Sensor packaging structure, sensor, and electronic device

Abstract

This utility model relates to the field of sensor technology, specifically to a sensor packaging structure, a sensor, and electronic equipment. The sensor packaging structure includes a substrate, a waterproof adhesive layer, a radio frequency (RF) shielding structure, a housing, and a light-shielding structure. A chip is mounted on the substrate, and the waterproof adhesive layer covers the outside of the chip, serving to transmit external pressure. The RF shielding structure surrounds the circumferential boundary of the waterproof adhesive layer, defining the packaging area. The housing is positioned outside the RF shielding structure and has an opening. The light-shielding structure is located inside the housing, with one end connected to the opening and the other end extending inwards into the housing. The light-shielding structure blocks external optical fibers from directly irradiating the waterproof adhesive layer through the opening. According to this sensor packaging structure, by providing a light-shielding structure at the opening of the housing, external light is effectively blocked from directly irradiating the waterproof adhesive layer and the chip, significantly reducing light noise interference to the chip.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, specifically to sensor packaging structures, sensors, and electronic devices. Background Technology

[0002] In the consumer electronics field, sensors are commonly used in terminal devices such as smartphones and watches to detect environmental parameters such as air pressure and water depth. Because MEMS chips are highly sensitive to external light, especially under infrared and visible light, they are prone to signal shifts, leading to decreased detection accuracy or even false triggering. Therefore, stringent requirements are placed on the sensor's resistance to light noise interference. Current technologies typically use black waterproof adhesive to suppress light noise interference. However, adding black pigment to the adhesive alters the adhesive's hardness, affecting its pressure transmission characteristics and causing problems such as slow response and decreased sensitivity in the MEMS chip. Furthermore, the choice of black adhesive limits the flexibility of the encapsulation process and increases manufacturing costs. Therefore, there is an urgent need for a solution that can effectively shield external light and avoid light noise interference without relying on black adhesive, achieving a higher-performance and more adaptable sensor encapsulation method. Utility Model Content

[0003] The purpose of this invention is to at least solve the problem of light interference with sensor chips. This purpose is achieved through the following technical solution:

[0004] The first aspect of this utility model provides a sensor packaging structure, comprising:

[0005] A substrate on which a chip is disposed;

[0006] A waterproof adhesive layer covers the outside of the chip and is used to transmit external pressure to the chip;

[0007] A radio frequency shielding structure surrounds the circumferential boundary of the waterproof adhesive layer to enhance anti-radio frequency interference performance and define the encapsulation area of ​​the waterproof adhesive layer;

[0008] An outer casing, which covers the radio frequency shielding structure, and the outer casing has an opening;

[0009] A light-shielding structure is provided inside the housing. The first end of the light-shielding structure is connected to the side wall of the opening, and the second end of the light-shielding structure extends into the housing to block external light from directly irradiating the waterproof adhesive layer from the opening.

[0010] According to the sensor packaging structure of this utility model, by setting a light-shielding structure at the opening of the outer shell and extending it inward, it effectively blocks external light (such as natural light or infrared light) from directly irradiating the waterproof adhesive layer and the chip, significantly reducing light noise interference to the chip and improving the signal stability and measurement accuracy of the sensor. Furthermore, the light-shielding structure avoids the problem of relying on black opaque waterproof adhesive for light shielding; therefore, transparent or non-black waterproof adhesive materials can be used, improving material processing flexibility and avoiding hardness variations caused by black adhesive, which helps maintain the sensitivity and consistency of the chip's pressure response. Finally, the layout of the light-shielding structure, with one end connected to the opening and the other end extending inward, does not occupy additional space and actively blocks light path interference, ensuring the compactness and manufacturability of the packaging structure, which is beneficial for the integrated packaging design of miniaturized sensors.

[0011] In addition, the sensor packaging structure of this utility model may also have the following additional technical features:

[0012] In some embodiments of this utility model, the opening is located at the top of the outer shell and is parallel to the substrate, and the opening is offset from the waterproof adhesive layer.

[0013] In some embodiments of this utility model, along a direction parallel to the substrate, the projection surface of the light-shielding structure and the projection surface of the radio frequency shielding structure have overlapping portions.

[0014] In some embodiments of this utility model, along a direction parallel to the substrate, the second end of the light-shielding structure is located on the side of the first end of the light-shielding structure away from the waterproof adhesive layer.

[0015] In some embodiments of this utility model, the light-shielding structure and the waterproof adhesive layer are spaced apart.

[0016] In some embodiments of this utility model, the radio frequency shielding structure is a copper ring.

[0017] In some embodiments of this invention, the chip includes an ASIC chip and a MEMS chip that are electrically connected to each other.

[0018] In some embodiments of this utility model, the outer casing is a stainless steel casing.

[0019] The second aspect of this invention provides a sensor comprising the sensor packaging structure described above.

[0020] A third aspect of this invention provides an electronic device comprising the aforementioned sensor. Attached Figure Description

[0021] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0022] Figure 1 A schematic diagram of the sensor packaging structure according to an embodiment of the present invention is shown.

[0023] Figure 2 for Figure 1 A cross-sectional view of plane AA.

[0024] The attached figures are labeled as follows:

[0025] 100. Sensor packaging structure;

[0026] 10. Substrate; 20. Shell; 21. Opening; 22. Light-shielding structure; 221. First end; 222. Second end; 30. Radio frequency shielding structure; 40. ASIC chip; 50. MEMS chip; 60. Gold wire; 70. Waterproof adhesive layer. Detailed Implementation

[0027] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0028] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0029] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0030] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations.

[0031] like Figure 1 and Figure 2 As shown, according to an embodiment of the present invention, a sensor packaging structure 100 is proposed. The sensor packaging structure 100 includes a substrate 10, a waterproof adhesive layer 70, a radio frequency shielding structure 30, a housing 20, and a light-shielding structure 22. A chip is disposed on the substrate 10. The waterproof adhesive layer 70 covers the outside of the chip and is used to transmit external pressure and achieve sealing. The radio frequency shielding structure 30 surrounds the circumferential boundary of the waterproof adhesive layer 70, enhancing its anti-radio frequency interference performance and defining the packaging area of ​​the waterproof adhesive layer 70. The housing 20 covers the outside of the radio frequency shielding structure 30 and has an opening 21. The light-shielding structure 22 is disposed inside the housing 20. A first end 221 of the light-shielding structure 22 connects to the opening 21, and a second end 222 of the light-shielding structure 22 extends into the housing 20. The light-shielding structure 22 is used to block external optical fibers from directly irradiating the waterproof adhesive layer 70 from the opening 21.

[0032] According to the sensor packaging structure 100 of this utility model, by setting a light-shielding structure 22 at the opening 21 of the outer shell 20 and extending it into the inner part of the outer shell 20, external light (such as natural light or infrared light) is effectively blocked from directly irradiating the waterproof adhesive layer 70 and the chip, significantly reducing the interference of light noise on the chip and improving the signal stability and measurement accuracy of the sensor. Furthermore, the setting of the light-shielding structure 22 avoids the problem of having to rely on black opaque waterproof adhesive for light shielding; therefore, transparent or non-black waterproof adhesive materials can be used, improving the flexibility of material processing and avoiding the hardness changes caused by black adhesive, which is beneficial to maintaining the sensitivity and consistency of the chip's pressure response. Finally, the layout of the light-shielding structure 22, with one end connected to the opening 21 and the other end extending inward, does not occupy additional space and simultaneously achieves active blocking of light path interference, ensuring the compactness and manufacturability of the packaging structure, which is beneficial to the integrated packaging design of miniaturized sensors.

[0033] Understandably, along a direction parallel to the substrate 10, the second end 222 of the light-shielding structure 22 is located on the side of the first end 221 of the light-shielding structure 22 away from the waterproof adhesive layer 70. That is, the light-shielding structure 22 extends in a direction away from the waterproof adhesive layer 70 to form an inclined angle with the outer shell 20. Since the RF shielding structure 30 surrounds the circumferential boundary of the waterproof adhesive layer 70, only one side of the waterproof adhesive layer 70 can receive light, and this side is the light-receiving surface of the waterproof adhesive layer 70. The light-shielding structure 22 is inclined in a direction away from the light-receiving surface, forming an inclined shield rather than a simple vertical blockage. This can effectively block obliquely incident light or scattered light, further reducing the possibility of light entering the opening 21 and irradiating the waterproof adhesive layer 70 at multiple angles, thus improving the anti-light noise performance. Furthermore, since an inclined surface is more effective at blocking incident light than a vertical baffle, it is particularly suitable for dealing with complex lighting environments at different angles, structurally suppressing interference from non-direct light, and improving the robustness of the sensor in practical application scenarios.

[0034] It is understandable that the light-shielding structure 22 and the waterproof adhesive layer 70 are spaced apart. If the light-shielding structure 22 were close to or in contact with the waterproof adhesive layer 70, it might cause compression or contamination during the potting and curing process, resulting in uneven surface, uneven thickness, or residual air bubbles on the surface of the waterproof adhesive layer 70. By spaced them apart, the light-shielding structure 22 avoids interfering with the geometry of the waterproof adhesive layer 70, ensuring that the waterproof adhesive layer 70 can naturally level and uniformly cover the chip area, improving sealing reliability and pressure transmission accuracy. At the same time, the effective spacing allows the light-shielding structure 22 to form a front-mounted or suspended shielding effect, providing a wide-angle light-shielding path even under the influence of light incident at large angles or from different directions, enhancing the shielding capability against lateral and oblique light. Finally, in application environments with large temperature variations, the waterproof adhesive layer 70 and the light-shielding structure 22 may have different coefficients of thermal expansion. By spaced them apart, mutual pressure or stress transfer due to thermal expansion and contraction can be avoided, improving the thermal stability and long-term reliability of the entire sensor packaging structure 100.

[0035] In some embodiments, the RF shielding structure 30 is a copper ring. First, copper has excellent conductivity and shielding effectiveness. When the RF shielding structure 30 adopts a copper ring structure, it can effectively reflect and absorb external high-frequency electromagnetic waves, preventing them from interfering with the chip signal, significantly improving the sensor's anti-electromagnetic interference performance, and ensuring the accuracy and stability of the output signal. Second, the copper ring can be arranged around the chip, forming a defined encapsulation area frame in the structure, so that the waterproof adhesive potting only cures within this area, ensuring that the adhesive has a uniform shape and consistent thickness, which helps maintain the consistency and repeatability of the sensor's response characteristics.

[0036] Furthermore, in a specific embodiment, the sensor packaging structure 100 includes a copper ring for surrounding the chip and disposed on the substrate 10. The copper ring simultaneously serves as an anti-radio frequency interference function and a barrier function for the waterproof adhesive layer 70. The copper ring surrounds the chip, forming the packaging boundary of the waterproof adhesive layer 70, and defining the injection area of ​​the waterproof adhesive layer 70. The waterproof adhesive layer 70 is preferably a high-viscosity, flexible, transparent silicone. The waterproof adhesive layer 70 is tightly bonded to the inner wall of the copper ring to prevent water from seeping into the chip area through the micro-slits between the copper ring and the waterproof adhesive layer 70 under high water pressure, which could lead to sensor failure. The flexibility of the waterproof adhesive layer 70 helps to accurately transmit external air or water pressure to the chip surface, ensuring the sensitivity and accuracy of the sensing response. In the fabrication process, a copper ring is first fixed to the substrate 10, forming a ring structure around the chip. Then, waterproof adhesive is slowly injected into the copper ring using a potting device. After potting, air bubbles are removed by vacuuming. Finally, the mixture is heated and cured at a high temperature (preferably 150°C) for 1 hour to fully form the waterproof adhesive layer 70 and achieve hermetically sealed packaging. This process design not only achieves efficient and reliable anti-RF interference packaging but also improves the waterproof performance of the product under complex environments such as high humidity and high pressure, avoiding problems such as uneven potting, residual air bubbles, or leakage, thereby significantly improving the overall performance and lifespan of the sensor.

[0037] In some embodiments, the chip includes an ASIC chip 40 and a MEMS chip 50 electrically connected to each other. The ASIC chip 40 and MEMS chip 50 are electrically connected to each other via gold wires 60. The ASIC chip 40 is used to condition and process the analog signals acquired by the MEMS chip 50. The direct interconnection between the MEMS chip 50 and the ASIC chip 40 via the gold wires 60 results in a short signal transmission path and strong anti-interference capability, helping to prevent external radio frequency, electromagnetic, and other interference signals from entering the signal chain and improving the stability and reliability of the sensor output. Simultaneously, the gold wires 60 are also encapsulated in a waterproof adhesive layer 70.

[0038] Furthermore, the ASIC chip 40 is fixed to the substrate 10 with silicone, and the MEMS chip 50 is fixed to the ASIC chip 40 with silicone.

[0039] In some embodiments, the substrate 10 is a PCB circuit board or a ceramic substrate 10. The PCB substrate 10 has good electrical performance and structural processability, making it suitable for mass production of electronic products. It facilitates wiring, electrical connections, and system integration, while also having relatively low cost, making it suitable for consumer electronics or light industrial applications. The ceramic substrate 10 has high thermal conductivity, a low coefficient of thermal expansion, and excellent insulation properties, making it suitable for harsh environments such as high temperature, high humidity, and high corrosion, significantly improving the reliability and lifespan of sensors in automotive, industrial control, and other scenarios.

[0040] In some embodiments, the opening 21 is located at the top of the housing 20 and is offset from the waterproof adhesive layer 70 along a direction parallel to the substrate 10. The top opening 21 allows the light-shielding structure 22 to extend naturally in the vertical direction and cover the light path, thereby forming a smooth and effective light-shielding path at the structural level, preventing low-angle or scattered light from directly irradiating the waterproof adhesive layer 70. By offsetting the opening 21 from the waterproof adhesive layer 70 on a flat surface, light or foreign objects can be prevented from directly penetrating the opening 21 and falling vertically onto the waterproof adhesive. This effectively complements the angled shielding of the light-shielding structure 22, achieving better resistance to light noise interference and foreign object prevention.

[0041] Furthermore, along a direction parallel to the substrate 10, the projection surfaces of the light-shielding structure 22 and the radio frequency shielding structure 30 overlap. The overlap of the projections on the light-shielding structure 22 and the radio frequency shielding structure 30 means that they form a light-shielding coverage area above the waterproof adhesive layer 70, thereby effectively blocking external light from entering the surface of the waterproof adhesive layer 70 vertically or obliquely, enhancing the light noise shielding effect on the chip.

[0042] In some embodiments, the housing 20 is made of stainless steel, preferably SUS304 or SUS316L stainless steel. This stainless steel housing 20 covers the outside of the RF shielding structure 30, forming a physical protective barrier for core components such as the chip, waterproof adhesive layer 70, and RF shielding structure 30. Stainless steel possesses excellent mechanical strength, corrosion resistance, and thermal stability, effectively resisting damage to internal sensor components caused by harsh operating environments such as high-pressure water flow, particle impact, and temperature and humidity changes. Furthermore, stainless steel has high rigidity, maintaining the integrity of the housing structure even under drop, compression, or high-frequency vibration scenarios, improving the structural reliability and environmental adaptability of sensor products in consumer electronics, automotive electronics, and industrial control applications. Preferably, the surface of the stainless steel housing 20 can be sandblasted, electropolished, or passivated to further enhance its corrosion resistance and improve the consistency of the product's appearance. By using stainless steel as the material for the housing 20, this sensor packaging structure 100 achieves a harmonious balance between high protection level, high environmental adaptability, and good processing performance while maintaining a compact package.

[0043] It is understood that the outer shell 20 and the light-shielding structure 22 are an integral structure, meaning that the light-shielding structure 22 is formed by extending the material of the outer shell 20 as a whole, without the need for additional assembly or bonding. Specifically, the outer shell 20 can be integrally processed by stamping, injection molding, or other integrated processing techniques, so that there is no dividing line or splicing gap between the light-shielding structure 22 and the main structure of the outer shell 20. The light-shielding structure 22 naturally extends and bends within the inner wall area of ​​the outer shell 20, thereby blocking the path of light from the opening 21 to the waterproof adhesive layer 70. This embodiment avoids additional welding, bonding, or mechanical clamping processes between the light-shielding structure 22 and the outer shell 20, reducing manufacturing steps and assembly errors, improving production efficiency and yield, and is especially suitable for mass automated production.

[0044] Furthermore, the outer shell 20 is bonded to the substrate 10 using solder paste or silver paste. Specifically, solder paste or silver paste is pre-printed or dotted at the contact point between the bottom of the outer shell 20 and the substrate 10, and then the outer shell 20 is firmly bonded to the surface of the substrate 10 through reflow soldering (if solder paste) or thermosetting curing (if silver paste). Solder paste has good conductivity and solderability, making it suitable for scenarios with electrical connection requirements, while silver paste has excellent conductivity, thermal stability, and flexible bonding ability, making it more suitable for scenarios with micro-deformation absorption requirements or requiring room temperature curing. Both methods can achieve a strong, efficient, and process-compatible bonding effect, improving assembly efficiency and reliability. This bonding method simplifies the structural reservations required by traditional mechanical snap-fit ​​or screw connections, and is particularly suitable for applications in micro-sensor packaging with high requirements for space and processing precision, helping to achieve miniaturization, weight reduction, and high integration of the overall structure.

[0045] In some embodiments, the waterproof adhesive layer 70 is an adhesive soft silicone rubber used to cover the chip and fill the potting area defined by the copper ring. This soft silicone rubber has high adhesion and flexibility, and after potting, it can form a tight bond with the inner wall of the copper ring, effectively preventing external high-pressure water or particles from seeping into the chip area along the boundary, ensuring the reliability of the sensor's waterproof seal. Furthermore, the soft silicone rubber has good elasticity and deformability, capable of deforming under external air or water pressure, and accurately transmitting pressure to the underlying chip surface, ensuring high sensitivity and high linearity of pressure response. This silicone rubber is preferably a room-temperature curing or high-temperature curing transparent silicone rubber, which can be injected using a potting device, followed by vacuum degassing and curing at 150°C for 1 hour to form the final product.

[0046] This embodiment also includes a sensor, which includes the sensor packaging structure 100 described above.

[0047] This embodiment also includes an electronic device comprising the aforementioned sensors. Preferably, the electronic device can be a smartphone, smartwatch, vehicle terminal, wearable device, drone, home appliance, or industrial automation equipment, etc., used to realize functions such as environmental pressure detection, air pressure altitude determination, underwater depth sensing, or sealing monitoring. By integrating the aforementioned sensors, the electronic device can acquire real-time information on changes in external air or water pressure and input the detection data to the control system for processing, thereby realizing functions such as environmental perception, adaptive adjustment, or safety control. Simultaneously, the aforementioned sensor packaging structure 100 possesses excellent anti-interference capabilities, structural stability, and material compatibility, ensuring reliable operation and stable output during long-term use in various electronic devices.

[0048] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A sensor packaging structure, characterized in that, include: A substrate on which a chip is disposed; A waterproof adhesive layer, which covers the outside of the chip and is used to transmit external pressure to the chip; A radio frequency shielding structure surrounds the circumferential boundary of the waterproof adhesive layer to enhance anti-radio frequency interference performance and define the encapsulation area of ​​the waterproof adhesive layer; An outer casing, which covers the radio frequency shielding structure, and the outer casing has an opening; A light-shielding structure is provided inside the housing. The first end of the light-shielding structure is connected to the side wall of the opening, and the second end of the light-shielding structure extends into the housing to block external light from directly irradiating the waterproof adhesive layer from the opening.

2. The sensor packaging structure according to claim 1, characterized in that, The opening is located at the top of the outer casing and is parallel to the substrate, and is offset from the waterproof adhesive layer.

3. The sensor packaging structure according to claim 2, characterized in that, Along a direction parallel to the substrate, the projection surfaces of the light-shielding structure and the radio frequency shielding structure have overlapping portions.

4. The sensor packaging structure according to claim 1, characterized in that, Along a direction parallel to the substrate, the second end of the light-shielding structure is located on the side of the first end of the light-shielding structure away from the waterproof adhesive layer.

5. The sensor packaging structure according to claim 1, characterized in that, The light-shielding structure is spaced apart from the waterproof adhesive layer.

6. The sensor packaging structure according to claim 1, characterized in that, The radio frequency shielding structure is a copper ring.

7. The sensor packaging structure according to any one of claims 1 to 6, characterized in that, The chip includes an ASIC chip and a MEMS chip that are electrically connected to each other.

8. The sensor packaging structure according to any one of claims 1 to 6, characterized in that, The outer casing is made of stainless steel.

9. A sensor, characterized in that, The sensor includes the sensor packaging structure according to any one of claims 1 to 8.

10. An electronic device, characterized in that, The electronic device includes the sensor according to claim 9.

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