Pressure sensor and electronic equipment

Abstract

An embodiment of the utility model discloses a pressure sensor and an electronic device, the pressure sensor comprises a substrate, a diaphragm, a support structure and a backboard which are stacked, the substrate is provided with a first cavity penetrating through the substrate, the support structure is provided with a second cavity penetrating through the support structure, and the diaphragm is arranged in the first cavity. The projection of the first cavity on the vibrating diaphragm is overlapped with the projection of the second cavity on the vibrating diaphragm. Wherein the back plate is provided with a plurality of release holes penetrating through the back plate, a dry film is attached to the surface of the side, away from the vibrating diaphragm, of the back plate, the dry film covers each release hole, the dry film is provided with a plurality of blocking protruding blocks in a protruding mode, the blocking protruding blocks correspond to the release holes in a one-to-one mode, and the corresponding release holes are filled with the blocking protruding blocks. According to the invention, the dry film is adhered to the surface of the side, deviating from the vibrating diaphragm, of the back plate, the dry film can directly cover the release hole and seal the second release hole, and even if the aperture of the release hole is large, the dry film can also seal the second release hole. And meanwhile, the plugging bump is filled in the release hole, so that the plugging stability is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of pressure sensors, in particular to a pressure sensor and electronic equipment. Background Art

[0002] A capacitive pressure sensor consists of a substrate, a diaphragm, and a backplate. Its working principle is to utilize the bending of the diaphragm under the action of pressure difference, resulting in a change in capacitance value, and then detect this change through an electronic circuit and output a corresponding pressure difference signal. In order to allow the diaphragm to deform freely when it senses pressure, a cavity is usually provided between the diaphragm and the backplate. The existing technology usually sets a sacrificial structure between the diaphragm and the backplate. After the backplate is manufactured, multiple release holes are made on the backplate. The corrosive liquid corrodes the sacrificial structure through the release holes on the backplate to form a cavity between the diaphragm and the backplate. In order to prevent the diaphragm from entering the cavity in the electronic device and damaging it, the release holes usually need to be sealed after the cavity is formed.

[0003] Existing semiconductor processes use thin film deposition to seal release holes. Due to process characteristics, the sidewall deposition thickness is generally thinner than the horizontal deposition thickness, and the insulating material deposition thickness is generally less than 5μm. Therefore, when the release hole diameter is large, relying on thin film deposition to seal the hole is difficult. Utility Model Content

[0004] The embodiments of the present invention provide a pressure sensor and an electronic device, so as to provide a technical solution capable of effectively blocking a release hole with a large aperture.

[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 sensor is provided, comprising: a stacked substrate, a diaphragm, a support structure, and a backplate, wherein the substrate has a first cavity extending therethrough, and the support structure has a second cavity extending therethrough, wherein, in a stacking direction, a projection of the first cavity on the diaphragm and a projection of the second cavity on the diaphragm overlap;

[0007] Among them, the back plate is provided with a plurality of release holes that pass through the back plate, and a dry film is attached to the surface of the back plate facing away from the diaphragm, and the dry film covers each of the release holes, and the dry film is provided with a plurality of blocking protrusions protruding toward the back plate, and the blocking protrusions correspond to the release holes one by one and fill the corresponding release holes.

[0008] In addition to or as an alternative to one or more of the features disclosed above, the dry film and the blocking protrusion are integrally formed, and a side of the blocking protrusion facing the diaphragm is located in the corresponding release hole.

[0009] In addition to one or more of the features disclosed above, or as an alternative, the blocking protrusion has an edge portion and a center portion connected to each other, the center portion is located within the edge portion, the edge portion is connected to the hole wall of the corresponding release hole, and on the side facing the diaphragm, the distance between the edge portion and the diaphragm is smaller than the distance between the center portion and the diaphragm.

[0010] In addition to or as an alternative to one or more of the features disclosed above, the side of the back plate facing the diaphragm is provided with an anti-sticking protrusion protruding toward the diaphragm.

[0011] In addition to one or more of the features disclosed above, or as an alternative, the dry film and the sealing protrusion are formed integrally, the side of the sealing protrusion facing the diaphragm protrudes from the side of the back plate facing the diaphragm, and the side of the sealing protrusion facing the diaphragm is farther away from the diaphragm than the side of the anti-sticking protrusion facing the diaphragm.

[0012] In addition to or as an alternative to one or more features disclosed above, the backplane includes a conductive structure and an insulating structure arranged along the stacking direction, the insulating structure is connected to the supporting structure, and the release hole passes through the conductive structure and the insulating structure.

[0013] In addition to one or more features disclosed above, or as an alternative, the invention further includes a first electrical connection structure and a second electrical connection structure, wherein the first electrical connection structure is electrically connected to the diaphragm, and the second electrical connection structure is electrically connected to the conductive structure.

[0014] In addition to one or more of the features disclosed above, or as an alternative, the present invention further includes a pressure equalizing hole that penetrates the back plate and the diaphragm along the stacking direction, and the back plate and the diaphragm both have open ends facing the pressure equalizing hole. The pressure sensor also includes a sealing portion, which extends along the hole wall of the pressure equalizing hole to close the open end and the second cavity located between the back plate and the diaphragm.

[0015] On the other hand, an electronic device is provided, comprising any pressure sensor disclosed above.

[0016] One of the above technical solutions has the following advantages or beneficial effects: before being cured, the dry film material has a certain viscosity and fluidity, but its fluidity is low, and after being heated or irradiated with a light source, the dry film material will solidify and lose its fluidity. In the present application, by adhering the dry film to the surface of the back plate facing away from the diaphragm, the dry film can directly cover the release hole and close the second release hole. Even if the aperture of the release hole is large, the dry film can still block it. At the same time, because the dry film before being cured has low fluidity, the dry film can enter the release hole along the hole wall of the release hole and adhere to the hole wall of the release hole to form a blocking bump, thereby improving the stability of the blockage and avoiding the blockage failure caused by the movement of the dry film due to external force or environmental changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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.

[0018] Figure 1 This is a schematic diagram of a pressure sensor structure provided by this application Figure 1 ;

[0019] Figure 2 This is a schematic diagram of a pressure sensor structure provided by this application Figure 2 ;

[0020] Figure 3 yes Figure 1 Magnified view of point A.

[0021] Description of reference numerals:

[0022] 10. substrate; 11. first cavity;

[0023] 20. Diaphragm;

[0024] 30. Support structure; 31. Second cavity;

[0025] 40. Back plate; 41. Release hole; 42. Anti-sticking bump; 43. Insulation structure; 44. Conductive structure;

[0026] 50, dry film; 51, blocking bump; 511, edge; 512, center;

[0027] 60. Pressure equalizing hole;

[0028] 70. First electrical connection structure; 71. Second electrical connection structure. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and beneficial effects of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described in this specification are only for the purpose of explaining the present invention and are not intended to limit the present invention.

[0030] In the description of the present invention, 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, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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 limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the 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 invention, the meaning of "multiple" refers to two or more, unless otherwise clearly and specifically defined.

[0031] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections, direct connections, or indirect connections through an intermediate medium; they may refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0032] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0033] The utility model discloses a pressure sensor, referring to Figure 1The pressure sensor includes a stacked substrate 10, a diaphragm 20, a support structure 30, and a backplate 40. The substrate 10 has a first cavity 11 extending through it, and the support structure 30 has a second cavity 31 extending through it. In the stacking direction, the projection of the first cavity 11 on the diaphragm 20 overlaps with the projection of the second cavity 31 on the diaphragm 20. The first cavity 11 and the second cavity 31 on either side of the diaphragm 20 together form a deformation space for the diaphragm 20, allowing it to deform freely when it senses pressure.

[0034] Furthermore, the second cavity 31 is typically formed by removing a portion of the support structure 30. In the embodiment disclosed herein, the back plate 40 is provided with a plurality of release holes 41 extending therethrough. These release holes 41 are used to remove a portion of the support structure 30 to form the second cavity 31 for the diaphragm 20 to deform. After the second cavity 31 is formed, a dry film 50 is attached to the surface of the back plate 40 facing away from the diaphragm 20 in the embodiment of the present application. The dry film 50 covers each release hole 41, and the dry film 50 has a plurality of blocking bumps 51 protruding toward the back plate 40. These blocking bumps 51 correspond one-to-one with the release holes 41 and fill the corresponding release holes 41. Specifically, the dry film 50 has a certain viscosity and low fluidity before curing. When the dry film 50 is laid on the side of the back plate 40 facing away from the diaphragm 20, so that it covers the side of the back plate 40 facing away from the diaphragm 20, the uncured dry film 50 can flow into the release hole 41 along the hole wall of the release hole 41 and adhere to the hole wall of the release hole 41 to form a blocking bump 51. Because the dry film 50 has low fluidity, it will not drip onto the diaphragm 20 after curing in time. Therefore, the dry film 50 can block the release hole 41 with a larger aperture without damaging the diaphragm 20. The dry film 50 adheres to the hole wall of the release hole 41 to form the blocking bump 51, which can also improve the stability of the blockage and prevent the blockage from failing due to external force or environmental changes causing the dry film 50 to move. As can be seen from the above, the dry film 50 and the blocking protrusion 51 are integrally formed. In different embodiments, the blocking protrusion 51 blocks the release hole 41 to different degrees. In some embodiments, the side of the blocking protrusion 51 facing the diaphragm 20 is located in the corresponding release hole 41, that is, the blocking protrusion 51 does not completely block the release hole 41 (refer to FIG. Figure 1 ). Specifically, refer to Figure 3 The blocking protrusion 51 has an edge portion 511 and a center portion 512 connected to each other. The center portion 512 is located inside the edge portion 511. The edge portion 511 is connected to the hole wall of the corresponding release hole 41. When the side of the blocking protrusion 51 facing the diaphragm 20 is located inside the corresponding release hole 41, the distance between the edge portion 511 and the diaphragm 20 on the side facing the diaphragm 20 is smaller than the distance between the center portion 512 and the diaphragm 20. In some embodiments, referring to Figure 2The side of the back plate 40 facing the diaphragm 20 is provided with an anti-sticking bump 42 protruding toward the diaphragm 20. The dry film 50 and the blocking bump 51 are integrally formed. The side of the blocking bump 51 facing the diaphragm 20 protrudes from the side of the back plate 40 facing the diaphragm 20. The side of the blocking bump 51 facing the diaphragm 20 is further away from the diaphragm 20 than the side of the anti-sticking bump 42 facing the diaphragm 20. In other words, the blocking bump 51 completely blocks the release hole 41 and protrudes from the surface of the back plate 40 facing the diaphragm 20. The anti-sticking bump 42 prevents the diaphragm 20 and the back plate 40 from being attracted to each other.

[0035] Furthermore, in some embodiments, the backplate 40 has a double-layer structure. Specifically, the backplate 40 includes a conductive structure 44 and an insulating structure 43 arranged along the stacking direction. The insulating structure 43 is connected to the support structure 30, and the release hole 41 passes through the conductive structure 44 and the insulating structure 43. In this arrangement, the conductive structure 44 constitutes the fixed electrode of the pressure sensor, and the diaphragm 20 constitutes the movable electrode of the pressure sensor. The presence of the insulating structure 43 ensures that even if the diaphragm 20 contacts the backplate 40 during deformation or vibration, it will not cause an electrical short circuit.

[0036] Furthermore, the pressure sensor also includes a first electrical connection structure 70 and a second electrical connection structure 71. The first electrical connection structure 70 is electrically connected to the diaphragm 20, and the second electrical connection structure 71 is electrically connected to the conductive structure 44. Specifically, a first conductive hole can be opened, and the first conductive hole can pass through the back plate 40 and the support structure 30. The first conductive hole can also pass through the back plate 40, and the back plate 40 and the diaphragm 20 are sealed at the opening facing the first conductive hole. The diaphragm 20 is exposed in the first conductive hole. The first electrical connection structure 70 is connected to the diaphragm 20 exposed in the first conductive hole and is exposed at the first conductive hole. The second electrical connection structure 71 can be provided on the side surface of the conductive structure 44 facing away from the diaphragm 20, and the dry film 50 does not cover the second electrical connection structure 71.

[0037] In some embodiments, the pressure sensor also includes a pressure equalizing hole 60 that passes through the back plate 40 and the diaphragm 20 along the stacking direction, and both the back plate 40 and the diaphragm 20 have open ends facing the pressure equalizing hole 60. The pressure sensor also includes a sealing portion that extends along the hole wall of the pressure equalizing hole 60 to close the open end and the second cavity 31 located between the back plate 40 and the diaphragm 20. Furthermore, the sealing portion can be composed of the material for manufacturing the insulating structure 43, the material for manufacturing the conductive structure 44, and the material for manufacturing the dry film 50. When the pressure sensor is actually manufactured, the insulating structure 43 and the conductive structure 44 are both deposited on the support structure 30. First, a through hole connecting the first cavity 11 and the outside is opened on the support structure 30. When the insulating structure 43 and the conductive structure 44 are deposited, the material for manufacturing the insulating structure 43 and the material for manufacturing the conductive structure 44 both extend along the hole wall of the through hole. Finally, after part of the support structure 30 is removed through the release hole 41 to form the second cavity 31, when the dry film 50 is made to block the release hole 41, the material of the dry film 50 also extends along the hole wall of the through hole, and finally a sealing portion is formed for closing the open end and the second cavity 31 located between the back plate 40 and the diaphragm 20.

[0038] An embodiment of the present utility model further discloses an electronic device, comprising any one of the pressure sensors disclosed above.

[0039] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above 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.

[0040] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A pressure sensor, characterized in that: include: A substrate (10), a diaphragm (20), a support structure (30), and a back plate (40) are stacked, wherein the substrate (10) has a first cavity (11) extending through the substrate, and the support structure (30) has a second cavity (31) extending through the substrate, and in a stacking direction, a projection of the first cavity (11) on the diaphragm (20) and a projection of the second cavity (31) on the diaphragm (20) overlap. The back plate (40) is provided with a plurality of release holes (41) penetrating the back plate (40), and a dry film (50) is attached to the surface of the back plate (40) on the side facing away from the diaphragm (20), and the dry film (50) covers each of the release holes (41), and the dry film (50) is provided with a plurality of blocking protrusions (51) protruding toward the back plate (40), and the blocking protrusions (51) correspond to the release holes (41) one by one and fill the corresponding release holes (41).

2. The pressure sensor according to claim 1, wherein The dry film (50) and the blocking protrusion (51) are integrally formed, and the side of the blocking protrusion (51) facing the diaphragm (20) is located in the corresponding release hole (41).

3. The pressure sensor according to claim 2, wherein: The blocking protrusion (51) has an edge portion (511) and a center portion (512) connected to each other, the center portion (512) is located inside the edge portion (511), the edge portion (511) is connected to the hole wall of the corresponding release hole (41), and on the side facing the diaphragm (20), the distance between the edge portion (511) and the diaphragm (20) is smaller than the distance between the center portion (512) and the diaphragm (20).

4. The pressure sensor according to claim 1, wherein An anti-sticking protrusion (42) is provided on a side of the back plate (40) facing the diaphragm (20) and convexly facing the diaphragm (20).

5. The pressure sensor according to claim 4, characterized in that The dry film (50) and the blocking protrusion (51) are integrally formed, and the side of the blocking protrusion (51) facing the diaphragm (20) protrudes from the side of the back plate (40) facing the diaphragm (20), and the side of the blocking protrusion (51) facing the diaphragm (20) is farther away from the diaphragm (20) than the side of the anti-sticking protrusion (42) facing the diaphragm (20).

6. The pressure sensor according to claim 1, wherein The back plate (40) comprises a conductive structure (44) and an insulating structure (43) arranged along the stacking direction, the insulating structure (43) is connected to the support structure (30), and the release hole (41) passes through the conductive structure (44) and the insulating structure (43).

7. The pressure sensor according to claim 6, characterized in that It also includes a first electrical connection structure (70) and a second electrical connection structure (71), wherein the first electrical connection structure (70) is electrically connected to the diaphragm (20), and the second electrical connection structure (71) is electrically connected to the conductive structure (44).

8. The pressure sensor according to claim 1, wherein The pressure sensor further includes a pressure equalizing hole (60) that passes through the back plate (40) and the diaphragm (20) along the stacking direction, and the back plate (40) and the diaphragm (20) both have open ends facing the pressure equalizing hole (60). The pressure sensor further includes a sealing portion that extends along the hole wall of the pressure equalizing hole (60) to close the open end and a second cavity (31) located between the back plate (40) and the diaphragm (20).

9. An electronic device, characterized in that: The device comprises a pressure sensor as claimed in any one of claims 1 to 8.

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