Waterproof barometer

Abstract

The application discloses a waterproof air pressure gauge, which comprises a base plate, an air pressure sensing assembly and a shell, one side of the base plate is provided with a containing groove; the air pressure sensing assembly comprises a MEMS chip and an ASIC chip, the ASIC chip is installed in the containing groove and connected with the bottom wall of the containing groove, and the MEMS is arranged on the side of the ASIC chip away from the bottom wall of the containing groove; the shell is arranged on the periphery of the containing groove and is sealingly connected with the base plate, and the shell is provided with a gas permeable hole; the containing groove is filled with wrapping glue, and the wrapping glue is solidified to cover the ASIC chip. In the application, the gas permeable hole is arranged to ensure that the internal space is consistent with the external environment air pressure, the wrapping glue is filled in the containing groove to protect the pads of the ASIC chip, the reliability of the air pressure gauge is ensured, and the sensing end of the MEMS chip is exposed to the wrapping glue, so that the air pressure detection precision is ensured.

Description

Technical Field

[0001] This invention relates to the field of barometer technology, and more particularly to a waterproof barometer. Background Technology

[0002] Smartphones need to be equipped with barometers for emergency call positioning, enabling fire protection system customers to quickly locate the geographical location and floor. This requires the barometer product to have an accuracy within ±36Pa to meet the ±3m height measurement requirement. Because smartphones have many applications, to ensure the barometer maintains its measurement accuracy in various scenarios, it must be waterproof, dustproof, and corrosion-resistant. Currently, there are two main waterproof, dustproof, and corrosion-resistant designs in the industry. The first is to use waterproof adhesive to fill and protect the chip and packaging materials. This solution results in lower measurement accuracy due to the introduction of the waterproof adhesive. The second is to use a waterproof and breathable membrane solution. However, this waterproof and breathable membrane cannot prevent corrosive gases from affecting the chip and internal packaging materials, leading to poor barometer reliability.

[0003] Therefore, it is necessary to provide a new waterproof barometer to solve the above-mentioned technical problems. Summary of the Invention

[0004] The main objective of this invention is to provide a waterproof barometer, which aims to solve the problems of low measurement accuracy and susceptibility to corrosion affecting the reliability of existing barometers.

[0005] To achieve the above objectives, the waterproof barometer proposed in this invention includes a substrate, a pressure sensing component, a housing, and a waterproof and breathable membrane. A receiving groove is formed on one side of the substrate. The pressure sensing component includes a MEMS chip and an ASIC chip. The ASIC chip is mounted within the receiving groove and connected to the bottom wall of the receiving groove. The MEMS chip is disposed on the side of the ASIC chip away from the bottom wall of the receiving groove. The housing covers the periphery of the receiving groove and is sealed to the substrate. A vent is formed on the housing. The receiving groove is filled with an adhesive, which cures to encapsulate the ASIC chip, with the sensing end of the MEMS chip exposed in the adhesive.

[0006] In one embodiment of the present invention, the substrate includes a plate body and an isolation protrusion disposed on one side of the plate body, the isolation protrusion and the plate body forming the receiving groove, and the height of the isolation protrusion is greater than the thickness of the ASIC chip.

[0007] In one embodiment of the present invention, a grounding pad is provided on the plate body, the grounding pad is located outside the isolation protrusion, and the outer shell is electrically connected to the grounding pad.

[0008] In one embodiment of the present invention, the plate body is coated with conductive silver paste at the position corresponding to the grounding pad, the outer shell is electrically connected to the grounding pad through the conductive silver paste, and the isolation protrusion is used to separate the conductive silver paste and the encapsulating adhesive.

[0009] In one embodiment of the present invention, the pads of the ASIC chip are aluminum pads, and gold fingers are provided on the substrate. The aluminum pads and the gold fingers are electrically connected by gold wires, and the aluminum pads are encapsulated in the encapsulating adhesive.

[0010] In one embodiment of the present invention, the waterproof barometer further includes a waterproof and breathable membrane, which covers the vent hole and the edge of the waterproof and breathable membrane is sealed to the outer shell.

[0011] In one embodiment of the present invention, the waterproof barometer further includes a protective sheet, which is disposed on the side of the waterproof and breathable membrane opposite to the vent hole, and the protective sheet has a vent opening.

[0012] In one embodiment of the present invention, the edge of the waterproof and breathable membrane is sealed to the outer shell by pressure-sensitive adhesive; and / or, the edge of the protective sheet is sealed to the waterproof and breathable membrane by pressure-sensitive adhesive.

[0013] In one embodiment of the present invention, the outer shell is recessed to form a mounting groove extending circumferentially therein, the mounting groove being used to install a sealing ring.

[0014] In one embodiment of the present invention, the side wall of the mounting groove away from the substrate is bent to form a stop ear.

[0015] In one embodiment of the present invention, the stop ear is arranged in a ring shape, the stop ear is located outside the vent hole, and the top surface of the stop ear protrudes from the side of the waterproof and breathable membrane opposite to the substrate along the direction away from the substrate.

[0016] In one embodiment of the present invention, the outer shell is an integrally stamped part; and / or, the substrate is a ceramic substrate.

[0017] In this invention, one side of the outer casing is open, and a vent is provided at the end of the outer casing opposite to the open. The substrate is placed over the open part of the outer casing, thereby forming an installation space between the substrate and the outer casing. The air pressure sensing component is disposed on the bottom wall of the receiving groove and electrically connected to the substrate. The vent ensures that the air pressure inside the installation space is consistent with the external environment. By filling the receiving groove with encapsulating adhesive, the encapsulating adhesive completely covers the ASIC chip, protecting the ASIC chip pad and isolating the ASIC chip pad from air, thereby preventing the ASIC chip pad from being corroded by corrosive gases and ensuring the reliability of the barometer. Furthermore, the sensing end of the MEMS chip is exposed to the encapsulating adhesive, thereby ensuring the accuracy of air pressure detection. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0019] Figure 1 This is a cross-sectional view of the waterproof barometer in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the waterproof barometer from one perspective in an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the waterproof barometer without its outer shell in an embodiment of the present invention.

[0022] Explanation of icon numbers:

[0023] label name label name 100 Waterproof barometer 31 Ventilation holes 1 substrate 32 Mounting slot 11 Container slot 33 stop ear 12 plate body 4 Waterproof and breathable membrane 121 Grounding pad 5 Protective film 13 Isolation protrusion 51 Vent 2 Barometric pressure sensing components 61 Coating adhesive 21 MEMS chip 62 Conductive silver paste 22 ASIC chips 63 Pressure-sensitive adhesive 3 shell 64 silicone

[0024] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0027] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0028] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0030] like Figures 1 to 3 As shown, in one embodiment of the present invention, the waterproof barometer 100 includes a substrate 1, a pressure sensing component 2, and a housing 3. A receiving groove 11 is formed on one side of the substrate 1. The pressure sensing component 2 includes a MEMS chip 21 and an ASIC chip 22. The ASIC chip is installed in the receiving groove and connected to the bottom wall of the receiving groove. The MEMS chip is disposed on the side of the ASIC chip away from the bottom wall of the receiving groove. The housing 3 covers the periphery of the receiving groove 11 and is sealed to the substrate 1. A vent hole 31 is formed on the housing 3. The receiving groove 11 is filled with a coating adhesive 61, which is cured to cover the ASIC chip 22. The sensing end of the MEMS chip is exposed in the coating adhesive.

[0031] In the above embodiment, one side of the outer shell 3 is open, and a vent 31 is opened at the end of the outer shell 3 opposite to the open. The substrate 1 is covered at the open part of the outer shell 3, thereby forming an installation space between the substrate 1 and the outer shell 3. The air pressure sensing component 2 is disposed on the bottom wall of the receiving groove 11 and electrically connected to the substrate 1. By setting a waterproof and breathable membrane 4, the air pressure inside the installation space is consistent with the external environment, preventing external water from entering the encapsulation structure. By filling the receiving groove 11 with encapsulating adhesive 61, the encapsulating adhesive 61 completely covers the ASIC chip 22 to protect the pad of the ASIC chip 22, isolating the pad of the ASIC chip 22 from contact with the air, thereby avoiding the pad of the ASIC chip 22 from being corroded by corrosive gases, ensuring the reliability of the barometer, and the sensing end of the MEMS chip 21 is exposed to the encapsulating adhesive 61, thereby ensuring the accuracy of air pressure detection.

[0032] In the above embodiments, the MEMS chip 21 and the ASIC chip 22 can be stacked. Specifically, the MEMS chip 21 is disposed on the ASIC chip 22, and the ASIC chip 22 is disposed on the substrate 1. The MEMS chip 21 is fixed to the ASIC chip 22 with adhesive, and the ASIC chip 22 is fixed to the substrate 1 with adhesive. In practical applications, as needed, the MEMS chip 21 can be disposed on the ASIC chip 22 or disposed on the substrate 1, with the ASIC chip 22 connected to the bottom wall of the receiving groove 11, and the MEMS chip 21 connected to the portion of the substrate 1 outside the receiving groove 11. The MEMS chip 21 is electrically connected to the ASIC chip 22 via gold wires, and the ASIC chip 22 is electrically connected to the substrate 1 via gold wires.

[0033] The MEMS chip 21 is fixed to the ASIC chip 22 by silicone 64, and the ASIC chip 22 is fixed to the substrate 1 by silicone 64. The silicone 64 has a Young's modulus of less than 1 MPa, which, together with the substrate 1, can effectively reduce the packaging stress.

[0034] In one embodiment of the present invention, the substrate 1 includes a plate body 12 and an isolation protrusion 13 disposed on one side of the plate body 12. The isolation protrusion 13 and the plate body 12 form a receiving groove 11, and the height of the isolation protrusion 13 is greater than the thickness of the ASIC chip 22. The isolation protrusion can effectively control the flow of the encapsulating adhesive 61 and prevent the encapsulating adhesive 61 from spreading outward. When filling the receiving groove 11 with encapsulating adhesive 61, the height of the isolation protrusion 13 being greater than the thickness of the ASIC chip 22 ensures that the encapsulating adhesive 61 completely covers the ASIC chip 22 and does not overflow from the isolation protrusion 13, thus not affecting the subsequent packaging process.

[0035] In one embodiment of the present invention, a grounding pad 121 is provided on the plate 12. The grounding pad 121 is located outside the isolation protrusion 13, and the outer shell 3 is electrically connected to the grounding pad 121. The outer shell 3 is made of conductive material. The outer shell 3 is grounded by being electrically connected to the grounding pad 121. Grounding the outer shell 3 can increase the electromagnetic shielding characteristics, thereby avoiding the operation of external electronic components from affecting the detection structure of the waterproof barometer 100, and further improving the detection accuracy of the waterproof barometer 100.

[0036] Based on the above embodiments, there are multiple grounding pads 121, which are arranged at intervals along the outer periphery of the isolation protrusion 13. A layer of conductive silver paste 62 is coated on the substrate 1 at the position corresponding to the outer periphery of the isolation protrusion 13, ensuring that each grounding pad 121 is coated with conductive silver paste 62. By arranging multiple grounding pads 121, even if individual grounding pads 121 are blocked, the housing 3 can still be grounded. When the substrate 1 is square, a grounding pad 121 is provided at each of the four corners of the substrate 1. In other embodiments, a ring of stop protrusions is also formed on the substrate 1. The stop protrusions are located outside the isolation protrusion 13, and conductive silver paste 62 fills the space between the stop protrusions and the isolation protrusion 13 to prevent the conductive silver paste 62 from spreading outwards. Simultaneously, it limits the assembly position of the housing 3, ensuring that the lower edge of the housing 3 is in full contact with the conductive silver paste 62, thus ensuring the housing is grounded.

[0037] In one embodiment of the present invention, conductive silver paste 62 is coated on the plate 12 at the position corresponding to the grounding pad 121. The outer shell 3 is electrically connected to the grounding pad 121 through the conductive silver paste 62. The isolation protrusion 13 is used to separate the conductive silver paste 62 and the encapsulating adhesive 61. The inside of the isolation protrusion 13 is the encapsulating adhesive 61, and the outside of the isolation protrusion 13 is the conductive silver paste 62. The isolation protrusion 13 separates the conductive silver paste 62 and the encapsulating adhesive 61, effectively preventing the diffusion of the encapsulating adhesive 61 and the conductive silver paste 62, which would affect other packaging processes. At the same time, it prevents the encapsulating adhesive 61 and the conductive silver paste 62 from mixing with each other, ensuring the yield rate of the waterproof barometer 100.

[0038] In one embodiment of the present invention, the waterproof barometer 100 further includes a protective sheet 5, which is disposed on the side of the waterproof breathable membrane 4 away from the vent holes 31, and has vent openings 51. The protective sheet 5 is located on top of the waterproof breathable membrane 4, and the vent openings 51 on the protective sheet 5 serve to allow air to pass through and prevent damage to the waterproof breathable membrane 4. In actual production, there are multiple vent holes 31 on the outer shell 3, which are spaced apart. The area of ​​the waterproof breathable membrane 4 is larger than the area where the vent holes 31 are located, and the waterproof breathable membrane 4 can cover all the vent holes 31. The edge of the waterproof breathable membrane 4 is sealed to the outer shell 3 with pressure-sensitive adhesive to avoid blocking the vent holes 31 when the waterproof breathable membrane 4 is glued to the outer shell 3. The shape of the protective sheet 5 matches that of the waterproof breathable membrane 4, and the edge of the protective sheet 5 is sealed to the waterproof breathable membrane 4 with pressure-sensitive adhesive. In other embodiments, the area of ​​the protective sheet 5 may be larger than the area of ​​the waterproof and breathable membrane 4. The edge of the protective sheet 5 is sealed to the outer shell 3, and the waterproof and breathable membrane 4 is located between the protective sheet 5 and the outer shell 3. The vent 51 of the protective sheet 5 is composed of multiple micropores to prevent the area of ​​the vent 51 from being too large, which would cause external structures to extend into the waterproof and breathable membrane 4 and damage it.

[0039] In one embodiment of the present invention, the outer casing 3 has a recessed mounting groove 32 extending circumferentially therein, the mounting groove 32 being used to mount a sealing ring. The waterproof barometer 100 is applied to a mobile terminal, such as a smartphone. The mounting groove 32 is used to assemble with the housing supporting the phone, and a sealing ring is provided between the groove wall of the mounting groove 32 and the housing to provide waterproofing for the entire device.

[0040] In one embodiment of the present invention, the side wall of the mounting groove 32 away from the substrate 1 is bent to form a stop ear 33. The stop ear 33 is provided to prevent the sealing ring from shifting or falling off. The stop ear 33 is formed by the upper side wall of the mounting groove 32 protruding obliquely upward at 45°, and the outer contour of the stop ear 33 is arc-shaped to avoid forming a sharp angle structure.

[0041] In one embodiment of the present invention, the stop ear 33 is arranged in a ring shape and is located outside the vent hole 31. The top surface of the stop ear 33 protrudes from the side of the waterproof and breathable membrane 4 opposite to the substrate 1 along the direction away from the substrate 1. That is, the stop ear 33 can also protect the waterproof and breathable membrane 4 and the protective sheet 5, preventing them from coming into contact with the waterproof and breathable membrane 4 and the protective sheet 5 from the side when assembling or moving the waterproof barometer 100.

[0042] In one embodiment of the present invention, the outer shell 3 is an integral stamped part; the outer shell 3 is processed by die stamping, which is lower in cost than CNC machining, and the stamping method is more feasible for processing irregular structures.

[0043] Specifically, the outer casing 3 includes a connecting section, a mounting section, a stop ear 33 and a top plate connected in sequence. The end of the connecting section away from the mounting section forms an opening and is sealed to the base plate 1. The mounting section is recessed relative to the connecting section to form a mounting groove 32. The stop ear 33 is located on the outer periphery of the top plate. A vent hole 31 is opened on the top plate and is positioned directly opposite the air pressure sensing component 2.

[0044] In one embodiment of the present invention, the substrate 1 is a ceramic substrate 1. The ceramic substrate 1 has waterproof and corrosion-resistant properties. Pads are also provided on the substrate 1, through which the substrate 1 is electrically connected to external devices. In other embodiments, the substrate 1 may also be a PCB substrate 1.

[0045] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A waterproof barometer, characterized in that the waterproof barometer comprises: A substrate, wherein a receiving groove is formed on one side of the substrate; A pressure sensing component, comprising a MEMS chip and an ASIC chip, wherein the ASIC chip is mounted in a receiving groove and connected to the bottom wall of the receiving groove, and the MEMS chip is disposed on the side of the ASIC chip away from the bottom wall of the receiving groove. The outer casing is provided around the accommodating groove and is sealed to the substrate. The outer casing has ventilation holes. The receiving groove is filled with encapsulating adhesive, which is cured to cover the ASIC chip, and the sensing end of the MEMS chip is exposed in the encapsulating adhesive. The substrate includes a plate body and an isolation protrusion disposed on one side of the plate body. The isolation protrusion and the plate body form the receiving groove, and the height of the isolation protrusion is greater than the thickness of the ASIC chip.

2. The waterproof barometer as described in claim 1, characterized in that a grounding pad is provided on the plate, the grounding pad is located outside the isolation protrusion, and the outer shell is electrically connected to the grounding pad.

3. The waterproof barometer as described in claim 2, characterized in that the plate body is coated with conductive silver paste at the position corresponding to the grounding pad, the outer shell is electrically connected to the grounding pad through the conductive silver paste, and the isolation protrusion is used to separate the conductive silver paste and the encapsulating adhesive.

4. The waterproof barometer as described in claim 1, characterized in that the pads of the ASIC chip are aluminum pads, gold fingers are provided on the substrate, the aluminum pads and the gold fingers are electrically connected by gold wires, and the aluminum pads are encapsulated in the encapsulating adhesive.

5. The waterproof barometer according to any one of claims 1 to 4, characterized in that the waterproof barometer further includes a waterproof and breathable membrane, the waterproof and breathable membrane being disposed over the vent hole, and the edge of the waterproof and breathable membrane being sealed to the outer casing.

6. The waterproof barometer as described in claim 5, characterized in that the waterproof barometer further includes a protective sheet, the protective sheet being disposed on the side of the waterproof and breathable membrane opposite to the vent hole, and the protective sheet having a vent opening.

7. The waterproof barometer as described in claim 6, characterized in that the edge of the waterproof and breathable membrane is sealed to the outer shell by pressure-sensitive adhesive; and / or, the edge of the protective sheet is sealed to the waterproof and breathable membrane by pressure-sensitive adhesive.

8. The waterproof barometer as claimed in claim 5, characterized in that the housing has an inwardly recessed mounting groove extending circumferentially therein, the mounting groove being used to install a sealing ring.

9. The waterproof barometer as claimed in claim 8, wherein the side wall of the mounting groove away from the substrate is bent to form a stop ear.

10. The waterproof barometer as claimed in claim 9, characterized in that the stop ear is arranged in a ring shape, the stop ear is located outside the vent hole, and the top surface of the stop ear protrudes from the side of the waterproof and breathable membrane opposite to the substrate along the direction away from the substrate.

11. The waterproof barometer according to any one of claims 1 to 4, characterized in that the outer shell is an integrally stamped part; and / or the substrate is a ceramic substrate.

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