Pressure sensing module and pressure sensor
By employing a pressure sensing module with a metal film resistor and an island beam structure, the problems of complex manufacturing process and low accuracy in existing technologies have been solved, achieving high sensitivity and high accuracy pressure detection, which is suitable for consumer electronics and industrial production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-28
- Publication Date
- 2026-03-17
AI Technical Summary
The existing pressure sensing modules use silicon-doped piezoresistors, which have a complex fabrication process and are difficult to control in terms of accuracy, resulting in poor sensor performance consistency, especially in the detection of small-range pressure with insufficient sensitivity and accuracy.
A varistor is fabricated using a metal film resistor and an island beam structure through processes such as sputtering, evaporation, and reactive ion etching. The pressure is concentrated by the island beam structure to improve the sensitivity and accuracy of the sensing module.
The manufacturing process has been simplified, and the sensitivity and accuracy of the sensor have been improved. In particular, it has achieved high sensitivity and good linear output in small-range pressure detection, and is suitable for high-temperature environments and high signal-to-noise ratio applications.
Smart Images
Figure CN224004556U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of microelectromechanical technology, and in particular to a pressure sensing module and a pressure sensor. Background Technology
[0002] Micro-Electro-Mechanical Systems (MEMS) pressure sensing modules are miniature devices with pressure detection capabilities fabricated using MEMS technology. They are mainly divided into three categories: piezoresistive, capacitive, and resonant, and can be applied in consumer electronics, industrial production, and other fields. Among them, piezoresistive MEMS pressure sensing modules have advantages such as small size, light weight, simple structure, low cost, and high measurement accuracy, and therefore have been widely used.
[0003] Existing pressure sensing modules typically use silicon-doped varistors, which require ion implantation or diffusion processes for fabrication. This process is not only complex, but also makes it difficult to control the dimensional accuracy of the resistors, resulting in poor performance consistency of the sensors. Utility Model Content
[0004] This invention provides a pressure sensing module and a pressure sensor. The pressure sensing module improves the accuracy of the pressure sensor by improving the manufacturing process.
[0005] In a first aspect, this application provides a pressure sensing module. The pressure sensing module includes: a first substrate and a second substrate disposed opposite to each other, with a cavity formed between the first substrate and the second substrate; a varistor and an island beam structure are disposed on the side of the first substrate away from the second substrate, the varistor being disposed on the side of the island beam structure away from the second substrate, and the varistor being a metal film resistor; the island beam structure extends along a predetermined direction, and the varistor is disposed at the end of the island beam structure in its own extension direction.
[0006] Based on the above solutions, some embodiments of this application provide a pressure sensing module that improves its sensitivity through a metal film resistor and an island beam structure. The varistor is a metal film resistor, thus avoiding the problems of complex manufacturing processes and low accuracy associated with silicon varistors. Furthermore, the pressure sensing module in this application has a small range, and the pressure is relatively small for a metal film resistor. Therefore, the island beam structure is added to concentrate the pressure onto the varistor, thereby improving the sensitivity and accuracy of the pressure sensing module.
[0007] In some embodiments, the first substrate includes a first substrate layer, a buried oxide layer, a device layer, and a first metal layer sequentially stacked in a direction away from the second substrate; at least a portion of the island beam structure is formed by the device layer, and the varistor is formed by the first metal layer.
[0008] In some embodiments, the pressure sensing module includes: the first substrate further includes a first insulating layer disposed between the device layer and the first metal layer; a portion of the island beam structure is formed by the first insulating layer.
[0009] In some embodiments, the device layer further includes a peripheral portion surrounding the island beam structure and the varistor; the peripheral portion and the island beam structure form a plurality of first grooves.
[0010] In some embodiments, the pressure sensing module further includes: interconnecting wires formed of the first metal layer and electrically connected to the piezoresistor; the interconnecting wires are disposed on a peripheral portion of the device layer and surround the piezoresistor and the plurality of first grooves.
[0011] In some embodiments, the spacing between the interconnecting wires and the boundary of the first groove is equal.
[0012] In some embodiments, there is a gap between the bottom surface of the first groove and the buried oxide layer.
[0013] In some embodiments, the first substrate layer has a through hole extending along its own thickness direction, and the first substrate layer and the buried oxide layer form a second groove, the second groove being used to form the cavity.
[0014] In some embodiments, the island beam structure includes a plurality of beams extending in different directions and intersecting at the center of the first substrate.
[0015] In some embodiments, the plurality of beams includes a first beam and a second beam, the first beam extending from one side of the first substrate to the opposite side along a first direction, and the second beam extending from one side of the first substrate to the opposite side along a second direction; the first direction and the second direction intersect; the number of varistors is four, and the four varistors are respectively disposed at both ends of the first beam and both ends of the second beam.
[0016] Secondly, this application provides a pressure sensor, which includes a pressure sensing module and an integrated circuit, wherein the integrated circuit is electrically connected to the pressure sensing module.
[0017] The beneficial effects of pressure sensors are the same as those of pressure sensing modules, and will not be repeated here.
[0018] Thirdly, this application provides an electronic device comprising: the pressure sensor described above.
[0019] The beneficial effects of electronic devices are the same as those of pressure sensors, and will not be repeated here. Attached Figure Description
[0020] The accompanying drawings, which are included to provide a further understanding of embodiments of this disclosure and form part of the embodiments of this disclosure, illustrate exemplary embodiments of this disclosure and are used to explain this disclosure, but do not constitute an undue limitation of this disclosure. In the drawings:
[0021] Figure 1 A schematic diagram of a pressure sensing module provided for some embodiments of this disclosure;
[0022] Figure 2 A side view of a pressure sensing module provided for some embodiments of this disclosure;
[0023] Figure 3 A top view of a first substrate provided for some embodiments of this disclosure;
[0024] Figure 4 A schematic diagram of the back side of a first substrate provided for some embodiments of this disclosure;
[0025] Figure 5 A top view of a second substrate provided for some embodiments of this disclosure;
[0026] Figure 6 A schematic diagram of another pressure sensing module provided for some embodiments of this disclosure;
[0027] Figure 7 A schematic diagram of a pressure sensor provided for some embodiments of this disclosure;
[0028] Figure 8 This is a schematic diagram of an electronic device provided for some embodiments of the present disclosure.
[0029] Figure Labels
[0030] 10. First substrate; 20. Second substrate; 11. Varistor; 12. Island beam structure; 121. First groove; 122. Second groove; 123. Beam; 1231. First beam; 1232. Second beam; 13. Device layer; 14. Buried oxide layer; 15. First substrate layer; 161. First metal layer; 162. Second metal layer; 163. Third metal layer; 17. First interconnect layer; 18. Metal pad; 19. Interconnect wire; 21. Second substrate layer; 22. Second interconnect layer; 31. First insulating layer; N. Cavity; 100. Pressure sensing module; 150. Integrated circuit; 200. Pressure sensor; 300. Electronic device; 310. Housing. Detailed Implementation
[0031] The technical solutions in some embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application are within the scope of protection of this application.
[0032] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this application. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific feature, structure, material, or characteristic may be included in any suitable manner in any one or more embodiments or examples.
[0033] Micro-Electro-Mechanical Systems (MEMS) pressure sensing modules are miniature devices with pressure detection capabilities fabricated using MEMS technology. They are mainly divided into three categories: piezoresistive, capacitive, and resonant, and can be applied in consumer electronics, industrial production, and other fields. Among them, piezoresistive MEMS pressure sensing modules have advantages such as small size, light weight, simple structure, low cost, and high measurement accuracy, and therefore have been widely used.
[0034] Existing pressure sensing modules typically employ doped silicon varistors, which require ion implantation or diffusion processes for fabrication. This process is not only complex, but also makes it difficult to control the dimensional accuracy of the resistors, resulting in poor sensor performance consistency. Furthermore, silicon varistors inherently have high noise levels, further reducing the sensor's signal-to-noise ratio.
[0035] Meanwhile, existing pressure sensing modules are typically divided into large-range and small-range modules. Large-range pressure sensing modules are mainly used to measure larger pressure values, typically in environments requiring high pressure. Small-range pressure sensing modules are mainly used to measure smaller pressure values, typically in environments requiring high precision and sensitivity. Large-range modules, due to their larger measurement range, may have relatively lower accuracy and resolution, but they can still meet the needs of most industrial applications. Small-range modules, on the other hand, due to their smaller measurement range, typically have higher accuracy and resolution to meet the need for precise measurement of minute pressure changes.
[0036] It should be noted that a piezoresistive MEMS pressure sensing module includes a pressure-sensitive membrane (also called a strain membrane), a piezoresistive resistor, and a circuit structure. The piezoresistive resistor and the circuit structure are electrically connected. The working principle of the piezoresistive MEMS pressure sensing module is as follows: a piezoresistive resistor is fabricated on the strain membrane. Under external pressure, the strain membrane deforms, generating stress. The piezoresistive resistor changes resistance under stress. Finally, the change in resistance is converted into a voltage output through an interconnect structure (such as a Wheatstone bridge). Therefore, the magnitude of the external pressure can be reflected by the voltage output value.
[0037] Based on this, some embodiments of this application provide a pressure sensing module. For example... Figure 1 As shown, the pressure sensing module 100 includes a first substrate 10 and a second substrate 20 disposed opposite to each other.
[0038] A cavity is formed between the first substrate 10 and the second substrate 20; a varistor 11 and an island beam structure 12 are provided on the side of the first substrate 10 away from the second substrate 20, and the varistor 11 is provided on the side of the island beam structure 12 away from the second substrate 20.
[0039] Among them, the varistor 11 is a metal film resistor, and the island beam structure 12 extends along a preset direction, with the varistor 11 disposed at the end of the island beam structure 12 in its own extension direction.
[0040] First, the pressure sensing module 100 in this application uses a metal film resistor as the pressure-sensitive resistor. This avoids the problems of complex manufacturing process and low precision of silicon pressure-sensitive resistors. At the same time, metal film resistors have a high strain coefficient, low material noise factor, and low temperature coefficient of resistance, which means higher sensitivity, better temperature stability, and lower noise. This is helpful for high-temperature environments and signal-to-noise ratio. In terms of manufacturing process, metal films may not require complex ion implantation or diffusion, which simplifies the steps and improves precision.
[0041] Metal film resistors are generally used in pressure sensing modules 100 with large range because although their sensitivity is high, they require a large pressure value. However, the pressure sensing module 100 in this application has a small range and a low pressure value, so an island beam structure is required.
[0042] The island beam structure 12 is located below the varistor 11. By limiting the deformation of the central region of the first substrate 10, it concentrates the external pressure to the region below the varistor 11, effectively improving the uniformity and concentration of stress distribution. At the same time, combined with the high sensitivity characteristics of the metal film resistor, the pressure sensing module 100 can still achieve high sensitivity and good linearity in small or ultra-small range pressure detection.
[0043] Meanwhile, the metal film resistor is directly formed on the surface of the first substrate 10 through processes such as sputtering, evaporation, reactive ion etching, and lift-off.
[0044] Sputtering is a physical vapor deposition technique used to deposit thin films on a substrate. During sputtering, a metal target is bombarded by high-energy particles in an inert gas environment (such as argon), causing atoms or molecules on the target surface to be sputtered out and deposited on the substrate to form a thin film. For the fabrication of metal film resistors, sputtering can be used to uniformly deposit a metal film on a first substrate 10, which will serve as the resistive material for the varistor 11.
[0045] Evaporation is another commonly used physical vapor deposition technique. During evaporation, the metal is heated to a sufficiently high temperature, causing its atoms or molecules to gain enough energy to evaporate from the surface and condense on the substrate to form a thin film. For the fabrication of metal film resistors, evaporation technology is typically used to heat a metal target in a vacuum environment, causing it to evaporate and deposit onto a ceramic or glass substrate. By controlling the evaporation rate and time, the thickness of the metal film can be precisely controlled, thereby adjusting the resistance value of the varistor 11.
[0046] Reactive ion etching (RIE) is a dry etching technique that combines physical bombardment and chemical reaction to remove material. During RIE etching, the etching gas is ionized to form plasma. Ions in the plasma are accelerated by an electric field and bombard the material surface, simultaneously reacting chemically with it. This dual physical and chemical action gives RIE the advantages of high precision and high selectivity.
[0047] Lift-off is a stripping process used to remove unwanted thin-film material. In the lift-off process, a layer of photoresist or a metal mask is first coated onto a substrate, and the desired pattern is formed using photolithography. Then, a target coating (such as a metal film) is deposited onto the mask. Finally, the photoresist is dissolved using a stripper or the metal mask is mechanically removed, peeling away the unwanted coating along with the mask, leaving the desired pattern structure on the substrate. For the fabrication of metal film resistors, the lift-off process may not be the primary manufacturing step, but in some cases, it may be used to remove unwanted metal film portions or to adjust the shape and size of the varistor 11. However, it is more common to use techniques such as grooving to adjust the resistance value of the metal film resistor.
[0048] In some embodiments, the material of the metal film varistor 11 may be nickel-chromium alloy NiCr, platinum Pt, iron-nickel alloy FeNi, boron titanium bismuth (TiB), tantalum nitride (TaN), titanium nitride (TiN), etc.
[0049] Based on the above solutions, some embodiments of this application provide a pressure sensing module that improves its sensitivity through a metal film resistor and an island beam structure. The varistor is a metal film resistor, thus avoiding the problems of complex manufacturing processes and low accuracy associated with silicon varistors. Furthermore, the pressure sensing module in this application has a small range, and the pressure is relatively small for a metal film resistor. Therefore, the island beam structure is added to concentrate the pressure onto the varistor, thereby improving the sensitivity and accuracy of the pressure sensing module.
[0050] like Figure 1 As shown, in some embodiments, the first substrate 10 includes a first substrate layer 15, a buried oxide layer 14, a device layer 13 and a first metal layer 161 sequentially stacked in a direction away from the second substrate 20.
[0051] At least a portion of the island beam structure 12 is formed by the device layer 13, and the varistor 11 is formed by the first metal layer 161.
[0052] The varistor 11 is formed through the first metal layer 161, that is, the varistor 11 is a metal film resistor, thereby avoiding the doping process error of traditional silicon-based resistors and improving the sensitivity and accuracy of the varistor 11.
[0053] The island beam structure 12 can be partially formed by the device layer 13, or it can be entirely formed by the device layer 13.
[0054] In some embodiments, the first substrate 10 further includes a first insulating layer 31 disposed between the device layer 13 and the first metal layer 161.
[0055] The island beam structure is partially formed by the first insulating layer 31.
[0056] like Figure 1 As shown, in some embodiments, device layer 13 also includes a peripheral portion surrounding island beam structure 12 and varistor 11.
[0057] Among them, the peripheral part and the island beam structure 12 form a plurality of first grooves 121.
[0058] Two adjacent first grooves 121 are spaced apart; the island beam structure 12 is located between two adjacent first grooves 121.
[0059] First, by locally weakening the rigidity of the device layer 13, the first groove 121 can concentrate the external pressure to the island beam structure 12 area, thereby making the pressure on the varistor 11 greater. Moreover, the varistor 11 is a metal film resistor, which is suitable for high pressure conditions and can improve sensitivity.
[0060] Meanwhile, the spacing of the first groove 121 can be designed to avoid the risk of fracture caused by excessive stress concentration.
[0061] In some embodiments, the island beam structure 12 includes microelectronic materials, the device layer 13 includes microelectronic materials, and the microelectronic materials included in the island beam structure 12 are the same as those included in the device layer 13.
[0062] In other words, the island beam structure 12 is disposed in the device layer 13, and the island beam structure 12 is formed by etching the device layer 13.
[0063] In this design, both the island-beam structure 12 and the device layer 13 use the same microelectronic material (single-crystal silicon). Using the same material can avoid thermal mismatch stress at the interface of heterogeneous materials and reduce the risk of structural failure under high temperature or cyclic loading. At the same time, the island-beam structure 12 can be formed directly through etching without additional material deposition or bonding steps, which can reduce costs and improve yield.
[0064] In some embodiments, there is a gap between the bottom surface of the first groove 121 and the buried oxide layer 14.
[0065] In other words, a certain gap is maintained between the bottom of the first groove 121 and the buried oxide layer 14, without penetrating to the buried oxide layer 14. This preserves a portion of the device layer 13 thickness as bottom support for the first groove, preventing the island beam structure 12 from becoming too rigid due to excessive etching and ensuring the pressure sensing module 100's overload resistance. Simultaneously, the spacing design provides tolerance space for the etching process, avoiding exposure or damage to the buried oxide layer 14 due to etching depth errors.
[0066] The island beam structure 12 includes multiple beams 123, which extend in different directions and intersect at the center of the first substrate 10 (see reference). Figure 2 and Figure 3 ).
[0067] like Figure 3 As shown, the plurality of beams 123 include: a first beam 1231 and a second beam 1232. The first beam 1231 extends from one side of the first substrate 10 to the opposite side along a first direction X, and the second beam 1232 extends from one side of the first substrate 10 to the opposite side along a second direction Y. The first direction X and the second direction Y intersect.
[0068] There are four varistor 11s, which are respectively located at both ends of the first beam 1231 and both ends of the second beam 1232.
[0069] For example, there are four varistors 11 arranged around the circumference of the first substrate 10; there are four first grooves 121, one of which surrounds the varistor 11 on the side away from the center of the first substrate 10.
[0070] The first groove 121 is arranged around the outside of the varistor 11, which guides the strain caused by pressure to be evenly distributed in the resistive region, and can suppress nonlinear errors caused by asymmetric deformation.
[0071] like Figure 1 As shown, the first substrate layer 15 has a through hole extending along its own thickness direction, and the first substrate layer 15 and the buried oxide layer 14 form a second groove 122, which is used to form a cavity.
[0072] In some embodiments, the pressure sensing module 100 further includes: interconnecting wires 19 electrically connected to a plurality of piezoresistors 11; the interconnecting wires 19 are disposed on a peripheral portion of the device layer 13 and are disposed around the plurality of piezoresistors 11 and a plurality of first grooves 121.
[0073] The equidistant interconnect design ensures that the length of each resistor lead is consistent with its impedance, reducing electrical crosstalk and signal delay differences.
[0074] In some embodiments, the spacing between the interconnecting wires 19 and the boundary of the first groove 121 is equal.
[0075] The second substrate 20 includes: a second substrate layer 21, a third metal layer 163, and a second interconnect layer 22.
[0076] The third metal layer 163 is annular, and the side of the third metal layer 163 away from the first substrate 10 is connected to the second substrate layer 21; the side of the second connecting layer 22 away from the first substrate 10 is connected to the second metal layer 22, and the side of the second connecting layer 22 close to the first substrate 10 is connected to the first substrate 10.
[0077] For example, the material of the second metal layer 162 or the third metal layer 163 may be a Cr / Au layer, a Ti / Cr / Au layer, a Cr / Ni / Au layer, etc.
[0078] The first substrate 10 includes four varistors 11 and four metal pads 18. The four varistors 11 are connected in series and end to end to form a loop circuit.
[0079] Among them, the four varistors 11 are located at the center of the four edges of the varistor film (refer to...). Figure 2 The four resistive films have consistent edge spacing, and the width of the four varistor 11 is the same as the total length. The number of folds can be 1-10. The top and bottom varistor 11 have the same structural dimensions, and the left and right varistor 11 have the same structural dimensions. (Refer to...) Figure 3 In this application, the discount is 60%.
[0080] For example, the material of the interconnecting wire 19 can be a low resistivity material, such as any one or more combinations of Al, Ti / Al, Au and Cr / Au, so that a good circuit path can be formed.
[0081] In this way, the varistor 11 is located on the first substrate 10, the interconnecting wire 19 is located on the first substrate 10, the varistor 11 and the interconnecting wire 19 are electrically connected, and multiple metal pads 18 are connected to the middle section of the interconnecting wire 19, that is, the four corners of the first substrate 10, thereby forming a Wheatstone bridge structure.
[0082] The Wheatstone bridge structure includes: one input terminal, two output terminals, and one ground terminal.
[0083] It should be noted that the two output terminals of the Wheatstone bridge structure are located diagonally, while the positions of the input terminal and the ground terminal are not required.
[0084] The metal pad 18 can be square, rectangular, circular, elliptical, or other shapes, with a side length or straight dimension of 50-150μm.
[0085] In some embodiments, the first substrate layer 15 is an SOI substrate layer. The SOI substrate layer can be etched down to the buried oxide layer 14 to form a cavity, or a portion of the substrate layer can be etched to form a cavity, and a pressure-sensitive film can be formed inside the cavity.
[0086] For example, the first substrate layer 15 can be made of silicon. The buried oxide layer 14 can be made of an insulating material, such as any one or more combinations of SiO2, SiN, and glass. In this case, the first substrate layer 15 and the buried oxide layer 14 can constitute a pressure-sensitive film.
[0087] In other words, the region where the varistor 11 is located is directly opposite to the region where the varistor film is located, corresponding to the orthogonal projection of the multiple varistor 11 onto the first substrate layer 15, and is located within the region where the varistor film is located. The second metal layer 162 and the first connecting layer 17 surround it from above, and the third metal layer 163 and the second connecting layer 22 surround it from below. The third metal layer 163 and the second connecting layer 22 are then fixed to the second substrate layer 21, thereby forming a sealed or vacuum structure.
[0088] For example, refer to Figure 4 and Figure 5 The material of the first connecting layer 17 or the second connecting layer 22 can be a eutectic solder, such as one or more combinations of AuSn, AgSn, CuSn and SnAgCu.
[0089] Reference Figure 4 and Figure 5In some embodiments, when the first substrate 10 and the second substrate 20 enclose a vacuum cavity N, the pressure sensing module 100 further includes a getter 24 located within the vacuum cavity N.
[0090] The pressure sensing module 100 mentioned above is an absolute pressure sensing module 100, which can measure the absolute value of pressure changes and has the advantages of high accuracy and large measurement range.
[0091] like Figure 6 and Figure 7 As shown, some embodiments of this disclosure also provide a pressure sensor 200. The pressure sensor 200 includes a pressure sensing module 100 and an integrated circuit 150 provided in the above-described technical solutions.
[0092] The integrated circuit 150 is electrically connected to the metal pad 18 of the pressure sensing module 100.
[0093] Understandably, the pressure-sensitive resistor 11 generates a voltage signal when it receives pressure, and transmits this voltage signal to the integrated circuit 150. The integrated circuit 150 can further process the voltage signal and output it as a digital signal to provide feedback on the pressure magnitude. In this way, pressure measurement data can be transmitted.
[0094] like Figure 8 As shown, some embodiments of this disclosure also provide an electronic device 300. The electronic device 300 includes a housing 310 and a pressure sensor 200 disposed on the housing 310.
[0095] In some examples, the electronic device 300 can be a mobile phone or a computer; it can also be a portable electronic device 300, so that the pressure sensing module 100 can be applied to technical scenarios that require pressure measurement, such as automobiles and industrial manufacturing.
[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A pressure sensing module, characterized by, The pressure sensing module comprises a first substrate and a second substrate oppositely arranged, and a cavity is formed between the first substrate and the second substrate; The first substrate is provided with a pressure sensitive resistor and an island beam structure on a side away from the second substrate, the pressure sensitive resistor is arranged on a side of the island beam structure away from the second substrate, and the pressure sensitive resistor is a metal film resistor; The island beam structure extends along a preset direction, and the pressure sensitive resistor is arranged at an end of the island beam structure in the extending direction of the island beam structure.
2. The pressure sensing module of claim 1, wherein, The first substrate comprises a first substrate layer, a buried oxygen layer, a device layer and a first metal layer which are sequentially arranged in a direction away from the second substrate; At least part of the island beam structure is formed by the device layer, and the pressure sensitive resistor is formed by the first metal layer.
3. The pressure sensing module of claim 2, wherein, The first substrate further comprises a first insulating layer arranged between the device layer and the first metal layer; Part of the island beam structure is formed by the first insulating layer.
4. The pressure sensing module of claim 2, wherein, The device layer further comprises a peripheral portion surrounding the island beam structure and the pressure sensitive resistor; The peripheral portion and the island beam structure enclose a plurality of first grooves.
5. The pressure sensing module of claim 4, wherein, The pressure sensing module further comprises: An interconnection wire formed by the first metal layer and electrically connected with the pressure sensitive resistor; the interconnection wire is arranged on the peripheral portion of the device layer and surrounds the pressure sensitive resistor and the plurality of first grooves.
6. The pressure sensing module of claim 5, wherein, The spacing between the interconnection wire and the boundary of the first groove is equal.
7. The pressure sensing module of claim 4, wherein, The spacing between the groove bottom surface of the first groove and the buried oxygen layer is equal.
8. The pressure sensing module of claim 2, wherein, The first substrate layer is provided with a through hole penetrating through the thickness direction of the first substrate layer, the first substrate layer and the buried oxygen layer form a second groove, and the second groove is used for forming the cavity.
9. The pressure sensing module according to any one of claims 1 to 8, characterized in that The island beam structure comprises a plurality of beams, the extending directions of the plurality of beams are different, and the plurality of beams intersect at a central position of the first substrate; The plurality of beams comprise a first beam and a second beam, the first beam extends from one side of the first substrate to the opposite side along a first direction, and the second beam extends from one side of the first substrate to the opposite side along a second direction; the first direction and the second direction intersect; The number of the pressure sensitive resistors is four, and the four pressure sensitive resistors are respectively arranged at two ends of the first beam and two ends of the second beam.
10. A pressure sensor, characterized by The pressure sensing module comprises: The pressure sensing module according to any one of claims 1 to 9; An integrated circuit electrically connected with the pressure sensing module.