CN113008420A

CN113008420A - Pressure sensor and method for manufacturing the same

Info

Publication number: CN113008420A
Application number: CN202110225364.XA
Authority: CN
Inventors: 吕萍; 胡维; 李刚
Original assignee: Memsensing Microsystems Suzhou China Co Ltd
Current assignee: Memsensing Microsystems Suzhou China Co Ltd
Priority date: 2021-03-01
Filing date: 2021-03-01
Publication date: 2021-06-22

Abstract

The present application provides a pressure sensor and a method of manufacturing the same, the pressure sensor including: the device comprises a substrate, a first substrate and a second substrate, wherein an accommodating cavity is formed in the substrate; the pressure sensor main body is arranged in the accommodating cavity; the first beam structure is arranged in the accommodating cavity and is connected with the pressure sensor main body and the substrate, so that the pressure sensor main body is suspended in the accommodating cavity; the barrier layer is arranged on one side, far away from the substrate, of the pressure sensor main body, and a first protruding structure is arranged between the barrier layer and the pressure sensor main body. The pressure sensor provided by the embodiment of the application can effectively improve the reliability and the impact resistance of the pressure sensor.

Description

Pressure sensor and method for manufacturing the same

Technical Field

The application relates to the field of sensors, in particular to a pressure sensor and a manufacturing method thereof.

Background

Micro-Electro-Mechanical System (MEMS) pressure sensors mainly include piezoresistive, capacitive, and piezoelectric pressure sensors, and piezoresistive pressure sensors manufactured by using the piezoresistive effect of semiconductors have the advantages of simple process, large output signal, simple subsequent processing, and the like, and thus are widely applied to the fields of automobiles, medical treatment, wearable electronic devices, and the like.

For some specific applications, in order to reduce stress sensitivity, a beam structure may be provided in a piezoresistive pressure sensor, and in the packaging or assembling process of the piezoresistive pressure sensor, the stress introduced by a substrate may affect the pressure sensor body, so that the performance of the device is drifted. Especially when the stress is too large, it can lead to fracture of the beam structure in the pressure sensor, resulting in device failure.

Disclosure of Invention

In view of this, embodiments of the present application provide a pressure sensor and a method for manufacturing the same, which can effectively improve the reliability and impact resistance of the pressure sensor.

In a first aspect, the present application provides a pressure sensor comprising: the device comprises a substrate, a first substrate and a second substrate, wherein an accommodating cavity is formed in the substrate; the pressure sensor main body is arranged in the accommodating cavity; the first beam structure is arranged in the accommodating cavity and is connected with the pressure sensor main body and the substrate, so that the pressure sensor main body is suspended in the accommodating cavity; the barrier layer is arranged on one side, far away from the substrate, of the pressure sensor main body, and a first protruding structure is arranged between the barrier layer and the pressure sensor main body.

In some embodiments, a surface of the pressure sensor body near the barrier layer is provided with a first bump-like structure, and the first bump-like structure is located at an edge position of the pressure sensor body.

In some embodiments, a surface of the barrier layer proximate to the substrate is provided with a first bump-like structure, the first bump-like structure being located on the barrier layer at a position corresponding to a position of the pressure sensor body.

In some embodiments, at least one through hole is provided in a middle position of the barrier layer, and a position of the first protrusion-like structure on the barrier layer corresponds to an edge position of the pressure sensor body.

In some embodiments, the at least one via includes a plurality of vias arranged in a matrix.

In some embodiments, the barrier layer is provided with at least one through hole at an edge position, and the first protrusion-like structure is located on the barrier layer at a position corresponding to a middle position of the pressure sensor body.

In some embodiments, the surface of the barrier layer close to the substrate is further provided with a second convex-shaped structure, and the first convex-shaped structure and the second convex-shaped structure are respectively positioned on two sides of the first beam structure.

In some embodiments, the first bump-like structures are distributed along the extension direction of the first beam structure.

In some embodiments, the first bump-like structure comprises a plurality of bump points distributed along the extension direction of the first beam structure.

In some embodiments, a distance between the bottom surface of the pressure sensor body and the bottom surface of the receiving cavity is greater than or equal to 4 microns and less than or equal to 6 microns.

In some embodiments, the pressure sensor further includes a second beam structure disposed in the receiving cavity and connecting the pressure sensor body and the substrate, the first beam structure and the second beam structure being symmetrically disposed between the pressure sensor body and the substrate.

In some embodiments, a third bump-like structure is further disposed on a surface of the barrier layer adjacent to the substrate, where a position of the third bump-like structure on the barrier layer corresponds to a position of the pressure sensor body, the first bump-like structure corresponds to the first beam structure, and the third bump-like structure corresponds to the second beam structure.

In some embodiments, a fourth bump-like structure is further disposed on a surface of the barrier layer close to the substrate, and the third bump-like structure and the fourth bump-like structure are respectively located on two sides of the second beam structure.

In some embodiments, the pressure sensor body includes a pressure sensor sensing diaphragm disposed adjacent to the barrier layer, and a cavity is disposed within the pressure sensor body and below the pressure sensor sensing diaphragm.

In a second aspect, the present application provides a method of manufacturing a pressure sensor, comprising: the method comprises the steps that an accommodating cavity, a pressure sensor main body and a first beam structure are arranged in a substrate, wherein the pressure sensor main body and the first beam structure are located in the accommodating cavity, and the first beam structure is connected with the pressure sensor main body and the substrate, so that the pressure sensor main body is suspended in the accommodating cavity; and arranging a barrier layer on one side of the pressure sensor main body, which is far away from the substrate, wherein a first convex structure is arranged between the barrier layer and the pressure sensor main body.

In some embodiments, before providing the barrier layer on a side of the pressure sensor body away from the substrate, the method of manufacturing further comprises: and arranging a first convex structure on one side of the pressure sensor main body, which is far away from the substrate, wherein the first convex structure is positioned at the edge position of the pressure sensor main body.

In some embodiments, the method of manufacturing a pressure sensor further comprises: at least one through hole is formed in the substrate, and a first protruding structure is arranged on one side of the substrate to form a barrier layer, wherein the position of the first protruding structure on the barrier layer corresponds to the position of the pressure sensor main body.

In some embodiments, providing a barrier layer on a side of the pressure sensor body remote from the substrate comprises: arranging at least one blind hole on a substrate and arranging a first bulge-shaped structure on one side of the substrate, which is provided with the at least one blind hole; arranging a base on one side of the pressure sensor body far away from the substrate; and thinning the substrate, wherein the position of the first bulge-shaped structure on the barrier layer corresponds to the position of the pressure sensor main body.

The embodiment of the application provides a pressure sensor and a manufacturing method thereof, and the convex structure is arranged between the barrier layer and the pressure sensor main body, so that the displacement of the beam structure in the direction towards the barrier layer can be limited, and the beam structure can be effectively prevented from being broken due to overlarge displacement of the beam structure in the direction towards the barrier layer when the pressure sensor is subjected to impact acting force, and the reliability and the impact resistance of the pressure sensor can be effectively improved.

Drawings

Fig. 1 is a schematic cross-sectional view of a pressure sensor according to an embodiment of the present disclosure.

Fig. 2 is a top view of a substrate portion of a pressure sensor provided in an embodiment of the present application.

Fig. 3 is a bottom view of a barrier layer of a pressure sensor according to an embodiment of the present disclosure.

Fig. 4 is a schematic cross-sectional view of a pressure sensor according to another embodiment of the present application.

Fig. 5 is a bottom view of a barrier layer of a pressure sensor according to another embodiment of the present application.

Fig. 6 is a bottom view of a barrier layer of a pressure sensor according to another embodiment of the present application.

Fig. 7 is a schematic cross-sectional view of a pressure sensor according to another embodiment of the present application.

Fig. 8 is a schematic flow chart illustrating a method for manufacturing a pressure sensor according to an embodiment of the present disclosure.

Fig. 9 is a schematic flow chart illustrating a method for manufacturing a pressure sensor according to another embodiment of the present disclosure.

Fig. 10a to 10c are schematic structural diagrams of devices corresponding to steps in the manufacturing method of the pressure sensor provided in the embodiment of fig. 4.

Fig. 11 is a schematic cross-sectional view of a pressure sensor according to another embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments.

The piezoresistive effect is a phenomenon that when a semiconductor crystal material is stressed in a certain direction and deformed, the resistivity of the material changes. A Wheatstone bridge consisting of four resistors is made on a membrane area of the pressure sensor, and under the action of pressure, the membrane deforms, so that the resistance values of the four resistors forming the Wheatstone bridge are changed, and the pressure sensor outputs an electric signal corresponding to the pressure.

The piezoresistive principle determines that the pressure sensing film is sensitive to stress induced by packaging and external environmental changes. For example, the stress generated by the chip during packaging or assembly, and the stress generated due to the difference of thermal expansion coefficients between different materials can be transmitted to the pressure-sensitive film through the substrate, so that the performance of the device can be shifted. Especially in some specific applications, such as altimeters, drones, etc., which have high requirements on the accuracy and temperature sensitivity of the pressure sensor, it is necessary to accurately measure the altitude and control the attitude of the drone under different altitudes and weather conditions. Some technical solutions employ a pressure sensor with a stress relief structure to minimize the effect of stress on the product.

However, the above-mentioned pressure sensor realizes stress release by technical means such as a cantilever beam, a bending beam or a spring beam, and the reliability is not good enough, for example, the pressure sensor vibrates in the processes of assembly, transportation, falling, and the like, and the cantilever beam, the bending beam or the spring beam is too large to be broken due to deformation, resulting in product failure.

Therefore, it is desirable to provide a highly reliable, impact resistant pressure sensor.

Fig. 1 is a schematic cross-sectional view of a pressure sensor 100 according to an embodiment of the present disclosure. As shown in fig. 1, the pressure sensor 100 includes a substrate 110, a pressure sensor body 120, a first beam structure 130, and a barrier layer 140.

The substrate 110 has a receiving cavity 111 provided therein, and the pressure sensor body 120 is disposed in the receiving cavity 111. The first beam structure 130 is disposed in the receiving cavity 111 and connects the pressure sensor body 120 and the substrate 110 such that the pressure sensor body 120 is suspended in the receiving cavity 111. The barrier layer 140 is disposed on a side of the pressure sensor body 120 away from the substrate 110, and a first protrusion-shaped structure 141 is disposed between the barrier layer 140 and the pressure sensor body 120, where the first protrusion-shaped structure 141 can be used to limit displacement of the first beam structure 130 in a direction toward the barrier layer 140, and prevent the first beam structure 130 from being broken due to excessive deformation.

In an embodiment, a first bump-like structure 141 is disposed on a surface of the barrier layer 140 near the substrate 110, and a position of the first bump-like structure 141 on the barrier layer 140 corresponds to a position of the pressure sensor body 120.

Referring to fig. 1 and 2, the substrate 110 and the pressure sensor body 120 may be connected by a first beam structure 130, so that the pressure sensor body 120 may be suspended in the receiving cavity 111 to sense a change in external pressure (e.g., air pressure, hydraulic pressure, etc.). The shape of the first beam structure 130 may be linear, polygonal, or curved.

Further, in an embodiment, the pressure sensor 100 further comprises a second beam structure 150. The second beam structure 150 is disposed in the receiving cavity 111 and connects the pressure sensor body 120 and the substrate 110, and the first beam structure 130 and the second beam structure 150 are symmetrically distributed between the pressure sensor body 120 and the substrate 110.

Specifically, the first beam structure 130 and the second beam structure 150 may be symmetrically distributed about the center of the pressure sensor body 120, i.e., the first beam structure 130 may be rotated 180 degrees around the center of the pressure sensor body 120, and may coincide with the second beam structure 150. Therefore, the symmetrically distributed beam structure can provide the pressure sensor body 120 with good structural stability, thereby improving the reliability of the device. Here, the number of the beam structures may be set to be more as needed, and the embodiment of the present application does not limit this.

The substrate 110 may be a silicon substrate, the barrier layer 140 may be made of silicon, glass or other materials, and the first protrusion-shaped structures 141 may be made of silicon oxide, silicon nitride, metal, resin, or other materials. Here, the barrier layer 140 may prevent foreign objects from falling on the surface of the pressure sensor body 120, affecting the accuracy of the device measurement result. The first protrusion-shaped structures 141 can limit the first beam structure 130 from being deformed too much in the direction toward the blocking layer 140, so as to prevent the first beam structure 130 from being broken.

For example, when the first beam structure 130 and the pressure sensor body 120 move together in a direction away from the substrate 110, the first protrusion-shaped structures 141 may limit displacement of the pressure sensor body 120 in a direction toward the barrier layer 140, and thus displacement of the first beam structure 130 in a direction toward the barrier layer 140, so that breakage of the first beam structure 130 due to excessive displacement of the first beam structure 130 in a direction toward the barrier layer 140 may be effectively prevented.

When the pressure sensor 100 further includes the second beam structure 150, the first bump-like structure 141 may limit displacement of the first beam structure 130 and the second beam structure 150 in a direction toward the barrier layer 140, avoiding fracture of both.

Alternatively, in other embodiments, the first bump-like structure may be disposed on a surface of the pressure sensor body proximate to the barrier layer. In particular, the first bulge-like structure may be provided at an edge position of the pressure sensor body. Therefore, when the first beam structure and the pressure sensor body move towards the direction far away from the substrate together, the first convex structure also moves towards the direction far away from the substrate, and the first convex structure can effectively limit the displacement of the first beam structure after contacting the barrier layer, so that the first beam structure is prevented from being broken due to overlarge deformation. In addition, the first bulge-shaped structures are arranged at the edge positions of the pressure sensor main body, so that the first bulge-shaped structures can be prevented from interfering with a sensing area in the middle of the pressure sensor main body.

The beam structure can play a certain stress releasing role, but in the processes of product assembly, transportation, falling and the like, larger impact force can be generated, and larger deformation displacement can be generated under the action of the impact force because the beam structure is softer. In particular, a portion of the beam structure connected to the pressure sensor body 120 and a portion of the beam structure connected to the substrate 110 are largely deformed, and are likely to be broken.

The embodiment of the application provides a pressure sensor, through set up protruding column structure between barrier layer and pressure sensor main part, can restrict the displacement of beam structure in the orientation barrier layer's direction to can effectively prevent because of the fracture of beam structure that the displacement of beam structure in the orientation barrier layer's direction is too big and arouse when pressure sensor receives the impact force, consequently can improve pressure sensor's reliability and shock resistance effectively.

In one embodiment, the pressure sensor body 120 has a cavity 121 therein, and the pressure sensor body 120 includes a pressure sensor sensing diaphragm 122 disposed adjacent to the barrier layer 140, the cavity 121 being located below the pressure sensor sensing diaphragm 122. In particular, the pressure sensor body 120 may include a first portion and a second portion, i.e., a pressure sensor sensing diaphragm. During the preparation process, an opening may be formed in the first portion, and then a pressure sensor sensitive film covers the opening, and the pressure sensor sensitive film seals the opening to form a cavity. The pressure sensor sensitive membrane positioned on the cavity can sense the change of the external pressure (such as air pressure or hydraulic pressure). When cavity 121 is approximately at vacuum, pressure sensor 100 is an absolute pressure sensor. The edge position of the substrate 110 is provided with a connection layer 160, correspondingly, the edge position of the barrier layer 140 is provided with a connection layer 170, and the substrate 110 and the barrier layer 140 are connected together through the connection layer 160 and the connection layer 170. The material of the connection layer 160 and the connection layer 170 may be a resin material or a metal material. When the material of the connecting layer is a resin material, it may be epoxy resin, SU8 glue or other resin materials. When the material of the connection layer is a metal material, it may be gold, aluminum or other metal materials. At least one pad 180 may be disposed on the substrate 110. The surface of the pressure sensor body 120 may be provided with a metal layer (not shown in fig. 1), the surfaces of the first and

second beam structures

130 and 150 may be provided with metal traces (not shown in fig. 1), and the metal layer of the surface of the pressure sensor body 120 may be connected to the corresponding pads 180 through the metal traces of the surfaces of the first and

second beam structures

130 and 150. The connection between the substrate 110 and the barrier layer 140 may be a metal eutectic bond or a colloidal bond.

According to an embodiment of the present disclosure, at least one through hole 142 is disposed at a middle position of the barrier layer 140, and a position of the first protrusion-like structure 141 on the barrier layer 140 corresponds to an edge position of the pressure sensor body 120.

The shape of the through-hole 142 may be rectangular, circular, diamond, or other shape. The through hole 142 is disposed at the middle position of the barrier layer 140, so that the through hole 142 directly corresponds to the middle position or most area of the pressure sensor body 120, and thus, the pressure sensor body 120 can better sense the external pressure or the pressure change, and the accuracy of the detection result is improved.

As shown in fig. 2, the pressure sensor body 120 is rectangular in plan view. The position of the first protrusion-shaped structure 141 on the barrier layer 140 corresponds to the edge position of the pressure sensor body 120, which may mean that the first protrusion-shaped structure 141 corresponds to one edge of the pressure sensor body 120. In this way, the first bump-like structures 141 can effectively protect the beam structure from breaking when the beam structure and the pressure sensor body 120 move together in a direction away from the substrate 110. Because, if the first bump-like structures 141 are disposed near the middle of the barrier layer 140, there may occur a phenomenon in which the middle portion of the pressure sensor body 120 is blocked by the first bump-like structures 141 and the edge portions thereof continue to move away from the substrate 110, which may cause a breakage of the beam structure. Therefore, the position of the first bump-shaped structure 141 on the barrier layer 140 corresponds to the edge position of the pressure sensor body 120, and the beam structure can be effectively protected from being broken. For example, the position of the first bump-like structure 141 on the barrier layer 140 corresponds to the edge position of the pressure sensor body 120 near the beam structure (the first beam structure 130 and/or the second beam structure 150).

Of course, the top view of the pressure sensor body 120 may also be a circle, a diamond, or another shape, the number of the first protrusion-shaped structures 141 may be one or more, and the position thereof on the barrier layer 140 may be other suitable positions, which is not limited by the embodiment of the present application.

According to an embodiment of the present application, the first bump-like structures 141 are distributed on the barrier layer 140 along an extending direction of the first beam structure 130.

Specifically, the first protrusion-like structure 141 may be an elongated bar, which may be disposed at a position close to the first beam structure 130 and has an extending direction that coincides with the extending direction of the first beam structure 130 or coincides with the extending direction of a portion of the first beam structure 130. Thus, the first bump-like structures 141 can effectively protect the first beam structure 130 and prevent the first beam structure 130 from being broken due to excessive deformation.

When the first bump-like structures 141 are provided on the surface of the pressure sensor body, the first bump-like structures 141 may also be distributed along the extending direction of the first beam structure 130.

Optionally, the first bump-like structure 141 comprises a plurality of bumps distributed along the extension direction of the first beam structure 130 on the barrier layer 140.

Specifically, a plurality of projection points may be disposed at positions close to the first beam structure 130, and the plurality of projection points are spaced apart along the extending direction of the first beam structure 130, or spaced apart along the extending direction of a portion of the first beam structure 130. Thus, the plurality of protruding points can effectively protect the first beam structure 130, prevent the first beam structure 130 from being broken due to excessive deformation, and simultaneously save materials and realize light weight of the device.

When a plurality of projection points are provided on the surface of the pressure sensor body, the plurality of projection points may also be distributed along the extending direction of the first beam structure 130.

According to an embodiment of the present disclosure, as shown in fig. 3, the at least one through hole 142 includes a plurality of through holes 142, and the plurality of through holes 142 are arranged in a matrix.

Specifically, the size of each through hole 142 can be reduced by providing the plurality of through holes 142, so that external foreign matter can be effectively prevented from falling on the surface of the pressure sensor body 120, and the plurality of through holes 142 can reduce the weight of the entire pressure sensor, achieving the lightweight of the device. In addition, the plurality of through holes 142 are located in the middle of the blocking layer 140 and arranged in a matrix, so that the structural stability of the device can be improved.

According to an embodiment of the present disclosure, a distance between the bottom surface of the pressure sensor body 120 and the bottom surface of the receiving cavity 111 is greater than or equal to 4 micrometers and less than or equal to 6 micrometers.

Specifically, when the distance between the bottom surface of the pressure sensor body 120 and the bottom surface of the housing cavity 111 is excessively large, it will be difficult to restrict the displacement of the beam structure and the pressure sensor body 120 in the direction toward the substrate 110, and a situation may occur in which the beam structure is broken. When the distance between the bottom surface of the pressure sensor body 120 and the bottom surface of the housing cavity 111 is too small, it is difficult to achieve stress relief. Therefore, the distance between the bottom surface of the pressure sensor body 120 and the bottom surface of the housing cavity 111 is limited to a certain range, and it is possible to effectively release stress and improve the reliability of the device. For example, the distance between the bottom surface of the pressure sensor body 120 and the bottom surface of the receiving cavity 111 is greater than or equal to 4 micrometers and less than or equal to 6 micrometers.

As shown in fig. 1, the bottom surface of the pressure sensor body 120 and the bottom surface of the receiving cavity 111 are both uneven surfaces, which are caused by an etching or etching process. In this case, the distance between the bottom surface of the pressure sensor body 120 and the bottom surface of the receiving cavity 111 may be an average distance therebetween or a minimum distance therebetween.

Fig. 4 is a schematic cross-sectional view of a pressure sensor 200 according to another embodiment of the present disclosure. The pressure sensor 200 shown in fig. 4 is similar to the pressure sensor 100 shown in fig. 1, and in order to avoid redundancy, the same parts are not repeated, and the differences are mainly described here. As shown in fig. 4, the pressure sensor 200 includes a substrate 210, a pressure sensor body 220, a first beam structure 230, and a barrier layer 240.

The substrate 210 has a receiving cavity 211, a cavity 221 inside the pressure sensor body 220, and a plurality of through holes 242 formed in the middle of the barrier layer 240. The edge position of the substrate 210 is provided with a connection layer 260, and correspondingly, the edge position of the barrier layer 240 is provided with a connection layer 270. The barrier layer 240 is provided with a first convex-shaped structure 241 and a second convex-shaped structure 243 on a surface close to the substrate 210, and the first convex-shaped structure 241 and the second convex-shaped structure 243 are respectively located at two sides of the first beam structure 230.

Specifically, the position of the first bump-like structure 241 on the barrier layer 240 corresponds to the edge position of the pressure sensor body 220 near the first beam structure 230. That is, as shown in fig. 4, the first bump-like structure 241 is located on the right side (the side close to the pressure sensor main body 220) of the first beam structure 230, and can effectively limit the displacement of the pressure sensor main body 220 in the direction toward the barrier 240, and thus effectively limit the displacement of the first beam structure 230 in the direction toward the barrier 240. The second projection-like structure 243, which is located on the left side (the side away from the pressure sensor main body 220) of the first beam structure 230, can effectively restrict the displacement of the pressure sensor main body 220 in the oblique upward direction, that is, can effectively restrict the displacement of the pressure sensor main body 220 in both the upward and leftward directions. The second bump-like structure 243 may correspond to a gap between the first beam structure 230 and the substrate 210, or may correspond to an edge position of the substrate 210 near the first beam structure 230.

Further, the pressure sensor 200 further includes a second beam structure 250, and the first beam structure 230 and the second beam structure 250 are symmetrically distributed between the pressure sensor body 220 and the substrate 210. The barrier layer 240 is further provided with a third protrusion-like structure 244 on a surface close to the substrate 220, a position of the third protrusion-like structure 244 on the barrier layer 240 corresponds to a position of the pressure sensor body 220, the first protrusion-like structure 241 corresponds to the first beam structure 230, and the third protrusion-like structure 244 corresponds to the second beam structure 250. The first bump-like structures 241 may protect the first beam structure 230 from breakage, and the third bump-like structures 244 may protect the second beam structure 250 from breakage. The first and

third bump structures

241 and 244 may be symmetrically distributed about the center of the pressure sensor body 220, which may improve structural stability of the device.

In addition, a fourth bump-like structure 245 may be further disposed on the surface of the barrier layer 240 close to the substrate 210, and the third bump-like structure 244 and the fourth bump-like structure 245 are respectively located on two sides of the second beam structure 250.

Specifically, as shown in fig. 4, the third bump-like structure 244 is located on the left side (the side close to the pressure sensor body 220) of the second beam structure 250, which can effectively limit the displacement of the pressure sensor body 220 in the direction toward the barrier layer 240, and thus effectively limit the displacement of the second beam structure 250 in the direction toward the barrier layer 240. The fourth bump-like structure 245 is located on the right side (the side away from the pressure sensor main body 220) of the second beam structure 250, and can effectively restrict the displacement of the pressure sensor main body 220 in the oblique upward direction, that is, can effectively restrict the displacement of the pressure sensor main body 220 in both the upward and rightward directions. The fourth bump-like structures 245 may correspond to a gap between the second beam structure 250 and the substrate 210, or may correspond to an edge position of the substrate 210 near the second beam structure 250.

The second protrusion-shaped structure 243 and the fourth protrusion-shaped structure 245 may be symmetrically distributed about the center of the pressure sensor body 220, so that the structural stability of the device may be further improved, and the first beam structure 230 and the second beam structure 250 may be effectively protected from being broken.

As shown in fig. 5, the first and second

convex structures

241 and 243 are distributed along the extending direction of the first beam structure 230 on the barrier layer 240. The third and fourth bump-

like structures

244 and 245 are distributed on the barrier layer 240 along the extending direction of the second beam structure 250. The protrusion-like structures are distributed on the barrier layer 240 along the extending direction of the corresponding beam structure, which may mean that the direction of the protrusion-like structures is consistent with the direction (or partial direction) of the corresponding beam structure. The moving direction of the convex-shaped structures is set to be consistent with that of the corresponding beam structures, so that the displacement of the beam structures can be effectively limited, and the beam structures are prevented from being broken. For example, the first beam structure 230 and the second beam structure 250 may be bending beams, each of which may include two segments (refer to the first beam structure 130 and the second beam structure 150 in fig. 2), and correspondingly, as shown in fig. 5, the number of the first convex structures 241 may be two, respectively distributed along each segment of the bending beam. Similarly, the number of the second convex structures 243, the third convex structures 244 and the fourth convex structures 245 may be two.

Alternatively, in other embodiments, the second, third and fourth bump-like structures may also be disposed at an edge position of the surface of the pressure sensor body near the barrier layer. Of course, it is also possible to provide the pressure sensor body with a bulge-like structure on both the surface of the barrier layer and the surface of the barrier layer adjacent to the substrate.

Fig. 6 is a bottom view of a barrier layer 340 of a pressure sensor according to another embodiment of the present disclosure. The barrier layer 340 shown in fig. 6 is similar to the barrier layer 240 shown in fig. 5, and in order to avoid redundancy, the same parts are not repeated, and the differences are mainly described here. As shown in fig. 6, a plurality of through holes 342 are formed in the middle of the barrier layer 340, and a connection layer 370 is formed at the edge of the barrier layer 340. The surface of the barrier layer 340 near the substrate is provided with a first bump-shaped structure, a second bump-shaped structure, a third bump-shaped structure and a fourth bump-shaped structure. The first and second convex structures are located on two sides of the first beam structure, respectively, and the third and fourth convex structures are located on two sides of the second beam structure, respectively.

The first bump-like structure includes a plurality of bumps 341, and the plurality of bumps 341 are distributed on the barrier layer 340 along an extending direction of the first beam structure. Similar to the first bump-like structure, the second bump-like structure comprises a plurality of bump points 343, the third bump-like structure comprises a plurality of bump points 344, and the fourth bump-like structure comprises a plurality of bump points 345, which are distributed along the extension direction of the corresponding beam structure on the barrier layer 340. The plurality of protrusions are distributed on the barrier layer 340 along the extending direction of the corresponding beam structure, which may mean that the direction of the plurality of protrusions is identical to the direction (or partial direction) of the corresponding beam structure. The moving directions of the plurality of convex points are set to be consistent with the moving directions of the corresponding beam structures, so that the displacement of the beam structures can be effectively limited, and the beam structures are prevented from being broken. In addition, the convex structures are arranged into a plurality of convex points which are distributed at intervals, so that materials can be saved, and the light weight of the device is realized.

Fig. 7 is a schematic cross-sectional view of a pressure sensor 400 according to another embodiment of the present application. Pressure sensor 400 shown in FIG. 7 is similar to pressure sensor 100 shown in FIG. 1, and for the sake of avoiding redundancy, the same parts are not repeated, and the differences are emphasized here. As shown in fig. 7, the pressure sensor 400 includes a substrate 410, a pressure sensor body 420, a first beam structure 430, and a barrier layer 440.

The substrate 410 is provided with a receiving cavity 411, and the edge of the barrier layer 440 is provided with at least one through hole 442. A first bump-like structure 441 is disposed on a surface of barrier layer 440 proximate to substrate 410, the first bump-like structure 441 being located on barrier layer 440 at a position corresponding to an intermediate position of pressure sensor body 420. Alternatively, the first bump-like structures 441 are located on the barrier layer 440 at positions corresponding to the edge positions of the pressure sensor body 420, i.e., at positions near the through-holes 442.

The through hole 442 is disposed at an edge of the barrier layer 440, so that external foreign objects can be effectively prevented from falling onto the surface of the pressure sensor body 420 through the through hole 442 and interfering with the measurement result. The number of the through holes 442 may be one or more, for example, the number of the through holes 442 is two, and two through holes 442 are respectively disposed at both ends of the barrier layer 440, so that the structural stability of the barrier layer 440 can be maintained.

The first bump-like structure 441 may be an elongated bar, or the first bump-like structure 441 may include a plurality of spaced-apart bumps. The thickness of the first protruding structure 441 may be set according to actual needs, so as to ensure that the displacement of the pressure sensor body 420 in the direction toward the barrier layer 440 can be effectively limited, and thus, the displacement of the beam structure in the direction toward the barrier layer 440 can be effectively limited, and the beam structure is prevented from being broken.

Fig. 11 is a schematic cross-sectional view of a pressure sensor 500 according to another embodiment of the present application. The pressure sensor 500 shown in fig. 11 is similar to the pressure sensor 100 shown in fig. 1, and in order to avoid redundancy, the same parts are not repeated, and the differences are mainly described here. As shown in fig. 5, the pressure sensor 500 includes a substrate 510, a pressure sensor body 520, a first beam structure 530, and a barrier layer 540.

The substrate 510 is provided therein with a housing chamber 511, and the pressure sensor body 520 is disposed in the housing chamber 511. The first beam structure 530 is disposed in the receiving cavity 511 and connects the pressure sensor body 520 and the substrate 510 such that the pressure sensor body 520 is suspended in the receiving cavity 511. A barrier layer 540 is disposed on a side of the pressure sensor body 520 remote from the substrate 510. A first bump-like structure 541 is disposed on a surface of the pressure sensor body 520 proximate the barrier layer 540.

In one embodiment, the first bump-like structure 541 is disposed at an edge location of the pressure sensor body 520. The first bump-like structures 541 may be used to limit the displacement of the first beam structure 530 in a direction toward the barrier layer 540, so as to prevent the first beam structure 530 from being broken due to excessive deformation.

In an embodiment, a second bump-like structure (not shown) is disposed on a surface of the barrier layer 540 close to the substrate 510, and the first bump-like structure 541 and the second bump-like structure are respectively located at two sides of the first beam structure 530. The second bump-like structure can effectively restrict the displacement of the pressure sensor body 520 in the oblique upper direction, that is, can effectively restrict the displacement of the pressure sensor body 520 in both the upward and leftward directions.

Further, the pressure sensor 500 also comprises a second beam structure 550. The second beam structure 550 is disposed in the receiving cavity 511 and connects the pressure sensor body 520 and the substrate 510, and the first beam structure 530 and the second beam structure 550 are symmetrically distributed between the pressure sensor body 520 and the substrate 510.

In an embodiment, a third bump-like structure (not shown) may be further disposed on a surface of the pressure sensor body 520 close to the barrier layer 540, and the third bump-like structure is disposed at an edge position of the pressure sensor body 520. The first protrusion-like structure 541 corresponds to the first beam structure 530, and the third protrusion-like structure 544 corresponds to the second beam structure 550.

Of course, more convex structures may be disposed on the surface of the pressure sensor body 520 close to the barrier layer 540, and the specific manner of disposing the convex structures on the surface of the barrier layer may be referred to in the above embodiments.

Fig. 8 is a schematic flow chart illustrating a method for manufacturing a pressure sensor according to an embodiment of the present disclosure. As shown in fig. 8, the manufacturing method includes the following.

S810: the pressure sensor comprises a substrate, and is characterized in that an accommodating cavity, a pressure sensor main body and a first beam structure are arranged in the substrate, wherein the pressure sensor main body and the first beam structure are positioned in the accommodating cavity, and the first beam structure is connected with the pressure sensor main body and the substrate, so that the pressure sensor main body is suspended in the accommodating cavity.

Specifically, the process of providing the accommodating cavity, the pressure sensor body, and the first beam structure in the substrate may be implemented by a method combining etching, and an epitaxial single crystal silicon process.

S820: and arranging a barrier layer on one side of the pressure sensor main body, which is far away from the substrate, wherein a first convex structure is arranged between the barrier layer and the pressure sensor main body.

In an embodiment, a first bump-like structure is disposed on a surface of the barrier layer adjacent to the substrate, and a position of the first bump-like structure on the barrier layer corresponds to a position of the pressure sensor body.

Alternatively, in other embodiments, the first bump-like structure may be disposed on a surface of the pressure sensor body proximate to the barrier layer.

Specifically, first protruding column structure can play limiting displacement, can restrict the displacement of pressure sensor main part in the direction towards the barrier layer, and then restricts the displacement of first beam structure in the direction towards the barrier layer to can effectively prevent because of the fracture of first beam structure that first beam structure arouses because of the too big displacement of first beam structure in the direction towards the barrier layer.

The materials of the substrate, the barrier layer, and the first protrusion structure in this embodiment may be as described in the above embodiments of fig. 1 to 7, and are not repeated herein to avoid repetition.

The embodiment of the application provides a manufacturing method of a pressure sensor, and the convex structure is arranged between the barrier layer and the pressure sensor main body, so that the displacement of the beam structure in the direction towards the barrier layer can be limited, and the beam structure can be effectively prevented from being broken due to overlarge displacement of the beam structure in the direction towards the barrier layer when the pressure sensor is subjected to impact acting force, and the reliability and the impact resistance of the pressure sensor can be effectively improved.

In one embodiment, the position of the first bump-like structure on the barrier layer corresponds to the edge position of the pressure sensor body close to the first beam structure, so that the first beam structure can be effectively prevented from being broken.

In an embodiment, the barrier layer may further include a second protrusion structure, and the first protrusion structure and the second protrusion structure are respectively located on two sides of the first beam structure.

In an embodiment, the substrate may further include a second beam structure, and the barrier layer may further include a third protrusion structure and a fourth protrusion structure, where the third protrusion structure and the fourth protrusion structure are respectively located on two sides of the second beam structure, so as to effectively prevent the second beam structure from being broken.

Here, the shapes and distribution manners of the first convex structures, the second convex structures, the third convex structures and the fourth convex structures may refer to the description in the embodiments of fig. 1 to 7, and in order to avoid repetition, the description is not repeated here.

According to an embodiment of the present application, the method of manufacturing a pressure sensor further includes: at least one through hole is formed in the substrate, and a first protruding structure is arranged on one side of the substrate to form a barrier layer, wherein the position of the first protruding structure on the barrier layer corresponds to the position of the pressure sensor main body.

Specifically, the number and the distribution manner of the through holes may be as described in the embodiments of fig. 1 to fig. 7, and are not described herein again to avoid repetition.

According to an embodiment of the present application, providing a barrier layer on a side of the pressure sensor body remote from the substrate, as shown in fig. 9, includes the following.

S821: at least one blind hole is arranged on the substrate, and a first bulge-shaped structure is arranged on one side of the substrate, which is provided with the at least one blind hole.

Specifically, the material of the substrate may be silicon, glass or other materials. As shown in fig. 10a-10b, at least one blind hole 11 may be etched in the substrate 10, and the first bump-like structure 12 and the connection layer 13 may be provided on the side of the substrate 10 where the blind hole 11 is etched. The material of the connection layer can be as described in the embodiments of fig. 1 to fig. 7, and is not described herein again to avoid repetition.

Further, a second bump-like structure 14, a third bump-like structure 15 and a fourth bump-like structure 16 may be disposed on the side of the substrate 10 where the blind hole 11 is etched.

S822: a base is provided on a side of the pressure sensor body remote from the substrate.

Specifically, a base provided with blind holes, bump-like structures, and a connection layer is connected to a substrate. As shown in fig. 10c, the substrate 20 is provided with a connection layer 21 on a side thereof close to the base 10, and the substrate 20 and the base 10 are previously connected by the connection layer 13 and the connection layer 21. The substrate 20 and the base 10 may be connected by metal eutectic bonding or colloid bonding.

S823: and thinning the substrate, wherein the position of the first bulge-shaped structure on the barrier layer corresponds to the position of the pressure sensor main body.

Specifically, a thinning process or an etching process may be employed so that the blind holes become through holes.

By the manufacturing method of the pressure sensor provided by the embodiment of the application, the pressure sensor of any embodiment shown in fig. 1 to 7 can be obtained, and the specific structure of the pressure sensor can be referred to the description above.

All the above optional technical solutions can be combined arbitrarily to form optional embodiments of the present application, and are not described herein again.

In the description herein, references to the description of the terms "one embodiment," "some embodiments," "an example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Furthermore, the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, whereby the features defining "first", "second" may explicitly or implicitly include at least one such feature.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modifications, equivalents and the like that are within the spirit and principle of the present application should be included in the scope of the present application.

Claims

1. A pressure sensor, comprising:

the device comprises a substrate, a first substrate and a second substrate, wherein an accommodating cavity is formed in the substrate;

the pressure sensor main body is arranged in the accommodating cavity;

a first beam structure disposed in the receiving cavity and connecting the pressure sensor body and the substrate such that the pressure sensor body is suspended in the receiving cavity;

the barrier layer is arranged on one side, far away from the substrate, of the pressure sensor main body, and a first protruding structure is arranged between the barrier layer and the pressure sensor main body.

2. The pressure sensor of claim 1, wherein the surface of the pressure sensor body proximate the barrier layer is provided with the first bump-like structure, the first bump-like structure being located at an edge of the pressure sensor body.

3. A pressure sensor according to claim 1, wherein the barrier layer is provided with at least one through-hole in an intermediate position.

4. The pressure sensor of claim 3, wherein the at least one through-hole comprises a plurality of through-holes arranged in a matrix.

5. A pressure sensor according to claim 1, characterized in that at least one through hole is provided at an edge location of the barrier layer.

6. A pressure sensor according to claim 2, wherein the surface of the barrier layer adjacent to the substrate is provided with a second bump-like structure, the first and second bump-like structures being located on either side of the first beam structure.

7. A pressure sensor according to claim 1, wherein the first bump-like structures are distributed along the extension of the first beam structure.

8. The pressure sensor of claim 1, wherein the first bump-like structure comprises a plurality of bump points distributed along an extension direction of the first beam structure.

9. The pressure sensor according to any one of claims 1 to 8, wherein a distance between a bottom surface of the pressure sensor body and a bottom surface of the housing cavity is greater than or equal to 4 micrometers and less than or equal to 6 micrometers.

10. A pressure sensor according to any of claims 1 to 8, wherein the pressure sensor body comprises a pressure sensor sensitive membrane disposed adjacent the barrier layer, the interior of the pressure sensor body being provided with a cavity, the cavity being located below the pressure sensor sensitive membrane.

11. A method of manufacturing a pressure sensor, comprising:

arranging a containing cavity, a pressure sensor main body and a first beam structure in a substrate, wherein the pressure sensor main body and the first beam structure are positioned in the containing cavity, and the first beam structure is connected with the pressure sensor main body and the substrate, so that the pressure sensor main body is suspended in the containing cavity;

and arranging a barrier layer on one side of the pressure sensor main body, which is far away from the substrate, wherein a first convex structure is arranged between the barrier layer and the pressure sensor main body.

12. The method of manufacturing of claim 11, wherein prior to disposing the barrier layer on a side of the pressure sensor body away from the substrate, the method of manufacturing further comprises:

and arranging the first convex structure on one side of the pressure sensor main body, which is far away from the substrate, wherein the first convex structure is positioned at the edge position of the pressure sensor main body.

13. The manufacturing method according to claim 11, further comprising:

and arranging at least one through hole on a substrate and arranging the first convex-shaped structure on one side of the substrate to form the barrier layer, wherein the position of the first convex-shaped structure on the barrier layer corresponds to the position of the pressure sensor main body.

14. The method of manufacturing of claim 11, wherein providing the barrier layer on a side of the pressure sensor body away from the substrate comprises:

arranging at least one blind hole on a substrate and arranging the first convex structure on one side of the substrate, which is provided with the at least one blind hole;

disposing the base on a side of the pressure sensor body remote from the substrate;

thinning the substrate, wherein the position of the first bump-shaped structure on the barrier layer corresponds to the position of the pressure sensor main body.

15. A manufacturing method according to any one of claims 11 to 14, wherein the pressure sensor body comprises a pressure sensor sensitive membrane arranged close to the barrier layer, and a cavity is arranged inside the pressure sensor body, the cavity being located below the pressure sensor sensitive membrane.