pressure sensitive component to the circuit in the substrate 300 .

[0060] Continue to refer to Figure 1 As shown, the pressing protrusion 210 is arranged on the side of the pressure sensitive component away from the substrate 300, and the pressing protrusion 210 is connected to the third dielectric layer 150 in the pressure sensitive component through the first dielectric layer 220. The material of the first dielectric layer 220 can be silicon oxide, and the first dielectric layer 220 is bonded to the third dielectric layer 150. The material of the first dielectric layer 220 can also be glue, and the pressing protrusion 210 is bonded to the surface of the third dielectric layer 150 through the first dielectric layer 220 with viscosity. In the thickness direction of the substrate 110, the orthographic projection of the pressing protrusion 210 on the substrate 110 is located within the range where the orthographic projection of the cavity 121 on the substrate 110 is located. The material of the pressing protrusion 210 includes a hard material with relatively high rigidity, such as silicon or metal. The deformation amount of the pressing protrusion 210 when it is compressed is extremely small, and the pressure can directly act on the pressure sensitive component through the pressing protrusion 210, so that the pressure sensing device of the present application has better sensitivity. The pressing protrusion 210 made of hard material makes the signal output by the pressure sensitive component change linearly with the increase of pressure, thereby improving the reliability of the pressure sensing device of the present application.

[0061] In some embodiments, the shape of the pressing component includes a cube or a cylinder, and the shape of the window is adapted to the shape of the pressing component.

[0062] Specifically, the aperture of the window is aperture D1, and the diameter of the pressing component is diameter D2, satisfying D1>D2, so that while the pressing component is accommodated in the window, there is a gap between the pressing component and the shell 400 to avoid the pressing component from contacting the arc shell 400, so that the friction force generated between the two affects the output signal of the pressure sensitive component.

[0063] Furthermore, the material of the shell 400 includes one or more of metal material and resin material, and the shell 400 including the metal material has an anti-interference effect.

[0064] For example, in combination Figure 2As shown, when the pressure is applied to the pressure-bearing component in the thickness direction of the substrate 110, the pressure is transmitted to the device structure layer 130 in the pressure-sensitive component through the pressing component, and the pressure-sensitive area in the device structure layer 130 is deformed toward the substrate 110 due to the pressure. The cavity 121 provides a deformation space for the pressure-sensitive area. The piezoresistors 160 arranged in the pressure-sensitive area sequentially output signals about the pressure magnitude through the leads 171, the pads 170, and the first wires 180 to the circuit on the substrate 300. When the pressure exceeds a preset threshold, the pressure-sensitive area in the device structure layer 130 abuts against the substrate 110, and the pressure-sensitive area no longer continues to deform, so as to limit the pressure-sensitive area and prevent the pressure-sensitive area from being damaged by the pressure exceeding the range.

[0065] The pressure sensing device of the present application installs the pressing protrusion 210 on the pressure sensitive component at a position corresponding to the cavity 121 through the first dielectric layer 220 to serve as a pressure-bearing component, thereby improving sensitivity and reliability, and reducing the difficulty of the production process and production cost. Specifically, compared with the method of forming a pressure-bearing component by metal eutectic bonding in the prior art, the present application has the advantages of low equipment requirements and low production costs. Compared with the method of using stainless steel balls as pressure-bearing components in the prior art, the present application has the advantages of simple manufacturing process. Compared with the method of using hard resin as a pressure-bearing component in the prior art, the present application has the advantages of higher sensitivity and better reliability.

[0066] Reference Figure 3 As shown, Figure 3 The schematic diagram of the structure of a pressure sensing device provided according to the second embodiment of the utility model is shown. Compared with the first embodiment, the pressure sensitive component in the second embodiment includes a substrate 110, a device structure layer 130, a piezoresistor 160 and a third dielectric layer 150 which are sequentially stacked in a thickness direction of the substrate 300. The substrate 110 is directly connected to the device structure layer 130, and a groove 112 which is recessed in the thickness direction of the substrate 110 is provided on a surface of the substrate 110 facing the device structure layer 130, and the groove 112 is configured to form the cavity 121.

[0067] Furthermore, the depth h of the cavity 121 satisfies 1 μm≤h≤2 μm.

[0068] Specifically, the groove 112 is formed by dry etching or wet etching.

[0069] Reference Figure 4 As shown, Figure 4The schematic diagram of the structure of a pressure sensing device provided according to the third embodiment of the utility model is shown. Compared with the first embodiment, the substrate 110 in the third embodiment has a back cavity 113 running through its thickness, and the back cavity 113 is connected to the cavity 121 in the second dielectric layer 120. The substrate 300 has a through hole 310 running through its thickness direction, and the pressure sensitive component covers the through hole 310, and the through hole 310 is connected to the back cavity 113 in the substrate 110, so that the cavity 121 can be connected to the external environment through the back cavity 113 and the through hole 310 in turn. The cavity 121 in the first embodiment is formed by the substrate 110, the second dielectric layer 120 and the device structure layer 130. The cavity 121 in the first embodiment is a closed chamber. In the absence of external pressure, there is already an atmospheric pressure acting on the pressure sensing device. However, in some fields with relatively high precision requirements, such as medical and industrial control, changes in the air pressure of the external environment will affect the output of the pressure sensing device. The back cavity 113 and the through hole 310 in the third embodiment enable the cavity 121 to communicate effectively with the external environment, thereby reducing the influence of changes in the atmospheric pressure in the external environment on the pressure signal output by the pressure sensing device of the present application, and further improving the reliability of the present application.

[0070] Reference Figure 5 As shown, Figure 5 A schematic structural diagram of a pressure sensing device provided according to a fourth embodiment of the utility model is shown. Compared with the first embodiment, the second dielectric layer 120 in the fourth embodiment has at least one channel 122, and the channel 122 connects the cavity 121 and the accommodating cavity 401, and the extension direction of the channel 122 is perpendicular to the thickness direction of the substrate 110.

[0071] like Figure 6 As shown, Figure 6 A top view of a first dielectric layer 220 in a pressure sensing device provided according to the first embodiment of the present invention is shown. The cavity 121 in the first embodiment penetrates the second dielectric layer 120 along the thickness direction of the second dielectric layer 120. The cavity 121 in the first embodiment is formed by the substrate 110, the second dielectric layer 120 and the device structure layer 130. The cavity 121 in the first embodiment is a closed chamber.

[0072] Combination Figure 5 , Figure 7 and Figure 8 As shown, Figure 7 and Figure 8According to a top view of a second dielectric layer 120 in a pressure sensing device provided in Embodiment 4 of the utility model, in Embodiment 4, the top view of the second dielectric layer 120 is a square structure, the second dielectric layer 120 has four centrally symmetrical channels 122, the extension directions of adjacent channels 122 are perpendicular to each other, and the four channels 122 are cross-arranged or diagonally arranged in the second dielectric layer 120.

[0073] In other embodiments, the arrangement direction of the channels 122 may be a straight-line arrangement or other arrangement methods, and the number of the channels 122 may be more than four or less than four, which is not specifically limited herein.

[0074] In this embodiment, the channel 122 penetrates the second dielectric layer 120 along the thickness direction of the second dielectric layer 120, and the second dielectric layer 120, the substrate 110 and the device structure layer 130 are together formed to enclose the channel 122. In other embodiments, the channel 122 is buried in the second dielectric layer 120, which is not specifically limited here.

[0075] In this embodiment, the cavity 121 and the channel 122 are formed as one body, and the method of forming the cavity 121 and the channel 122 includes dry etching, wet etching or photolithography.

[0076] The channel 122 and the through hole 310 in the fourth embodiment allow the cavity 121 to communicate effectively with the external environment through the accommodating cavity 401 and the gap between the pressing protrusion 210 and the housing 400, reducing the influence of the change of atmospheric pressure in the external environment on the pressure signal output by the pressure sensing device of the present application, and further improving the reliability of the present application. In addition, the fourth embodiment only needs to form the channel 122 in the second dielectric layer 120 to achieve the communication between the cavity 121 and the external environment, without forming the back cavity 113 in the substrate 110 and forming the through hole 310 on the substrate 300 as in the third embodiment. The pressure sensing device in the fourth embodiment has a simple process and is friendly to packaging.

[0077] Reference Fig. 9 As shown, Fig. 9 The schematic diagram of the structure of a pressure sensing device provided according to the fifth embodiment of the utility model is shown. Compared with the first embodiment, the second dielectric layer 120 in the fifth embodiment includes a second peripheral portion 1201 and a second central portion 1202 separated from each other. The second peripheral portion 1201 surrounds the outer periphery of the second central portion 1202, and an annular cavity 121 is formed between the second peripheral portion 1201 and the second central portion 1202. The first dielectric layer 220 includes a first dielectric layer body 2201 and a through region 2202 penetrating along the thickness direction thereof. The first dielectric layer body 2201 is an annular structure. Fig.10 As shown, Fig.10A perspective view of the second dielectric layer 120 and the first dielectric layer 220 in Example 5 is shown. In the thickness direction of the substrate 110, the orthographic projection of the first dielectric layer body 2201 on the substrate 110 is located within the range of the orthographic projection of the cavity 121 on the substrate 110, the orthographic projection of the second center portion 1202 on the substrate 110 is located within the range of the orthographic projection of the through region 2202 on the substrate 110, and the orthographic projection of the varistor 160 on the substrate 110 is located within the range of the orthographic projection of the first dielectric layer body 2201 on the substrate 110.

[0078] Specifically, when the pressing protrusion 210 in the fifth embodiment is subjected to external pressure along the thickness direction of the substrate 110, the pressure is transmitted through the annular first dielectric layer body 2201 to act on the pressure sensitive area of ​​the device structure layer 130 corresponding to the first dielectric layer body 2201, and the pressure sensitive area is deformed toward the direction of the cavity 121 by force, and the piezoresistor 160 corresponding to the pressure sensitive area outputs a signal about the pressure. In the fifth embodiment, the area of ​​the first dielectric layer body 2201 that causes the device structure layer 130 to deform and the cavity 121 for the pressure sensitive area in the device structure layer 130 to deform are reduced compared to those in the first embodiment, so that the deformation amount of the pressure sensitive area in this embodiment is greatly reduced compared to the pressure sensitive area in the first embodiment when subjected to the same pressure, so that the pressure sensing device of the present application can be applied to higher range pressure detection without changing the size of the pressure sensitive area in the device structure layer 130 and the height of the cavity 121.

[0079] Reference Fig.11 As shown, Fig.11 The structure diagram of a pressure sensing device according to the sixth embodiment of the present invention is shown. Compared with the first embodiment, the first dielectric layer 220 in the sixth embodiment includes a first peripheral portion 221 and a first central portion 222 separated from each other. The first peripheral portion 221 surrounds the outer periphery of the first central portion 222, and an annular groove 223 is formed between the first peripheral portion 221 and the first central portion 222. Fig.12 As shown, Fig.12 A perspective view of the first dielectric layer 220 in the sixth embodiment is shown. In the thickness direction of the substrate 110, the orthographic projection of the first peripheral portion 221 on the substrate overlaps with the orthographic projection of the second dielectric layer 120 on the substrate. The orthographic projection of the cavity 121 on the substrate 110 is located within the range of the orthographic projection of the pressing protrusion 210 on the substrate 110. The orthographic projection of the first central portion 222 on the substrate 110 is located within the range of the orthographic projection of the cavity 121 on the substrate 110. The orthographic projection of the varistor 160 on the substrate 110 is located within the range of the orthographic projection of the annular groove 223 on the substrate 110.

[0080] Specifically, when the pressing protrusion 210 in the sixth embodiment is subjected to external pressure along the thickness direction of the substrate 110, the outer edge of the pressing protrusion 210 is supported by the first peripheral portion 221 in the first dielectric layer 220 and the second dielectric layer 120, and the central area of ​​the pressing protrusion 210 corresponding to the first central portion 222 of the first dielectric layer 220 is deformed. Since the pressing protrusion 210 is made of a hard material with greater rigidity, the deformation of the central area of ​​the pressing protrusion 210 is small, and the deformation of the first central portion 222 of the first dielectric layer 220 and the pressure sensitive area in the device structure layer 130 corresponding to the central area of ​​the pressing protrusion 210 is also small, so that the pressure sensing device of the present application can be suitable for higher range pressure detection without changing the size of the pressure sensitive area in the device structure layer 130 and the height of the cavity 121.

[0081] Reference Fig.12 As shown, Fig.12 The structure diagram of a pressure sensing device provided according to the seventh embodiment of the utility model is shown. Compared with the first embodiment, the pressure sensing device in the seventh embodiment further includes a signal processing chip 500, which is arranged on the first surface of the substrate 300 and accommodated in the accommodating cavity 401. The signal processing chip 500 is electrically connected to the substrate 300 through a second wire 501. The pressure sensing device in the seventh embodiment can be calibrated by the signal processing chip 500, and the signal output by the pressure sensitive component is processed into a signal of a specific output interface, which is convenient for customers to use and further improves the functionality of the present application.

[0082] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A pressure sensing device, characterized in that: include: substrate; A shell, which is arranged on one side of the substrate, the shell and the substrate together form a receiving cavity, and a window is provided on the shell, and the window is communicated with the receiving cavity; A pressure sensitive component, which is arranged on the substrate and accommodated in the accommodating cavity, the pressure sensitive component comprises a substrate and a device structure layer which are stacked, and a cavity is arranged between the substrate and the device structure layer; A pressing protrusion, the pressing protrusion is accommodated in the window, and the pressing protrusion is connected to a side of the device structure layer away from the substrate through a first dielectric layer; In the thickness direction of the substrate, the orthographic projection of the pressing protrusion on the substrate is located within the range of the orthographic projection of the cavity on the substrate; and the side of the pressing protrusion facing away from the substrate is convexly arranged on the shell.

2. The pressure sensing device according to claim 1, characterized in that: The pressure sensitive component also includes a varistor, which is embedded in a surface of the device structure layer on a side away from the substrate; in the thickness direction of the substrate, the orthographic projection of the varistor on the substrate is contained within the orthographic projection of the cavity on the substrate.

3. The pressure sensing device according to claim 1, characterized in that: The pressure sensitive component further includes a second dielectric layer, which is sandwiched between the device structure layer and the substrate; the second dielectric layer has the cavity, and the cavity penetrates the second dielectric layer along the thickness direction of the second dielectric layer.

4. The pressure sensing device according to claim 1, characterized in that: A groove sunken along the thickness direction of the substrate is provided on one side of the substrate facing the device structure layer, and the groove is configured to form the cavity.

5. The pressure sensing device according to claim 1, characterized in that: The substrate has a back cavity penetrating along the thickness direction thereof, the base plate is provided with a through hole penetrating along the thickness direction thereof, and the cavity is connected with the through hole through the back cavity.

6. The pressure sensing device according to claim 3, characterized in that: The second dielectric layer has at least one channel, the channel connects the cavity and the accommodating cavity, and an extending direction of the channel is perpendicular to a thickness direction of the substrate.

7. The pressure sensing device according to claim 3, characterized in that: The second dielectric layer comprises a second peripheral portion and a second central portion separated from each other, the second peripheral portion surrounds the outer periphery of the second central portion, and the cavity is formed between the second peripheral portion and the second central portion; The first dielectric layer includes a first dielectric layer body and a through region penetrating along the thickness direction of the first dielectric layer body; in the thickness direction of the substrate, the orthographic projection of the first dielectric layer body on the substrate is accommodated within the orthographic projection of the cavity on the substrate.

8. The pressure sensing device according to claim 1, wherein: In the thickness direction of the substrate, the cavity has a height h satisfying 1 μm≤h≤2 μm.

9. The pressure sensing device according to claim 1, characterized in that: It also includes a signal processing chip, which is arranged on the substrate and accommodated in the accommodating cavity.

10. The pressure sensing device according to claim 2, characterized in that: The pressure sensitive component also includes: a third dielectric layer, the third dielectric layer being disposed on a side of the device structure layer away from the substrate; A pad, the pad being arranged on a surface of the third dielectric layer on a side facing away from the substrate; A lead is connected between the pad and the varistor.

11. A pressure sensing device, characterized in that: include: substrate; A shell is arranged on one side of the substrate, the shell and the substrate are combined to form a receiving cavity, a window is arranged on the shell, and the window is communicated with the receiving cavity; the shell has a first surface on a side away from the substrate; A pressure sensitive component, which is arranged on the substrate and accommodated in the accommodating cavity, the pressure sensitive component comprises a substrate and a device structure layer which are stacked, and a cavity is arranged between the substrate and the device structure layer; A pressing protrusion is accommodated in the window and connected to the side of the device structure layer away from the substrate through a first dielectric layer; the first dielectric layer includes a first peripheral portion and a first central portion separated from each other, and the first peripheral portion surrounds the outer periphery of the first central portion; in the thickness direction of the substrate, the orthographic projection of the first peripheral portion on the substrate overlaps with the orthographic projection of the second dielectric layer on the substrate, and the orthographic projection of the first central portion on the substrate is accommodated in the orthographic projection of the cavity on the substrate; the side of the pressing protrusion away from the substrate is convexly arranged on the shell.

12. The pressure sensing device according to claim 11, characterized in that: The pressure sensitive component also includes a varistor, which is embedded in a surface of the device structure layer on a side away from the substrate; in the thickness direction of the substrate, the orthographic projection of the varistor on the substrate is contained within the orthographic projection of the cavity on the substrate.

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