A pressure sensor and electronic device

Abstract

The application relates to a pressure sensor and an electronic device, wherein the pressure sensor comprises: a first substrate with a first surface and a second surface arranged oppositely, a plurality of pads being arranged on the second surface at intervals; a MEMS chip arranged on the first surface; and a solder ring arranged on the second surface, each of the pads being surrounded by the solder ring, and the solder ring being electrically connected with a pad for ground coupling among the plurality of pads. The solder ring surrounds the pads at the periphery of the pads, can effectively prevent water vapor from penetrating, and avoids that the pads are eroded by water vapor. Meanwhile, the solder ring is electrically connected with the pad for ground coupling through a connecting rib, the ground area of the pressure sensor is increased, and the electromagnetic shielding performance of the pressure sensor is improved. Thus, the reliability of the pressure sensor is effectively improved.

Description

Technical Field

[0001] This application relates to the field of pressure sensors, and more particularly to a pressure sensor and electronic device. Background Technology

[0002] MEMS pressure sensors commonly use a land grid array (LGA) package. In a LGA package, the sensor undergoes a surface mount technology (SMT) process on a pick-and-place machine to align the sensor's pads with corresponding pads on the printed circuit board (PCB), and then the solder joints are connected using a reflow soldering process. This packaging method not only achieves mechanical fixation to the PCB but also ensures reliable transmission of electrical signals.

[0003] However, in order to achieve pressure introduction, MEMS pressure sensors packaged with grid arrays often have ventilation / pressure tapping holes on the sidewalls or top layer of the package. These openings destroy the shielding integrity of the MEMS pressure sensor, allowing external electromagnetic fields to be directly coupled into the sensor chip through the gaps between the pads and the pressure tapping holes. The electromagnetic shielding performance of the packaged pressure sensor is poor. Moreover, in high humidity or high salt spray environments, the SMT solder joints of the packaged pressure sensor are prone to rusting and oxidation due to water vapor penetration or vapor phase corrosion, leading to solder joint detachment, electrical open circuit, and ultimately causing the pressure sensor to fail. Utility Model Content

[0004] This application provides a pressure sensor and an electronic device, which aims to protect the solder joints of the pressure sensor, improve the reliability of the pressure sensor, and enhance the electromagnetic shielding performance of the pressure sensor.

[0005] To achieve the above objectives, according to a first aspect of this application, a pressure sensor is provided, comprising: a first substrate having a first surface and a second surface disposed opposite to each other, wherein a plurality of pads are spaced apart on the second surface;

[0006] A MEMS chip is disposed on the first surface;

[0007] A solder ring is disposed on the second surface, and each of the solder pads is surrounded by the solder ring, and the solder ring is electrically connected to the solder pads among the plurality of solder pads used for grounding coupling.

[0008] Optionally, multiple solder rings are provided, and each solder ring corresponds to a solder pad, with each solder ring surrounding the corresponding solder pad.

[0009] When the pad is used for grounding coupling, a connecting rib is provided between the corresponding solder ring and the pad, and the connecting rib connects the pad and the solder ring.

[0010] Optionally, each of the pads is surrounded by the same solder ring;

[0011] Wherein, when the pad is used for ground coupling, a connecting rib is provided between the pad for ground coupling and the solder ring, and the connecting rib connects the solder ring and the pad for ground coupling.

[0012] Optionally, it further includes a second substrate, the second substrate and the first substrate being electrically connected via the solder ring and solder pad.

[0013] Optionally, the second substrate is a circuit board.

[0014] Optionally, it further includes: an ASIC chip disposed on the first surface and electrically connected to the MEMS chip.

[0015] Optionally, it also includes:

[0016] The housing has a first through hole that passes through it. The housing is fixed to the first surface and together with the first substrate, they enclose a cavity. The MEMS chip and the ASIC chip are both located in the cavity.

[0017] Optionally, the housing is filled with a colloid that covers the MEMS chip.

[0018] Optionally, the first substrate is a ceramic substrate.

[0019] According to a second aspect of this application, an electronic device is provided, comprising the pressure sensor described in any one of the foregoing claims.

[0020] In the embodiments disclosed in this application, the solder ring surrounds the solder pad, effectively preventing moisture penetration and corrosion of the pad. Simultaneously, the solder ring is electrically connected to the solder pad used for grounding coupling via connecting ribs, increasing the grounding area of ​​the pressure sensor and improving its electromagnetic shielding performance. This design effectively improves the reliability of the pressure sensor.

[0021] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0024] Figure 1 This is a schematic diagram of the structure of a pressure sensor disclosed in an embodiment of this application. Figure 1 ;

[0025] Figure 2 This is a schematic diagram of the structure of a pressure sensor disclosed in an embodiment of this application. Figure 2 ;

[0026] Figure 3 This is a schematic diagram of the structure of a pressure sensor disclosed in an embodiment of this application. Figure 3 ;

[0027] Figure 4 This is a schematic diagram of the structure of a pressure sensor disclosed in an embodiment of this application. Figure 4 .

[0028] Explanation of reference numerals in the attached figures:

[0029] 1. First substrate; 11. Pad; 2. MEMS chip; 3. Bonding ring; 4. Connecting rib; 5. Second substrate; 6. ASIC chip; 8. Housing; 81. First through hole; 9. Colloid; 10. Receiving cavity. Detailed Implementation

[0030] The technical solutions of the embodiments of this application 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 this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0031] As described in the background section, MEMS pressure sensors often employ a Land Grid Array (LGA) package. To facilitate pressure input, the packaged MEMS pressure sensor typically has vent / pressure tapping holes on its sidewalls or top layer. These openings compromise the shielding integrity of the MEMS pressure sensor, allowing external electromagnetic fields to couple directly into the sensor chip through the pad gaps and pressure tapping holes. This results in poor electromagnetic shielding performance for the packaged pressure sensor. Furthermore, in high humidity or high salt spray environments, the SMT solder joints of the packaged pressure sensor are prone to rusting and oxidation due to moisture penetration or vapor corrosion, leading to solder joint detachment, electrical open circuits, and ultimately, pressure sensor failure.

[0032] To prevent solder joints from rusting and oxidizing due to moisture penetration or vapor corrosion, which could lead to solder joint detachment, electrical breakage, and ultimately pressure sensor failure, some implementations apply a ring of silicone or epoxy sealant around the solder joints after reflow soldering to create a physical barrier layer. While this method can block moisture intrusion to some extent, it also has significant drawbacks: firstly, the additional dispensing process increases the complexity of the production process and manufacturing costs; secondly, the consistency of the dispensing amount and position is difficult to control precisely—too little sealant fails to form an effective moisture barrier, while too much sealant can cause interference with adjacent components or affect subsequent maintenance and testing.

[0033] Therefore, in order to protect the solder joints of the pressure sensor, improve the reliability of the pressure sensor, and enhance the electromagnetic shielding performance of the pressure sensor, this application discloses a pressure sensor.

[0034] Reference Figure 1 Embodiment 1 of this application discloses a pressure sensor comprising: a first substrate 1, a MEMS chip 2, and a bonding ring 3. The first substrate 1 has a first surface and a second surface disposed opposite to each other, and a plurality of bonding pads 11 are spaced apart on the second surface. The MEMS chip 2 is disposed on the first surface. The bonding ring 3 is disposed on the second surface, and each bonding pad 11 is surrounded by the bonding ring 3, and the bonding ring 3 is electrically connected to the bonding pad 11 among the plurality of bonding pads 11 used for grounding coupling.

[0035] Reference Figure 2 In the first embodiment disclosed in this application, four pads 11 are provided, each pad 11 being surrounded by the same solder ring 3. Among them, at least one of the four pads 11 is used for ground coupling, and a connecting rib 4 is provided between the pad 11 used for ground coupling and the solder ring 3, the connecting rib 4 connecting the solder ring 3 and the pad 11 used for ground coupling.

[0036] It should be noted that the welding ring 3, welding pad 11 and connecting rib 4 are made of the same material and can be formed through the same process steps.

[0037] In this embodiment, the solder ring 3 is electrically connected to the solder pad 11 for grounding coupling, which increases the grounding area of ​​the pressure sensor and improves the electromagnetic shielding performance of the pressure sensor. This design effectively improves the reliability of the pressure sensor.

[0038] Specifically, increasing the grounding area of ​​the pressure sensor is equivalent to increasing the conductive area through which current flows in the loop. The resistance (R) and inductance (L) of the grounding loop are inversely proportional to the loop area. Increasing the grounding area can effectively reduce the loop impedance, thereby reducing current radiation in the loop and lowering electromagnetic interference (EMI).

[0039] It is worth mentioning that, compared with the existing technology that improves the waterproof performance of the pad 11 through the dispensing process, this application improves the waterproof performance of the pad 11 and the electromagnetic shielding performance of the pressure sensor by setting a welding ring 3 that is electrically connected to the grounding pad 11 and surrounds all the pads 11. This also eliminates the dispensing process, simplifies the process flow of the pressure sensor, and improves production efficiency.

[0040] Reference Figure 3 In Embodiment 2 of this application, unlike Embodiment 1, multiple solder rings 3 are provided, and each solder ring 3 corresponds to a solder pad 11, with each solder ring 3 surrounding the corresponding solder pad 11. When the solder pad 11 is used for grounding coupling, a connecting rib 4 is provided between the corresponding solder ring 3 and the solder pad 11, and the connecting rib 4 connects the solder pad 11 and the solder ring 3.

[0041] Multiple solder rings 3 surround the pad 11 and are electrically connected to the pad 11 used for grounding coupling. On the one hand, each solder ring 3 can provide local shielding for the corresponding pad 11, enhance the overall pressure sensor's immunity to external electromagnetic interference (EMI), and prevent external moisture and corrosive gases from directly intruding into the pad 11. On the other hand, by increasing the ground plane, the electromagnetic shielding performance of the pressure sensor can also be improved.

[0042] Furthermore, in some embodiments, the pressure sensor further includes an ASIC chip 6, which is disposed on the first surface and electrically connected to the MEMS chip 2. Specifically, in some embodiments, both the ASIC chip 6 and the MEMS chip 2 can be bonded to the first substrate 1 using die-attach adhesive. The MEMS chip 2 and the ASIC chip 6 are electrically connected via leads.

[0043] Furthermore, in some embodiments, the pressure sensor also includes a housing 8, which has a first through hole 81 extending through itself. The housing 8 is fixed to the first surface and together with the first substrate 1 forms a receiving cavity 10, in which the MEMS chip 2 and the ASIC chip 6 are both located.

[0044] In some embodiments, the housing 8 is further filled with a colloid 9, which covers the MEMS chip 2 and the ASIC chip 6. The colloid 9 can be epoxy resin or silicone. Covering the MEMS chip 2 and the ASIC chip 6 with the colloid 9 prevents the chips from being corroded.

[0045] Reference Figure 4 In some embodiments, the pressure sensor further includes a second substrate 5, which is electrically connected to the first substrate 1 via a solder ring 3 and a solder pad 11. External atmospheric pressure can enter the accommodating cavity 10 through the first through hole 81 on the housing 8, and the colloid 9 can deform to transmit pressure to the MEMS chip 2.

[0046] In some embodiments, the first substrate 1 may be a ceramic substrate, and the second substrate 5 may be a circuit board.

[0047] When the pressure sensor is working, it senses changes in external atmospheric pressure through the first through hole 81, which causes the pressure sensing membrane of the MEMS chip 2 to deform and output a voltage proportional to the sensed pressure. The voltage value is amplified and calculated by the ASIC chip 6 and then transmitted to the second substrate 5 through the pad 11, thereby realizing pressure measurement.

[0048] In some embodiments, the housing 8 is a metal housing 8, which is soldered to the first substrate 1 to effectively shield against external electromagnetic interference. Specifically, the housing 8 can protect the chip from interference by external electromagnetic waves and also prevent electromagnetic waves inside the housing 8 from leaking out, thus avoiding interference with other electronic devices and improving the electromagnetic compatibility of the pressure sensor.

[0049] This application also discloses an electronic device that includes a pressure sensor as described in any of the above embodiments.

[0050] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0051] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0052] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0053] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A pressure sensor, characterized by include: The first substrate (1) has a first surface and a second surface disposed opposite to each other, and a plurality of pads (11) are disposed at intervals on the second surface; MEMS chip (2) is disposed on the first surface; A solder ring (3) is disposed on the second surface, and each of the solder pads (11) is surrounded by the solder ring (3), and the solder ring (3) is electrically connected to the solder pad (11) used for grounding coupling among the plurality of solder pads (11).

2. The pressure sensor of claim 1, wherein, The welding rings (3) are provided in multiple ways, and the multiple welding rings (3) correspond one-to-one with the multiple solder pads (11). Each welding ring (3) surrounds the corresponding solder pad (11). When the pad (11) is used for grounding coupling, a connecting rib (4) is provided between the corresponding welding ring (3) and the pad (11), and the connecting rib (4) connects the pad (11) and the welding ring (3).

3. The pressure sensor of claim 1, wherein, Each of the said pads (11) is surrounded by the same said pad ring (3); When the pad (11) is used for grounding coupling, a connecting rib (4) is provided between the pad (11) used for grounding coupling and the ring (3), and the connecting rib (4) connects the ring (3) and the pad (11) used for grounding coupling.

4. The pressure sensor of claim 1, wherein, It also includes a second substrate (5), which is electrically connected to the first substrate (1) via the solder ring (3) and the solder pad (11).

5. The pressure sensor of claim 4, wherein, The second substrate (5) is a circuit board.

6. The pressure sensor of claim 1, wherein, Also includes: An ASIC chip (6) is disposed on the first surface and is electrically connected to the MEMS chip (2).

7. The pressure sensor of claim 6, wherein, Also includes: The housing (8) has a first through hole (81) through itself. The housing (8) is fixed on the first surface and together with the first substrate (1) forms a receiving cavity (10). The MEMS chip (2) and the ASIC chip (6) are both located in the receiving cavity (10).

8. The pressure sensor of claim 7, wherein, The housing (8) is filled with colloid (9), which covers the MEMS chip (2).

9. The pressure sensor of claim 1, wherein, The first substrate (1) is a ceramic substrate.

10. An electronic device, comprising: Including the pressure sensor as described in any one of claims 1-9.

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