CN118294046A

CN118294046A - MEMS pressure sensor, pressure detection device and manufacturing method thereof

Info

Publication number: CN118294046A
Application number: CN202410340931.XA
Authority: CN
Inventors: 刘俊; 丁金玲; 刘建华
Original assignee: Hangzhou Hikmicro Sensing Technology Co Ltd
Current assignee: Hangzhou Hikmicro Sensing Technology Co Ltd
Filing date: 2024-03-22
Publication date: 2024-07-05

Abstract

The application discloses a MEMS pressure sensor, a pressure detection device and a manufacturing method thereof. The MEMS pressure sensor includes a sensor die and a substrate. The sensor chip comprises a pressure sensing structure, a detection circuit connected with the pressure sensing structure and a first interconnection point connected with the detection circuit; the substrate is provided with a signal processing circuit and a second interconnect point connected to the signal processing circuit. The sensor chip and the substrate are arranged oppositely, and the first interconnection point and the second interconnection point are electrically connected in the direction perpendicular to the sensor chip. The first interconnection point and the second interconnection point are electrically connected in the direction perpendicular to the sensor chip, so that the transmission channel of an original signal between the detection circuit and the signal processing circuit is short, interference from external environment noise in the original signal transmission process is small, anti-interference performance is improved, signals are not easy to attenuate, and device performance is improved.

Description

MEMS pressure sensor, pressure detection device and manufacturing method thereof

Technical Field

The application relates to the technical field of integrated circuits, in particular to an MEMS pressure sensor, a pressure detection device and a manufacturing method thereof.

Background

The MEMS pressure sensor is a micro device with pressure detection capability, which is prepared by MEMS technology and is mainly divided into three categories of piezoresistive type, capacitive type and resonant type, and is applied to the fields of consumer electronics, industrial production and the like. The piezoresistive MEMS pressure sensor has the advantages of small volume, light weight, simple structure, low cost, high measurement precision and the like, and is widely applied.

The working principle of the piezoresistive MEMS pressure sensor is that a piezoresistor is prepared on a strain film (also called a pressure sensitive film), the strain film deforms under the action of external pressure to generate stress, the piezoresistor is subjected to the action of stress to generate resistance change, and finally the resistance change is converted into voltage output through a detection circuit, and the voltage output value is used for reflecting the magnitude of the external pressure.

In practical use, it has been found that the original signal of the MEMS pressure sensor (not limited to the piezoresistive MEMS pressure sensor) is susceptible to external environmental interference during transmission.

Disclosure of Invention

The application aims to disclose a MEMS pressure sensor, a pressure detection device and a manufacturing method thereof.

The application discloses a MEMS pressure sensor. The MEMS pressure sensor includes a sensor die and a substrate. The sensor chip comprises a pressure sensing structure, a detection circuit connected with the pressure sensing structure and a first interconnection point connected with the detection circuit; the substrate is provided with a signal processing circuit and a second interconnection point connected with the signal processing circuit; the sensor chip and the substrate are arranged oppositely, and the first interconnection point and the second interconnection point are electrically connected in the direction perpendicular to the sensor chip.

In some embodiments, the sum of the height of the first interconnect point and the height of the second interconnect point is h.ltoreq.40 um.

In some embodiments, the sensor tile includes an SOI buried oxide layer; the surface of the SOI buried oxide layer forms the detection circuit and the first interconnection point; the substrate comprises a ROIC sheet, an insulating layer is arranged on the surface of the ROIC sheet, and the insulating layer is provided with the second interconnection point; the SOI buried oxide layer covers an insulating layer on the ROIC chip.

In some embodiments, the detection circuit is a wheatstone bridge, and the first interconnection point is correspondingly arranged at the intersection point of every two adjacent bridge arms.

In some embodiments, the sensor die is disposed opposite the substrate to form a closed cavity, the detection circuit including a first trace connected to the first interconnect point; the signal processing circuit comprises a second wire connected with the second interconnection point, and the first interconnection point, the first wire, the second interconnection point and the second wire are all positioned in the cavity;

Or the sensor chip and the substrate are oppositely arranged to form a cavity with a through hole, the cavity is communicated with the outside through the through hole, and the detection circuit comprises a first wiring connected with the first interconnection point; the signal processing circuit comprises a second wire connected with the second interconnection point, and the first interconnection point, the first wire, the second interconnection point and the second wire are all positioned in the cavity.

In some embodiments, the substrate comprises a ROIC sheet, the interior of the ROIC sheet comprising the signal processing circuitry; and the signal processing circuit at least amplifies the original signal generated by the pressure sensing structure.

In some embodiments, the sensor chip includes a first solder in a ring shape, and the first interconnection point is located in an area surrounded by the first solder; the substrate comprises annular second solder, the second interconnection point is located in an area surrounded by the second solder, and the position of the second solder corresponds to the position of the first solder; the sensor chip and the substrate are bonded by the first solder and the second solder.

In some embodiments, the first interconnect point and the first solder have a height difference of ±3um; and/or, the height difference between the second interconnection point and the second solder is + -3 um.

In some embodiments, the sensor tile includes an SOI substrate layer and an SOI buried oxide layer that provides the detection circuitry; etching the SOI substrate layer to form a cavity so as to form a pressure sensitive film of the pressure sensing structure; the cavity penetrates through the SOI substrate layer to the buried oxide layer, or the depth of the cavity is smaller than the thickness of the SOI substrate layer.

In some embodiments, the cavity has a square or circular shape projected in a plane parallel to the SOI substrate layer.

In some embodiments, the first interconnection point is located outside a membrane edge of the pressure sensitive membrane, and a distance between the membrane edge corresponding to the pressure sensitive membrane is 10um to 50um.

In a second aspect, the present application discloses a pressure sensing apparatus. The pressure detection means comprises any of the MEMS pressure sensors described above.

In a third aspect, the present application discloses a method of manufacturing a MEMS pressure sensor. The method comprises the following steps: forming a sensor sheet comprising: forming a pressure sensing structure, a detection circuit connected with the pressure sensing structure and a first interconnection point connected with the detection circuit on a sensor SOI (silicon on insulator) chip; forming a substrate, comprising: forming a signal processing circuit in a silicon chip to form an ROIC chip, and forming a second interconnection point connected with the signal processing circuit on the ROIC chip; the sensor chip is arranged opposite to the substrate, and the first interconnection point and the second interconnection point are electrically connected in a direction perpendicular to the sensor chip.

In some embodiments, the sensor SOI wafer comprises an SOI buried oxide layer and an SOI substrate layer; forming the sensor sheet includes: forming piezoresistors, first wirings and first interconnection points on the surface of the SOI buried oxide layer; the detection circuit is a Wheatstone bridge and comprises the piezoresistor and the first wiring; and etching the SOI substrate layer to form a cavity so as to form a pressure sensitive film of the pressure sensing structure.

In some embodiments, the sensor SOI wafer comprises an SOI buried oxide layer, and forming the sensor wafer comprises: forming a first interconnection point connected with the detection circuit on the surface of the SOI buried oxide layer; and/or forming the substrate comprises: forming an insulating layer on the surface of the ROIC sheet, forming openings in the insulating layer, and forming a bonding pad and the second interconnection point in the corresponding openings; the bonding pad is connected with the signal processing circuit.

In some embodiments, the method of manufacturing comprises: so that a closed cavity is formed between the sensor chip and the substrate; the detection circuit comprises a first wiring connected with the first interconnection point; the signal processing circuit comprises a second wire connected with the second interconnection point, and the first interconnection point, the first wire, the second interconnection point and the second wire are all positioned in the cavity.

In some embodiments, the forming a closed cavity comprises: forming a first solder material in a ring shape on the sensor SOI wafer; forming a second solder material in a ring shape on the ROIC sheet; bonding the first and second solders to form the enclosed cavity.

In some embodiments, the method of manufacturing comprises: the sensor chip and the substrate are oppositely arranged to form a cavity with a through hole, the cavity is communicated with the outside through the through hole, and the detection circuit comprises a first wiring connected with the first interconnection point; the signal processing circuit comprises a second wire connected with the second interconnection point, and the first interconnection point, the first wire, the second interconnection point and the second wire are all positioned in the cavity.

In some embodiments, the method of manufacturing comprises: forming an insulating layer on the surface of the ROIC sheet, and forming a through hole penetrating the ROIC sheet and the insulating layer; forming a first solder material in a ring shape on the sensor SOI wafer; forming a second solder material in a ring shape on the ROIC sheet; and bonding the first solder and the second solder to form the cavity, wherein the cavity is communicated with the outside through the through hole.

With the MEMS pressure sensor and the pressure detection device, the transmission channel of the original signal between the detection circuit and the signal processing circuit is short due to the electric connection of the first interconnection point and the second interconnection point in the direction perpendicular to the sensor chip, so that the interference of external environment noise in the transmission process of the original signal is small, the anti-interference performance can be improved, the signal is not easy to attenuate, and the device performance is improved. Because the anti-interference capability is improved, the interference of the external environmental noise on the signal in the secondary transmission process (the signal output by the ROIC is output to the circuit board functional unit through the signal transmission channel formed by WB wire bonding, shell pin, circuit board wiring and the like) is small. For the manufacturing method, the manufacturing process of the MEMS pressure sensor is simple, and the manufactured MEMS pressure sensor has the beneficial effects.

Drawings

FIG. 1 is an exploded view of a MEMS pressure sensor shown in accordance with an embodiment of the present application;

FIG. 2 is a schematic illustration of a sensor wafer bonded to a substrate to form a cavity;

FIG. 3 is a schematic view of a sensor tile;

FIG. 4 is a front view of the sensor chip shown in FIG. 3;

FIG. 5 is a schematic illustration of a substrate;

FIG. 6 is a schematic diagram of a signal processing circuit, a second interconnect point, and a pad;

FIG. 7 is another schematic illustration of a sensor chip bonded to a substrate to form a cavity;

fig. 8 is a schematic view of a ROIC sheet formed with an insulating layer;

FIG. 9 is a schematic illustration of forming a pad, a second interconnect point, and a second solder;

FIG. 10 is a schematic diagram of a sensor SOI wafer;

FIG. 11 is a schematic diagram of a sensing circuit formed on a sensor SOI wafer;

FIG. 12 is a schematic illustration of forming a first interconnect point and a first solder on a sensor SOI wafer;

FIG. 13 is a schematic illustration of bonding a sensor sheet to a substrate;

FIG. 14 is another schematic illustration of bonding a sensor sheet to a substrate.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus consistent with aspects of the application as detailed in the accompanying claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The terms "first," "second," and the like in the description and in the claims, are not used for any order, quantity, or importance, but are used for distinguishing between different elements. Likewise, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. "plurality" or "plurality" means two or more. Unless otherwise indicated, the terms "front," "rear," "lower," and/or "upper" and the like are merely for convenience of description and are not limited to one location or one spatial orientation. The word "comprising" or "comprises", and the like, means that elements or items appearing before "comprising" or "comprising" are encompassed by the element or item recited after "comprising" or "comprising" and equivalents thereof, and that other elements or items are not excluded. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

Aiming at the problem that the original signal of the MEMS pressure sensor is easily interfered by the external environment in the transmission process, the inventor of the application discovers through research: in the existing pressure sensor, the surface of the pressure sensor is routed, and then the signal transmission is realized along the side surface of the pressure sensor, so that the transmission channel of the original signal is longer. The long transmission channel makes the original signal susceptible to interference and attenuation. Based on this, the inventors of the present application developed a MEMS pressure sensor. The structure of the pressure sensor is described below with reference to the accompanying drawings

Referring to fig. 1 in combination with fig. 2 and 7, an embodiment of the present application discloses a MEMS pressure sensor. The MEMS pressure sensor includes a sensor die 100 and a substrate 200. Referring to fig. 3 and 4 again, the sensor chip 100 includes a pressure sensing structure, a detection circuit connected to the pressure sensing structure, and a first interconnection point 4 connected to the detection circuit. The pressure sensing structure and the detection circuit are not limited to the structure described later. The pressure sensitive structure is used to generate the raw signal and in an embodiment of the application comprises a pressure sensitive membrane 21. The detection circuit is in this embodiment a wheatstone bridge. In this embodiment, the MEMS pressure sensor is a piezoresistive MEMS pressure sensor, and the pressure sensitive membrane 21 is pressed to deform the pressure sensitive membrane 21, so as to generate an original signal. The original signal is detected by the wheatstone bridge. The skilled person will understand that, for a capacitive pressure sensor or a resonant pressure sensor, the pressure sensing structure is a corresponding structure that generates an original signal by the capacitive pressure sensor or the resonant pressure sensor, for example, a corresponding sensitive film, etc., and accordingly, the detection circuit is not necessarily a wheatstone bridge, and may be capable of detecting the original signal. The detection circuit comprises a first track 3. For piezoresistive pressure sensors as shown, the first trace comprises a connection between piezoresistors 2, and for capacitive pressure sensors or resonant pressure sensors, the first trace 3 is the line from which the detection circuit outputs a signal to the signal processing circuit. The first interconnection point 4 is connected to the detection circuit, i.e. the first interconnection point 4 is connected to the first track 3.

Referring to fig. 1, 5 and 6, the substrate 200 includes a signal processing circuit 7 and a second interconnection point 10 connected to the signal processing circuit 7. How the signal processing circuit 7 is configured is not limited, and in one embodiment of the present application, the signal processing circuit 7 is configured as follows: the substrate 200 includes a ROIC sheet 6. The ROIC chip 6 internally includes the signal processing circuit 7, and the signal processing circuit 7 includes a signal processing element 70 and a corresponding second trace. The second wires include a signal input wire 71 between the signal processing circuit 7 and the detection circuit, a signal output wire 72, a drive wire 73 connecting the detection circuit, and a ground wire 74 grounding the detection circuit and the signal processing circuit 7. For further visualization, the signal processing circuit (signal processing element 70 and the second trace) is shown in fig. 1 as a dashed line inside the ROIC chip 6. The signal processing circuit 7 (the signal processing element 70 and the second trace) may be disposed inside the ROIC chip 6 in any manner, for example, the inside of a silicon wafer (not the surface of the silicon wafer) is manufactured into the signal processing element 70 and the second trace by an integrated circuit process, so that the silicon wafer, the signal processing element 70, the interconnection trace, and the like constitute the ROIC chip 6.

Based on the above-described structure, the second interconnection point 10 is connected to the signal processing circuit 7, that is, as shown in fig. 6, the second interconnection point 10 is connected to the signal input trace 71, the signal output trace 72, the driving trace 73 of the connection detection circuit, and the ground trace 74, respectively. Of course, the structure of the second wiring is not limited to the above structure.

Referring to fig. 2 and 7 in combination with fig. 1, the sensor chip 100 and the substrate 200 are disposed opposite to each other, the first interconnection point 4 and the second interconnection point 10 are electrically connected in a direction perpendicular to the sensor chip 100, and after the connection, the signal processing circuit 7 is connected to the detection circuit, so as to realize transmission of a driving signal to the detection circuit and transmission of an original signal detected by the detection circuit to the signal processing circuit 7. The signal processing circuit 7 obtains a processing result. The processing results are transmitted out through the signal output trace 72. How to process the functional determination is not limited to the amplification described in the present application.

As the first interconnection point 4 and the second interconnection point 10 are electrically connected in the direction perpendicular to the sensor chip 100, the transmission channel of the original signal between the detection circuit and the signal processing circuit is short, so that the interference of external environmental noise in the transmission process of the original signal is small, the anti-interference performance can be improved, the signal is not easy to attenuate, and the device performance is improved. For example, the transmission channel may be made short at least without routing the surface of the sensor to the side. Because the anti-interference capability is improved, the interference of the external environment noise on the signal in the secondary transmission process (the signal is output to the circuit board functional unit through the signal transmission channel formed by WB wire bonding, shell pin, circuit board wiring and the like) is small, and the signal is not easy to attenuate.

Referring to fig. 2 and 7, the sum of the height of the first interconnection point and the height of the second interconnection point is h which is less than or equal to 40um (micrometers).

As set up above, h is less than or equal to 40um, the signal transmission channel between the detection circuit and the signal processing circuit 7 is also ensured to be short, and then, the interference from external environmental noise in the original signal transmission process is small, the anti-interference performance is improved, the signal is not easy to attenuate, and the device performance is improved.

In some embodiments, in conjunction with fig. 1, the sensor tile 100 includes an SOI buried oxide layer 11; the surface of the SOI buried oxide layer 11 forms the detection circuit and the first interconnection point 4; an insulating layer 8 is provided on the surface of the ROIC sheet 6, and the insulating layer 8 is provided with the second interconnection point 10. The SOI buried oxide layer 11 covers the insulating layer 8 on the ROIC chip 6. How the cover is not limited to the cover is achieved by bonding as follows.

As set forth above, the SOI buried oxide layer 11 covers the insulating layer 8, there are no other layers between the SOI buried oxide layer 11 and the insulating layer 8, so that the distance between the SOI buried oxide layer 11 and the insulating layer 8 in the direction perpendicular to the sensor chip 100 is further minimized, and further, the first interconnection point 4 and the second interconnection point 10 are electrically connected and then are shorter, the signal transmission channel between the detection circuit and the signal processing circuit is shorter, the interference caused by external environmental noise in the original signal transmission process is small, the anti-interference performance is improved, the signal is not easy to attenuate, and the device performance is improved. In addition, the detection circuit and the first interconnection point 4 are formed on the SOI buried oxide layer 11, an insulating layer is formed on the ROIC sheet 6, the second interconnection point 10 is formed on the insulating layer, the first interconnection point 4 and the second interconnection point 10 are connected to realize the connection between the detection circuit and the signal processing circuit 7, the TSV is not required to be prepared, and the preparation process is simple.

Referring to fig. 3 and 4 in combination with fig. 1, the detection circuit is a wheatstone bridge, and the first interconnection point 4 is correspondingly arranged at the intersection point of every two adjacent bridge arms. In fig. 3,4 and 1, the wheatstone bridge has a square shape with four vertices, each vertex being provided with one of said interconnection points 4. Of course, the corresponding arrangement may be that the intersection point coincides with the projection of the first interconnection point in a direction perpendicular to the sensor chip 100, or that the first interconnection point 4 is at a distance from the intersection point, but this distance is smaller.

As the first interconnection point 4 is correspondingly arranged at the intersection point of every two adjacent bridge arms, the wiring between the first interconnection point 4 and the detection circuit is shorter, and the first interconnection point 4 and the second interconnection point 10 are combined to be connected in the direction vertical to the sensor chip 100, so that the signal transmission channel between the detection circuit and the signal processing circuit 7 is shorter, the interference of external environmental noise in the original signal transmission process is small, the anti-interference performance is improved, the signal is not easy to attenuate, and the device performance is improved.

Referring to fig. 2 in combination with fig. 1, the sensor chip 100 is disposed opposite the substrate 200 to form a closed cavity 61. The first interconnect point 4, the first trace 3, the second interconnect point 10, and the second trace (signal input trace 71, partial signal output trace 72, drive trace 73, and ground trace 74) are located within the cavity 61. Since the signal output trace 72 needs to output a signal, there must be a section outside the cavity 61, the second trace is located in the cavity 61 and includes a case where a part of the signal output trace 72 is located in the cavity 61 and another part of the signal output trace is located in the cavity 61. In this embodiment, the first interconnection point 4 and the second interconnection point 10 are electrically connected in a direction perpendicular to the sensor chip 100, which may be regarded as being electrically connected in a depth direction of the cavity 61. In a further embodiment, the cavity 61 is a vacuum cavity, the isolation effect of the vacuum cavity 61 is better, and further, the signal is less interfered by environmental noise in the transmission process, and the signal is not easy to attenuate.

As the first interconnection point 4, the first trace 3, the second interconnection point 10 and the second trace are located in the cavity 61, so that the transmission channel of the original signal is located in the cavity 61 formed by bonding and isolated from the external environment, the interference of noise from the external environment in the transmission process of the original signal is small, the anti-interference capability of the signal is improved, and the signal is not easy to attenuate. Because the anti-interference capability is stronger, the interference of external environmental noise on the signal transmission channel formed by the ROIC output signal through WB wire bonding, the shell pin, the circuit board wiring and the like in the secondary transmission process is small.

Referring to fig. 2, the cavity 61 shown in fig. 2 is a closed cavity, and is an absolute structure. Or may be a gauge structure as shown in fig. 7. As shown in fig. 7, a through hole 62 penetrating the ROIC sheet 6 is provided in the ROIC sheet 6. Thereby, the cavity 61 communicates with the outside through the through hole 62. The size of the through hole 62 is not required and is generally 0 to 100um. Of course, since the gauge structure and the absolute structure are mainly different in the presence or absence of the through hole 62, the cavity 61 may be bonded by solder as described later.

Compared with the absolute pressure structure, the gauge pressure structure still has an isolation function (for example, external signals are difficult to enter the cavity 61 from the through holes 62), so that the gauge pressure structure still can improve the anti-interference capability of the original signals, and the signals are difficult to attenuate. In addition, in the gauge pressure structure, the processing of the signals can still be completed in the ROIC sheet 6, so that the signals which are transmitted outwards are amplified, the interference of external environment noise on the signals in the signal transmission process can be reduced, the anti-interference capability of the signals is improved, and the signals are not easy to attenuate.

Referring to fig. 6 and 1 in combination with fig. 2 and 7, as previously described, the signal processing circuit 7 is disposed within the ROIC sheet 6, i.e., the signal processing element 70 of the signal processing circuit 7 is located within the ROIC sheet 6, such that signal processing (including at least amplification, and differential for piezoresistive pressure sensors in an embodiment of the present application) is accomplished within the ROIC sheet 6, with the outward transmission of the amplified signal. Therefore, the amplified signal has stronger anti-interference capability, and the interference of external environmental noise is small in the secondary transmission process (the ROIC output signal is output to the circuit board functional unit through a signal transmission channel formed by WB wire bonding, a shell pin, a circuit board wiring and the like), so that the performance of the sensor can be improved. In addition, in the above design, part of the circuit functions (such as the differential amplification function of the signal processing element 70) are integrated into the micro integrated circuit, thereby reducing the overall device volume and facilitating integration.

The method comprises the following three steps: 1) The first interconnection point 4 and the second interconnection point 10 are electrically connected in a direction perpendicular to the sensor chip 100; 2) The first interconnection point 4, the first trace 3, the second interconnection point 10 and the second trace are located within the cavity 61 (including the aforementioned closed cavity 61 and the cavity 61 with the through hole 62); 3) When the signal processing circuits 7 are all satisfied in the ROIC sheet 6, the original signal transmission channel is short in distance and the transmission channels are all located in the cavity 61 and isolated from the external environment, and the signals are output after the processing (such as differential amplification) is completed in the ROIC sheet 6, so that the interference of external environment noise on the signals in the signal transmission process can be reduced, the anti-interference capability of the signals is improved, and the signals are not easy to attenuate.

In the above-mentioned various corresponding embodiments, since the signal processing element 70 and the second wires (the signal input wire 71, the signal output wire 72, the driving wire 73 and the ground wire 74) of the signal processing circuit 7 are formed inside the ROIC chip 6, the insulating layer 8 is further disposed, and the insulating layer 8 is perforated to form the second interconnection point 10 in the opening area, the TSV is not required to be prepared, and the preparation process is also simple. Furthermore, the ROIC sheet 6 has no MEMS structure, and the process of MEMS bulk silicon etching patterning is not required for the ROIC sheet 6, so that the circuit can have a large usable area, and more structures can be provided, and the device performance is good, for example, the MEMS structure and the circuit are prevented from being affected by each other, and for example, noise crosstalk is prevented.

Referring to fig. 1, the getter 13 is formed on the upper surface of the roic sheet 6, the position of the getter 13 corresponds to the pressure sensitive film 21, and the distance between the outer edge of the getter 13 and the second interconnection point 10 is greater than 50um, so that a safe distance can be ensured, and reliability can be ensured.

The manner in which the sensor sheet 100 is bonded to the substrate 200 in the present application is described as follows:

Referring to fig. 3 and 4, the sensor wafer 100 includes a sensor SOI wafer 1. The sensor SOI wafer 1 is provided with a first solder 51 having a ring shape (the first solder 51 is formed in a ring shape around the sensor SOI wafer 1). As shown in fig. 3, the first interconnection point 4 is located in an area surrounded by the first solder. Referring to fig. 5 and 1, the substrate 200 includes a second solder in a ring shape, and in this embodiment, the substrate 200 includes a ROIC sheet 6, and the ROIC sheet 6 is provided with the second solder 52 in a ring shape. The first solder 51 and the second solder 52 may be eutectic solder, but are not limited thereto. As shown in fig. 5, the second solder 52 is looped around the ROIC sheet 6 for one revolution. The second interconnect point 10 is located within the area enclosed by the second solder 52. Referring to fig. 2, the position of the second solder 52 corresponds to the position of the first solder 51. The corresponding purpose is that the first solder 51 and the second solder 52 can bond, and this condition is satisfied. The position corresponds to the second solder 52 being located directly under the first solder 51 in fig. 2. The ring shape is not limited, and in the present embodiment, the ring shape is square. Referring to fig. 2 in combination with fig. 1, the sensor chip 100 (sensor SOI chip 1) and the substrate 200 (ROIC chip 6) are bonded by the first solder 51 and the second solder 52 to constitute the cavity 61. Of course, as shown in fig. 7, for the gauge structure, the cavity 61 may be formed by bonding the first solder 51 and the second solder 52.

By bonding the first solder 51 and the second solder 52, the cavity 61 is surrounded by the solder, the cavity 61 is not formed by etching, and the process is simple, and the cavity 61 is stable. In addition, the first interconnection point 4 is located in the area surrounded by the first solder 51, and the second interconnection point 10 is located in the area surrounded by the second solder 52, which is also beneficial to shortening the signal transmission channel between the detection circuit and the signal processing circuit 7, reducing the interference of external environmental noise in the original signal transmission process, improving the anti-interference performance, reducing the signal attenuation, improving the device performance, and being beneficial to isolating the first interconnection point 4 and the second interconnection point 10 in the cavity 61, reducing the interference of external environmental noise in the original signal transmission process, and reducing the signal attenuation.

In the above manner, the sensor SOI sheet 1 is provided with a pressure sensing structure, a detection circuit, and the like, and these structures face the ROIC sheet 6, and the sensor SOI sheet 1 may be referred to as a flip-chip integrated structure.

Referring to fig. 3 and 4, other features of the first solder 51 are described as follows:

1) The distance between the outer edge of the first solder 51 and the outer edge of the integrated circuit device is greater than 50um;

2) The inner edge of the first solder 51 is spaced from the first interconnection point 4 by more than 50um;

3) The width of the first solder 51 is larger than 600um, and the thickness of the first solder 51 is 10-60 um;

4) A first solder 51 is formed on the surface of the SOI buried oxide layer 11 at the outer edge of the device and is not electrically connected to the first interconnect point 4.

At least one of the foregoing features satisfies that, in the case where the distance between the outer edge of the first solder 51 and the outer edge of the integrated circuit device is greater than 50um, and/or the distance between the inner edge of the first solder 51 and the first interconnection point 4 is greater than 50um, a safe distance can be provided, and reliability can be ensured, for example, a distance that is too small may affect reliability due to solder overflow. When the first solder 51 satisfies the width and/or thickness, the size of the cavity 61 can be ensured, bonding is facilitated, and the like.

Referring to fig. 5 and 1, other features of the second solder 52 are described as follows: the distance between the outer edge of the second solder 52 and the outer edge of the integrated circuit device is greater than 50um, the distance between the inner edge of the second solder 52 and the second interconnection point 10 is greater than 50um, the width of the second solder 52 is greater than 600um, and the thickness of the second solder 52 is 10-60 um. At least one of the foregoing features is satisfied, and in the case where the distance between the outer edge of the second solder 52 and the outer edge of the integrated circuit device is greater than 50um, and/or the distance between the inner edge of the second solder 52 and the second interconnection point 10 is greater than 50um, a safe distance can be provided, and reliability can be ensured, for example, a distance that is too small may affect reliability due to solder overflow. When the first solder 51 satisfies the width and/or thickness, the size of the cavity 61 can be ensured, bonding can be facilitated, and the like.

Referring to fig. 3 and 4 in combination with fig. 1 and 2, the detection circuit comprises a first interconnection point 4 connected to the first track 3, which first interconnection point 4 is also visible from the dashed line of fig. 1. In the embodiment of the present application, the first interconnection points 4 have four, and the connection lines of the four first interconnection points 4 form a square. The difference in height between the first interconnection point 4 and the first solder 51 is ±3um, and it can be understood that the heights of the two are substantially identical.

As set forth above, since the height difference between the first interconnection point 4 and the first solder 51 is ±3um, the bonding strength and the interconnection reliability of the first interconnection point 4 and the second interconnection point 10 can be ensured.

Referring to fig. 2 and 7, the difference in height between the second interconnection point 10 and the second solder 52 is ±3um, which can be understood as the substantial coincidence of the heights of the two.

As set forth above, since the height difference between the second interconnection point 10 and the second solder 52 is ±3um, the bonding strength and the interconnection reliability of the second interconnection point 10 and the first interconnection point 4 can be ensured.

For the first interconnection point 4 and the second interconnection point 10 of the foregoing various embodiments, the first interconnection point 4 and the second interconnection point 10 may further include at least one of the following features:

1) The first interconnection point 4 and the second interconnection point 10 are square, rectangular, round, elliptic and other structures, and correspondingly, the side length or diameter of the first interconnection point 4 is 50 um-100 um;

2) The material of the first interconnect point 4 and the second interconnect point 10 may be Au, auSn, agSn, cuSn, snAgCu or the like.

When the first interconnection point 4 and the second interconnection point 10 satisfy one of the above characteristics, the electrical conductivity is good and the transmission of the original signal is good.

In the above embodiment, the respective structures of the first interconnection point 4 and the second interconnection point 10 are not limited.

In the above embodiment, the interconnection of the first interconnection point 4 with the second interconnection point 10 achieves that the original signal generated by the pressure-sensitive structure can be transmitted to the signal processing circuit 7. As follows, a transmission scheme is described in connection with fig. 6 and 4 as follows: with reference to the orientations in fig. 6 and 4, the connection relationship is as follows:

upper left corner: the pad 9, the driving wire 73, the second interconnection point 10, and the first interconnection point 4 are connected;

Upper right corner: the second interconnect point 10 is connected to the first interconnect point 4, and the second interconnect point 10 is connected to an input of a signal processing element 70 through a signal input trace 71, an output of the signal processing element 70 being connected to the pad 9 in the upper right corner through an output signal trace 72;

Lower right corner: the second interconnection point 10 is connected with the first interconnection point 4, and the two signal processing elements 70 are connected with the second interconnection point 10 and are grounded through a grounding trace 74 at the lower right corner to connect the bonding pad 9;

lower left corner: the second interconnect point 10 is connected to the first interconnect point 4 and the second interconnect point 10 is connected to the input of a further signal processing element 70 via a signal input trace 71, the output of the signal processing element 70 being connected to the lower left hand pad 9 via an output signal trace 72.

Based on the above connection relation: external driving signals are connected into a Wheatstone bridge (one type of detection circuit) formed by the piezoresistor 2 and the first wiring 3 through a bonding pad 9 at the upper left corner, a second interconnection point 10 at the upper left corner and a first interconnection point 4 at the upper left corner to drive the sensor to work; after the pressure sensitive film 21 is pressed, the signal of the corresponding varistor 2 passes through the first trace 3→the first interconnection point 4 in the upper right corner and the second interconnection point 10 in the upper right corner (the first interconnection point 4 in the lower left corner and the second interconnection point 10 in the lower left corner) →the signal input trace 71→the corresponding signal processing element 70→the output signal trace 72 and the corresponding pad 9 and WB wire to be transmitted outwardly, specifically, the processing result of one signal processing element 70 is transmitted outwardly through the signal output trace 72, the pad 9 in the upper right corner and the WB wire, and the processing result of the other signal processing element 70 is transmitted outwardly through the signal output trace 72, the pad 9 in the lower left corner and the WB wire.

Other features of the pad 9 are described as follows:

1) The material of the pad 9 may be a low resistivity material of Al, ti/Al, au, cr/Au, etc. to form a good circuit path.

2) The pad 9 is located at the periphery of the second solder 52.

3) The pads 9 may be square, rectangular, circular, oval, etc. in configuration. The bonding pad 9 has a side length or straight dimension of 50-150 um.

The above-described various embodiments mainly relate to transmission between the original signal detected by the detection circuit and the signal processing circuit 7, and thus are applicable to piezoresistive pressure sensors, capacitive pressure sensors, and resonant pressure sensors. In the case of a piezoresistive pressure sensor, some of the structures of the pressure sensing structure and the detection circuit are described below.

Referring to fig. 1, 3 and 4, the pressure sensing structure includes a pressure sensitive membrane 21. The detection circuit is a wheatstone bridge (of course, other structures are possible as long as the original signal can be detected) formed by the piezoresistor 2 and the first trace 3. For the sake of illustration, the detection circuit (piezo-resistor 2 and pressure sensitive membrane 21. Piezo-resistor 2 may be doped silicon piezo-resistor, metal membrane piezo-resistor etc.. The sensor wafer 100 comprises a sensor SOI wafer 1. The sensor SOI wafer 1 comprises an SOI buried oxide layer 11 and an SOI substrate layer 12. The surface of the SOI buried oxide layer 11 forms the detection circuit (piezo-resistor 2 and the first track 3) and a first interconnect point 4. The first interconnect point 4 is connected to the first track 3 and the signal processing circuit (e.g. via a second interconnect point 10 to the signal processing circuit 7) such that the first track 3 connects the first interconnect point 4 and the piezo-resistor 2 laterally (i.e. not in the thickness direction of the SOI buried oxide layer, vertical direction).

In the above arrangement, since the piezoresistor 2, the first trace 3 and the first interconnection point 4 are formed on the surface of the SOI buried oxide layer 11, the first trace 3 is not connected with the first interconnection point 4 in the thickness direction of the SOI buried oxide layer 11, and the TSV is not required to be prepared, so that the process is simple.

Other features of the wheatstone bridge are described as follows:

1) The four piezoresistors 2 are respectively located at the center positions (which may be the center positions and the center positions + -50 um) of the diaphragm edge 211 of the pressure sensitive film 21;

2) The distance between the four piezoresistors 2 and the corresponding diaphragm edge 211 is kept consistent and the distance d is a certain value between 0 and 20 um.

3) The widths and the total lengths of the four piezoresistors 2 are the same, and the folding number can be 1-10 folds;

4) The wheatstone bridge is square, and the structures of the piezoresistors 2 at opposite positions are the same, for example, the structures of the piezoresistors 2 at upper and lower opposite positions in fig. 4 are the same; the varistor 2 in the right and left opposite positions has the same structure.

The wheatstone bridge meets one of the characteristics, so that the stress is maximum, the sensitivity is high, the linearity is better, and finally, the measured original signal is better.

Some features of the first trace 3 are described as follows:

1) The length of the first wire 3 is smaller than 50um, and the width of the first wire 3 is smaller than 15um, so that the total volume of the first wire 3 on the surface of the SOI buried oxide layer 11 is reduced;

2) The first wire 3 material may be a low resistivity material such as Al, ti/Al, au, cr/Au, etc. to form a good circuit path.

Referring to fig. 1 in combination with fig. 3 and 4, the pressure sensitive structure comprises a pressure sensitive membrane 21, and the sensor SOI sheet 1 comprises an SOI substrate layer 12; etching the SOI substrate layer 12 to form a cavity to form the pressure sensitive film; the cavity penetrates through the SOI substrate layer 12, for example, through the SOI substrate layer 12 to the SOI buried oxide layer 11, or does not penetrate through the SOI substrate layer 12 when etched, so that the depth of the cavity is smaller than the thickness of the SOI substrate layer 12. Fig. 1,3 and 4 illustrate the cavity as being square in projection in a plane parallel to the SOI substrate layer 12, although in some embodiments the projection may be circular.

Such a shape enables the stress of the pressure sensitive membrane to be large and the sensitivity to be high when the projection is square or circular, as set forth above.

In the above embodiment, referring to fig. 4 in combination with fig. 3, the first interconnection point 4 is located outside the membrane edge 211 of the pressure sensitive membrane 21, and the distance e between the membrane edge corresponding to the pressure sensitive membrane 21 is 10um to 50um.

As set forth above, since the first interconnection point 4 is located outside the membrane edge 211 of the pressure sensitive membrane 21 and the distance e between the membrane edges corresponding to the pressure sensitive membrane 21 is 10um to 50um, the hysteresis of the signal can be reduced and the performance index of the pressure sensor can be improved. Of course, because the first interconnection point 4 is close to the detection circuit, and the first interconnection point 4 and the second interconnection point 10 are electrically connected in the direction perpendicular to the sensor chip 100, a signal transmission channel between the detection circuit and the signal processing circuit 7 is short, so that anti-interference capability is improved, and signals are not easy to attenuate.

In a second aspect, embodiments of the present application also disclose a pressure detection device. The pressure detection means comprises any of the MEMS pressure sensors described above. The pressure detection device can be used for detecting the pressure of a petroleum pipeline, tire pressure and the like. The MEMS pressure sensor may adopt any structure and other components to form the pressure detecting device, and will not be described again.

In a third aspect, embodiments of the present application disclose a method of manufacturing a MEMS pressure sensor, the method comprising the steps of:

Referring to fig. 8, S1: forming the substrate 200 includes: the signal processing circuit 7 is formed inside the silicon wafer, and the ROIC chip 6 is constituted, and only the signal processing circuit 7 is represented inside the silicon wafer by a broken line in fig. 8. A second interconnection point 10 connected to the signal processing circuit 7 is formed on the ROIC chip.

Referring to fig. 10 and 11, S2: forming the sensor chip 100 includes: a pressure sensing structure, a detection circuit connected to the pressure sensing structure, and a first interconnection point 4 connected to the detection circuit are formed on the sensor SOI wafer 1. The order of the steps of forming the sensor chip 100 and the steps of forming the substrate 200 is not limited.

S3: the sensor chip is arranged opposite to the substrate, and the first interconnection point and the second interconnection point are electrically connected in a direction perpendicular to the sensor chip. How the relative arrangement is not limited, for example, the relative arrangement is achieved by bonding as described above.

In the manufacturing method, the MEMS pressure sensor is formed simply, and in the manufactured MEMS pressure sensor, the first interconnection point 4 and the second interconnection point 10 are electrically connected in the direction perpendicular to the sensor chip 100, so that the transmission channel of the original signal between the detection circuit and the signal processing circuit is short, interference from external environmental noise in the transmission process of the original signal is small, anti-interference performance can be improved, signals are not easy to attenuate, and device performance is improved. In addition, the signal processing circuit 7 is formed inside the ROIC sheet 6, so that signal processing is completed inside the ROIC sheet 6, amplified signals are transmitted to the outside, signal transmission is combined with external isolation and outward transmission, and in the secondary transmission process (the ROIC output signals are output to the circuit board functional unit through a signal transmission channel formed by WB wire bonding, shell pin, circuit board wiring and the like), the interference of external environmental noise is small, and the signals are not easy to attenuate. In addition, in the above design, part of the circuit functions (such as the differential amplification function of the signal processing element 70) are integrated into the micro integrated circuit, thereby reducing the overall device volume and facilitating integration.

Referring to fig. 10 and 11, the sensor SOI wafer 1 includes an SOI buried oxide layer 11 and an SOI substrate layer 12. Forming the sensor sheet includes: forming the piezoresistor 2, the first wiring 3 and the first interconnection point 4 on the surface of the SOI buried oxide layer 11; the detection circuit comprises the piezo-resistor 2 and the first track 3. Etching the SOI substrate layer 12 forms the pressure sensitive film 21.

In this method, since the varistor 2 and the first trace 3 are formed on the SOI buried oxide layer 11 of the sensor SOI wafer 1, the varistor 2 and the first trace 3 constitute a detection circuit, and the pressure sensitive film 21 is formed on the SOI substrate layer 12, the first trace 3 is not connected to the first interconnect point 4 in the thickness direction of the SOI buried oxide layer 11, and the TSV is not prepared, which is simple in process. In the above method, the detection circuit and the first interconnect 4 are formed on the SOI buried oxide layer 11, the pressure sensitive film 21 is formed on the SOI substrate layer 12, and the sensor chip 100 is simple to manufacture.

In some embodiments, referring to fig. 9 in combination with fig. 8, forming the substrate comprises: forming an insulating layer 8 on the surface of the ROIC sheet 6, forming openings in the insulating layer 8 and providing pads 9 and second interconnection points 10 at the respective openings; the pad 9 is connected to the signal processing circuit 7.

As set forth above, the pads 9, the second interconnection points 10, the first interconnection points 4, and the detection circuits need only be formed on the respective surfaces, so that the manufacturing process is simple, for example, the connection of the first interconnection points 4 to the first wirings 3 does not require the manufacture of TSVs and the process is simple. In addition, the ROIC sheet 6 has no MEMS structure, and the process of MEMS bulk silicon etching patterning is not required for the ROIC sheet 6, so that the circuit can have a large usable area, more structures can be arranged, and the device performance is good, for example, the MEMS structure and the circuit are prevented from being affected by each other, for example, noise crosstalk is prevented.

In the manufacturing method, the first interconnection point, the first wiring, the second interconnection point and the second wiring are all positioned in the cavity and isolated from the external environment, so that interference of external environment noise on signals in the signal transmission process can be reduced, the anti-interference capability of the signals is improved, and the signals are not easy to attenuate.

Referring to fig. 9 and 12, the forming a closed cavity includes:

A first solder 51 having a ring shape is formed on the sensor SOI wafer 1 (specifically, on the SOI buried oxide layer 11). The first solder 51 is, for example, eutectic solder. The first interconnection point 4 is located in an area surrounded by the first solder; a second solder 52 having a ring shape is formed on the ROIC sheet 6. The second solder 52 may be a eutectic solder. The second interconnect point 10 is located within the area enclosed by the second solder 52.

Referring to fig. 13, the first solder 51 and the second solder 52 are bonded to form a closed cavity 61. Because the cavity 61 is closed, this structure is referred to as an absolute structure.

The cavity 61 is formed by a bonding process as set forth above, which also makes the manufacturing method of the MEMS pressure sensor simple. In addition, the cavity 61 is surrounded by the solder, the cavity 61 is not formed by etching, and the like, the process is simple, the cavity 61 is well stabilized, and the electrical connection between the first interconnection point 4 and the second interconnection point 10 is realized in a simple manner.

Referring to fig. 14, the application also discloses a method for manufacturing the MEMS pressure sensor with the gauge pressure structure. The manufacturing method comprises the following steps:

the manufacturing method comprises the following steps: the sensor chip is arranged opposite to the substrate to form a cavity 61 with a through hole 62, the cavity 61 is communicated with the outside through the through hole 62, and the detection circuit comprises a first wiring 3 connected with the first interconnection point 4; the signal processing circuit 7 comprises a second trace connected to the second interconnection point 10, and the first interconnection point 4, the first trace 3, the second interconnection point 10 and the second trace are all located in the cavity 61.

The formation of the cavity 61 having the through-hole 62 includes the steps of: forming an insulating layer 8 on the surface of the ROIC sheet 6, and forming a through hole 62 penetrating the ROIC sheet 6 and the insulating layer 8; the formation of the through-hole 62 may be performed in any step.

A first solder 51 having a ring shape is formed on the sensor SOI wafer 1. As previously described, the first solder 51 may be a eutectic solder. The first interconnection point 4 is located in an area surrounded by the first solder 51; a second solder 52 having a ring shape is formed on the ROIC sheet 6. As previously described, the second solder 52 may be a eutectic solder. The second interconnection point 10 is located in an area surrounded by the second solder 52, and the position of the second solder 52 corresponds to the position of the first solder;

Bonding the first solder 51 and the second solder 52 to form the cavity 61, wherein the cavity 61 is communicated with the outside through the through hole 62; correspondingly, the detection circuit comprises a first trace 3, a first interconnection point 4, a second interconnection point 10 and a second trace located within the cavity 61.

Compared with the absolute structure formed by the method, the manufacturing method only has more steps for forming the through holes 62, so other beneficial effects are the same as those of the insulating structure and are not repeated.

The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the application.

Claims

1. A MEMS pressure sensor, comprising a sensor die and a substrate, wherein;

The sensor chip comprises a pressure sensing structure, a detection circuit connected with the pressure sensing structure and a first interconnection point connected with the detection circuit;

the substrate is provided with a signal processing circuit and a second interconnection point connected with the signal processing circuit;

the sensor chip and the substrate are arranged oppositely, and the first interconnection point and the second interconnection point are electrically connected in the direction perpendicular to the sensor chip.

2. The MEMS pressure sensor of claim 1, wherein a sum of the height of the first interconnect point and the height of the second interconnect point is h.ltoreq.40 um.

3. The MEMS pressure sensor of claim 1 or 2 wherein the sensor die comprises an SOI buried oxide layer; the surface of the SOI buried oxide layer forms the detection circuit and the first interconnection point; the substrate comprises a ROIC sheet, an insulating layer is arranged on the surface of the ROIC sheet, and the insulating layer is provided with the second interconnection point;

the SOI buried oxide layer covers an insulating layer on the ROIC chip.

4. The MEMS pressure sensor of claim 1, wherein the detection circuit is a wheatstone bridge, and the first interconnection point is disposed corresponding to an intersection point of each two adjacent bridge arms.

5. The MEMS pressure sensor of claim 1, wherein the sensor die is disposed opposite the substrate to form a closed cavity, the detection circuit comprising a first trace connected to the first interconnect point; the signal processing circuit comprises a second wire connected with the second interconnection point, and the first interconnection point, the first wire, the second interconnection point and the second wire are all positioned in the cavity;

6. The MEMS pressure sensor of claim 1, wherein the substrate comprises a ROIC-sheet, an interior of the ROIC-sheet comprising the signal processing circuitry; and the signal processing circuit at least amplifies the original signal generated by the pressure sensing structure.

7. The MEMS pressure sensor of claim 1, wherein the sensor die comprises a first solder in a ring shape, the first interconnection point being located within an area enclosed by the first solder; the substrate comprises annular second solder, the second interconnection point is located in an area surrounded by the second solder, and the position of the second solder corresponds to the position of the first solder;

The sensor chip and the substrate are bonded by the first solder and the second solder.

8. The MEMS pressure sensor of claim 7, wherein a height difference of the first interconnect point and the first solder is ± 3um;

And/or, the height difference between the second interconnection point and the second solder is + -3 um.

9. The MEMS pressure sensor of claim 1, wherein the sensor die comprises an SOI substrate layer and an SOI buried oxide layer that provides the detection circuitry; etching the SOI substrate layer to form a cavity so as to form a pressure sensitive film of the pressure sensing structure;

the cavity penetrates through the SOI substrate layer to the buried oxide layer, or the depth of the cavity is smaller than the thickness of the SOI substrate layer.

10. The MEMS pressure sensor of claim 9, wherein the cavity has a square or circular shape projected in a plane parallel to the SOI substrate layer.

11. The MEMS pressure sensor of claim 9, wherein the first interconnection point is located outside a membrane edge of the pressure sensitive membrane and a distance of the membrane edge corresponding to the pressure sensitive membrane is 10um to 50um.

12. A pressure sensing device, characterized in that it comprises a MEMS pressure sensor according to any one of claims 1 to 11.

13. A method of manufacturing a MEMS pressure sensor, the method comprising the steps of:

forming a sensor sheet comprising: forming a pressure sensing structure, a detection circuit connected with the pressure sensing structure and a first interconnection point connected with the detection circuit on a sensor SOI (silicon on insulator) chip;

Forming a substrate, comprising: forming a signal processing circuit in a silicon chip to form an ROIC chip, and forming a second interconnection point connected with the signal processing circuit on the ROIC chip;

the sensor chip is arranged opposite to the substrate, and the first interconnection point and the second interconnection point are electrically connected in a direction perpendicular to the sensor chip.

14. The method of manufacturing a MEMS pressure sensor of claim 13, wherein the sensor SOI wafer comprises an SOI buried oxide layer and an SOI substrate layer; forming the sensor sheet includes: forming piezoresistors, first wirings and first interconnection points on the surface of the SOI buried oxide layer; the detection circuit comprises the piezoresistor and the first wiring;

And etching the SOI substrate layer to form a cavity so as to form a pressure sensitive film of the pressure sensing structure.

15. The method of manufacturing a MEMS pressure sensor of claim 13, wherein the sensor SOI wafer comprises an SOI buried oxide layer, the forming the sensor wafer comprising: forming a first interconnection point connected with the detection circuit on the surface of the SOI buried oxide layer;

And/or forming the substrate comprises: forming an insulating layer on the surface of the ROIC sheet, forming openings in the insulating layer, and forming a bonding pad and the second interconnection point in the corresponding openings; the bonding pad is connected with the signal processing circuit.

16. The method of manufacturing a MEMS pressure sensor of claim 13, wherein the method of manufacturing comprises:

so that a closed cavity is formed between the sensor chip and the substrate;

the detection circuit comprises a first wiring connected with the first interconnection point; the signal processing circuit comprises a second wire connected with the second interconnection point, and the first interconnection point, the first wire, the second interconnection point and the second wire are all positioned in the cavity.

17. The method of manufacturing a MEMS pressure sensor of claim 16, wherein the forming a closed cavity comprises:

Forming a first solder in a ring shape on the sensor SOI wafer, wherein the first interconnection point is positioned in an area surrounded by the first solder; forming a second solder in a ring shape on the ROIC sheet, the position of the second solder corresponding to the position of the first solder;

bonding the first solder and the second solder to form a closed cavity; the second interconnection point is located in an area surrounded by the second solder.

18. The method of manufacturing a MEMS pressure sensor of claim 13, wherein the method of manufacturing comprises:

The sensor chip and the substrate are oppositely arranged to form a cavity with a through hole, the cavity is communicated with the outside through the through hole, and the detection circuit comprises a first wiring connected with the first interconnection point; the signal processing circuit comprises a second wire connected with the second interconnection point, and the first interconnection point, the first wire, the second interconnection point and the second wire are all positioned in the cavity.

19. The method of manufacturing a MEMS pressure sensor of claim 18, wherein the method of manufacturing comprises:

Forming an insulating layer on the surface of the ROIC sheet, and forming a through hole penetrating the ROIC sheet and the insulating layer;

Forming a first solder in a ring shape on the sensor SOI wafer, wherein the first interconnection point is positioned in an area surrounded by the first solder; forming second solder in a ring shape on the ROIC sheet, wherein the second interconnection point is positioned in an area surrounded by the second solder, and the position of the second solder corresponds to the position of the first solder;

And bonding the first solder and the second solder to form the cavity, wherein the cavity is communicated with the outside through the through hole.