Pressure sensing chip and pressure sensor

Abstract

A pressure sensing chip and a pressure sensor, relating to the technical field of sensors, and aiming at prolonging the service life of sensors and expanding application scenarios. The pressure sensing chip comprises: a pressure sensing film; a substrate, connected to the pressure sensing film, wherein a cavity is formed between the pressure sensing film and the substrate; a pressure-sensitive assembly, located between the substrate and the pressure sensing film, wherein the orthographic projection of the pressure-sensitive assembly and the orthographic projection of the cavity on the substrate partially overlap; and a first signal output structure, arranged on the side of the substrate facing away from the pressure sensing film, wherein the first signal output structure is electrically connected to the pressure-sensitive assembly by means of a lead structure passing through the substrate.

Description

Pressure sensing chip and pressure sensor Technical Field

[0001] The present disclosure relates to the field of sensor technology, and in particular to a pressure sensing chip and a pressure sensor. Background Art

[0002] A pressure sensor is a device that can convert pressure signals into electrical signals. It usually consists of three parts: a sensitive chip, a processing circuit, and a package. The sensitive chip (also known as a pressure chip) is the structure that directly senses the pressure signal and is the core component of the entire sensor.

[0003] Overview

[0004] The present disclosure provides a pressure sensing chip, comprising:

[0005] pressure-sensitive film;

[0006] a substrate connected to the pressure-sensitive film, with a cavity formed between the pressure-sensitive film and the substrate;

[0007] a pressure-sensitive component located between the substrate and the pressure-sensitive film, wherein the pressure-sensitive component partially overlaps with an orthographic projection of the cavity on the substrate;

[0008] a first signal output structure, disposed on a side of the substrate away from the pressure-sensitive film;

[0009] The first signal output structure is electrically connected to the pressure-sensitive component through a lead structure running through the substrate.

[0010] For example, the orthographic projection of the pressure-sensitive component on the substrate is located within the orthographic projection of the cavity on the substrate; or, the orthographic projection of the pressure-sensitive component on the substrate overlaps with the orthographic projection of the cavity on the substrate.

[0011] For example, the pressure sensitive component is located on a side of the pressure sensitive film close to the substrate, or the pressure sensitive components are distributed on opposite sides of the cavity in a target direction, wherein the target direction is a direction perpendicular to the substrate toward the pressure sensitive film.

[0012] For example, the pressure-sensitive component includes a first electrode and a second electrode that are spaced apart, and the first electrode and the second electrode are both arranged on a side of the pressure-sensitive film close to the cavity;

[0013] The first electrode and the second electrode are configured to convert the deformation of the pressure-sensitive film into a resistance signal.

[0014] For example, the pressure-sensitive component includes a third electrode and a fourth electrode, and the third electrode and the fourth electrode are configured to convert the deformation of the pressure-sensitive film into a capacitance signal;

[0015] The third electrode is arranged on a side of the pressure-sensitive film close to the cavity, and the fourth electrode is arranged on a side of the substrate close to the cavity; the orthographic projection of the third electrode on the substrate overlaps with the fourth electrode.

[0016] For example, the pressure-sensitive film includes a thinned area and a non-thinned area, and the thickness of the thinned area is smaller than the thickness of the non-thinned area;

[0017] The orthographic projection of the thinned area on the substrate overlaps with the orthographic projection of the cavity on the substrate.

[0018] For example, the orthographic projection of the thinned area on the substrate is covered by the orthographic projection of the cavity on the substrate, and the orthographic projection of the non-thinned area on the substrate overlaps with the orthographic projection of the cavity on the substrate.

[0019] For example, the lead structure includes: a first lead post and a lead electrode, one end of the lead electrode is connected to the pressure sensitive component, and the other end passes through and is connected to one end of the first lead post, and the other end of the first lead post passes through the substrate and is electrically connected to the first signal output structure.

[0020] For example, the lead-out electrode and the pressure-sensitive component are arranged in the same layer.

[0021] For example, an orthographic projection of the extraction electrode on the substrate does not overlap with an orthographic projection of the cavity on the substrate.

[0022] For example, an insulating layer is further provided on a side of the pressure-sensitive film close to the substrate; wherein the pressure-sensitive component is located on a side of the insulating layer away from the pressure-sensitive film.

[0023] For example, the pressure sensing chip further includes: an isolation sheet, and a sealing ring located on at least one side of the isolation sheet;

[0024] The pressure-sensitive film is sealed and connected to the substrate through the sealing ring and the isolation sheet.

[0025] For example, the first signal output structure includes: a signal input terminal and a signal output terminal;

[0026] The signal input terminal is connected to the first lead post and the signal output terminal respectively, and the signal output terminal is configured to transmit the electrical signal input by the signal input terminal to an external signal processing circuit.

[0027] For example, the signal access terminal includes:

[0028] a metal binding area, disposed on a side of the substrate facing away from the cavity and electrically connected to the first lead post;

[0029] The metal transition region is arranged on a side of the substrate away from the pressure-sensitive film and is respectively connected to the metal binding region and the signal output end.

[0030] For example, the signal output terminal includes any one of a metal wire, a solder joint, and a first bonding bump;

[0031] The first bonding bump is integrally formed with the metal transition region and is used for bonding with a second bonding bump on an external signal processing circuit.

[0032] Among them, a pressure sensor includes the pressure sensing chip and a packaging structure, and the packaging structure includes:

[0033] signal processing circuit;

[0034] a packaging portion, on which the pressure sensing chip is mounted, the packaging portion having a sealed cavity, in which at least the signal processing circuit is located;

[0035] a second signal output structure, configured to the packaging portion;

[0036] Among them, the first signal output structure of the pressure sensing chip is electrically connected to the input end of the signal processing circuit, the output end of the signal processing circuit is electrically connected to the second signal output structure, and the second signal output structure is configured to output the electrical signal processed by the signal processing circuit to the outside.

[0037] For example, the pressure sensing chip is entirely located outside the sealed cavity, and the first signal output structure is connected to the packaging portion;

[0038] Alternatively, the pressure sensing chip is entirely located within the sealed cavity, wherein the pressure sensing film is sealedly connected to the packaging portion, the packaging portion is provided with a through hole allowing the medium to be measured to flow in, and the through hole is connected to the pressure sensing film.

[0039] For example, the packaging portion includes:

[0040] a mounting portion, wherein the pressure sensing chip and the signal processing circuit are mounted on the same side or on two opposite sides of the mounting portion;

[0041] a supporting portion, connected to the mounting portion and configured to support the mounting portion;

[0042] a sealing shell, hermetically connected to the support portion to form the sealed cavity with the support portion; or, the sealing shell is hermetically connected to the mounting portion to form the sealed cavity with the support portion;

[0043] Wherein, the second signal output structure is connected to the sealed shell.

[0044] For example, the pressure sensing chip and the signal processing circuit are located on the same side of the mounting portion, and the pressure-sensitive film of the pressure sensing chip is bonded to the mounting portion;

[0045] Wherein, a first through hole is provided on both the mounting portion and the supporting portion for allowing the medium to be measured to flow in, and a side of the pressure-sensitive membrane facing away from the cavity is communicated with the first through hole.

[0046] For example, the radius of the first through hole on the mounting portion is smaller than the radius of the first through hole on the supporting portion.

[0047] For example, the pressure sensing chip and the signal processing circuit are respectively located on opposite sides of the mounting portion, a gap exists between the pressure sensing chip and the supporting portion, and the first signal output structure is bonded to the mounting portion;

[0048] A third lead post passes through the mounting portion, one end of the third lead post is connected to the first signal output structure, and the other end of the third lead post is connected to the signal processing circuit.

[0049] For example, the mounting portion includes: a signal adapter plate and an insulating base arranged opposite to each other;

[0050] The signal transfer board is located in the sealed cavity, and the signal processing circuit is located on a side of the signal transfer board away from the support portion;

[0051] Wherein, a film thickness circuit is further provided on the signal transfer board, and the film thickness circuit is provided on the same side as the signal processing circuit and is electrically connected to the signal processing circuit;

[0052] Among them, the first signal output structure is encapsulated on the side of the insulating base away from the signal adapter board, one end of the third lead column is electrically connected to the first signal output structure, and the other end passes through the insulating base and the signal adapter board in sequence, and is electrically connected to the signal processing circuit.

[0053] For example, the support portion is provided with a penetrating second through hole, one end of the second through hole is used for the medium to be measured to flow in, and the other end is communicated with a side of the pressure-sensitive membrane away from the cavity.

[0054] For example, the insulating base and the pressure sensing chip are located at the liquid outlet of the second through hole; the second through hole is opened on the supporting portion;

[0055] Alternatively, the insulating base and the pressure sensing chip are located at the liquid inlet of the second through hole, and the insulating base and the second through hole are sealed and connected, and the two third lead posts pass through the insulating base and extend in the second through hole, and then pass through the signal adapter board.

[0056] For example, the first signal output structure is welded to one side of the mounting portion via a welding spot;

[0057] The mounting portion further includes a protective layer disposed on the same side as the pressure sensing chip, the protective layer completely covers the solder joints, and the thickness of the protective layer is less than the thickness of the pressure sensing chip.

[0058] For example, the first signal output structure includes a first bonding bump; further comprising a slurry bonding layer and spaced-apart second bonding bumps on the mounting portion; wherein the slurry bonding layer is located outside the first bonding bump;

[0059] The second bonding bump is bonded to the first bonding bump, and the slurry bonding layer is hermetically bonded to the substrate of the pressure sensing chip.

[0060] The pressure sensing chip disclosed in the present invention includes a pressure-sensitive film and a substrate sealed to the pressure-sensitive film, wherein the substrate and the pressure-sensitive film enclose a cavity; wherein a pressure-sensitive component is provided between the substrate and the pressure-sensitive film, the pressure-sensitive component is located between the substrate and the pressure-sensitive film, and the pressure-sensitive component and the positive projection of the cavity on the substrate partially overlap, and a first signal output structure is provided on one side of the substrate, and the first signal output structure is electrically connected to the pressure-sensitive component via a lead structure running through the substrate. The pressure sensing chip proposed in the present invention has a main electrical function in the pressure sensing chip, and the electrode structure having the main electrical function is protected between the substrate and the pressure-sensitive film, so that the pressure-sensitive component will not be affected by the external environment, and can directly measure the pressure of the corrosive medium to be measured.

[0061] The above description is only an overview of the technical solution of the present disclosure. In order to more clearly understand the technical means of the present disclosure, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present disclosure more obvious and easy to understand, the specific implementation methods of the present disclosure are listed below.

[0062] BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following is a brief introduction to the drawings required for the description of the embodiments or related technologies. Obviously, the drawings described below are some embodiments of the present disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without inventive efforts. It should be noted that the scales in the drawings are for illustration only and do not represent the actual scale.

[0064] FIG1 shows a schematic cross-sectional structure diagram of a pressure sensing chip according to an embodiment of the present disclosure;

[0065] FIG2 shows a schematic cross-sectional structure diagram of another pressure sensing chip according to an embodiment of the present disclosure;

[0066] FIG3 a shows a schematic cross-sectional view of a lead-out structure in a first signal output structure;

[0067] FIG3 b shows a schematic cross-sectional structure diagram of another lead-out structure in the first signal output structure;

[0068] FIG3 c shows a schematic cross-sectional structure diagram of another lead-out structure in the first signal output structure;

[0069] FIG4 shows a schematic cross-sectional structure diagram of another pressure sensing chip;

[0070] Figures 5a-5c respectively show schematic cross-sectional structures of three pressure sensing chips;

[0071] FIG6 a shows a schematic cross-sectional structure diagram of a piezoresistive pressure sensing chip;

[0072] FIG6 b shows a schematic cross-sectional structure diagram of a capacitive pressure sensing chip;

[0073] FIG6 c shows a schematic cross-sectional structure diagram of another capacitive pressure sensing chip;

[0074] FIG6 d shows a schematic cross-sectional structure diagram of the pressure sensing chip in Example A1;

[0075] FIG6e shows a schematic cross-sectional structure diagram of the pressure sensing chip in Example A2;

[0076] FIG7a and FIG7b respectively show schematic cross-sectional structures of two pressure sensors according to an embodiment of the present disclosure;

[0077] Figures 8a-8b show schematic cross-sectional structures of two pressure sensors respectively;

[0078] FIG9 shows a schematic structural diagram of a support portion in an embodiment of the present disclosure;

[0079] FIG10 shows a schematic structural diagram of a second signal output structure in an embodiment of the present disclosure;

[0080] FIG11a shows a schematic diagram of a packaging structure of a pressure sensing chip in an embodiment of the present disclosure;

[0081] FIG11 b shows a schematic diagram of a packaging structure of another pressure sensing chip according to an embodiment of the present disclosure;

[0082] FIG11c shows a schematic diagram of a packaging structure of a mounting portion and a pressure sensing chip in an embodiment of the present disclosure;

[0083] FIG11d and FIG11e respectively show schematic diagrams of packaging structures of two pressure sensors;

[0084] FIG12a shows a partial enlarged schematic diagram of the circular dotted frame in FIG11c;

[0085] FIG12b shows a schematic diagram of a changed structure in the circular dotted box in FIG12a;

[0086] FIG13 a shows a schematic cross-sectional structure diagram of a pressure sensor in Example B1;

[0087] FIG13 b shows a schematic cross-sectional structure diagram of a pressure sensor in Example B2;

[0088] FIG13c shows a schematic cross-sectional structure diagram of a pressure sensor in Example B3;

[0089] FIG14 shows a schematic diagram of the packaging process of the pressure sensor.

[0090] Explanation of the accompanying symbols: 10. Pressure sensing chip; 1. Pressure-sensitive film; 2. Substrate; 3. Cavity; 4. Pressure-sensitive component; 52. First signal output structure; 51. Lead structure; 511. First lead column; 512. Lead electrode; 521. Metal binding area; 522. Metal transition area; 523. Signal output end; 231. Metal wire; 232. Solder joint; 233. First bonding bump; 11. Thinning area; 12. Non-thinning area; 6. Insulating layer; 41. First electrode; 42. Second electrode; 43. Third electrode; 44. Fourth electrode; 7. Isolation sheet; 8. Sealing bonding ring; 20. Packaging part; 30. Sealed cavity; 40. Signal processing circuit; 401. ASI C chip; 402, RC component; 101, target area; 50, second signal output structure; 9, AF wire; 201, mounting portion; 202, supporting portion; 203, sealing shell; 2011, third lead column; 2012, signal adapter board; 2013, insulating base; 221, boss of the first mounting platform; 222, boss of the second mounting platform; 223, second through hole; 501, connector; 502, insulating member; 503, second lead column; 224, first through hole; 31, first area; 32, second area; 131, protective layer; 132, second bonding bump; 133, slurry bonding layer; 111, insulating portion; 112, metal portion.

[0091] Detailed description

[0092] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present disclosure without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0093] Pressure sensors can be classified into four main types based on the principle of the pressure chip: piezoresistive, capacitive, resonant, and piezoelectric. In related technologies, pressure chips are front-facing pressure-sensing and cannot be used directly for measuring the pressure of liquid pressure media. To measure pressure media in complex environments, such as corrosive gases or liquid pressure media, the pressure chip must be repackaged with oil to protect the main electrical structure of the pressure chip. However, this repackage increases the chip's size and cost.

[0094] In view of this, the present disclosure proposes a pressure chip that can directly measure the pressure of corrosive media, which can directly measure the pressure of liquids and corrosive gases. Specifically, the proposed pressure sensing chip can protect the electrode structure that performs the primary electrical function between the pressure-sensing film and the substrate, and be covered by the pressure-sensing film and the substrate, thereby preventing the electrode structure from contacting the external environment. This allows the pressure sensing chip to perform back-side pressure sensing. In this way, even if the pressure sensing chip comes into direct contact with liquid, the performance of the electrode structure that performs the primary electrical function will not be affected, and there will be no electrical performance drift or failure. Therefore, it can be directly used to measure the pressure of corrosive media.

[0095] The pressure sensing chip proposed in the present disclosure is described below with reference to the accompanying drawings.

[0096] 1 , which shows a schematic cross-sectional structure diagram of a pressure sensing chip, as shown in FIG1 , the pressure sensing chip 10 of this embodiment may include: a pressure-sensitive film 1, a substrate 2, a pressure-sensitive component 4, and a first signal output structure 52; wherein:

[0097] The pressure-sensitive membrane is sealed and connected to the pressure-sensitive membrane, and the base and the pressure-sensitive membrane enclose a cavity 3; wherein the pressure-sensitive membrane is configured to deform as the pressure of the external environment changes, and the cavity is configured to provide an environment in which the pressure-sensitive membrane is deformed under pressure;

[0098] The pressure-sensitive component is located between the substrate and the pressure-sensitive film, and the pressure-sensitive component partially overlaps with the orthographic projection of the cavity on the substrate. The pressure-sensitive component is configured to convert a deformation signal of the pressure-sensitive film into an electrical signal.

[0099] The substrate is provided with a first signal output structure, the first signal output structure is electrically connected to the pressure-sensitive component and is configured to output the electrical signal generated by the pressure-sensitive component;

[0100] Specifically, the first signal output structure can be electrically connected to the pressure-sensitive component 4 through a lead structure 51 running through the substrate.

[0101] In this embodiment, the sealing method of the pressure-sensitive film and the substrate can be a snap-fit ​​seal, a bonded seal or a welded seal. After the two are sealed and connected, a sealed cavity is formed between the pressure-sensitive film and the substrate. At least one side of the cavity wall can be one side of the pressure-sensitive film; or the side of the pressure-sensitive film close to the cavity and the side of the substrate close to the cavity can both serve as the cavity wall. Among them, the pressure-sensitive film can be deformed as the pressure of the external environment changes. In another example, the substrate can also be deformed as the pressure of the external environment changes. Thus, both the pressure-sensitive film and the substrate can be deformed as the pressure of the external environment changes. In practice, any one design method can be selected. Of course, the substrate can also be a rigid substrate that does not deform as the pressure of the external environment changes.

[0102] The cavity can provide a deformable environment for the pressure-sensitive film to deform. Specifically, the cavity can be a vacuum cavity, or can be a cavity containing a small amount of air. The size and shape of the cavity can be flexibly set. For example, the cross-sectional shape of the cavity can be trapezoidal, so that the cavity provides a more flexible deformation environment for the deformation of the pressure-sensitive film. The cross-sectional shape of the cavity can also be rectangular, semicircular, etc., which will not be elaborated here.

[0103] The size of the cavity can be determined according to the overall size of the pressure sensing chip. For example, the size of the cavity in the stacking direction of the pressure-sensitive film and the substrate can be 0.5 mm to 1 mm, and the size of the cavity in the extending direction of the pressure-sensitive film can be larger than the size in the stacking direction of the pressure-sensitive film and the substrate, such as 1 mm to 2 mm.

[0104] The pressure-sensitive film and substrate can be made of insulating materials such as silicon, fiberglass, polyethylene, polypropylene, etc., and the materials of the pressure-sensitive film and substrate can be the same or different. More specifically, the pressure-sensitive film or substrate can be made of a deformable insulating material, or both can be made of a deformable insulating material. In the case where both are made of deformable materials, the thickness of the pressure-sensitive film is smaller than that of the substrate, so that the pressure-sensitive film can more sensitively sense changes in external pressure.

[0105] Under the pressure of the medium to be measured in the external environment, the pressure causes the pressure-sensitive film to deform with the support of the cavity. More specifically, the thickness of the pressure-sensitive film at least at the location of the cavity needs to be small, that is, the thickness of the area covered by the orthographic projection of the cavity on the pressure-sensitive film needs to be small, so as to more sensitively sense the pressure signal at the cavity and improve the sensitivity of the pressure-sensitive film to deformation with pressure. The small thickness can mean that the pressure-sensitive film is thinned at the location of the cavity, while the thickness can be larger at locations outside the cavity.

[0106] Specifically, the substrate may also be thinned at the cavity location, while the thickness at the non-cavity location may be larger. For example, as shown in FIG1 , the thickness of region reg1 of the substrate at the cavity location is smaller, while the thickness of region reg2 at the non-cavity location is larger.

[0107] In order to form a cavity between the pressure-sensitive film and the substrate after they are sealed together, a groove can be formed on one side of the pressure-sensitive film or the substrate. When the pressure-sensitive film and the substrate are connected, the side with the groove can be sealed to another structure (the substrate or the pressure-sensitive film). After the connection, vacuum is applied so that the location of the groove becomes the location of the cavity. As shown in Figure 1, the groove can be provided on the substrate. Of course, in some other examples, the groove can also be provided on the pressure-sensitive film.

[0108] The pressure-sensitive component may include a plurality of electrodes, or include a deformation element and a signal generating element connected to the deformation element.

[0109] Among them, the pressure-sensitive component is located between the pressure-sensitive film and the substrate. Specifically, the pressure-sensitive component can be covered by the pressure-sensitive film and the substrate. Among them, one setting method in which the pressure-sensitive component and the positive projection of the cavity on the substrate partially overlap can be: part of the structure of the pressure-sensitive component is located at the junction between the pressure-sensitive film and the substrate, and the remaining structure is located in the cavity; or, the entire pressure-sensitive component is located in the cavity. The specific setting can be based on actual needs and is not particularly limited here.

[0110] Exemplarily, if the pressure-sensitive component includes an electrode and a deformation element, the electrode and the deformation element can be a thin film metal layer formed on the pressure-sensitive film, which can be insulated from the chamber wall of the cavity. As another example, if the pressure-sensitive component includes multiple electrodes, the multiple electrodes can be distributed on the same side of the cavity, or on different sides of the cavity, which can be determined specifically according to the type of pressure-sensitive chip. Of course, in some examples, there can be gaps between the multiple electrodes, such as capacitive and resistive pressure-sensitive chips. As another example, if the pressure-sensitive component includes a deformation element and a signal-generating element, the deformation element can be connected to the signal-generating element, and the deformation element deforms as the pressure-sensitive film deforms, and transmits the deformation signal to the signal-generating element, so that the signal-generating element can generate a corresponding electrical signal based on this deformation signal, such as a resonant pressure-sensing chip.

[0111] The electrodes and deformation elements in the pressure-sensitive assembly can be made of metal materials and can be either piezoresistors or ordinary electrodes. In the case of a piezoresistive resistor, its resistivity changes with the deformation of the pressure-sensitive film. In the case of an ordinary electrode, it can be configured so that its capacitance and resonant frequency change when the cavity deforms. Specifically, the multiple electrodes can generate corresponding electrical signals in response to the deformation of the pressure-sensitive film, such as resistance signals, capacitance signals, and resonant signals. This allows the pressure of the medium to be measured to be determined based on the electrical signals generated by the multiple electrodes in the pressure-sensitive assembly.

[0112] In which, the substrate can be configured with a first signal output structure, which is connected to the electrode in the pressure-sensitive component to receive the electrical signal generated by the electrode and transmit the electrical signal to an external signal processing circuit. In some examples, as shown in Figure 1, the first signal output structure can be electrically connected to the pressure-sensitive component through a lead structure connected to the pressure-sensitive component. The lead structure can be embedded in the substrate and sealed with the substrate. One end of the lead structure is connected to the pressure-sensitive component, and the other end is connected to the first signal output structure. Specifically, the lead structure can be a metal wire passed through the substrate. After the metal wire extends on the cavity wall of the cavity, it is connected to the electrode in the pressure-sensitive component. The first signal output structure can be located on the outside of the substrate away from the cavity, thereby realizing an electrical connection between the pressure-sensitive component in the cavity and the external signal processing circuit.

[0113] Among them, in some embodiments, the process of forming the above-mentioned pressure sensing chip can be: configuring a first signal output structure on the substrate, forming a groove on the substrate, forming a pressure-sensitive component on one side of the pressure-sensitive film, and then, using an anodic bonding process, bonding the side of the pressure-sensitive film where the pressure-sensitive component is set to the side of the substrate with the groove, and after bonding, evacuating the groove to form a cavity, wherein the pressure-sensitive component is located between the substrate and the pressure-sensitive film, and is covered by the two. In this way, the pressure-sensitive component, as a key structure of the pressure sensing chip, can be protected between the substrate and the pressure-sensitive film to avoid being affected by the external environment.

[0114] When measuring pressure, the pressure-sensitive film is affected by external pressure and will deform. This deformation will cause the pressure-sensitive component to generate a corresponding electrical signal, such as a resistance change signal or a capacitance change signal. The generated electrical signal is transmitted to the first signal output structure through the lead structure and output to the outside through the first signal output structure. Therefore, the pressure sensing chip can be understood as a back-sensing pressure detection.

[0115] By using the pressure sensing chip of this embodiment, the pressure-sensitive component is protected between the substrate and the pressure-sensitive film, so that the structure with the main electrical function in the pressure sensing chip is not directly exposed to the outside, thereby preventing the pressure-sensitive component from being affected by the external environment. In this way, even if the pressure sensing chip directly contacts corrosive media such as liquids, its pressure-sensitive component will not drift or fail, thereby enabling the pressure sensing chip to maintain long-term pressure detection capabilities.

[0116] In some exemplary embodiments, the pressure-sensitive film and the substrate can both be flexible substrates, that is, the pressure-sensitive film and the substrate can both produce a certain deformation. Under this setting, the thickness of the pressure-sensitive film is less than the thickness of the substrate, and the materials of the pressure-sensitive film and the substrate can be the same or different, such as both can be made of silicon material, or the pressure-sensitive film is silicon material and the substrate is a polymer material, such as polyurethane, polypropylene, polyimide and other materials. Since the substrate is a flexible material, when it serves as a carrier of the first signal output structure, it can provide deformation space for deformations such as stretching and compression generated by the first signal output structure, thereby reducing the probability of breakage, damage and other problems caused by deformation of the first signal output structure due to force majeure.

[0117] In some exemplary embodiments, the pressure-sensitive film is a flexible material, and the substrate can be a rigid substrate. In this configuration, the substrate can provide stronger support for the pressure-sensing chip and serve as a carrier for the first signal output structure. The pressure-sensitive film senses pressure changes. In this configuration, the substrate can be a glass substrate, which can reduce the difficulty of drilling holes for the metal wires of the first signal output structure. In addition, if the substrate is a rigid substrate, it can provide stable electrical support for the first signal output structure without deforming. In this configuration, the pressure-sensitive film that provides deformation and the substrate that provides support for the first signal output structure can be separated. In other words, the two functions of the pressure-sensing chip, namely, deformation and carrier, are assigned to different substrates. This can reduce the design difficulty of the pressure-sensing chip and improve manufacturing efficiency.

[0118] In this exemplary embodiment, the material of the pressure-sensitive film can be silicon, and the material of the rigid substrate can be glass. In this case, the difficulty of bonding between the glass substrate and the silicon pressure-sensitive film can be reduced when they are sealed together. In other examples, the material of the pressure-sensitive film can also be a flexible polymer material, and the material of the rigid substrate can also be quartz or ceramic.

[0119] In some exemplary embodiments, the first signal output structure may be disposed on the substrate, and may include a signal input terminal and a signal output terminal;

[0120] The signal input terminal is connected to the lead structure and the signal output terminal respectively, and the signal output terminal is configured to transmit the electrical signal inputted by the signal input terminal to an external signal processing circuit.

[0121] The signal input terminal and the signal output terminal may be located on the same side of the substrate, or on two adjacent sides of the substrate, which will not be described in detail here.

[0122] In a further example, the signal input terminal may include: a metal binding region and a metal transition region, wherein the metal binding region is disposed on a side of the substrate facing away from the cavity and is electrically connected to the lead structure; and the metal transition region is disposed on a side of the substrate facing away from the pressure-sensitive film and is respectively connected to the metal binding region and the signal output terminal. Referring to FIG2 , a schematic cross-sectional structure diagram of another pressure sensing chip is shown. As shown in FIG2 , the first signal output structure in the pressure sensing chip includes a metal binding region, a metal transition region, and a signal output terminal.

[0123] Specifically, the metal binding area 521 is provided on a side of the substrate away from the cavity and is connected to an end of the lead structure away from the cavity;

[0124] The metal transition region 522 is disposed on a side of the substrate away from the cavity and is connected to the metal binding region and the signal output terminal 523 .

[0125] The metal binding region can be located on the side of the substrate facing away from the cavity, such as the side of the substrate facing away from the pressure-sensitive film, or on the side of the substrate facing away from the cavity and adjacent to the pressure-sensitive film, such as on the outer wall of the substrate in FIG2 . The metal binding region can be electrically connected to the end of the lead structure facing away from the cavity, and to the metal transition region. The electrical connection to the lead structure can be achieved by welding, bonding with conductive adhesive, or other methods. The metal binding region can be a copper redistribution layer (RDL) of a wafer-level package, which can transmit electrical signals from the lead structure to the metal transition region.

[0126] Among them, the metal transition zone is also located on the side of the substrate away from the cavity, and it can be set in the same layer as the metal binding zone on one side of the substrate, or in a different layer; in the case of being set in the same layer, the metal transition zone can be located on the same side of the substrate together with the metal binding zone, such as both are located on the side of the substrate away from the pressure-sensitive film, or both are located on the side of the substrate away from the cavity and adjacent to the pressure-sensitive film; since the first signal output structure needs to be electrically connected to the external signal processing circuit, in this case, the difficulty of bonding with the signal processing circuit can be reduced.

[0127] In the case of different layer arrangements, the metal transition region can be located on the side of the substrate facing away from the pressure-sensitive film, and the metal binding region can be located on the side of the substrate facing away from the cavity and adjacent to the pressure-sensitive film; alternatively, the metal binding region can be located on the side of the substrate facing away from the pressure-sensitive film, and the metal transition region can be located on the side of the substrate facing away from the cavity and adjacent to the pressure-sensitive film; alternatively, the metal binding region and the metal transition region can be located on the same side of the substrate, or the metal binding region and the metal transition region can be stacked, with the metal transition region located on the side of the metal binding region facing away from the substrate. In practice, any of these arrangements can be selected, and will not be detailed here.

[0128] Among them, one end of the metal transition zone is electrically connected to the metal binding zone, and the other end can be electrically connected to the signal output terminal 523, which is used to transmit the electrical signal of the metal binding zone to the signal output terminal. In practice, the metal transition zone can be understood as a bonding layer that allows the metal binding zone and the signal output terminal to be electrically connected. In some specific implementation methods, the metal transition zone can be composed of multiple layers of metal films such as an adhesion layer, a diffusion barrier layer and a wetting layer, which can play the role of adhering the metal binding zone and the signal output terminal, as well as diffusion barrier.

[0129] Among them, the signal output end is made of metal material and is electrically connected to the metal transition zone. The connection method can be welding, bonding, and conductive adhesive bonding. In a specific implementation, the signal output end can be a metal solder point, a metal lead or a metal bonding point.

[0130] Using the first signal output structure in this example, if the pressure-sensitive component includes multiple electrodes, each electrode corresponds to the above-mentioned set of first signal output structures, that is, each electrode can be electrically connected to an external signal processing circuit through a lead structure, a metal binding area, a metal transition area, and a signal output terminal. The lead structure is sealed to the substrate, thereby ensuring the sealing of the cavity. The metal binding area can adopt the copper redistribution layer of wafer-level packaging, which can reduce design costs and support a larger number of pins. The metal binding area can also make the contact spacing between it and the lead structure more flexible and the bump area larger, thereby reducing the stress between the substrate and components such as the metal transition area, thereby improving the reliability of the pressure-sensitive chip. The metal transition area can adopt the copper redistribution layer of wafer-level packaging, which can reduce design costs and support a larger number of pins. The metal transition area can also make the contact spacing between it and the lead structure more flexible and the bump area larger, thereby reducing the stress between the substrate and components such as the metal transition area, thereby improving the reliability of the pressure-sensitive chip.

[0131] Furthermore, the signal output end can be a metal solder joint, a metal wire, or a metal bonding point, wherein the signal output end can include any one of the metal wire 231, the solder joint 232, and the first bonding bump 233. Of course, if the pressure sensing chip includes multiple electrodes, each electrode corresponds to a first signal output structure, and the signal output end of the multiple first signal output structures can be at least one of the metal wire, the solder joint, and the first bonding bump; that is, the signal output ends of the multiple first signal output structures can be of the same type or of different types. When the signal output ends are of the same type, when they are electrically connected to the signal processing circuit of the package structure, the packaging difficulty is reduced. Of course, it is not ruled out that in some cases, the multiple first signal output structures can have signal output ends of different types (metal wires, solder joints, and first bonding bumps).

[0132] In one example of this exemplary embodiment, the signal output end can be a metal wire, one end of which is connected to the metal transition region, and the other end is used to electrically connect to the signal processing circuit. Referring to Figure 3a, a schematic cross-sectional structure diagram of the first signal output structure is shown. As shown in Figure 3a, the signal output end is a metal wire, one end of which is electrically connected to the metal transition region, such as by welding, coupling, etc., and the other end is a free end used to electrically connect to the signal processing circuit. The material of the metal wire can be copper, silver, gold, or aluminum. When using this metal wire, the metal wire can be directly welded or connected to the signal processing circuit using a connector, which can reduce the difficulty of connection.

[0133] In one example of this exemplary embodiment, the signal output terminal includes a solder joint located on the metal transition region for soldering to the signal processing circuit to achieve electrical connection with the signal processing circuit. Referring to FIG3b , a cross-sectional schematic diagram of the first signal output structure is shown. As shown in FIG3b , a solder joint is provided on the side of the metal transition region facing away from the substrate. The solder joint is electrically connected to the metal transition region. The electrical connection can be achieved by welding or bonding with conductive adhesive. The solder joint can be made of tin, silver, or aluminum. Of course, when tin is used, due to its melting point, it easily melts upon heating and adheres to the desired soldering location. It also provides corrosion resistance, protecting the soldered signal processing circuit and the metal transition region. When using a solder joint, the metal transition region can be composed of multiple metal films, including an adhesion layer, a diffusion barrier layer, and a wetting layer.

[0134] In some specific implementations, the solder joints may be spherical solder joints, strip solder joints, wire solder joints, etc. Of course, in order to improve the welding quality, the solder joints may be spherical solder joints.

[0135] It should be noted that the solder joint is located on the metal transition zone, and its orthographic projection on the substrate can be located within the orthographic projection of the metal transition zone on the substrate, that is, the solder joint does not fully cover the metal transition zone. In practice, the size of the solder joint in the thickness direction of the substrate should not be too large.

[0136] Furthermore, in another example of this exemplary embodiment, the signal output terminal includes a first bonding bump, which is integrally formed with the metal transition region and is used to bond with a second bonding bump on the signal processing circuit to achieve electrical connection with the signal processing circuit. Referring to FIG3c , a schematic cross-sectional structure diagram of a pressure sensing chip is shown. As shown in FIG3c , the first bonding bump is electrically connected to the metal binding region. In this case, the first bonding bump can function as both a metal transition region and an electrical connection with the signal processing circuit. As shown in FIG3c , the dimension of the first bonding bump in the normal direction of the substrate plane can be greater than the dimension of the metal binding region in the normal direction of the substrate plane. In other words, the thickness of the first bonding bump is greater than the thickness of the metal binding region. When bonding, the first bonding bump serves as the bridging point between the first signal output structure and the signal processing circuit, while the signal processing circuit does not overlap with the metal binding region, thereby avoiding the problem of reduced detection accuracy caused by increased resistance in the circuit. The electrical connection between the first bonding bump and the metal binding area can be achieved by welding, bonding, overlapping, coupling, or the like. In this case, the first bonding bump can be bonded to an external packaging structure. This bonding method can achieve the connection between the first signal output structure and the signal processing circuit without generating high heat, polluting the environment, or consuming energy. The first bonding bump can be made of a metal material, specifically copper, silver, aluminum, tin, or the like, although other materials are also acceptable.

[0137] When such a signal output terminal is adopted, the metal transition region can be formed into a first bonding bump at one time, thereby simplifying the manufacturing process and improving manufacturing efficiency.

[0138] In some examples, the lead structure may only include a first lead post 511 embedded in the substrate, as shown in Figures 1 and 2 and the subsequent Figure 6b. The first lead post may not be exposed in the cavity, that is, the first lead post 511 does not need to extend into the cavity, but is connected to the pressure-sensitive component at the position where the pressure-sensitive film and the substrate are combined, so that the entire section of the lead structure is not exposed in the cavity. In this case, the pressure-sensitive component may also have a metal area extending beyond the cavity, that is, it has a partial area extending from the cavity to the substrate (see the subsequent Figure 6b), and the first lead post is electrically connected to the pressure-sensitive component through the metal area of ​​the pressure-sensitive component extending beyond the cavity. Of course, if this method is adopted, the size of the metal area of ​​the pressure-sensitive component extending beyond the cavity can be small enough, for example, in the length extension direction of the cavity, it can be 0.005mm-0.1mm in length.

[0139] In some embodiments, the lead structure may include a first lead post 511 embedded in the substrate and an extraction electrode 512. One end of the extraction electrode 512 is connected to the pressure-sensitive component, and the other end is connected to one end of the first lead post 511. The other end of the first lead post 511 passes through the substrate and is electrically connected to the first signal output structure. The extraction electrode may be located at the junction of the pressure-sensitive film and the substrate, separated from the cavity. One end of the extraction electrode is connected to an electrode in the pressure-sensitive component, and the other end is connected to the first lead post.

[0140] Among them, the first lead post is electrically connected to the lead-out electrode after passing through the substrate. In this example, the first lead post does not have a portion exposed in the cavity. As shown in Figure 1, the first lead post passes through the reg2 area of ​​the substrate. In this case, the first lead post will not be affected by the deformation of the cavity; accordingly, the end of the first lead post close to the pressure-sensitive film can be electrically connected to the pressure-sensitive component through the lead-out electrode.

[0141] The lead-out electrode may be made of a metal material, such as silver, copper, or the like. Of course, the materials of the lead-out electrode and the pressure-sensitive component may be the same or different, which will not be elaborated here.

[0142] In one example, the lead-out electrode can be arranged at the connection between the pressure-sensitive film and the substrate, that is, a lead-out electrode is arranged at the junction of the pressure-sensitive film and the substrate, and the opposite sides of the lead-out electrode are respectively connected to the pressure-sensitive film and the substrate; or, in another example, the lead-out electrode can also be embedded in the substrate.

[0143] The lead-out electrode may extend into the cavity and be connected to the pressure-sensitive component in the cavity, or the lead-out electrode may not extend into the cavity but be electrically connected to the pressure-sensitive component located at the junction of the pressure-sensitive film and the substrate.

[0144] The first lead post can pass through the substrate, and the penetration method can be to drill a hole in the substrate and pour a metal material into the formed hole to form the first lead post. The first lead post is sealed and connected to the substrate to ensure the vacuum environment of the cavity. The material of the first lead post can be copper, gold, silver, aluminum and other materials, which are not limited here. The end of the first lead post close to the cavity is electrically connected to the lead-out electrode, and one end of the lead-out electrode is connected to the pressure-sensitive component. If the pressure-sensitive component includes multiple electrodes, the end of the lead-out electrode close to the cavity is electrically connected to the electrode. It should be noted that in this case, multiple first lead posts and lead-out electrodes respectively connected to the multiple first lead posts can be included, so as to provide electrical connection between the respective first signal output structures and the pressure-sensitive component.

[0145] Referring to Figure 4, a schematic cross-sectional structure diagram of another pressure sensing chip is shown. As shown in Figure 4, the lead-out electrode is located at the connection between the pressure-sensitive film and the substrate, and the orthographic projection of the lead-out electrode on the substrate does not overlap with the orthographic projection of the cavity on the substrate. In other words, the lead-out electrode does not have a portion located in the cavity, that is, it does not extend to the cavity. In this case, the pressure-sensitive component may also not have a portion located at the connection between the pressure-sensitive film and the substrate, or the pressure-sensitive component may include a portion extending to the connection between the pressure-sensitive film and the substrate.

[0146] As shown in Figure 4, the orthographic projection of the pressure-sensitive component on the substrate may not overlap with the substrate and may be covered by the orthographic projection of the cavity on the substrate, wherein the electrical connection position between the pressure-sensitive component and the lead-out electrode may be an edge position of the cavity, wherein the lead-out electrode may fully cover the connection area between the pressure-sensitive film and the substrate, or partially cover the connection area between the pressure-sensitive film and the substrate, and Figure 4 shows the full coverage case, and the connection method between the first lead column and the lead-out electrode may be welding, overlapping, or the like.

[0147] Among them, the size of the lead-out electrode in the normal direction of the plane of the pressure-sensitive film can be the same as the size of the pressure-sensitive component in the normal direction of the plane of the pressure-sensitive film, that is, the height of the lead-out electrode and the height of the pressure-sensitive component can be the same; in this case, the pressure-sensitive component and the lead-out electrode can be arranged in the same layer. In this case, the step difference between the pressure-sensitive component and the lead-out electrode can be reduced. When the pressure-sensitive film and the substrate are sealed and connected, the lead-out electrode and the pressure-sensitive component can be used as the alignment reference. After the two are aligned, the pressure-sensitive film and the substrate can be encapsulated, thereby improving the electrical contact performance and reducing the manufacturing difficulty.

[0148] Alternatively, in one example, the size of the lead-out electrode in the normal direction of the plane of the pressure-sensitive film may be smaller than the size of the pressure-sensitive component in the normal direction of the plane of the pressure-sensitive film, that is, the height of the lead-out electrode is smaller than the height of the pressure-sensitive component; or, the size of the lead-out electrode in the normal direction of the plane of the pressure-sensitive film may be larger than the size of the pressure-sensitive component in the normal direction of the plane of the pressure-sensitive film, that is, the height of the lead-out electrode is larger than the height of the pressure-sensitive component.

[0149] In this example, since the first signal output structure adopts a lead-out electrode and the lead-out electrode can be separated from the cavity, the lead-out electrode is restricted by the pressure-sensitive film and the substrate and will not be affected by the pressure changes in the cavity. In this case, the first lead column does not include the portion exposed in the cavity. Therefore, the first lead column will not be affected by the pressure changes in the cavity. At the same time, it will not affect the sealing of the cavity, thereby improving the sealing performance of the pressure sensing chip, so that the pressure-sensitive component will not be affected by the lead structure in the process of converting the deformation signal of the pressure-sensitive film into an electrical signal, thereby ensuring the detection sensitivity.

[0150] In some exemplary embodiments, the orthographic projection of the pressure-sensitive component on the substrate is located within the orthographic projection of the cavity on the substrate; or, the orthographic projection of the pressure-sensitive component on the substrate overlaps with the orthographic projection of the cavity on the substrate.

[0151] In this example, the pressure-sensitive component may be entirely located within the vacuum cavity, or the pressure-sensitive component may overlap with the cavity. In the case where the pressure-sensitive component may overlap with the cavity, the pressure-sensitive component may overlap with both the cavity and the pressure-sensitive film, or the pressure-sensitive component may overlap with the cavity, the substrate, and the pressure-sensitive film.

[0152] When the pressure-sensitive component is entirely located within the cavity, the pressure-sensitive component can be entirely protected within the cavity. This can, on the one hand, enhance the protection of the pressure-sensitive component, and on the other hand, reduce the difficulty of bonding between the pressure-sensitive film and the pressure-sensitive component. That is, during bonding, there is no need to consider the impact of the bonding method on the sensitivity of the pressure-sensitive component.

[0153] In some exemplary embodiments, the pressure-sensitive component may be a capacitive or resistive pressure-sensitive component, which may include multiple electrodes. The multiple electrodes may be arranged on one side of the pressure-sensitive film, or on both the pressure-sensitive film and the substrate, that is, the pressure-sensitive components may all be located on the side of the pressure-sensitive film close to the substrate; or the pressure-sensitive components may be located on opposite sides of the cavity, such as the pressure-sensitive components may be distributed on opposite sides of the target direction of the cavity, where the target direction is the perpendicular direction from the substrate to the pressure-sensitive film.

[0154] Thus, depending on the layout of the pressure-sensitive components, they can generate electrical signals corresponding to the layout in response to the deformation of the pressure-sensitive film, such as resistance signals, capacitance signals, resonance signals, etc. For example, when the pressure-sensitive components are all arranged on one side of the pressure-sensitive film, they can generate resistance signals or resonance signals in response to the deformation of the pressure-sensitive film; when the pressure-sensitive components are distributed on opposite sides of the cavity, they can generate capacitance signals in response to the deformation of the pressure-sensitive film.

[0155] Specifically, regardless of the distribution method, the pressure-sensitive component can include a structure located on the side of the pressure-sensitive film closest to the substrate. Therefore, in order to make the pressure-sensitive film more sensitive to pressure deformation, the pressure-sensitive film can be thinned across its entire surface, that is, the entire surface of the pressure-sensitive film is a thinner film layer.

[0156] In some embodiments, in order to ensure the structural stability of the pressure sensing chip, the pressure-sensing film can be partially thinned, which may include a thinned area 11 and a non-thinned area 12 adjacent to the thinned area 11. The thickness of the thinned area is less than the thickness of the non-thinned area 15, so that the thinned area can sensitively respond to the applied pressure and deform.

[0157] The orthographic projection of the thinned area on the substrate overlaps with the orthographic projection of the cavity on the substrate.

[0158] Specifically, the thinned area may constitute a cavity wall; wherein part or all of the elements in the pressure-sensitive component are arranged on a side of the thinned area close to the cavity.

[0159] In this example, the thinning area can be arranged on the pressure-sensitive film, wherein the thinning area can constitute a chamber wall of the cavity, thereby, the orthographic projection of the thinning area on the substrate can cover the orthographic projection of the cavity on the substrate; or the thinning area can be a partial area of ​​a chamber wall of the cavity, thereby, the orthographic projection of the thinning area on the substrate can partially overlap with the orthographic projection of the cavity on the substrate, such as the orthographic projection of the thinning area on the substrate is covered by the orthographic projection of the cavity on the substrate, or, the orthographic projection of the thinning area on the substrate can be staggered with the orthographic projection of the cavity on the substrate.

[0160] The thickness of the non-thinned area on the pressure-sensitive film may be 200 μm to 700 μm, while the thickness of the thinned area on the pressure-sensitive film may be 5 μm to 100 μm. Specifically, the thickness of the non-thinned area may be 200 μm, 700 μm, or a thickness between 200 μm and 700 μm, such as 500 μm, 400 μm, or 600 μm; the thickness of the thinned area may be 5 μm, 100 μm, or a thickness between 5 μm and 100 μm, such as 10 μm, 50 μm, 40 μm, or 60 μm.

[0161] In one example, the thinned area may be surrounded by a non-thinned area, or the thinned area may be partially surrounded by a non-thinned area, i.e., the non-thinned area surrounds part of the edge of the thinned area, while the non-thinned area does not exist on other edges. Of course, if the non-thinned area completely surrounds the thinned area, the protection of the thinned area by the non-thinned area can be improved.

[0162] Among them, if the pressure-sensitive film includes a thinned area and a non-thinned area, and the thicknesses of the thinned area and the non-thinned area are different, a groove will be formed on one side of the pressure-sensitive film, and the surface of the other side of the pressure-sensitive film can be flush or uneven. When it is uneven, there are grooves on both opposite sides of the pressure-sensitive film. In this case, when the pressure-sensitive film is sealed with the substrate, the cavity can have three side walls that can respond to the pressure of the external environment, which can improve the flexibility in the subsequent packaging of the pressure sensing chip.

[0163] Among them, on the side of the pressure-sensitive film close to the cavity, the surfaces of the thinned area and the non-thinned area can be flush to reduce the difficulty of sealing connection; on the side of the pressure-sensitive film away from the cavity, due to the different thicknesses of the thinned area and the non-thinned area, the surface is not flush. Of course, in some other embodiments, on the side of the pressure-sensitive film close to the cavity, the surfaces of the thinned area and the non-thinned area can be uneven, while on the side of the pressure-sensitive film away from the cavity, the surfaces of the thinned area and the non-thinned area can be flush. In this case, the thinned area can serve as a complete cavity wall of the cavity, and the part of the non-thinned area close to the cavity can serve as a side wall of the cavity. In other words, the cavity can be a groove formed by thinning the pressure-sensitive film.

[0164] The thickness of the substrate may be greater than the thickness of the thinned area, or further, greater than the thickness of the non-thinned area, thereby ensuring the structural rigidity of the substrate to the first signal output structure; the entire surface of the substrate may also be thinned so that the thickness of the substrate may be slightly equal to the thickness of the thinned area, thereby reducing the overall size of the pressure sensing chip.

[0165] In a further example, the orthographic projection of the non-thinned area on the substrate overlaps with the orthographic projection of the cavity on the substrate, and the orthographic projection of the thinned area on the substrate is covered by the orthographic projection of the cavity on the substrate. In this case, as shown in FIG5a , the thinned area can be surrounded by the non-thinned area, and the orthographic projection of the pressure-sensitive component on the substrate can overlap with the orthographic projections of both the non-thinned area and the thinned area on the substrate. In this case, the non-thinned area can provide a certain degree of support for the pressure-sensitive component and also play a certain supporting role for the cavity, thereby ensuring the structural stability of the pressure-sensing chip.

[0166] Referring to Figures 5a and 5b, Figures 5a and 5b respectively show schematic cross-sectional structures of two pressure sensing chips. As shown in Figure 5a, part of the pressure-sensitive film is thinned, and the surface of the pressure-sensitive film facing away from the cavity is not flush, while the surface close to the cavity is flush. The thinned area of ​​the pressure-sensitive film forms the bottom wall of the cavity. All electrodes in the pressure-sensitive component can be set on the thinned area, or some electrodes can be set on the thinned area. Figure 5a shows the situation where the entire pressure-sensitive component is located on the thinned area.

[0167] As shown in Figure 5b, the entire area of ​​the pressure-sensitive film is thinned, so the thickness of the pressure-sensitive film is less than the thickness of the substrate. All elements in the pressure-sensitive assembly can be set on the thinned area, or some elements can be set on the thinned area. Figure 5b shows a situation where some elements in the pressure-sensitive assembly are located on the thinned area, and the remaining elements are located on the side of the substrate close to the cavity.

[0168] Of course, when the entire area of ​​the pressure-sensitive film is thinned, all components of the pressure-sensitive assembly can be arranged on the thinned area.

[0169] In a further example of this embodiment, referring to FIG5c , a cross-sectional schematic diagram of another pressure sensing chip is shown. As shown in FIG5c , an insulating layer 6 may be further provided on the pressure-sensitive film to prevent temperature and other factors from affecting the sensitivity of the pressure-sensitive component. The insulating layer may cover the entire surface of the pressure-sensitive film, or only cover the thinned area within the cavity (in this case, the thinned area is a portion of the cavity wall), or cover the area on one side of the pressure-sensitive film covered by the cavity. FIG5c shows a case where the insulating layer covers the area on one side of the pressure-sensitive film covered by the cavity. The components on the pressure-sensitive film in the pressure-sensitive component may be located on the side of the insulating layer close to the cavity.

[0170] In this example, the insulating layer can be located on the side of the thinned region closest to the cavity. Since the thinned region is relatively thin, it is easily affected by the ambient temperature and can easily lead to deterioration of insulation performance. Therefore, the insulating layer can be used to insulate the components in the pressure-sensitive assembly and reduce the effect of the ambient temperature on cavity deformation. When the insulating layer covers the entire surface of the pressure-sensitive film, it can minimize the effect of the ambient temperature on cavity deformation, making the entire pressure-sensing chip less susceptible to the effects of the ambient temperature.

[0171] Specifically, the insulating layer can be made of silicon dioxide, thereby forming a silicon oxide insulating layer. In this case, the material of the pressure-sensitive film can be silicon, thereby reducing the difficulty of forming the silicon oxide insulating layer on the pressure-sensitive film. The thickness of the insulating layer can be relatively small, for example, the insulating layer can be micron-level thick, thereby reducing its resistance to the pressure of the medium to be measured, allowing the pressure of the medium to be measured to reach the cavity.

[0172] Of course, in some specific implementations, an insulating layer may also be provided on the side of the substrate close to the cavity. The material of the insulating layer may be silicon dioxide material or other types of insulating materials, and its thickness may also be in the micron level. Specifically, the thickness of the insulating layer is less than the thickness of the above-mentioned thinning area, such as 1 μm, or the thickness of the insulating layer may be in the nanometer level. Specifically, it may be provided according to actual conditions, thereby ensuring the insulation of the elements (elements in the pressure-sensitive assembly) provided on one side of the substrate.

[0173] As mentioned above, according to the principle of pressure chips, they can be divided into four main types: piezoresistive, capacitive, resonant, and piezoelectric. In the following exemplary embodiments, several types of pressure sensing chips are introduced.

[0174] First, referring to Figure 6a, a schematic cross-sectional structure diagram of a piezoresistive pressure sensing chip is shown. As shown in Figure 6a, in the piezoresistive pressure sensing chip, its pressure-sensitive component may include a first electrode 41 and a second electrode 42; wherein the first electrode and the second electrode are configured to convert the deformation of the pressure-sensitive film into a resistance signal, and the first electrode and the second electrode are both arranged on a side of the pressure-sensitive film close to the cavity.

[0175] In this example, the first electrode and the second electrode may be force-sensitive resistors, which are configured to generate a change in resistance when the cavity deforms, thereby causing a change in voltage or current in the circuit. Thus, the pressure sensing chip may be a piezoresistive sensing chip. The metal material of the first electrode and the second electrode may be gold, platinum, aluminum, or the like. There is a gap between the first electrode and the second electrode, and the thickness of the first electrode and the thickness of the second electrode may be micrometer-level or submicrometer-level.

[0176] As shown in Figure 6a, the first electrode and the second electrode are both disposed on the side of the pressure-sensitive film closest to the cavity. If the pressure-sensitive film has a thinned region, the thinned region may be a portion of the pressure-sensitive film, and the thickness of the thinned region may be in the millimeter range. The first electrode and the second electrode may both be disposed on the side of the thinned region closest to the cavity. An insulating layer is formed on the side of the pressure-sensitive film closest to the cavity, and the insulating layer may fully cover the pressure-sensitive film. The first electrode and the second electrode may be disposed on the side of the insulating layer closest to the cavity.

[0177] In this example, since the pressure-sensitive component includes a first electrode and a second electrode, and the first electrode and the second electrode are both arranged on the side of the pressure-sensitive film close to the cavity, for the first electrode and the second electrode, they both correspond to a first signal output structure, and the first signal output structure may include: a metal binding area, a metal transition area and a metal wire; wherein the lead structure may include a lead-out electrode and a first lead post; the lead-out electrode is located at the junction of the pressure-sensitive film and the substrate and is separated from the cavity, one end of the lead-out electrode is electrically connected to the first electrode (or the second electrode), and the other end is electrically connected to the metal binding area through the first lead post, one end of the metal binding area is electrically connected to the metal transition area, and a metal wire is formed on the metal transition area, and the metal wire is used to electrically connect to an external signal processing circuit.

[0178] The first signal output structures to which the first electrode and the second electrode are respectively connected may also be electrically connected via the metal binding region, thereby forming a loop between the first electrode, the second electrode and the two first signal output structures.

[0179] Using the pressure sensing chip of this example, since the first electrode and the second electrode for sensing pressure are set in the cavity, the first electrode and the second electrode will not be affected by the medium to be measured, so the pressure of the medium to be measured can be directly measured, ensuring its service life.

[0180] Next, referring to Figure 6b, a schematic cross-sectional structure diagram of a capacitive pressure sensing chip is shown. As shown in Figure 6b, in a piezoresistive pressure sensing chip, its pressure-sensitive component may include a third electrode 43 and a fourth electrode 44, wherein the third electrode and the fourth electrode are configured to convert the deformation of the pressure-sensitive film into a capacitive signal; as shown in Figure 6b, the third electrode may be arranged on a side of the pressure-sensitive film close to the cavity, and the fourth electrode may be arranged on a side of the substrate close to the cavity, and the orthographic projection of the third electrode on the substrate overlaps with the fourth electrode.

[0181] In this example, the third and fourth electrodes can be resistors made of metal materials, configured such that when the cavity deforms, the capacitance formed between them changes. Thus, the pressure sensing chip can be a capacitive sensing chip. The orthographic projection of the third electrode on the substrate overlaps with the fourth electrode, and this overlapping area can be smaller than the length of the cavity wall on the side of the cavity closest to the substrate. Of course, the larger the area of ​​the overlapping area, the greater the capacitance change generated when the cavity deforms, thereby enabling more sensitive measurement of the pressure of the medium being measured.

[0182] As shown in Figure 6b, the pressure-sensitive film can be thinned on the entire surface, and the substrate can be formed with a groove, so that after bonding with the pressure-sensitive film, the groove can form a cavity, and for the third electrode and the fourth electrode, they both correspond to a first signal output structure, and the first signal output structure can include a metal binding area, a metal transition area and a solder joint; wherein, the lead structure includes a first lead post, the first lead post passes through the substrate and has no part located in the cavity; the third electrode and the fourth electrode can both have a part that exceeds the cavity, that is, a part of the third electrode is located in the cavity, and the other part is located outside the cavity and located in the substrate, wherein, the first lead post connected to the third electrode needs to pass through the entire substrate and then be electrically connected to the part of the third electrode that exceeds the cavity; the first lead post connected to the fourth electrode needs to pass through part of the substrate and then be electrically connected to the part of the fourth electrode that exceeds the cavity; wherein, the solder joint can be a spherical metal formed on the metal transition area, specifically a tin ball.

[0183] As shown in Figure 6b, the first signal output structures corresponding to the third electrode and the fourth electrode may not need to be electrically connected, that is, there is no need for conduction between the metal transition regions on the two first signal output structures, wherein the metal binding region on each first signal output structure can cover the end of the first lead column away from the cavity.

[0184] In a further exemplary capacitive pressure sensing chip, an isolation plate 7 and a sealing ring 8 may be further included between the pressure-sensitive film and the substrate; wherein the side of the isolation plate close to the pressure-sensitive film is sealed to the pressure-sensitive film through the sealing ring, and the side of the isolation plate close to the substrate is sealed to the substrate through the sealing ring.

[0185] Referring to FIG6c, a schematic diagram of the cross-sectional structure of another capacitive pressure sensing chip is shown. As shown in FIG6c, the entire surface of the pressure-sensitive film is thinned, and the substrate is a flat substrate, that is, it does not have a groove area. When the pressure-sensitive film and the substrate are sealed, they can be connected by an isolation sheet and a sealing ring. The opposite sides of the isolation sheet are respectively connected to the pressure-sensitive film and the substrate through sealing rings. That is, the side of the isolation sheet close to the substrate is sealed to the substrate through a sealing ring, and the side of the isolation sheet close to the pressure-sensitive film is sealed to the pressure-sensitive film through a sealing ring. The material of the gap isolation sheet can be an insulating material such as glass or ceramic, and the sealing ring can be an insulating material such as rubber, or a metal material.

[0186] Among them, the sealing ring is a ring-shaped sealing structure, and the isolation plate is used to separate the cavity. The orthographic projection of the third electrode on the pressure-sensitive film overlaps with the orthographic projection of the cavity and the isolation plate on the pressure-sensitive film; the orthographic projection of the fourth electrode on the substrate overlaps with the orthographic projection of the cavity and the isolation plate on the fourth substrate.

[0187] Of course, the packaging form using a spacer and a sealing ring can also be applied to a piezoresistive pressure sensing chip. FIG6 c only uses a capacitive pressure sensing chip as an example. When this packaging form is used, the sealing performance of the cavity can be improved.

[0188] Of course, only two examples of pressure sensing chips are listed above. In some other embodiments, there may also be two main types of chips, such as resonant vibration type and piezoelectric type. Their structures can refer to the structures of the above-mentioned capacitive pressure sensing chip and piezoresistive pressure sensing chip, and will not be elaborated here.

[0189] Below, two pressure sensing chips are given as examples.

[0190] Example A1, as shown in Figure 6d, includes a pressure-sensitive film, a substrate, a first signal output structure, and a lead structure. The pressure-sensitive film is a silicon substrate, and the substrate is a glass substrate, which are bonded using an anodic bonding process to form a cavity.

[0191] The pressure-sensitive film includes a thinned area and a non-thinned area, the thinned area constitutes a chamber wall on one side of the cavity, and the orthographic projection of the non-thinned area on the substrate overlaps with the orthographic projection of the cavity on the substrate; a silicon oxide insulating layer is formed on the side of the pressure-sensitive film close to the cavity, and the silicon oxide insulating layer covers the entire surface of the pressure-sensitive film, and a first electrode and a second electrode separated from each other are formed on the side of the silicon oxide insulating layer close to the cavity, wherein the first electrode and the second electrode are both located in the cavity.

[0192] The first and second electrodes each correspond to a first signal output structure and a lead structure. Each first signal output structure comprises a metal binding region, a metal transition region, and a signal output terminal. The lead structure comprises a first lead post and a lead-out electrode. The signal output terminal is a spherical solder joint disposed on the metal transition region. A metal binding region is disposed between the metal transition regions of the two first signal output structures, and the two are electrically connected via the metal binding region. The thinned region can convert a pressure signal into a deformation signal. The first and second electrodes are both force-sensitive resistors that can convert deformation in the thinned region into an electrical signal.

[0193] Among them, the lead-out electrode is located at the bonding point between the pressure-sensitive film and the substrate and does not extend to the cavity. One end of the lead-out electrode is electrically connected to the first electrode and the other end is electrically connected to the first lead post, which is used to transmit the electrical signal on the first electrode to the first lead post; the first lead post does not have a portion exposed in the cavity, which is the electrical connection structure of the first electrode, and transmits the electrical signal on the lead-out electrode to the metal binding area; the metal binding area is also the electrical connection structure of the pressure sensing chip, and the metal binding area uses a copper redistribution layer to transmit the electrical signal on the first lead post. The metal transition zone is composed of a multi-layer metal film including an adhesion layer, a diffusion barrier layer and a wetting layer. It has three main functions: 1) the electrical connection structure of the pressure sensing chip, transmitting the electrical signal on the metal binding area to the ball solder joint; 2) the bonding layer connecting the metal binding area and the ball solder joint; 3) preventing the diffusion of solder ball material atoms into the metal binding area; the ball solder joint has two main functions: 1) the input and output ports of the entire pressure sensing chip; 2) the bonding structure for flip-chip bonding with the packaging substrate during packaging;

[0194] Among them, when the pressure sensing chip is used to perform pressure detection on the medium to be measured, the pressure value in the cavity is the reference pressure for the pressure sensing chip to measure the pressure. When the pressure value of the medium to be measured is equal to the pressure value in the cavity, the first electrode and the second electrode will not generate an electrical signal, and the output of the pressure sensing chip is zero; when the pressure of the medium to be measured is greater than the pressure in the cavity, the output of the pressure sensing chip is the external atmospheric pressure minus the pressure in the cavity.

[0195] Unlike the pressure sensing chip shown in FIG6a , in which the signal output end is a metal wire, when the pressure sensing chip shown in FIG6b is used, since the signal output end is a ball solder joint, the base side of the pressure sensing chip can be soldered to the packaging substrate through the ball solder joint, thereby reducing the difficulty of packaging.

[0196] Example A2, as shown in Figure 6e, the structure of the pressure sensing chip includes: a pressure-sensitive film, a substrate, a lead structure, and a first signal output structure. The pressure-sensitive film is a silicon substrate, the substrate is a glass substrate, the entire surface of the pressure-sensitive film is thinned, the substrate is flat, and the pressure-sensitive film and the substrate are bonded via a glass isolation sheet and a sealing ring; the pressure-sensitive component includes a third electrode and a fourth electrode, the third electrode is arranged on the side of the pressure-sensitive film close to the cavity, and the fourth electrode is arranged on the side of the substrate close to the cavity; in this example, the pressure-sensitive film is also called a movable plate, the substrate is also called a fixed plate, the third electrode can also be called a movable plate electrode, and the fourth electrode can also be called a fixed plate electrode;

[0197] Among them, the sealing ring is made of metal material. It is the mechanical connection structure of the pressure sensing chip, connecting the fixed electrode plate, the isolation plate and the movable electrode plate together to form a cavity. Due to the effect of the isolation plate, a cavity is formed between the pressure-sensitive film and the substrate.

[0198] The third electrode is partially located in the cavity and partially located at the junction of the pressure-sensitive film and the substrate. The fourth electrode is partially located in the cavity and partially located at the junction of the pressure-sensitive film and the substrate.

[0199] The third electrode and the fourth electrode each correspond to a first signal output structure, and the first signal output structure includes: a metal binding area, a metal transition area and a signal output end. The two first signal output structures can be spaced apart, that is, not electrically connected;

[0200] The first lead post connected to the third electrode passes through the substrate and the isolation sheet and is then connected to the third electrode, and the first lead post connected to the fourth electrode passes through the substrate and is then connected to the fourth electrode;

[0201] Among them, the functions of the metal binding area and the metal transition area can refer to the description of the above example A1. In this example, the signal output end is the first bonding bump, which is integrally formed with the metal transition area and uses the same metal material. During packaging, it can be bonded to the packaging substrate.

[0202] When the pressure sensing chip is used to detect the pressure of a medium to be measured, the capacitance value of the chip is measured by measuring the electrical signal between the movable plate electrode and the fixed plate electrode to determine the pressure of the medium to be measured.

[0203] Based on the same inventive concept, the present disclosure also provides a pressure sensor encapsulating the aforementioned pressure sensing chip. The pressure sensor includes the aforementioned pressure sensing chip and a packaging structure, wherein the packaging structure is used to encapsulate the pressure sensing chip. Referring to Figures 7a and 7b , schematic cross-sectional structures of two pressure sensors are shown. As shown in Figures 7a and 7b , the pressure sensor includes the pressure sensing chip shown in any of the aforementioned examples and a packaging structure. The packaging structure is used to encapsulate the pressure sensing chip and allows a portion of the structure within the cavity of the pressure sensing chip to be exposed externally, thereby enabling the pressure sensing chip to directly detect the pressure of liquids or corrosive gases.

[0204] Specifically, the packaging structure may include a packaging part 20, a second signal output structure 20 and a signal processing circuit 40; wherein, the pressure sensing chip can be installed on the packaging part and electrically connected to the signal processing; the packaging part has a sealed cavity 30, in which at least the signal processing circuit exists; wherein, the second signal output structure is configured to the packaging part and electrically connected to the signal processing circuit, and is configured to output the electrical signal processed by the signal processing circuit to the outside.

[0205] The target area 101 of the pressure-sensing film of the pressure-sensing chip facing away from the cavity can be exposed outward, so that after the target area contacts the medium to be measured, the pressure of the medium to be measured is transmitted to the pressure-sensing film, causing the pressure-sensing film to deform under the support of the cavity.

[0206] As shown in Figure 7a, the pressure sensing chip can be soldered, bonded, or affixed to the packaging portion, and the pressure sensing chip can be located within a sealed cavity. Alternatively, as shown in Figure 7b, the pressure sensing chip can be located outside the sealed cavity. The target area can be the entire area of ​​the pressure-sensitive film facing away from the cavity, or it can refer only to the orthographic projection area of ​​the cavity on the side of the pressure-sensitive film facing away from the cavity. To protect the first signal output structure on the pressure sensing chip, the first signal output structure can be shielded from the external environment.

[0207] In one example, the packaging portion can be a rectangular frame structure with a hollow interior and can be supported by a metal material, such as stainless steel, alloy material, or other non-corrodible metal material. A signal processing circuit is encapsulated on a supporting surface within the packaging portion. The signal processing circuit can be electrically connected to the first signal output structure of the pressure sensing chip. Specifically, it can be electrically connected to the signal output terminal on the first signal output structure. The connection method can be bonding, coupling, welding, or overlapping, etc., which will not be described in detail here. Specifically, the signal processing circuit can include an ASIC (Application Specific Integrated Circuit) chip 401, a thick film circuit (not shown in the figure), and a resistor-capacitor component 402. The thick film circuit can be formed on a side of the packaging portion near the sealed cavity. It can be a printed circuit. In practice, it can be made of a printed circuit board. The ASIC chip is electrically connected to the resistor-capacitor component via the thick film circuit. The signal output terminal on the first signal output structure can be electrically connected to the thick film circuit, thereby introducing the electrical signal output by the pressure sensitive component of the pressure sensing chip into the thick film circuit, and then inputting it into the loop formed by the ASIC chip and the resistor-capacitor component through the thick film circuit.

[0208] Among them, the ASIC chip is mainly used for functions including filtering, amplification, compensation, etc.; the resistor and capacitor components are circuit processing and adjustment elements, filtering out interference signals and improving the overall performance of the circuit; among them, the electrical signal output by the pressure-sensitive component is input into the loop composed of the ASIC chip and the resistor and capacitor components through the thick film circuit. After the interference signal is filtered out by the resistor and capacitor components, it is filtered, amplified and compensated by the ASIC chip and then output to the second signal output structure.

[0209] The second signal output structure is electrically connected to the signal processing circuit, specifically, it can be connected to the output end of the ASIC chip through an AF wire 9, and the AF wire 9 is located in the sealed cavity.

[0210] In the pressure sensor using this embodiment, since the packaging portion is provided with a sealed cavity, the signal processing circuit for processing the signal output by the pressure sensing chip is located in the sealed cavity. As a result, the signal processing circuit will not be affected by the external environment, thereby ensuring its electrical performance of signal processing, thereby increasing the service life of the entire pressure sensor. In addition, since the target area on the side of the pressure-sensitive film in the pressure sensing chip facing away from the cavity is exposed outward, the medium to be measured can directly contact the side of the pressure-sensitive film facing away from the cavity, thereby achieving direct measurement of the medium to be measured.

[0211] In some embodiments, the entire pressure sensing chip may be located outside the sealed cavity, and the first signal output structure is connected to the packaging portion;

[0212] Alternatively, the entire pressure sensing chip is located within the sealed cavity, wherein the pressure sensing film is sealedly connected to the packaging portion, the packaging portion is provided with a through hole allowing the medium to be measured to flow in, and the through hole is connected to the pressure sensing film.

[0213] For example, a pressure sensing chip can be located within a sealed cavity 30, as shown in FIG7a . A target area of ​​the pressure-sensing film on the side facing away from the cavity needs to be exposed. In this case, the packaging structure can have a notch that exposes the target area. When the pressure sensing chip is mounted on the packaging structure, it can be installed in the notch, and the pressure sensing chip and the packaging structure can enclose the sealed cavity, with only the pressure-sensing film exposed. The pressure-sensing film of the pressure sensing chip can be sealed to the side of the packaging structure near the sealed cavity. The pressure-sensing film includes a thinned region and a non-thinned region. Specifically, the thinned region of the pressure-sensing film can be exposed, while the non-thinned region can be sealed to the side of the packaging structure near the sealed cavity. In this way, the target area is exposed to the external environment, while the first signal output structure on the substrate side is not exposed to the external environment and is located within the sealed cavity. This protects the signal processing circuit and the first signal output structure, thereby improving the service life of the pressure sensing chip. Of course, if the entire surface of the pressure-sensing film is thinned, it is also possible that only a portion of the pressure-sensing film is sealed to the side of the packaging structure near the sealed cavity, while the orthographic projection area of ​​the cavity is exposed.

[0214] The pressure sensing chip can be located outside the sealed cavity, as shown in FIG7b , and the side of its base facing away from the cavity is sealedly connected to the side of the packaging part facing away from the sealed cavity. Specifically, it can be a connection between the first signal output structure and the packaging part. The pressure-sensitive film can be completely exposed to the outside. Of course, in some cases, the pressure-sensitive film can also be exposed only in the target area of ​​the cavity part. This method can simplify the connection between the pressure sensing chip and the packaging part. For example, the signal output end on the first signal output structure can be a ball solder joint, and the electrical connection between the first signal output structure and the packaging part is achieved through the ball solder joint. In this example, a protective layer can be provided to protect the first signal output structure. The protective layer is made of insulating material, so that the first signal output structure can be protected from being exposed to the external environment and protected from being corroded by the medium to be measured.

[0215] In some embodiments, to reduce the packaging cost and volume of the packaging structure, the packaging portion can be assembled from multiple components, such as a component for mounting the pressure sensing chip, a component for supporting the pressure sensing chip, and a component for sealing. In a specific implementation, the packaging portion may include: a mounting portion 201, a supporting portion 202, and a sealing shell 203;

[0216] In which, the pressure sensing chip and the signal processing circuit are installed on the same side or opposite sides of the mounting part; the supporting part is connected to the mounting part for supporting the mounting part; the sealing shell is sealedly connected to the supporting part to form a closed cavity with the supporting part; or, the sealing shell is sealedly connected to the mounting part to form a closed cavity with the supporting part, and the second signal output structure is connected to the sealing shell.

[0217] The mounting portion can be made of insulating material, such as ceramic, and can be a plate-like structure to provide a flat surface for mounting the pressure sensing chip and the signal processing circuit. The side of the mounting portion where the signal processing circuit is mounted is located in the sealed cavity, while the pressure sensing chip and the signal processing circuit can be located on the same side of the mounting portion, or on opposite sides. When located on the same side, the side of the pressure sensing film of the pressure sensing chip facing away from the cavity is connected to the mounting portion, so that the pressure sensing chip can be located inside the sealed cavity, and the mounting portion can be provided with a notch for exposing the target area of ​​the pressure sensing chip to the outside, so that the first signal output structure of the pressure sensing chip is located in the sealed cavity, and the target area is exposed at the notch; when located on opposite sides, the side of the base of the pressure sensing chip facing away from the cavity is connected to the mounting portion. In this case, the mounting portion does not have a notch exposed to the outside, and the pressure sensing chip can be located outside the sealed cavity.

[0218] 8a-8b, schematic cross-sectional structures of two pressure sensors are shown respectively. As shown in FIG8a, the support portion can be connected to the side of the mounting portion facing away from the closed cavity to provide support for the mounting portion. The support portion can be made of a metal material, such as stainless steel. There can be one or more support portions to provide support for the mounting portion and provide a channel to expose the target area.

[0219] In which, the sealing shell can be sealed and connected to the supporting part or to the mounting part. Figure 8a shows a schematic diagram of the sealing connection between the sealing shell and the mounting part, wherein the sealing shell can also be made of metal material or ceramic material. Of course, in order to achieve the connection between the sealing shell and the mounting part, the mounting part can be coated with metal material at the position where it is connected to the sealing shell so as to be welded to the sealing shell. Of course, the metal material of the sealing shell and the metal material on the mounting part can be the same to reduce the difficulty of welding.

[0220] The sealing shell can be sealed and connected to the support portion. FIG8b shows a schematic diagram of the sealed connection between the sealing shell and the support portion. The sealing shell can also be made of a metal material. The metal material of the sealing shell and the metal material on the support portion can be the same material to reduce the difficulty of welding. As shown in FIG8b.

[0221] Accordingly, in some embodiments, since the first signal output structure of the pressure sensing chip can be located in the sealed cavity or not, the connection method between the pressure sensing chip and the mounting portion can also be: as shown in FIG8a, the pressure sensing chip is located in the sealed cavity, and the specific implementation method is: the side of the pressure sensing film of the pressure sensing chip facing away from the cavity is connected to the side of the mounting portion close to the sealed cavity, and the first signal output structure of the pressure sensing chip is electrically connected to the signal processing circuit through a metal wire. In this case, the mounting portion is provided with a first through hole 224 communicating with the outside world, and the first through hole 224 is connected to the outside world. The size of 4 can be smaller than the size of the cavity; or, as shown in FIG8b, the pressure sensing chip is located inside and outside the sealed cavity, and the specific implementation method is: the first signal output structure of the pressure sensing chip is connected to the side of the mounting portion away from the sealed cavity, and the first signal output structure of the pressure sensing chip is welded to the side of the mounting portion away from the sealed cavity through a ball solder joint. In order to achieve electrical connection between the first signal output structure and the signal processing circuit, a second metal lead column is further penetrated on the mounting portion, one end of the second metal lead column is electrically connected to the first signal output structure, and the other end is electrically connected to the signal processing circuit.

[0222] As shown in Figure 8b, a film thickness circuit can be formed on the side of the mounting portion facing away from the sealed cavity and the side close to the sealed cavity. The electrical signal of the first signal output structure is introduced into the second metal lead post through the film thickness circuit on the side of the mounting portion facing away from the sealed cavity. The second metal lead post introduces the electrical signal into the film thickness circuit through the side of the mounting portion close to the sealed cavity, and then introduces it into the signal processing circuit through the film thickness circuit.

[0223] With the structure of this embodiment, since the packaging part is composed of the mounting part, the supporting part and the sealing shell, when forming the packaging part, the three can be connected in sequence according to a certain packaging order, thereby reducing the difficulty of assembly. Moreover, since the mounting part, the supporting part and the sealing shell can be made of simple and easily available materials, the packaging cost can be reduced.

[0224] In some exemplary embodiments, the supporting portion can be used to form a support for the mounting portion, that is, a carrier structure of the pressure sensing chip and the mounting portion, wherein, since the sealed shell can be connected to the supporting portion to form a closed cavity, and the supporting portion is connected to the mounting portion, the supporting portion can include a structure connected to the sealed shell, and a structure connected to the mounting portion, wherein the structure connected to the sealed shell can form a closed cavity between the sealed shell, and the structure connected to the mounting portion can serve as a carrier of the pressure sensing chip.

[0225] 9 , a schematic structural diagram of the support portion is shown. As shown in FIG9 , the support portion may include: a T-shaped support portion, wherein the support surface of the T-shaped support portion includes a first mounting platform and a second mounting platform, the first mounting platform is located outside the second mounting platform, and the sealed shell is connected to the first mounting platform;

[0226] Among them, the T-shaped support portion is provided with a second through hole 223 running through it, and the mounting portion is connected to the second mounting platform and / or the side wall of the second through hole 223. One end of the second through hole allows the medium to flow in, and the other end exposes the target area. The second through hole can be realized by drilling a hole on the support portion. The second through hole can be cylindrical or rectangular, which will not be elaborated here.

[0227] Exemplarily, the support portion can form a T-shaped structure, the T-shaped structure has a support surface, and the support surface can be provided with a first mounting platform and a second mounting platform. As shown in Figure 9, the second mounting platform is a welding structure of the support portion and the mounting portion, and the first mounting platform is a welding structure of the support portion and the sealing shell. Specifically, the second mounting platform may include two bosses arranged opposite to each other on the support surface, and the area between the two bosses is for installation of the mounting portion. The first mounting platform may include two bosses arranged opposite to each other on the support surface, and the two bosses are located on the outside of the two bosses of the second mounting platform, and the height of the first mounting platform is less than the height of the second mounting platform. When the mounting portion is installed on the second mounting platform, the mounting portion can be welded to the two bosses of the second mounting platform; when the sealing shell is installed on the first mounting platform, the sealing shell can be welded to the two bosses of the first mounting platform.

[0228] The T-shaped support portion may include a second through-hole extending therethrough, the second through-hole extending along the axis of symmetry of the T-shaped support portion. Furthermore, the diameter of the second through-hole may be greater than the length of the cavity. In other words, the orthographic projection of the second through-hole on the pressure-sensitive membrane of the pressure-sensitive chip overlaps the orthographic projection of the cavity on the pressure-sensitive membrane. The second through-hole is used to expose the pressure-sensitive membrane to the external environment. Specifically, the second through-hole may extend through the second mounting platform. Thus, when the pressure-sensitive chip is mounted on the mounting portion, and the mounting portion is mounted on the second mounting platform, the target area of ​​the pressure-sensitive chip can be exposed through the second through-hole.

[0229] In particular, due to the presence of the second through hole, the pressure-sensing film of the pressure-sensing chip can be connected to the mounting portion, or the first signal output structure of the substrate can be connected to the mounting portion, so the mounting position of the mounting portion on the support portion can be flexibly set. For example, when the pressure-sensing chip is located as a whole in the sealed cavity, the mounting portion can be installed on the second mounting boss. In this case, the pressure-sensing film of the pressure-sensing chip is connected to the mounting portion, and the mounting portion can have a hole connected to the second through hole. For another example, when the pressure-sensing chip is located as a whole outside the sealed cavity, the first signal output structure of the pressure-sensing chip is connected to the side of the mounting portion away from the sealed cavity, and the mounting portion may not have a through hole. For another example, when the pressure-sensing chip is located as a whole outside the sealed cavity, the mounting portion can also be installed on the second mounting boss and connected to the side wall of the second through hole. In this case, it is sufficient to ensure that the side structure of the mounting portion close to the sealed cavity is sealed in the sealed cavity, and the pressure-sensing film of the pressure-sensing chip is exposed in the second through hole.

[0230] The material of the two boss structures of the first mounting platform can be the same as that of the sealing shell, and the material of the two boss structures of the second mounting platform can be the same as that of the mounting portion.

[0231] By adopting this support member, since it has a T-shaped structure, the stability of the packaging structure of the packaged pressure sensing chip can be improved.

[0232] In some exemplary embodiments, the second signal output structure is electrically connected to the signal processing circuit. To maintain the sealing of the sealed cavity, the second signal output structure can be configured on the packaging portion. For example, the second signal output structure can be sealed to the packaging portion, and the sealed connection can be welded, bonded, etc. Accordingly, the second signal output structure can include components connected to the packaging portion and components for connecting to the signal processing circuit. Referring to Figure 10, a schematic structural diagram of the second signal output structure is shown. As shown in Figure 10, the second signal output structure can include: a connector 502, an insulating member 502, and a second lead post 503.

[0233] The connector is sealed and connected to the packaging part, both ends of the insulating part are connected to the connector respectively, the second lead column passes through the insulating part, and the end of the second lead column close to the closed cavity is electrically connected to the signal processing circuit through the second metal lead.

[0234] In this embodiment, the connector can be connected to the packaging portion. Specifically, when the packaging portion includes a mounting portion, a support portion, and a sealed housing, the connector can be connected to the sealed housing. Generally, two connectors are included, wherein the insulating member can be connected to each of the two connectors. The second lead post passes through the insulating member and is electrically connected to the signal processing circuit located in the sealed cavity. In one example, the second lead post can be electrically connected to the signal processing circuit via an AF wire 9. The AF wire is a high-temperature wire with excellent corrosion resistance. It is resistant to oil, strong acids, strong alkalis, strong oxidants, etc., and can be used to measure the pressure of corrosive media to be measured.

[0235] As shown in FIG10 , the connector may be a T-shaped connector, wherein the supporting surface of the T-shaped connector is connected to the insulating member, and the raised portion is connected to the sealing shell. The connection to the insulating member may be welding or bonding. The T-shaped connector may be made of metal, which may be the same metal material as the sealing shell, thereby reducing the difficulty of welding the two.

[0236] The insulating member may be made of a ceramic material or a polymer material, which is not limited herein, and may be used to insulate the second lead post;

[0237] The second lead column can be made of copper, silver or aluminum. When forming the second lead column, a through hole can be formed on the insulating member, and then copper liquid is poured into the through hole to form the second lead column.

[0238] By adopting this second signal output structure, the second signal output structure and the packaging part can be independent components, and the second signal output structure can also be made up of multiple components welded and installed. Therefore, when packaging the pressure sensing chip, a certain packaging sequence can be used, such as first installing the pressure sensing chip and the packaging part, and then sealing the second signal output structure and the packaging part, thereby reducing the difficulty of packaging the pressure sensing chip, and the materials of the second signal output structure are easy to obtain, reducing its production cost.

[0239] Based on the aforementioned sealed shell, mounting portion, support portion, and second signal output structure, there are multiple options for packaging the pressure sensing chip. In one option, C1, the pressure sensing chip can be located within a sealed cavity together with the signal processing circuit. In this case, the sealed cavity can be used to protect the first signal output structure and signal processing circuit on the pressure sensing chip, preventing the first signal output structure from contacting the external environment while only exposing the target area to the external environment. This can improve the electrical protection of the pressure sensing chip and extend its service life. Since the pressure-sensitive film and the first signal output structure are located on opposite sides of the pressure sensing chip, and the pressure-sensitive film needs to be exposed to the external environment, when using the packaging method C1, as shown in FIG8a , the pressure-sensitive film of the pressure sensing chip needs to be bonded to the mounting portion so that the target area of ​​the pressure-sensitive film is exposed to the external environment, while the first signal output structure is located within the sealed cavity.

[0240] In another option, C2, the pressure-sensing chip can be located outside the sealed cavity, and its pressure-sensitive film can be exposed to the external environment. In this case, the first signal output structure on the pressure-sensing chip can be located on opposite sides of the mounting portion from the signal processing circuit. Similarly, since the pressure-sensing film and the first signal output structure are located on opposite sides of the pressure-sensing chip, and the pressure-sensing film needs to be exposed to the external environment, in this approach, the first signal output structure on the pressure-sensing chip is directly bonded to the mounting portion, thereby achieving electrical connection with the mounting portion, while the pressure-sensing film is exposed to the external environment. As shown in Figure 8b, in this option C2, since the first signal output structure is directly bonded to the mounting portion, the difficulty of electrical connection between the pressure-sensing chip and the mounting portion can be reduced.

[0241] The above methods are described below respectively.

[0242] In the above-mentioned Example C1, referring to FIG11a , a schematic diagram of a packaging structure of a pressure sensing chip is shown. As shown in FIG11a , using the packaging method of Option C1, the pressure sensor structure obtained has the pressure sensing chip and the signal processing circuit located on the same side of the mounting portion, and one side of the pressure-sensing film of the pressure sensing chip is bonded to the mounting portion. The pressure sensing chip is electrically connected to the signal processing circuit via a metal wire of the first signal output structure.

[0243] The mounting portion and the supporting portion are both provided with a first through hole 224 for allowing the medium to be measured to flow in. The first through hole 224 is communicated with a side of the pressure-sensitive membrane facing away from the cavity.

[0244] In this example, the description of the example in FIG8a can be referred to. Unlike the example in FIG8a, a support portion is used, and a first through hole leading to the target area is formed on the support portion. Since the hole is formed in the support portion, the pressure-sensitive membrane is exposed to the external environment. Since the first through hole is surrounded and protected by the material of the support portion, the problem of the package structure being greatly affected by the environment due to large-area contact with the medium to be measured is avoided. Among them, the pressure sensing chip can form a sealed structure with the mounting portion by glass paste or metal bonding. This method has high reliability and relatively simple structure. In this case, when electrically connecting the metal wire to the signal processing circuit, wire bonding can be used to transmit electrical signals.

[0245] In a further example of this embodiment, the radius of the first through hole on the mounting portion can be the same as the radius of the first through hole opened on the supporting portion, and the radius of the first through hole needs to be smaller than the size of the cavity of the pressure sensing chip in the radial direction of the supporting portion, thereby allowing only the pressure-sensitive membrane in the cavity area to contact the external environment, thereby improving the degree of protection of other electrical structures of the pressure sensing chip.

[0246] In a further example of this embodiment, the radius of the first through hole on the mounting portion may be smaller than the radius of the first through hole opened on the supporting portion.

[0247] In this embodiment, the diameter of the first through hole on the mounting portion needs to be smaller than the width of the cavity, that is, the orthographic projection of the cavity on the plane of the mounting portion covers the first through hole on the mounting portion. This can avoid the problem of other structures of the pressure-sensitive membrane of the pressure-sensing chip being corroded by contact with the medium to be measured, thereby improving the protection of the pressure-sensing chip; wherein, the orthographic projection of the cavity on the plane of the mounting portion can be covered by the first through hole on the supporting portion, thereby increasing the area of ​​the region allowing liquid to flow in, thereby ensuring the accuracy of pressure detection of the medium to be measured.

[0248] Referring to Figure 11b, a schematic diagram of a packaging structure of a pressure sensing chip is shown. As shown in Figure 11b, the packaging method C2 is selected, and the pressure sensing chip is located outside the closed cavity. In the structure of the pressure sensor obtained, the pressure sensing chip and the signal processing circuit are respectively located on opposite sides of the mounting portion, wherein there is a gap between the pressure sensing chip and the supporting portion, and the first signal output structure of the pressure sensing chip located on the substrate is bonded to the mounting portion; wherein a third lead column 2011 passes through the mounting portion, and one end of the third lead column is connected to the first signal output structure, and the other end is connected to the signal processing circuit.

[0249] In this example, reference can be made to the description of the example in FIG8b . The difference from the example in FIG8b is that a support portion is used, and a second through hole 223 leading to the target area is formed on the support portion. Since the target area is exposed to the external environment due to the hole design on the support portion, the second through hole is surrounded and protected by the material of the support portion, thereby avoiding the problem of the packaging structure being greatly affected by the environment due to a large area of ​​contact with the medium to be measured.

[0250] In this example, the second through hole of the support portion includes a first area 31 close to the mounting portion and a second area 32 away from the mounting portion, and the size of the first area in the radial direction is larger than the size of the second area in the radial direction. In this way, the first area and the second area constitute a T-shaped second through hole, wherein the pressure sensing chip is located in the first area, thereby, the first area can provide an installation environment for the pressure sensing chip and the mounting portion. The first area can be regarded as a mounting platform for the support portion to install the mounting portion and the pressure sensing chip. The area of ​​the pressure sensing chip except the pressure-sensitive membrane can be connected to the side wall of the first area, that is, the pressure sensing chip only has the pressure-sensitive membrane connected to the second area. In this case, other structures of the pressure sensing chip can be protected from being exposed to the external environment; wherein, when the second area is smaller than the size of the first area, it can ensure that the medium to be measured flowing to the pressure sensing chip is concentrated on the pressure-sensitive membrane, which is beneficial to the pressure detection of the medium to be measured.

[0251] Of course, as shown in FIG11b , there may be a gap between the pressure sensing chip and the hole wall of the first region, and a protective layer may be provided on the side of the mounting portion close to the pressure sensing chip to protect the first signal output structure so that the first signal output structure is not in contact with the external environment.

[0252] In this embodiment, since the pressure sensing chip can be welded to the mounting portion through the first signal output structure, compared with the structure shown in Figure 11a above, this structure can avoid the problem of relatively low production efficiency when the pressure sensing chip and the mounting seat are bonded by slurry, thereby improving production efficiency.

[0253] In a further example of this embodiment, the mounting portion housing the pressure sensing chip and the signal processing circuitry may be provided with separate components. For example, the pressure sensing chip and the signal processing circuitry may be located on two different components of the mounting portion, such that the pressure sensing chip and the signal processing circuitry are located on opposite sides of the mounting portion. Electrical connection between the pressure sensing chip and the signal processing circuitry may be achieved via a third lead post.

[0254] 11c , which shows a schematic diagram of a packaging structure of a mounting portion and a pressure sensing chip. As shown in FIG11c , the mounting portion may include a signal transfer plate and an insulating base that are relatively arranged;

[0255] Insulation base 2013, film thickness circuit and signal transfer board 2012:

[0256] The signal transfer board is located in the sealed cavity, and the signal processing circuit is located on a side of the signal transfer board away from the support portion;

[0257] Wherein, a film thickness circuit is further provided on the signal transfer board, and the film thickness circuit is provided on the same side as the signal processing circuit and is electrically connected to the signal processing circuit;

[0258] The pressure sensing chip is arranged on a side of the insulating base away from the signal adapter board;

[0259] Among them, the first signal output structure is encapsulated on the side of the insulating base away from the signal adapter board, one end of the third lead column is electrically connected to the first signal output structure, and the other end passes through the insulating base and the signal adapter board in sequence, and is electrically connected to the signal processing circuit.

[0260] In this example, the packaging method between the pressure sensing chip and the packaging structure can be described with reference to the structure shown in Figure 8b. Different from the structure shown in Figure 8b, the mounting part in this example includes an insulating base and a signal adapter board, wherein the insulating base can be connected to the sealing shell and the support part, and a closed cavity is formed between the insulating base and the sealing shell. The signal adapter board is located in the closed cavity, and the insulating base can be located outside the closed cavity; wherein, the signal processing circuit is located on one side of the signal adapter board, and the first signal output structure of the pressure sensing chip is packaged on the insulating base, and the insulating base and the signal adapter board can be connected by a third lead column running through the two. On the one hand, the third lead column is used to input the electrical signal output by the first signal output structure into the signal processing circuit, and on the other hand, it connects the insulating base and the signal adapter board and supports the signal adapter board.

[0261] Among them, the insulating base is made of insulating materials, such as ceramics, glass, etc. Of course, as mentioned above, when connected to a sealed shell made of metal material, both ends of the insulating base can have metal connectors to be sealed and connected to the sealed shell through the metal connectors; wherein, a film thickness circuit is arranged on the signal transfer board, and the thick film circuit can be a PCB circuit board, and the signal processing circuit is arranged on the side of the film thickness circuit away from the signal transfer board, and is electrically connected to the film thickness circuit.

[0262] With this pressure sensor structure, since the mounting portion includes a signal adapter board and an insulating base, the pressure sensing chip and the signal processing circuit can be separately installed on independent components. Therefore, compared with the structure shown in Figure 11b, the two (insulating base + pressure sensing chip, signal adapter board + signal processing circuit) can be simultaneously prepared in a parallel process, thereby improving production efficiency.

[0263] In one implementation of this example, the support portion defines a second through-hole 223 for admitting the medium to be measured. One end of the second through-hole allows the medium to flow in, while the other end exposes part or all of the area of ​​the insulating base facing away from the signal adapter board. As shown in FIG11c , two support portions may be provided, with the second through-hole formed between them, such that the second through-hole fully exposes the pressure sensing chip.

[0264] Specifically, referring to Figures 11d and 11e, schematic diagrams of the packaging structures of the two pressure sensors are shown respectively. As shown in Figure 11d, the support has a second through hole extending therethrough, and the insulating base can be located at the liquid outlet of the second through hole. As shown in Figure 11e, the insulating base can be located at the liquid inlet of the second through hole, wherein the liquid inlet is the position where the external medium to be measured flows into the support portion, and the liquid outlet is the end position of the second through hole in the support portion.

[0265] As shown in FIG11d , the insulating base and the pressure sensing chip are located at the end of the second through-hole away from the external environment, i.e., at the liquid outlet of the second through-hole. The second through-hole includes a first region and a second region connected to the first region. The radial dimension of the first region is larger than the radial dimension of the second region, thereby making the first region a mounting platform for connecting the insulating base and the pressure sensing chip. Thus, the insulating base and the pressure sensing chip are located in the first region. The arrangement of the second through-hole of the support portion shown in this example can be referred to as FIG11b . Unlike FIG11b , the mounting portion includes a signal adapter board and an insulating base. The insulating base is connected to the support portion and the sealed shell, thereby forming a sealed cavity between the insulating portion and the sealed shell. The signal adapter board is located in the sealed cavity, and two third lead posts are inserted into the insulating base. With this assembly method, the pressure sensing chip is located at the top of the support portion near the insulating base. The medium to be measured needs to be transferred to the pressure sensing chip through the second through-hole extending through the support portion. This packaging method has high reliability.

[0266] As shown in Figure 11e, the insulating base and the pressure sensing chip are located at one end of the second through hole close to the external environment, that is, the insulating base can be at the liquid inlet of the second through hole and sealed with the second through hole of the support part so that the pressure sensing chip is located at the liquid inlet. The two third lead columns pass through the insulating base and extend in the second through hole, and then pass through the signal adapter board.

[0267] The difference from the packaging structure shown in Figure 11d is that the insulating base and the support part in Figure 11d are sealed and connected near the top of the closed cavity. In this example, the insulating base and the support part are sealed and connected away from the bottom of the closed cavity, and are located in the second through hole opened in the support part. Specifically, it can be arranged near the liquid inlet of the second through hole and sealed and connected to the flow channel wall of the second through hole. The closed cavity is composed of the insulating base, the support part and the sealing shell, wherein the second through hole is part of the closed cavity in a section of the insulating base away from the pressure sensing chip.

[0268] In this example, the vertical distance between the side of the insulating base facing away from the enclosed cavity and the entrance of the support part can be greater than or equal to the total thickness of the pressure sensing chip. If it is greater than, the difference between it and the total thickness of the pressure sensing chip can be less than 1 mm, wherein the radial dimension of the second through hole can be greater than the dimension of the pressure sensing chip in the plane direction of the pressure sensing film to facilitate the installation of the pressure sensing chip.

[0269] With the packaging structure of this example, since the pressure sensing chip can be located at the liquid inlet of the second through hole, that is, at the end close to the external environment, the pressure sensing chip can be prevented from being in an official cavity environment, thereby avoiding the tube cavity effect brought about by the performance test of the pressure sensing chip, thereby removing the high-frequency limitation of the pressure sensing chip caused by the official cavity effect, and thus improving the frequency of use of the pressure sensing chip.

[0270] Among them, in the structure of the pressure sensor obtained by adopting the packaging method of option C2, the pressure sensing chip and the signal processing circuit are respectively located on opposite sides of the mounting portion (the pressure sensing chip is located outside the sealed cavity). In a further example, two methods of connecting the first signal output structure of the pressure sensing chip to the mounting portion are given. One method is shown in Figure 12a, which is a partially enlarged schematic diagram of Figure 11c. The first signal output structure can be welded to one side of the mounting portion through a solder joint provided on the pressure sensing chip. In this case, since the pressure-sensing film is exposed to the external environment and the first signal output structure is not located in the sealed cavity, the first signal output structure may also be corroded due to exposure to the external environment, affecting the electrical performance. Therefore, the mounting portion also includes a protective layer provided on the same side as the pressure sensing chip. The protective layer fully covers the solder joint, and the thickness of the protective layer is less than the thickness of the pressure sensing chip.

[0271] As shown in Figure 12a, the first signal output structure may include a spherical solder joint 523. During packaging, the pressure sensing chip can be packaged on the side of the mounting part away from the sealed cavity through the spherical solder joint, and glass slurry can be coated on the side of the mounting part away from the sealed cavity by coating to form a protective layer. The thickness of the protective layer is greater than the thickness of the spherical solder joint and less than the thickness of the pressure sensing chip, so as to completely cover the spherical solder joint and the lower end surface of the third lead column of the mounting part. Therefore, the protective layer can physically isolate the spherical solder joint from the medium to be measured, thereby achieving protection for the spherical solder joint and the first signal output structure, and can allow the medium to be measured to directly contact the target area to achieve pressure detection.

[0272] FIG12b shows another bonding method of FIG12a , in which the first signal output structure and one side of the mounting portion can be metal-bonded. The first signal output structure of the pressure sensing chip can include a first bonding bump. When the first signal output structure is connected to one side of the mounting portion, the pressure sensing chip can be bonded to the mounting portion via the first bonding bump provided on the pressure sensing chip.

[0273] Accordingly, in this example, the mounting portion further includes a slurry bonding layer disposed on the same side as the pressure sensing chip, and two second bonding bumps spaced apart from each other; wherein the third lead post is located outside the two first bonding bumps, and the slurry bonding layer is located outside the third lead post;

[0274] The second bonding bump is bonded to the first bonding bump on the pressure sensing chip, and the slurry bonding layer is sealed and bonded to a side of the substrate of the pressure sensing chip that is away from the cavity.

[0275] Compared with the packaging structure of Figure 12a, in this example, a second bonding bump and a paste bonding layer are added to the side of the mounting portion away from the sealed cavity; wherein, the material of the second bonding bump can be the same as the material of the first bonding bump to facilitate bonding between the two, and the paste bonding layer can be located on the outside of the third lead column, which can be made of glass material and can be formed by a glass paste screen printing process. The paste bonding layer is sealed and bonded to the side of the substrate of the pressure sensing chip away from the cavity to protect the first bonding bump and the second bonding bump located between the paste bonding layer, so that the first signal output structure of the pressure sensing chip is located in a sealed environment, thereby protecting it from the influence of the external environment.

[0276] With this packaging method, metal bonding is used between the pressure sensing chip and the mounting part to achieve electrical interconnection between the pressure sensing chip and the mounting part, and the slurry bonding layer is bonded to the first signal output structure to effectively control the size and dosage of the protective layer for the pressure sensing chip, reduce process difficulty, and improve the yield rate.

[0277] The following describes the structure of a pressure sensor through several examples to illustrate the various packaging methods of pressure sensing chips:

[0278] Example B1: Referring to FIG13a , a schematic cross-sectional structure diagram of a pressure sensor is shown. As shown in FIG13a , the pressure sensor in Example B1 is a piezoresistive sensing chip, and the packaging portion in the packaging structure includes: a supporting portion, a mounting portion, and a sealing shell;

[0279] The mounting portion may include an insulating portion 111 and a metal portion 112 connected to both ends of the insulating portion. The insulating portion may be ceramic. A signal processing circuit and a pressure sensing chip are respectively arranged on the same side of the mounting portion, so that the pressure sensing chip can be located within a sealed cavity. The pressure sensing film of the pressure sensing chip is connected to the insulating portion on the side facing away from the cavity. The first signal output structure of the pressure sensing chip is electrically connected to the thick film circuit on the insulating portion via a metal wire. The thick film circuit is electrically connected to the metal wire and the signal processing circuit respectively. The thick film circuit is a printed circuit board structure. The signal processing circuit includes an ASIC chip and a resistor-capacitor component.

[0280] The support portion is a T-shaped support portion, and the support surface of the T-shaped support portion includes a first mounting platform and a second mounting platform. The T-shaped support portion also includes a first through hole 224 running through the symmetry axis. The first mounting platform is located outside the second mounting platform. The two bosses 221 of the first mounting platform are welded to the sealing shell. The second mounting platform may include two bosses 222 arranged opposite to each other on the support surface. The two bosses 222 are welded to the metal part of the mounting portion.

[0281] The second signal output structure includes a connector, an insulating member, and a second lead post; the connector is sealed to the package shell, both ends of the insulating member are connected to the connector, the second lead post passes through the insulating member, and the end of the second lead post close to the sealed cavity is electrically connected to the signal processing circuit through the second metal lead;

[0282] The metal parts of the connector, the sealing shell, the support part and the mounting part are all made of metal, and the materials can be the same, such as copper, to reduce the difficulty of welding;

[0283] The insulating portion 111 of the mounting portion includes a first through hole, which is connected to the first through hole on the supporting portion. The diameter of the first through hole on the insulating portion is smaller than the diameter of the first through hole on the supporting portion, and the orthographic projection of the first through hole on the insulating portion on the mounting portion is covered by the orthographic projection of the cavity on the mounting portion.

[0284] Among them, the medium to be measured directly contacts one side of the pressure-sensitive film of the pressure-sensing chip through the first through-hole on the supporting part and the first through-hole on the insulating part, thereby applying pressure to the cavity to cause the cavity to deform, thereby outputting the generated electrical signal through the first signal output structure. The electrical signal is input to the thick-film circuit layer by the metal wire, and is transmitted to the resistor-capacitor component and the ASIC chip in sequence through the thick-film circuit layer. After amplification, filtering and other processing by the two, it is transmitted to the second lead column by the AF wire, and then transmitted to the external measuring equipment.

[0285] Example B2: Referring to FIG13b , a schematic cross-sectional structure diagram of a pressure sensor is shown. As shown in FIG13b , the pressure sensor in Example B2 is a piezoresistive sensing chip, and the packaging portion in the packaging structure includes: a T-shaped support portion, a mounting portion, and a sealing shell;

[0286] The mounting portion may include an insulating base and a signal adapter board. The insulating base includes an insulating portion 111 and a metal portion 112 connected to the insulating portion. The insulating portion may be ceramic. The metal portion is welded to the two bosses of the second mounting platform of the T-shaped support portion, thereby sealingly connecting the insulating base to the T-shaped support portion. The two bosses of the first mounting platform are welded to the sealing shell. Thus, the sealing shell, the T-shaped support portion, and the insulating base enclose a sealed cavity. The signal adapter board is located in the sealed cavity. The signal adapter board may be arranged opposite to the insulating base, and the two may be parallel. A signal processing circuit is formed on the side of the signal adapter board facing away from the insulating base. The signal processing circuit is the same as that in the above-mentioned example B1, and the second signal output structure is the same as that in the above-mentioned example B1.

[0287] The pressure sensing chip is located outside the sealed cavity. The first signal output structure of the pressure sensing chip is soldered to the side of the insulating base 2013 facing away from the signal adapter board via a ball solder joint. The insulating base is penetrated by a third lead post 2011, which also extends to the signal adapter board 2012 and is electrically connected to the thick-film circuit on the signal adapter board. The side of the insulating base 2013 facing away from the signal adapter board 2012 is coated with a circuit layer, which is used to achieve an electrical connection between the third lead post and the first signal output structure.

[0288] A protective layer 131 is applied to the side of the insulating base facing away from the signal adapter board. The protective layer can cover the welding area between the first signal output structure and the insulating base, thereby protecting the circuit of the first signal output structure from being affected by the external environment. The protective layer is coated with glass paste. The thickness of the protective layer needs to be less than the thickness of the pressure sensing chip to expose the pressure-sensing film.

[0289] The second through hole 223 on the T-shaped support portion includes a first area and a second area. The radial size of the first area is larger than the radial size of the second area. The pressure sensing chip is located in the first area and has a gap with the second through hole wall in the first area.

[0290] Among them, the medium to be measured directly contacts one side of the pressure-sensitive film of the pressure-sensing chip through the second through-hole 223 on the supporting part, thereby applying pressure to the cavity to cause the cavity to deform, thereby outputting the generated electrical signal through the first signal output structure. The electrical signal is transmitted from the welding area to the third lead post, and is transmitted to the thick film circuit layer on the signal adapter board through the third lead post, and is transmitted to the resistor-capacitor component and the ASIC chip in sequence through the thick film circuit layer. After amplification, filtering and other processing by the two, it is transmitted to the second lead post by the AF wire, and then transmitted to the external measuring equipment.

[0291] Example B3: Referring to FIG13c , a schematic cross-sectional structure diagram of a pressure sensor is shown. As shown in FIG13c , the packaging portion of the pressure sensor in Example B3 includes: a supporting portion, a mounting portion, and a sealing shell;

[0292] The mounting portion may include an insulating base and a signal transfer board, the insulating base includes an insulating portion and a metal portion connected to the insulating portion, and the insulating portion may be ceramic;

[0293] The T-shaped support portion has a second through hole extending along the axis of symmetry. The insulating base is located at the entrance of the second through hole, that is, on a side of the T-shaped support portion close to the bottom. The insulating base is welded to the side wall of the second through hole via a metal portion.

[0294] The two bosses of the first mounting platform of the T-shaped support portion are welded to the sealed shell, whereby the sealed shell, the T-shaped support portion, and the insulating base enclose a sealed cavity. The signal adapter board is located in the sealed cavity. The signal adapter board can be arranged opposite to the insulating base, and the two can be parallel. The size of the insulating base can be smaller than the size of the signal adapter board. A signal processing circuit is formed on the side of the signal adapter board facing away from the insulating base. The signal processing circuit is the same as that of Example B1 above, and the second signal output structure is the same as that of Example B1 above.

[0295] The first signal output structure of the pressure sensing chip is welded to a side of the insulating base facing away from the signal adapter board via a ball solder joint. A third lead pin extends through the insulating base, which also extends into the signal adapter board and is electrically connected to the thick-film circuit on the signal adapter board. A circuit layer is coated on a side of the insulating base facing away from the signal adapter board, which is used to achieve an electrical connection between the third lead pin and the first signal output structure.

[0296] A protective layer is coated on the side of the insulating base away from the signal transfer board. The setting of the protective layer is the same as that of the above example B2. The pressure sensing chip is located at the entrance of the second through hole and can be flush with the T-shaped support portion, thereby avoiding the official cavity effect.

[0297] Example B4: Different from Example B3 above, the first signal output structure of the pressure sensing chip is bonded to the second bonding bump 132 of the insulating base via the first bonding bump, and a slurry bonding layer is provided on the side of the insulating base facing away from the signal adapter board. The specific structure is shown in FIG12b;

[0298] Example B5: Different from the above examples B1-B3, the pressure sensing chip is a capacitive sensing chip.

[0299] Based on the same inventive concept, the present disclosure further provides a packaging method for the pressure sensor described above, for packaging the pressure sensor in any of the exemplary embodiments described above. The method may specifically include the following steps:

[0300] Step S101: mounting a pressure sensing chip on a packaging portion in a packaging structure; the packaging portion has a sealed cavity, and at least the signal processing circuit is located in the sealed cavity;

[0301] Step S102: electrically connecting a first signal output structure on the pressure sensing chip to a signal processing circuit in the packaging structure; wherein at least the signal processing circuit is present in the sealed cavity.

[0302] The pressure sensing chip may be mounted on the packaging portion of the packaging structure by sealingly connecting the pressure sensing film of the pressure sensing chip to the packaging portion, and the first signal output structure and the signal processing circuit may be electrically connected by welding one end of a metal wire on the first signal output structure to the packaging portion.

[0303] Alternatively, the first signal output structure on the substrate of the pressure sensing chip may be connected to the packaging portion by welding, and the first signal output structure may be electrically connected to the signal processing circuit during the welding connection.

[0304] A packaging process is described using the pressure sensor shown in Example B1 above as an example. Referring to FIG. 14 , a schematic diagram of the packaging process is shown, as shown in FIG. 14 :

[0305] S1: Bonding of the pressure sensing chip, as shown in Figure 14. The mounting portion is cleaned with an organic solvent, and a bonding glass paste is prepared on the insulating portion of the mounting portion by screen printing. Note that the glass paste cannot block the first through-hole structure of the insulating portion. The pressure-sensing film of the pressure sensing chip is placed on the glass paste, and after heating and curing, the pressure sensing chip is bonded to the insulating portion. In addition to glass paste bonding, copper-copper, copper-tin, gold-tin and other bonding methods can also be used to bond the pressure sensing chip to the insulating portion.

[0306] S2: Soldering the ASIC chip and resistors and capacitors, as shown in Figure 14. Reflow soldering is used to solder the ASIC chip and resistors and capacitors to the insulating portion. After soldering, ultrasonic thermocompression bonding is used to bond metal wires to the pressure sensing chip and the insulating portion, and to the ASIC chip and the insulating portion, respectively. This transfers the electrical signals from the pressure sensing chip and ASIC to the insulating portion.

[0307] S3: Welding the mounting portion, as shown in FIG14 . Laser welding or electron beam welding is used to weld the metal portion of the mounting portion to the second mounting platform of the T-shaped support portion. To ensure welding quality, the metal material of the metal portion and the T-shaped support portion should preferably be the same metal material.

[0308] S4: AF wire welding, as shown in Figure 14. The AF wire is welded to the thick film circuit of the insulation part by soldering, thereby transferring the electrical signal on the signal processing circuit to the AF wire.

[0309] S5: Sealing shell welding, as shown in Figure 14. Laser welding or electron beam welding is used to weld the sealing shell and the first mounting platform of the T-shaped support. To ensure welding quality, the sealing shell and the T-shaped support are preferably made of the same material.

[0310] S6: Soldering the second signal output structure, as shown in Figure 14 . This is done by brazing. The AF wire is brazed to the second lead pin, transferring the electrical signal from the signal processing circuit to the second lead pin. Laser welding or electron beam welding are used to secure the sealed housing and connector together. Alternatively, the two can be secured by gluing or threading.

[0311] This packaging method can simplify the packaging of the pressure sensing chip, thereby reducing the packaging cost.

[0312] The first signal output structure on the substrate of the pressure sensing chip can be welded to the packaging unit, and the welding connection can also realize the electrical connection between the first signal output structure and the signal processing circuit. The following are two packaging processes for packaging the first signal output structure and the packaging unit:

[0313] In one example, the packaging part includes a mounting part, a supporting part and a sealing shell, the mounting part is connected to the supporting part, and the sealing shell, the mounting part and the supporting part enclose the closed cavity; the solder joints in the first signal output structure can be welded to the solder joints of the mounting part, so that the first signal output structure and the signal processing circuit are respectively located on opposite sides of the mounting part; accordingly, the signal processing circuit can be formed on one side of the mounting part; and the solder joints in the first signal output structure are welded on the side of the mounting part away from the signal processing circuit, so that the first signal output structure is electrically connected to the signal processing circuit; then a protective layer is formed on the side of the mounting part away from the signal processing circuit, the protective layer covers the welding area between the first signal output structure and the mounting part, and the thickness of the protective layer is less than the thickness of the pressure sensing chip.

[0314] In this example, the packaging portion may include a supporting portion, a mounting portion, and a sealing shell. The pressure sensing chip is packaged with the mounting portion. The structures of the supporting portion, the mounting portion, and the sealing shell may refer to the structures shown in the above examples B1-B3.

[0315] The packaging method of this example can be used to obtain the structure of the above examples B2-B3;

[0316] Specifically, the packaging process can be performed in combination with the process described in FIG14 . The difference from FIG14 lies in the welding of the mounting portion and the welding of the pressure sensing chip. In this example, the welding process of the pressure sensing chip can be:

[0317] Use organic solvent to clean the insulating base in the installation part, aim the laser at the welding point to weld the welding point and the surface of the insulating base together, and apply glass paste on the insulating base. After curing, it forms a protective layer to protect the welding area. When applying, pay attention to the thickness of the glass paste not exceeding the lower surface of the pressure-sensitive film.

[0318] The welding process of the mounting portion may be:

[0319] First, the metal portion of the insulating base is welded to the second mounting platform of the T-shaped support using laser welding or electron beam welding. To ensure welding quality, the metal portion and the T-shaped support are preferably made of the same metal material. Due to the support of the third lead post, the signal adapter board is simultaneously fixed after the insulating base is welded.

[0320] The packaging method between the signal adapter board and the signal processing circuit can refer to the above step S2.

[0321] In another example, the packaging part includes a mounting part, a supporting part and a sealing shell, the mounting part is connected to the supporting part, and the sealing shell, the mounting part and the supporting part enclose the closed cavity; a slurry bonding layer and spaced-apart second bonding bumps are formed on the mounting part, and the slurry bonding layer is located at the two first bonding bumps.

[0322] The first bonding bump on the pressure sensing chip can be bonded to the second bonding bump so that the first signal output structure and the signal processing circuit are respectively located on opposite sides of the mounting portion; specifically, the signal processing circuit can be formed on the side of the mounting portion away from the second bonding bump; and the first bonding bump on the pressure sensing chip can be bonded to the second bonding bump so that the first signal output structure is electrically connected to the signal processing circuit; and one side of the substrate on the pressure sensing chip can be bonded to the slurry bonding layer.

[0323] In this example, the packaging portion may include a supporting portion, a mounting portion, and a sealing shell. The pressure sensing chip is packaged with the mounting portion. The structures of the supporting portion, the mounting portion, and the sealing shell may refer to the structures of Examples B2-B3 above. Using the packaging method of this example, the pressure sensor of Example B4 above may be obtained.

[0324] Specifically, the packaging process can be performed in combination with the process described in FIG14 . The difference from FIG14 lies in the welding of the mounting portion and the welding of the pressure sensing chip. In this example, the welding process of the pressure sensing chip can be:

[0325] The insulating base of the mounting portion is cleaned with an organic solvent, the second bonding bump on the insulating base is aligned with the first bonding bump on the pressure sensing chip, and the slurry bonding layer on the insulating base is aligned with the substrate, and then bonding is started. After bonding, the first signal output structure is sealed and protected by the slurry bonding layer. Compared with the welding method in the above example, this method can reduce the process difficulty;

[0326] The welding process of the mounting portion may be:

[0327] First, the metal portion of the insulating base is welded to the second mounting platform of the T-shaped support using laser welding or electron beam welding. To ensure welding quality, the metal portion and the T-shaped support are preferably made of the same metal material. Due to the support of the third lead post, the signal adapter board is simultaneously fixed after the insulating base is welded.

[0328] Alternatively, the metal portion of the insulating base is welded to the first through-hole of the T-shaped support portion near the entrance by laser welding or electron beam welding. To ensure welding quality, the metal portion and the T-shaped support portion are preferably made of the same metal material. Due to the support of the third lead post, the signal adapter board is simultaneously fixed after the insulating base is welded.

[0329] The packaging method between the signal adapter board and the signal processing circuit can refer to the above step S2.

[0330] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0331] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity, or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, commodity, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, commodity, or device that includes the element.

[0332] The above is a detailed introduction to a pressure sensing chip and a pressure sensor provided by the present disclosure. Specific examples are used herein to illustrate the principles and implementation methods of the present disclosure. The description of the above embodiments is only used to help understand the method and core idea of ​​the present disclosure. At the same time, for those skilled in the art, according to the idea of ​​the present disclosure, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present disclosure.

[0333] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.

[0334] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

[0335] References herein to "one embodiment," "an embodiment," or "one or more embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Furthermore, please note that instances of the phrase "in one embodiment" do not necessarily all refer to the same embodiment.

[0336] In the description provided herein, numerous specific details are described. However, it is understood that embodiments of the present disclosure may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0337] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present disclosure may be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third etc. does not indicate any order. These words may be interpreted as names.

[0338] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present disclosure.

Claims

1. A pressure sensing chip, characterized in that, include: Pressure sensitive film; A substrate connected to the pressure-sensitive film, wherein a cavity is formed between the pressure-sensitive film and the substrate; A pressure-sensitive component is located between the substrate and the pressure-sensitive film, and the pressure-sensitive component and the orthographic projection of the cavity on the substrate partially overlap; A first signal output structure is arranged on a side of the substrate away from the pressure-sensitive film; Wherein, the first signal output structure is electrically connected to the pressure-sensitive component through a lead structure penetrating through the substrate.

2. The pressure sensing chip according to claim 1, characterized in that, The orthographic projection of the pressure-sensitive component on the substrate is located within the orthographic projection of the cavity on the substrate.

3. The pressure sensing chip according to claim 1 or 2, characterized in that, The pressure sensitive component is located on a side of the pressure sensitive film close to the substrate, or the pressure sensitive components are distributed on two opposite sides of the target direction of the cavity; wherein the target direction is a vertical direction from the substrate to the pressure sensitive film.

4. The pressure sensing chip according to claim 3, wherein The pressure-sensitive component comprises a first electrode and a second electrode which are arranged at intervals, and the first electrode and the second electrode are both arranged on a side of the pressure-sensitive film close to the cavity; The first electrode and the second electrode are configured to convert the deformation of the pressure-sensitive film into a resistance signal.

5. The pressure sensing chip according to claim 3, characterized in that, The pressure-sensitive component includes a third electrode and a fourth electrode, and the third electrode and the fourth electrode are configured to convert the deformation of the pressure-sensitive film into a capacitance signal; The third electrode is arranged on a side of the pressure-sensitive film close to the cavity, and the fourth electrode is arranged on a side of the substrate close to the cavity; the orthographic projection of the third electrode on the substrate overlaps with the fourth electrode.

6. The pressure sensing chip according to claim 1, characterized in that, The pressure-sensitive film comprises a thinning area and a non-thinning area, and the thickness of the thinning area is smaller than the thickness of the non-thinning area; The orthographic projection of the thinned area on the substrate overlaps with the orthographic projection of the cavity on the substrate.

7. The pressure sensing chip according to claim 6, wherein The orthographic projection of the thinned area on the substrate is covered by the orthographic projection of the cavity on the substrate, and the orthographic projection of the non-thinned area on the substrate overlaps with the orthographic projection of the cavity on the substrate.

8. The pressure sensing chip according to any one of claims 1-7, characterized in that, The lead structure includes: a first lead post and a lead electrode, one end of the lead electrode is connected to the pressure sensitive component, and the other end passes through and is connected to one end of the first lead post, and the other end of the first lead post passes through the substrate and is electrically connected to the first signal output structure.

9. The pressure sensing chip according to claim 8, characterized in that, The lead-out electrode is arranged in the same layer as the pressure-sensitive component.

10. The pressure sensing chip according to claim 8, characterized in that, The orthographic projection of the extraction electrode on the substrate has no overlap with the orthographic projection of the cavity on the substrate.

11. The pressure sensing chip according to claim 1, wherein An insulating layer is also arranged on a side of the pressure-sensitive film close to the substrate; wherein the pressure-sensitive component is located on a side of the insulating layer away from the pressure-sensitive film.

12. The pressure sensing chip according to claim 1, wherein The pressure sensing chip further includes: an isolation sheet, and a sealing ring located on at least one side of the isolation sheet; Wherein, the pressure-sensitive film is sealed and connected to the substrate through the sealing ring and the isolation sheet.

13. The pressure sensing chip according to claim 1, characterized in that, The first signal output structure comprises: a signal input terminal and a signal output terminal; The signal access terminal is connected to the first lead post and the signal output terminal respectively, and the signal output terminal is configured to transmit the electrical signal input by the signal access terminal to an external signal processing circuit.

14. The pressure sensing chip according to claim 13, wherein, The signal access terminal comprises: A metal bonding area is provided on a side of the substrate facing away from the cavity and is electrically connected to the first lead post; A metal transition area is provided on a side of the substrate facing away from the pressure sensing film and is respectively connected to the metal bonding area and the signal output end.

15. The pressure sensing chip according to claim 14, characterized in that, The signal output end includes any one of a metal wire, a solder joint, and a first bonding bump; Wherein, the first bonding bump is integrally formed with the metal transition area and is used for bonding with a second bonding bump on an external signal processing circuit.

16. A pressure sensor, characterized in that, It includes the pressure sensing chip according to any one of claims 1-15 and a packaging structure, and the packaging structure includes: A signal processing circuit; A packaging part, the pressure sensing chip is mounted on the packaging part, the packaging part has a sealed cavity, and at least the signal processing circuit exists in the sealed cavity; A second signal output structure is configured on the packaging part; Wherein, a first signal output structure of the pressure sensing chip is electrically connected to an input end of the signal processing circuit, an output end of the signal processing circuit is electrically connected to the second signal output structure, and the second signal output structure is configured to output the electrical signal processed by the signal processing circuit outward.

17. The pressure sensor according to claim 16, characterized in that, The whole pressure sensing chip is located outside the sealed cavity, and the first signal output structure is connected to the packaging part; Or, the whole pressure sensing chip is located inside the sealed cavity, wherein, a sealed connection is formed between the pressure sensing film and the packaging part, and the packaging part is provided with a through hole allowing a medium to be measured to flow in, and the through hole is communicated with the pressure sensing film.

18. The pressure sensor according to claim 16 or 17, characterized in that, The packaging part includes: A mounting part, the pressure sensing chip and the signal processing circuit are mounted on the same side or opposite sides of the mounting part; A supporting part, connected to the mounting part and used for supporting the mounting part; A sealing shell, hermetically connected to the supporting part to form the sealed cavity with the supporting part; or, the sealing shell is hermetically connected to the mounting part to form the sealed cavity with the supporting part; Wherein, the second signal output structure is connected to the sealing shell.

19. The pressure sensor according to claim 18, characterized in that, The pressure sensing chip and the signal processing circuit are located on the same side of the mounting part, and the pressure sensing film of the pressure sensing chip is bonded to the mounting part; Wherein, first through holes allowing a medium to be measured to flow in are provided on both the mounting part and the supporting part, and a side of the pressure sensing film facing away from the cavity is communicated with the first through holes.

20. The pressure sensor according to claim 19, characterized in that, The radius of the first through hole on the mounting part is smaller than the radius of the first through hole provided on the supporting part.

21. The pressure sensor according to claim 18, characterized in that, The pressure sensing chip and the signal processing circuit are respectively located on opposite sides of the mounting part, there is a gap between the pressure sensing chip and the supporting part, and the first signal output structure is bonded to the mounting part; Wherein, a third lead post penetrates through the mounting part, one end of the third lead post is connected to the first signal output structure, and the other end is connected to the signal processing circuit.

22. The pressure sensor according to claim 21, wherein The mounting part includes: a signal transfer board and an insulating base which are oppositely arranged; Wherein, the signal transfer board is located inside the sealed cavity, and the signal processing circuit is located on a side of the signal transfer board facing away from the supporting part; Wherein, a film thickness circuit is further provided on the signal transfer board. The film thickness circuit is arranged on the same side as the signal processing circuit and is electrically connected to the signal processing circuit; Wherein, the first signal output structure is encapsulated on the side of the insulating base away from the signal transfer board. One end of the third lead post is electrically connected to the first signal output structure, and the other end sequentially penetrates through the insulating base and the signal transfer board and is then electrically connected to the signal processing circuit.

23. The pressure sensor according to claim 21, characterized in that, The support portion is provided with a through second through hole. One end of the second through hole is used for flowing in the medium to be measured, and the other end is communicated with the side of the pressure sensing film away from the cavity.

24. The pressure sensor according to claim 22, wherein The insulating base and the pressure sensing chip are located at the liquid outlet of the second through hole; the second through hole is opened on the support portion; Alternatively, the insulating base and the pressure sensing chip are located at the liquid inlet of the second through hole, and the insulating base is hermetically connected to the second through hole. After the two third lead posts penetrate through the insulating base and extend in the second through hole, they penetrate through the signal transfer board.

25. The pressure sensor according to any one of claims 22-24, characterized in that, The first signal output structure is welded to one side of the mounting portion through a solder joint; Wherein, a protective layer arranged on the same side as the pressure sensing chip is further included on the mounting portion. The protective layer completely covers the solder joint, and the thickness of the protective layer is less than the thickness of the pressure sensing chip.

26. The pressure sensor according to any one of claims 22-24, characterized in that, The first signal output structure includes a first bonding bump; a paste bonding layer and spaced second bonding bumps are further included on the mounting portion; wherein, the paste bonding layer is located outside the first bonding bump; Wherein, the second bonding bump is bonded to the first bonding bump, and the paste bonding layer is hermetically bonded to the substrate of the pressure sensing chip.

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