Pressure sensor

Abstract

The utility model provides a pressure sensor, relates to the technical field of pressure sensor packaging, and aims to improve the test precision of the pressure sensor. The pressure sensor comprises a packaging base, a bearing structure and a pressure-sensitive element. The packaging base comprises a first surface and a first groove located in the packaging base, and an opening of the first groove faces the first surface. The bearing structure is located in the first groove, the side wall of the bearing structure is connected with the side wall of the first groove, a gap is formed between the bottom of the bearing structure and the bottom of the first groove, and the pressure-sensitive element is arranged at the top of the bearing structure and connected with the bearing structure. Due to the suspension design, the heat transfer and mechanical coupling degree between the pressure-sensitive element and the packaging base is reduced under high and low temperature changes. The main source of thermal stress is isolated by the bearing structure, and the stress is buffered by the bearing structure before acting on the pressure-sensitive element, so that the deformation and signal drift of the pressure-sensitive element can be reduced, and the test accuracy of the pressure sensor is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to pressure sensor packaging technical field, concretely relates to a pressure sensor. BACKGROUND

[0002] The pressure sensor is a kind of sensor that can feel pressure and convert into usable output signal, is widely used in various fields, for example, pressure sensor is widely used in industrial automation, medical equipment, automobile, environmental monitoring and other fields.

[0003] In the process of packaging pressure-sensitive element, some stress is inevitably introduced, which directly affects the accuracy of pressure sensor test, in addition, with the increase of pressure sensor use time, the stress introduced in the packaging process will be released irregularly, and the change of this part of stress is difficult to compensate by algorithm, and the transmission to pressure-sensitive element will affect the accuracy of pressure sensor output.

[0004] In addition, the pressure-sensitive element packaging, pressure sensor use, transportation process may also be affected by external stress, for example, pressure sensor is subjected to drop impact, which will cause the output accuracy of pressure sensor to be greatly reduced. UTILITY MODEL CONTENT

[0005] The utility model embodiment provides a kind of pressure sensor, to improve the test accuracy of pressure sensor.

[0006] To achieve the above object, the embodiment of the utility model adopts the following technical scheme:

[0007] The pressure sensor provided by the application includes a packaging base, a supporting structure and a pressure-sensitive element. The packaging base includes a first surface and a first recess inside the packaging base. The opening of the first recess faces the first surface. The supporting structure is located in the first recess, and the side wall of the supporting structure is connected to the side wall of the first recess. There is a gap between the bottom of the supporting structure and the bottom of the first recess. The pressure-sensitive element is arranged on the top of the supporting structure and connected to the supporting structure.

[0008] The side wall of the supporting structure in the pressure sensor provided by the application is connected to the side wall of the first recess, that is, the supporting structure is embedded in the first recess. There is a gap between the bottom of the supporting structure and the bottom of the first recess, which means that the supporting structure is suspended. The pressure-sensitive element is arranged on the top of the supporting structure. Compared with the traditional direct installation on the packaging base, the suspended design reduces the degree of heat transfer and mechanical coupling between the pressure-sensitive element and the packaging base under high and low temperature changes. Since the main source of thermal stress is isolated by the supporting structure, the packaging stress acts on the pressure-sensitive element first and is buffered by the supporting structure, so the deformation and signal drift of the pressure-sensitive element can be reduced, thereby ensuring the test accuracy of the pressure sensor.

[0009] As a possible implementation, a glass insulator is arranged between the sidewall of the support structure and the sidewall of the first recess, the glass insulator is in contact with at least part of the sidewall of the support structure and in contact with the sidewall of the first recess.

[0010] As a possible implementation, the first recess comprises a connecting wall connecting the bottom and the sidewall of the first recess, the connecting wall is in a stepped shape; the connecting wall comprises a first transition surface and a second transition surface, the first transition surface is connected with the sidewall, and the second transition surface is connected with the bottom, and the first transition surface is closer to the first surface than the bottom.

[0011] As a possible implementation, the glass insulator is also located on the first transition surface of the connecting wall, and at least part of the sidewall of the support structure is in contact with the second transition surface of the connecting wall.

[0012] As a possible implementation, the surface of the glass insulator close to the pressure sensitive element is farther away from the pressure sensitive element than the surface of the support structure close to the pressure sensitive element.

[0013] As a possible implementation, the material of the glass insulator comprises glass, the material of the support structure comprises glass, and the melting point of the glass insulator is lower than the melting point of the support structure.

[0014] As a possible implementation, the dimension of the surface of the support structure in contact with the pressure sensitive element along the first direction is smaller than the dimension of the surface of the pressure sensitive element in contact with the support structure along the first direction; the first direction is parallel to the first surface.

[0015] As a possible implementation, the difference between the thermal expansion coefficient of the support structure and the thermal expansion coefficient of the pressure sensitive element is less than a set value.

[0016] As a possible implementation, the thermal expansion coefficient of the support structure is the same as the thermal expansion coefficient of the pressure sensitive element.

[0017] As a possible implementation, the pressure sensor further comprises a gas guide tube. The packaging base comprises a second surface opposite to the first surface, and the packaging base comprises a second recess, the opening of the second recess faces the second surface. The gas guide tube is inserted into the second recess, and one end of the gas guide tube abuts against the bottom of the second recess. The first cavity is formed between the bottom of the second recess and the bottom of the first recess. The second cavity is formed inside the support structure. The gas guide tube and the first cavity are in communication, and the second cavity is in communication with the first cavity.

[0018] As a possible implementation, a glass insulator is arranged between the sidewall of the gas guide tube and the sidewall of the second recess.

[0019] As a possible implementation manner, the package base comprises a third groove, which is arranged at the side of the first groove close to the first surface, and the bottom of the third groove is communicated with the opening of the first groove. The pressure sensor further comprises a lead post, and the package base further comprises a lead cavity arranged between the bottom of the third groove and the second surface, the lead post is arranged in the lead cavity, and one end of the lead post is inserted into the third groove and the other end penetrates through the second surface. A glass insulator is arranged between the periphery of the lead post and the lead cavity.

[0020] As a possible implementation manner, the opening of the third groove faces the first surface. The pressure sensor further comprises a cover structure arranged at the side of the first surface of the package base and connected with the first surface. The cover structure comprises a corrugated diaphragm and a compression ring, the corrugated diaphragm is connected with the first surface, and the compression ring is arranged at the side of the corrugated diaphragm away from the first surface. The first groove and the third groove are filled with liquid medium.

[0021] As a possible implementation manner, the package base further comprises a liquid injection cavity inside, one end of the liquid injection cavity is communicated with the bottom of the third groove, and the other end penetrates through the surface of the package base. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A schematic diagram of a pressure sensor package structure provided by an embodiment of the present application;

[0023] Figure 2 A schematic diagram of another pressure sensor package structure provided by an embodiment of the present application;

[0024] Figure 3 A schematic diagram of another pressure sensor package structure provided by an embodiment of the present application;

[0025] Figure 4 A schematic diagram of another pressure sensor package structure provided by an embodiment of the present application. DETAILED DESCRIPTION

[0026] 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. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0028] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, when describing pipelines, the terms "connected" and "linked" in this utility model have the meaning of establishing conductivity. The specific meaning needs to be understood in conjunction with the context.

[0029] In this embodiment of the invention, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" or "for example" in this embodiment of the invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0030] With the diversification and increasing complexity of industrial applications, pressure sensors are being used more and more widely in various harsh environments. To ensure the reliability and accuracy of pressure sensors in environments such as high temperature, low temperature, and strong corrosion, the packaging technology of pressure sensors becomes crucial.

[0031] In view of this, embodiments of this application provide a pressure sensor, exemplarily, such as... Figure 1 As shown. The pressure sensor 100 includes an encapsulation base 1, a support structure 2, and a pressure-sensitive element 3. The encapsulation base 1 includes a first surface 11 and a first groove 12 located inside the encapsulation base 1, with the opening of the first groove 12 facing the first surface 11. The support structure 2 is located within the first groove 12, and the sidewall of the support structure 2 is connected to the sidewall 121 of the first groove 12. There is a gap between the bottom of the support structure 2 and the bottom 122 of the first groove 12. The pressure-sensitive element 3 is disposed on the top of the support structure 2 and connected to the support structure 2.

[0032] The sidewall of the support structure 2 in the pressure sensor 100 provided in this application is connected to the sidewall 121 of the first groove 12, meaning that the support structure 2 is embedded in the first groove 12. There is a gap between the bottom of the support structure 2 and the bottom 122 of the first groove 12, indicating that the support structure 2 is suspended. The pressure-sensitive element 3 is disposed on top of the support structure 2. Compared to the traditional direct mounting on the encapsulation base 1, the suspended design reduces the thermal transfer and mechanical coupling between the pressure-sensitive element 3 and the encapsulation base 1 under high and low temperature changes. Because in the encapsulation of traditional pressure sensors, the pressure-sensitive element 3 is in direct contact with the stainless steel encapsulation base 1, external stress is directly transmitted to the pressure-sensitive element 3 through the encapsulation base 1 during the encapsulation process, during the transportation of the pressure sensor 100, and when using the pressure sensor 100 under harsh conditions. When using the pressure sensor 100 provided in this application embodiment, the external stress is first buffered by the supporting structure 2 before it acts on the pressure-sensitive element 3, thus reducing the deformation and signal drift of the pressure-sensitive element 3 and ensuring the testing accuracy of the pressure sensor 100.

[0033] The suspended design of the support structure 2 also suspends the pressure-sensitive element 3 located on it, effectively reducing interference from external stresses. These stresses include assembly stress generated during the threaded connection between the pressure sensor 100 and the pipe under test, welding stress generated during silicone oil injection and sealing during encapsulation, and stresses from impacts and vibrations under harsh operating conditions. The suspended design of the support structure 2 reduces the impact on the pressure-sensitive element 3, improving the stress isolation capability of the pressure sensor 100.

[0034] For example, refer to Figure 2 The first groove 12 includes a connecting wall that connects the bottom 122 and the side wall 121 of the first groove 12. Figure 2 (As shown by the bold black line in the middle), the connecting wall is stepped. The connecting wall includes a first transition surface 123 and a second transition surface 124. The first transition surface 123 is connected to the side wall 121, and the second transition surface 124 is connected to the bottom 122. The first transition surface 123 is closer to the first surface than the bottom 122. The stepped shape of the connecting wall means that there is a height difference between the first transition surface 123 and the second transition surface 124 constituting the connecting wall.

[0035] As one possible implementation, such as Figure 2As shown, the glass insulator 4 is arranged between the side wall of the supporting structure 2 and the side wall 121 of the first groove 12. The glass insulator 4 is in contact with at least part of the side wall of the supporting structure 2 and the side wall 121 of the first groove 12. The side wall of the supporting structure 2 is connected with the side wall 121 of the first groove 12 through the glass insulator 4 and is suspended in the first groove 12 by the glass insulator. The glass insulator 4 filled between the side wall of the supporting structure 2 and the side wall 121 of the first groove 12 makes the pressure sensor 100 not directly act on the pressure-sensitive element when subjected to horizontal external force, but is transmitted to the pressure-sensitive element through the glass insulator 4 and the buffering of the supporting structure 2 in turn, thereby reducing the mechanical deformation of the pressure-sensitive element 3 and ensuring the test accuracy of the pressure sensor 100.

[0036] As a possible implementation, the glass insulator 4 is also located on the first transition surface 123 of the connecting wall, and at least part of the side wall of the supporting structure 2 is in contact with the second transition surface 124 of the connecting wall. At least part of the supporting structure 2 is clamped in the stepped area, and part of the side wall of the supporting structure 2 is supported by the glass insulator 4, thereby achieving the suspended arrangement.

[0037] In some embodiments, referring to Figure 2 The surface of the glass insulator 4 close to the pressure-sensitive element 3 is farther away from the pressure-sensitive element 3 than the surface of the supporting structure 2 close to the pressure-sensitive element 3. This means that the surface of the glass insulator 4 close to the pressure-sensitive element 3 is not flush with the surface of the supporting structure 2 close to the pressure-sensitive element 3, that is, the glass insulator 4 cannot contact the pressure-sensitive element 3, which ensures that the pressure-sensitive element 3 is in a suspended state by the supporting structure, so that stress cannot be transmitted to the pressure-sensitive element 3 through the glass insulator 4.

[0038] As a possible implementation, the material of the glass insulator 4 includes glass, the material of the supporting structure 2 includes glass, and the melting point of the glass insulator 4 is lower than the melting point of the supporting structure 2. When connecting the glass insulator 4 between the side wall of the supporting structure 2 and the side wall 121 of the first groove 12, high temperature is needed to convert the physical state of the glass insulator 4 to a molten state, and the melting point of the supporting structure 2 is higher than that of the glass insulator 4, which ensures that the physical state of the supporting structure 2 does not change, thereby ensuring the flatness of the top surface of the supporting structure 2 and preventing the supporting structure 2 from being deformed at the top when fixed in the first groove 12, which affects the installation and measurement of the pressure-sensitive element 3.

[0039] As a possible implementation, referring to Figure 2The surface of the supporting structure 2 in contact with the pressure sensitive element 3 along the first direction, i.e. the X direction shown by the arrow in the figure, is smaller than the surface of the pressure sensitive element 3 in contact with the supporting structure 2 along the first direction. The first direction is parallel to the first surface 11. The pressure sensitive element 3 is attached to the top surface of the supporting structure 2 made of glass by flexible glue. In conventional packaging, the pressure sensitive element 3 is directly attached to the metal base, which has poor electrical insulation and is easily affected by the external environment, thereby affecting the stability of the sensor. First, the composition of the supporting structure 2 includes glass, which has good electrical insulation, can effectively isolate the electrical interference between the pressure sensitive element 3 and the packaging base 1, and is helpful to improve the signal stability and anti-interference ability of the pressure sensor, and improve the reliability of the device. In addition, glass has a high melting point and heat resistance, and can maintain excellent physical form and performance in high temperature environment, which means that the supporting structure 2 can not only withstand high temperature solidification during the packaging process of the pressure sensor 100, but also maintain stable performance in high temperature application scenarios.

[0040] And because the surface of the supporting structure 2 in contact with the pressure sensitive element 3 along the first direction is smaller than the surface of the pressure sensitive element 3 in contact with the supporting structure 2 along the first direction, it is ensured that when the pressure sensitive element 3 is fixed to the top surface of the supporting structure 2, the situation of dispensing glue to the side of the pressure sensitive element 3 does not occur, ensuring the sensitivity of the pressure sensitive element 3.

[0041] In some embodiments, as shown in Figure 2 The difference between the thermal expansion coefficient of the supporting structure 2 and the thermal expansion coefficient of the pressure sensitive element 3 is less than a set value. For example, the set value is 0.5*10 -6 / ℃. The difference between the thermal expansion coefficient of the supporting structure 2 and the thermal expansion coefficient of the pressure sensitive element 3 being less than a set value means that the thermal expansion coefficient of the supporting structure 2 is similar to the thermal expansion coefficient of the pressure sensitive element 3. As a possible implementation, the thermal expansion coefficient of the supporting structure 2 is the same as the thermal expansion coefficient of the pressure sensitive element 3.

[0042] The thermal expansion coefficient is a parameter describing the degree of expansion or contraction of a material when heated or cooled. If material A and material B have different thermal expansion coefficients, it means that when the temperature rises, material A may expand faster or more, while material B expands slower or less. Conversely, when the temperature decreases, material A will contract more, while material B will contract less. In a packaging structure, if different materials are tightly bonded or fixed together, due to the inconsistency of material expansion or contraction, the interaction stress will be generated due to the constraint of adjacent materials. For example, when a material with a larger thermal expansion coefficient tries to expand, it will be limited by a material with a smaller thermal expansion coefficient, which will cause a compression stress in the material with a smaller thermal expansion coefficient, and a tensile stress in the material with a larger thermal expansion coefficient.

[0043] This internal stress due to the inconsistent thermal expansion can have a significant impact on the stability of the structure and the material, especially in multiple temperature cycles or extreme temperature environments, which can cause material fatigue, performance degradation or even cracking. For such a precision device as the pressure sensor 100, this thermal stress can cause a small deformation of the pressure sensing element 3, affecting the output of the electrical signal, causing the output signal to drift or be unstable, reducing the accuracy of the pressure sensor.

[0044] In the case where the thermal expansion coefficient of the support structure 2 is the same as that of the pressure sensing element 3, when the external temperature changes, the thermal expansion and contraction between the pressure sensing element 3 and the support structure 2 are synchronized, which can avoid the thermal stress generated between the support structure 2 and the pressure sensing element 3 due to the difference in thermal expansion coefficient. In addition, such a design can effectively isolate the stress transmission path of the external environment under rapid temperature changes or extreme temperature conditions, avoiding the hysteresis phenomenon caused by uneven stress transmission.

[0045] Temperature hysteresis refers to the phenomenon that the output signal of the pressure sensor 100 is inconsistent during heating and cooling. Due to the non-linear characteristics of the hysteresis effect, it is difficult to correct the output of the pressure sensor 100 through linear compensation. By using a glass material with the same thermal expansion coefficient as the pressure sensing element 3 as the support structure 2, the thermal expansion and contraction between the pressure sensing element 3 and the support structure 2 can be synchronized. This matching of thermal expansion coefficients significantly reduces the internal stress generated between different materials due to the difference in thermal expansion and contraction, thereby reducing the mechanical deformation of the pressure sensing element 3 and reducing the hysteresis effect.

[0046] In some embodiments, an exemplary embodiment is shown in Figure 2 The pressure sensor 100 also includes a gas guide tube 5. The package base 1 includes a second surface 13 opposite the first surface 11, and the package base 1 includes a second groove 14 with an opening facing the second surface 13. The gas guide tube 5 is inserted into the second groove 14, and one end of the gas guide tube 5 abuts the bottom 141 of the second groove 14. The first cavity 15 passes through between the bottom 141 of the second groove 14 and the bottom of the first groove 12. The second cavity 21 passes through inside the support structure 2. The gas guide tube 5 and the first cavity 15 are in communication, and the second cavity 21 is in communication with the first cavity 15.

[0047] As a possible implementation, the diameter of the first groove 12 is 3-5 mm, and the depth of the first groove is 1-2 mm. The outer diameter of the support structure 2 is 2-4 mm, the inner diameter is 0.5-1.2 mm, and the depth of the support structure 2 is 1-2 mm. There is a 0.1-0.3 mm gap between the bottom of the fixed support structure 2 and the bottom of the first groove 14. The inner diameter of the support structure 2 is also the inner diameter of the second cavity 21.

[0048] The air duct 5 is in communication with the first cavity 15, and the second cavity 21 is in communication with the first cavity 15, which means that the air duct 5 can transmit external pressure to the back of the pressure-sensitive element 3 in a stable and rapid manner, avoiding the dispersion and weakening of the pressure in the transmission process, thereby ensuring the sensitivity and response speed of the pressure sensor 100.

[0049] As a possible implementation, as shown in Figure 2 A glass insulator 4 is arranged between the side wall of the air duct 5 and the side wall of the second groove 14. The arrangement of the glass insulator 4 between the side wall of the air duct 5 and the side wall of the second groove 14 ensures the sealing between the air duct 5 and the second groove 14, ensures that there is no air leakage in the pressure sensor 100, prevents pressure relief, and prevents external impurities or contaminants from entering the interior of the pressure sensor 100, ensuring the integrity and stability of the pressure transmission path, thereby improving the reliability and long-term stability of the pressure sensor 100.

[0050] In some embodiments, an example is shown in Figure 3 The packaging base 1 includes a third groove 16 arranged on the side of the first groove 12 close to the first surface 11, and the bottom of the third groove 16 is in communication with the opening of the first groove 12. The pressure sensor 100 further includes a lead column 7, and the packaging base 1 further includes a lead cavity 17 arranged between the bottom of the third groove 16 and the second surface 13, the lead column 7 is arranged in the lead cavity 17, one end of the lead column 7 is inserted into the third groove 16, and the other end of the lead column 7 penetrates through the second surface 13. A glass insulator 4 is arranged between the periphery of the lead column 7 and the lead cavity 17.

[0051] As a possible implementation, the PAD on the pressure-sensitive element 3 is electrically connected to the lead column 7 by a wire bonder, so that the electrical signal output by the pressure-sensitive element 3 can be transmitted to the lead column 7, greatly enhancing the flexibility of the pressure sensor 100.

[0052] In some embodiments, as shown in Figure 3 The third groove 16 is internally provided with a ceramic cover 161, the height of the ceramic cover 161 is less than the depth of the third groove 16, and an incompressible liquid medium such as silicone oil, fluorine oil, vegetable oil, etc. is filled between the ceramic covers 161. Taking silicone oil as an example of the incompressible liquid medium, since the height of the ceramic cover 161 is less than the depth of the third groove 16, after packaging is completed, the surface of the third groove 16 is sealed by silicone oil, which can effectively prevent the internal pressure of the pressure sensor 100 from leaking. Silicone oil can provide a stable transmission path during pressure transmission, helping to disperse and absorb the impact of external pressure, avoiding direct impact on the pressure-sensitive element 3, thereby protecting the pressure-sensitive element 3 and prolonging the service life of the pressure sensor 100.

[0053] In addition, since the silicone oil has good thermal stability and chemical inertness, it can maintain stable performance in a wide temperature range, reduce the hysteresis effect and signal drift caused by temperature changes, and improve the long-term stability of the sensor. Moreover, the combination of the ceramic cover 161 and the silicone oil can provide good electrical insulation, avoiding the influence of external electrical interference on the pressure sensor 100, and ensuring the stability and accuracy of the output signal of the pressure sensor 100.

[0054] As a possible implementation, as shown in Figure 3 The inside of the packaging base 1 also includes a liquid injection cavity 18, one end of the liquid injection cavity 18 communicates with the bottom of the third groove 16, and the other end of the liquid injection cavity 18 penetrates the surface of the packaging base 1. The incompressible liquid medium is injected through the liquid injection cavity 18, and the injection port is sealed with a steel ball or a pin at the opening of the liquid injection cavity 18 penetrating the surface of the packaging base 1.

[0055] In some embodiments, an example is shown in Figure 4 The opening of the third groove 16 faces the first surface 11. The pressure sensor 100 also includes a cover structure 80 arranged on the side of the first surface 11 of the packaging base 1 and connected with the first surface 11. The cover structure 80 includes a corrugated diaphragm 81 and a compression ring 82, the corrugated diaphragm 81 is connected with the first surface 11, and the compression ring 82 is arranged on the side of the corrugated diaphragm 81 away from the first surface 11. The first groove 12 and the third groove 16 are filled with liquid medium.

[0056] The cover structure 80 is arranged on the first surface 11 of the packaging base 1, and the cover structure 80 includes the corrugated diaphragm 81 and the compression ring 82, which means that the corrugated diaphragm 81 is located at the top position of the pressure sensor 100. When external pressure is applied to the pressure sensor, the corrugated diaphragm 81 deforms, and the deformation of the corrugated diaphragm 81 is proportional to the pressure applied to the pressure sensor 100. Through precise structural design, the external physical pressure can be accurately and stably transmitted to the pressure-sensitive element 3 located below the corrugated diaphragm 81.

[0057] The corrugated diaphragm 81 has good elasticity and ductility, so when the pressure is transmitted to the corrugated diaphragm 81, the corrugated diaphragm 81 can uniformly disperse the pressure applied to the corrugated diaphragm 81 and transmit it to the pressure-sensitive element 3 below. In addition to transmitting pressure, the cover structure 80 also has the functions of isolation and protection. The cover structure 80 can protect the precise pressure-sensitive element 3 inside the pressure sensor 100 from mechanical damage or impact of particulate matter, thereby prolonging the service life of the pressure sensor 100.

[0058] As a possible implementation manner, the corrugated diaphragm 81 is connected to the first surface of the packaging base 1 by laser welding. Since the laser beam has high energy density and local heat input, laser welding can produce small and depth-controllable welds, provide high-quality welding results, and has high precision and good controllability, and can realize micron-level control of weld size and position, and is suitable for processing small and complex structure welding. The sealing cover structure 80 and the packaging base 1 form a sealed whole after welding, which ensures that the external pressure can be completely transmitted to the pressure sensitive element, thereby ensuring the accuracy of the pressure sensor 100 measurement.

[0059] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope of the application being indicated by the following claims.

[0060] Finally, it should be noted that: the above, only for the specific embodiments of the present application, but the protection scope of the present application is not limited to this, any change or replacement within the technical scope disclosed in the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A pressure sensor, characterized by The pressure sensor comprises: a package base, the package base comprising a first surface, and a first recess inside the package base, the opening of the first recess facing the first surface; a supporting structure inside the first recess, and the side wall of the supporting structure is connected with the side wall of the first recess, and there is a gap between the bottom of the supporting structure and the bottom of the first recess; a pressure sensitive element on the top of the supporting structure, and the pressure sensitive element is connected with the supporting structure.

2. The pressure sensor of claim 1, wherein, A glass insulator is arranged between the side wall of the supporting structure and the side wall of the first recess, and the glass insulator is in contact with at least part of the side wall of the supporting structure and the side wall of the first recess.

3. The pressure sensor of claim 2, wherein, The first recess comprises a connecting wall connecting the bottom and the side wall of the first recess, and the connecting wall is in a stepped shape. The connecting wall comprises a first transition surface and a second transition surface, the first transition surface is connected with the side wall, and the second transition surface is connected with the bottom, and the first transition surface is closer to the first surface than the bottom.

4. The pressure sensor of claim 3, wherein, The glass insulator is also on the first transition surface of the connecting wall, and at least part of the side wall of the supporting structure is in contact with the second transition surface of the connecting wall.

5. The pressure sensor of claim 2, wherein, The surface of the glass insulator close to the pressure sensitive element is farther away from the pressure sensitive element than the surface of the supporting structure close to the pressure sensitive element.

6. The pressure sensor of claim 2, wherein, The material of the glass insulator comprises glass, the material of the supporting structure comprises glass, and the melting point of the glass insulator is lower than the melting point of the supporting structure.

7. The pressure sensor of claim 1, wherein, The size of the surface of the supporting structure in contact with the pressure sensitive element along the first direction is smaller than the size of the surface of the pressure sensitive element in contact with the supporting structure along the first direction. The first direction is parallel to the first surface.

8. The pressure sensor of claim 1, wherein, The difference between the thermal expansion coefficient of the supporting structure and the thermal expansion coefficient of the pressure sensitive element is less than a set value.

9. The pressure sensor of claim 8, wherein, The thermal expansion coefficient of the supporting structure is the same as the thermal expansion coefficient of the pressure sensitive element.

10. The pressure sensor of claim 1, wherein, The pressure sensor further comprises a gas guide tube. The package base comprises a second surface opposite to the first surface, and the package base comprises a second recess, the opening of the second recess facing the second surface; the gas guide tube is inserted into the second recess, and one end of the gas guide tube abuts against the bottom of the second recess. The bottom of the second recess and the bottom of the first recess are penetrated by a first cavity; the inside of the supporting structure is penetrated by a second cavity; the gas guide tube and the first cavity are in communication, and the second cavity is in communication with the first cavity.

11. The pressure sensor of claim 10, wherein, A glass insulator is arranged between the side wall of the gas guide tube and the side wall of the second recess.

12. The pressure sensor of claim 10, wherein, The package base comprises a third recess, the third recess is arranged on the side of the first recess close to the first surface, and the bottom of the third recess is in communication with the opening of the first recess. The pressure sensor further comprises a lead column, and the package base further comprises a lead cavity arranged between the bottom of the third recess and the second surface, the lead column is arranged in the lead cavity, one end of the lead column is inserted into the third recess, and the other end of the lead column penetrates through the second surface. A glass insulator is arranged between the periphery of the lead column and the lead cavity.

13. The pressure sensor of claim 12, wherein, The opening of the third recess faces the first surface. The pressure sensor further comprises a cover structure arranged on one side of the first surface of the packaging base and connected with the first surface; The cover structure comprises a corrugated diaphragm connected with the first surface and a compression ring arranged on the side of the corrugated diaphragm away from the first surface; The first groove and the third groove are filled with liquid medium.

14. The pressure sensor of claim 13, wherein, The packaging base further comprises a liquid injection cavity inside, one end of the liquid injection cavity being in communication with the bottom of the third groove and the other end penetrating through the surface of the packaging base.

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