A sensing assembly and pressure sensor

Abstract

This utility model relates to a sensing component and a pressure sensor, including a substrate, a piezoresistive junction, side guard rings, a protective layer, and a shielding layer. Several piezoresistive junctions are disposed on one side of the substrate. Several side guard rings are disposed on the substrate and surround each piezoresistive junction. The protective layer is disposed on the substrate. The shielding layer is disposed on the side of the protective layer away from the substrate, covering each piezoresistive junction, and has several through holes or blind holes vertically formed on it. By providing a shielding layer with a porous structure, this invention not only improves the sensor's anti-interference capability but also reduces thin-film stress, thereby improving the sensor's output sensitivity. Furthermore, the side guard rings and protective layer structure provide excellent protection, preventing damage and contamination to the components and ensuring stable sensor operation.

Description

Technical Field

[0001] This utility model relates to the field of sensing component technology, and in particular to a sensing component and a pressure sensor. Background Technology

[0002] A sensing component is a device that converts pressure signals into electrical signals. Currently, sensing components developed based on MEMS (Micro-Electro-Mechanical Systems) technology are characterized by their small size, low cost, and high integration, and are widely used in automotive electronics, healthcare, and military aerospace. Among them, piezoresistive sensing components occupy the main market due to their wide applicability, mature technology, and low manufacturing difficulty.

[0003] Sensing components can monitor pressure signals from parts of industrial equipment, spacecraft, and other devices in real time to ensure safe and reliable operation. This requires sensors with excellent long-term stability and anti-interference capabilities. However, in current piezoresistive sensing components, surface ion residues and environmental electric field interference during manufacturing can generate delocalized electrons that affect the piezoresistive junction, ultimately leading to increased zero drift and decreased stability during sensor operation. Utility Model Content

[0004] Therefore, the technical problem to be solved by this utility model is to overcome the problem that in the prior art, ion residues on the surface of the piezoresistive sensing component during the manufacturing process and interference from the ambient electric field will form delocalized electrons, which will affect the piezoresistive junction and ultimately lead to abnormalities such as increased zero drift and decreased stability when the sensor is working.

[0005] To solve the above-mentioned technical problems, this utility model provides a sensing component, including,

[0006] Substrate;

[0007] A plurality of piezoresistive junctions are provided and are respectively disposed on one side of the substrate;

[0008] Side protection rings, wherein a plurality of side protection rings are provided, and the plurality of side protection rings are disposed on the substrate and respectively surround each of the piezoresistive junctions;

[0009] A protective layer is disposed on the side of the substrate on which the piezoresistive junction is located;

[0010] A shielding layer is disposed on the side of the protective layer away from the substrate, the shielding layer covers each of the piezoresistive junctions, and a plurality of through holes or blind holes are vertically formed on the shielding layer.

[0011] In one embodiment of this utility model, the shielding layer is provided with one or more pieces.

[0012] In one embodiment of this invention, the shielding layer is made of aluminum or polycrystalline silicon.

[0013] In one embodiment of the present invention, a groove is etched on the side of the substrate away from the piezoresistive junction.

[0014] In one embodiment of the present invention, an elastic diaphragm is disposed in the substrate between the piezoresistive junction and the groove.

[0015] In one embodiment of this utility model, a piezoresistive connection region is included. Several piezoresistive connection regions are provided, and the several piezoresistive connection regions are respectively disposed on one side of each piezoresistive junction and respectively connected to each piezoresistive junction.

[0016] In one embodiment of the present invention, a metal wiring is further included, one end of which is connected to one of the piezoresistive connection areas, and the other end extends outward through the protective layer.

[0017] In one embodiment of this utility model, the through hole or blind hole is a circular hole, a rectangular hole, a hexagonal hole, or a triangular hole.

[0018] In one embodiment of this utility model, the protective layer is a silicon dioxide layer.

[0019] A pressure sensor comprising a sensing component as described in any of the preceding claims.

[0020] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art:

[0021] The sensing component and pressure sensor described in this utility model, by incorporating a shielding layer with a perforated structure, not only enhance the sensor's anti-interference capability but also reduce thin-film stress, thereby improving the sensor's output sensitivity. Furthermore, the side protective ring and protective layer structure provide excellent protection, preventing damage and contamination to the components and ensuring stable sensor operation. The overall sensor structure is compact and rationally designed, with coordinated cooperation between components, ensuring sensor performance while facilitating processing and production. Attached Figure Description

[0022] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0023] Figure 1 This is a schematic diagram (first view) of the first structural form of the sensing component of a preferred embodiment of the present invention.

[0024] Figure 2This is a schematic diagram (second view) of the first structural form of the sensing component of a preferred embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram (first view) of a second structural form of the sensing component according to a preferred embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram (second view) of a second structural form of the sensing component according to a preferred embodiment of the present invention.

[0027] Figure 5 This is a schematic diagram of the shielding layer of the sensing component of a preferred embodiment of the present invention having through holes or blind holes of different shapes (where a is a schematic diagram of a circular hole, b is a schematic diagram of a square hole, c is a schematic diagram of a hexagonal hole, and d is a schematic diagram of a triangular hole);

[0028] Figure 6 This is a cross-sectional view of the shielding layer of the sensing component of the preferred embodiment of the present invention, showing a blind hole or a through hole (where e is a schematic diagram of a through hole and f is a schematic diagram of a blind hole).

[0029] Figure 7 This is a schematic diagram of the relative position of the piezoresistive junction and the shielding layer of the sensing component in a preferred embodiment of the present invention (where g is a schematic diagram of the piezoresistive junction located between a via or a blind via, and h is a schematic diagram of the piezoresistive junction having an overlapping area with the via or blind via).

[0030] Explanation of reference numerals in the accompanying drawings: 1. Substrate; 11. Groove; 2. Piezoresistive junction; 3. Side guard ring; 4. Protective layer; 5. Shielding layer; 6. Piezoresistive connection area; 7. Metal wiring. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0032] Example 1, refer to Figures 1-6 As shown, a sensing component of this utility model includes,

[0033] Substrate 1 serves as the foundational support structure for the entire sensing assembly, providing a stable platform for the placement of other components. A groove 11 is etched on the side of substrate 1 away from the piezoresistive junction 2. The groove 11 alters the mechanical properties of substrate 1, improving the sensor's pressure sensitivity. Simultaneously, an elastic diaphragm is disposed within substrate 1, located between the piezoresistive junction 2 and the groove 11. When external pressure is applied to the sensor, the elastic diaphragm deforms, causing a change in the resistance of the piezoresistive junction 2, thus enabling pressure detection.

[0034] Piezoresistive junction 2, several piezoresistive junctions 2 are provided and respectively disposed on one side of the substrate 1. The piezoresistive junction 2 is the core sensing component of the sensing component. Its resistance value changes with the pressure it is subjected to, thereby converting the pressure signal into an electrical signal.

[0035] Side protection ring 3, several side protection rings 3 are provided, several side protection rings 3 are provided on the substrate 1 and surround each piezoresistive junction 2 respectively. The side protection rings 3 can effectively protect the piezoresistive junction 2, prevent external impurities, moisture and other substances from entering the piezoresistive junction 2 area, avoid the piezoresistive junction 2 from being contaminated and damaged, and at the same time reduce the interference of the external environment on the piezoresistive junction 2, and ensure the normal operation of the piezoresistive junction 2.

[0036] The protective layer 4 is disposed on the side of the substrate 1 where the piezoresistive junction 2 is located. The protective layer 4 can effectively protect the piezoresistive junction 2, the side protection ring 3 and other components from external physical and chemical damage. At the same time, it can also play the role of insulation and isolation to prevent short circuits and other faults between components.

[0037] A shielding layer 5 is disposed on the side of the protective layer 4 away from the substrate 1. The shielding layer 5 covers each piezoresistive junction 2, and several through holes or blind holes are vertically formed on the shielding layer 5. By setting the shielding layer 5, external electromagnetic interference can be effectively blocked, improving the sensor's anti-interference capability and ensuring the accuracy of the measurement signal. The through holes or blind holes on the shielding layer 5 do not affect the overall structure and shielding effect of the shielding layer 5, and can also reduce the weight of the shielding layer 5 to a certain extent, reducing the stress impact on other components of the sensor.

[0038] This invention discloses a sensing component that, by incorporating a shielding layer 5 with a perforated structure, not only enhances the sensor's anti-interference capability but also reduces thin-film stress, thereby improving the sensor's output sensitivity. Furthermore, the side protective ring 3 and protective layer 4 provide excellent protection, preventing damage and contamination to the components and ensuring stable sensor operation. The overall sensor structure is compact and rationally designed, with coordinated operation between components, guaranteeing sensor performance while facilitating processing and production.

[0039] Furthermore, the shielding layer 5 is made of highly conductive, low-stress materials such as polycrystalline silicon, aluminum, or graphene. Aluminum possesses excellent conductivity and shielding performance, and is relatively inexpensive and easy to process. Polycrystalline silicon exhibits good stability and high-temperature resistance, making it suitable for some special high-temperature environments. Graphene, with its ultra-thin structure and excellent electrical and temperature properties, is the preferred material for electromagnetic shielding. Honeycomb porous graphene can shield 99.999999% of incident electromagnetic waves, far superior to traditional metal / polycrystalline silicon materials. Moreover, due to its excellent mechanical properties, graphene introduces almost no stress when used as the material for shielding layer 5, allowing for large-area coverage of the graphene shielding layer.

[0040] Furthermore, a groove 11 is etched on the side of the substrate 1 away from the piezoresistive junction 2.

[0041] Furthermore, an elastic diaphragm is disposed in the substrate 1 between the piezoresistive junction 2 and the groove 11.

[0042] Furthermore, the system includes several piezoresistive connection regions 6, each located on one side of a piezoresistive junction 2 and connected to that junction. The piezoresistive connection regions 6 serve to connect the piezoresistive junction 2 to other components, facilitating the connection between the piezoresistive junction 2 and external circuits.

[0043] Reference Figure 1 and Figure 3 As shown, it further includes a metal wiring 7, one end of which is connected to a piezoresistive junction area 6, and the other end extends outward through the protective layer 4. The metal wiring 7 is used to transmit the electrical signal generated by the piezoresistive junction 2 to an external circuit for signal processing and analysis.

[0044] Furthermore, the side protection ring 3 and the shielding layer 5 can be connected by metal wiring 7 and simultaneously connected to an external detection circuit; and the side protection ring 3 can also be disconnected from the shielding layer 5, and instead each be connected to an external detection circuit via metal wiring 7. At the same time, neither the side protection ring 3 nor the shielding layer 5 can be connected to an external detection circuit.

[0045] Furthermore, the protective layer 4 is a silicon dioxide layer. Silicon dioxide has good insulation properties and chemical stability, and can play a good protective role.

[0046] The fabrication process of the sensing component:

[0047] First, the piezoresistive region (i.e., the piezoresistive junction 2 mentioned above), the piezoresistive connection region 6, and the side guard ring 3 are formed through multiple exposure and implantation / doping processes. The dopant material of the side guard ring 3 can be boron / indium / arsenic / phosphorus / antimony; the piezoresistive region and the piezoresistive connection region 6 are doped in the same way, and can be boron / indium / arsenic / phosphorus / antimony.

[0048] Then, a layer of SiO2 with a wavelength of 50nm-2000nm is formed, namely the protective layer 4, through methods such as thermal oxidation / LPCVD (low-pressure vapor deposition) / PECVD (plasma-enhanced vapor deposition);

[0049] Next, the metal wiring 7 and the piezoresistive connection region 6 are exposed by photolithography and etching methods;

[0050] Next, an aluminum layer of 100nm-1500nm is sputtered / evaporated by photolithography and then peeled off; or an aluminum layer of 100nm-1500nm is sputtered / evaporated and removed by photolithography, dry etching or wet etching to form an external circuit connection area.

[0051] Next, single-layer / multi-layer graphene is transferred to the chip surface by a transfer method, and the target shielding layer 5 region is obtained by photolithography and etching processes; or graphene is laid on the chip surface by spin coating, and the target shielding layer 5 region is obtained by drying, photolithography and etching.

[0052] Finally, the window is etched out by photolithography on the back and the groove 11 is etched out by etching / deep silicon etching. Example

[0053] Reference Figures 1-4 As shown, the shielding layer 5 is further provided as one or more pieces. Specifically, the shielding layer 5 can be configured as a single piece structure with a large area, covering all the piezoresistive junctions 2 with one shielding layer 5; at the same time, multiple shielding layers 5 with smaller areas can also be provided, in which case each shielding layer 5 corresponds to a set of piezoresistive junctions 2 and is respectively disposed on top of each piezoresistive junction 2 to cover it, further reducing the stress effect. Example

[0054] Reference Figure 5 As shown, based on Embodiment 1, the through hole or blind hole can be a circular hole, a rectangular hole, a hexagonal hole, or a triangular hole. Furthermore, the through hole or blind hole can also include other arbitrary shapes, which are not listed here. The number and distribution of holes are not limited, and the depth of the blind hole is also not limited. Example

[0055] Reference Figure 6 As shown, based on Embodiment 2, two hole arrangement methods for the shielding layer 5 are provided. One method is to place each piezoresistive junction 2 between the through holes / blind holes of its corresponding shielding layer 5 (i.e., the holes are located on both sides of the piezoresistive junction 2) without overlapping areas. The other method is to have overlapping areas between each piezoresistive junction 2 and the through holes / blind holes of its corresponding shielding layer 5.

[0056] In embodiment five, this utility model also discloses a pressure sensor, including the sensing component as in embodiment one, and converting the pressure signal of the sensing component into an output electrical signal.

[0057] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A sensing component, characterized in that: include, Substrate; A plurality of piezoresistive junctions are provided and are respectively disposed on one side of the substrate; Side protection rings, wherein a plurality of side protection rings are provided, and the plurality of side protection rings are disposed on the substrate and respectively surround each of the piezoresistive junctions; A protective layer is disposed on the side of the substrate on which the piezoresistive junction is located; A shielding layer is disposed on the side of the protective layer away from the substrate, the shielding layer covers each of the piezoresistive junctions, and a plurality of through holes or blind holes are vertically formed on the shielding layer.

2. The sensing component according to claim 1, characterized in that: The shielding layer consists of one or more layers.

3. The sensing component according to claim 1, characterized in that: The shielding layer is made of aluminum or polycrystalline silicon.

4. The sensing component according to claim 1, characterized in that: The substrate has grooves etched on the side away from the piezoresistive junction.

5. The sensing component according to claim 4, characterized in that: An elastic diaphragm is disposed in the substrate between the piezoresistive junction and the groove.

6. The sensing component according to claim 5, characterized in that: It includes a piezoresistive connection region, and several piezoresistive connection regions are provided. The several piezoresistive connection regions are respectively provided on one side of each piezoresistive junction and are respectively connected to each piezoresistive junction.

7. The sensing component according to claim 1, characterized in that: It also includes metal wiring, one end of which is connected to one of the piezoresistive connection areas, and the other end extends outward through the protective layer.

8. The sensing component according to claim 1, characterized in that: The through hole or blind hole can be a circular hole, a rectangular hole, a hexagonal hole, or a triangular hole.

9. The sensing component according to claim 1, characterized in that: The protective layer is a silicon dioxide layer.

10. A pressure sensor, characterized in that: Includes the sensing component as described in any one of claims 1-9.

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