Pressure sensor

Abstract

The invention 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 present invention relates to the technical field of pressure sensor packaging, and in particular to a pressure sensor. Background Art

[0002] A pressure sensor is a sensor that can sense pressure and convert it into a usable output signal. It is widely used in various fields. For example, pressure sensors are widely used in industrial automation, medical equipment, automobiles, environmental monitoring and other fields.

[0003] In the process of packaging the pressure sensitive element, it is inevitable to introduce some stress, which directly affects the accuracy of the pressure sensor test. In addition, as the pressure sensor is used for a longer time, the stress introduced in the packaging process will be released irregularly, and this part of the stress change is difficult to compensate through the algorithm. When it is transmitted to the pressure sensitive element, it will affect the accuracy of the pressure sensor output.

[0004] In addition, during the packaging of pressure-sensitive elements, the use and transportation of pressure sensors, they may also be affected by external stress. For example, the pressure sensor may be subjected to a drop shock, which will cause a significant reduction in the output accuracy of the pressure sensor. Summary of the invention

[0005] An embodiment of the present invention provides a pressure sensor, aiming to improve the test accuracy of the pressure sensor.

[0006] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0007] The pressure sensor provided by the present application includes a packaging base, a supporting structure and a pressure-sensitive element. The packaging base includes a first surface and a first groove located inside the packaging base, and the opening of the first groove faces the first surface. The supporting structure is located in the first groove, and the side wall of the supporting structure is connected to the side wall of the first groove, and there is a gap between the bottom of the supporting structure and the bottom of the first groove, and 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 present application is connected to the side wall of the first groove, that is, the supporting structure is embedded in the first groove. There is a gap between the bottom of the supporting structure and the bottom of the first groove, 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 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, and the packaging stress is first buffered by the supporting structure before acting on the pressure-sensitive element, it can reduce the deformation and signal drift of the pressure-sensitive element, thereby ensuring the test accuracy of the pressure sensor.

[0009] As a possible implementation manner, a glass insulator is disposed between the side wall of the supporting structure and the side wall of the first groove, and the glass insulator contacts at least a portion of the side wall of the supporting structure and contacts the side wall of the first groove.

[0010] As a possible implementation method, the first groove includes a connecting wall connecting the bottom and side wall of the first groove, and the connecting wall is step-shaped; the connecting wall includes a first transition surface and a second transition surface, the first transition surface is connected to the side wall, and the second transition surface is connected to the bottom, and the first transition surface is closer to the first surface than the bottom.

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

[0012] As a possible implementation manner, 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.

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

[0014] As a possible implementation, the dimension of the surface of the supporting 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 supporting structure along the first direction; the first direction is parallel to the first surface.

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

[0016] As a possible implementation manner, the supporting structure and the pressure-sensitive element have the same thermal expansion coefficient.

[0017] As a possible implementation, the pressure sensor further includes an air duct. The package base includes a second surface opposite to the first surface, and the package base includes a second groove, the opening of the second groove faces the second surface. The air duct is inserted into the second groove and one end of the air duct abuts against the bottom of the second groove. A first cavity runs through the bottom of the second groove and the bottom of the first groove. A second cavity runs through the inside of the supporting structure. The air duct is connected to the first cavity, and the second cavity is connected to the first cavity.

[0018] As a possible implementation manner, a glass insulator is provided between the side wall of the air guide tube and the side wall of the second groove.

[0019] As a possible implementation, the package base includes a third groove, the third groove is arranged on the side of the first groove close to the first surface, and the bottom of the third groove is connected to the opening of the first groove. The pressure sensor also includes a lead post, and the package base also includes 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 is inserted into the third groove, and the other end passes through the second surface. A glass insulator is arranged around the lead post and between the lead cavity.

[0020] As a possible implementation, the opening of the third groove faces the first surface. The pressure sensor also includes a cover structure disposed on one side of the first surface of the package base and connected to the first surface. The cover structure includes a corrugated diaphragm and a pressure ring, the corrugated diaphragm is connected to the first surface, and the pressure ring is disposed on a side of the corrugated diaphragm away from the first surface. The first groove and the third groove are filled with a liquid medium.

[0021] As a possible implementation manner, the packaging base further includes a liquid injection cavity inside, one end of the liquid injection cavity is connected to the bottom of the third groove, and the other end thereof passes through the surface of the packaging base. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

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

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, when describing the pipeline, the "connected" and "connection" used in the present invention have the meaning of conduction. The specific meaning needs to be understood in conjunction with the context.

[0029] In the embodiments of the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0030] With the diversification and complexity of application scenarios in the industrial field, pressure sensors are increasingly used in various harsh environments. In order to ensure the reliability and accuracy of pressure sensors in high temperature, low temperature, strong corrosion and other environments, the packaging technology of pressure sensors is crucial.

[0031] In view of this, an embodiment of the present application provides a pressure sensor, exemplarily, as Figure 1 As shown. The pressure sensor 100 includes a package base 1, a supporting structure 2 and a pressure sensitive element 3. The package base 1 includes a first surface 11 and a first groove 12 located inside the package base 1, and the opening of the first groove 12 faces the first surface 11. The supporting structure 2 is located in the first groove 12, and the side wall of the supporting structure 2 is connected to the side wall 121 of the first groove 12, and there is a gap between the bottom of the supporting structure 2 and the bottom 122 of the first groove 12, and the pressure sensitive element 3 is arranged on the top of the supporting structure 2 and connected to the supporting structure 2.

[0032] The side wall of the supporting structure 2 in the pressure sensor 100 provided in the present application is connected to the side wall 121 of the first groove 12, that is, the supporting structure 2 is embedded in the first groove 12. There is a gap between the bottom of the supporting structure 2 and the bottom 122 of the first groove 12, which means that the supporting structure 2 is suspended. The pressure-sensitive element 3 is arranged on the top of the supporting structure 2. Compared with the traditional direct installation on the packaging base 1, the suspended design reduces the degree of heat transfer and mechanical coupling between the pressure-sensitive element 3 and the packaging base 1 under high and low temperature changes. Since in the packaging of the traditional pressure sensor, the pressure-sensitive element 3 is directly in contact with the stainless steel packaging base 1, the external stress will be directly transmitted to the pressure-sensitive element 3 through the packaging base 1 during the packaging of the pressure-sensitive element 3, when the pressure sensor 100 is transported, and when the pressure sensor 100 is used under harsh working conditions. With the pressure sensor 100 provided in the embodiment of the present application, the external stress will first be buffered by the supporting structure 2 before acting on the pressure-sensitive element 3, so that the deformation and signal drift of the pressure-sensitive element 3 can be reduced, thereby ensuring the test accuracy of the pressure sensor 100.

[0033] The suspended setting of the supporting structure 2 makes the pressure-sensitive element 3 on the supporting structure 2 relatively suspended, which can effectively reduce the interference of external stress, such as the assembly stress generated when the pressure sensor 100 is threadedly connected to the pipeline to be tested, such as the welding stress generated when silicone oil is injected during the packaging process, and the impact and vibration stress generated by the outside world under harsh working conditions. By setting the supporting structure 2 in the air, the impact on the pressure-sensitive element 3 can be reduced, and the stress isolation capability of the pressure sensor 100 can be improved.

[0034] For example, refer to Figure 2 The first groove 12 includes a connecting wall ( Figure 2 The connecting wall is in a step shape. 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 step 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 a possible implementation, Figure 2As shown, a glass insulator 4 is provided between the side wall of the supporting structure 2 and the side wall 121 of the first groove 12. The glass insulator 4 contacts at least part of the side wall of the supporting structure 2 and contacts the side wall 121 of the first groove 12. The side wall of the supporting structure 2 is connected to 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 ensures that the pressure sensor 100 will not directly act on the pressure-sensitive element when subjected to horizontal external force, but will be transmitted to the pressure-sensitive element after being buffered by the glass insulator 4 and the supporting structure 2 in sequence, 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 a portion of the side wall of the supporting structure 2 is in contact with the second transition surface 124 of the connecting wall. At least a portion of the supporting structure 2 is stuck in the step-shaped area, and a portion of the side wall of the supporting structure 2 is supported by the glass insulator 4, thereby realizing a suspended arrangement.

[0037] In some embodiments, reference Figure 2 , the surface of the glass insulator 4 close to the piezoresistive element 3 is farther away from the piezoresistive element 3 than the surface of the supporting structure 2 close to the piezoresistive element 3. This means that the surface of the glass insulator close to the piezoresistive element 3 will not be flush with the surface of the supporting structure 2 close to the piezoresistive element 3, that is, the glass insulator 4 cannot contact the piezoresistive element 3, which ensures that the piezoresistive element 3 is in a state of being suspended by the supporting structure, so that stress cannot be transmitted to the piezoresistive 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 the glass insulator 4 is connected to the side wall of the supporting structure 2 and the side wall 121 of the first groove 12, a high temperature is required to convert the physical state of the glass insulator 4 into a molten state. The melting point of the supporting structure 2 is higher than the melting point of the glass insulator 4, which ensures that the physical state of the supporting structure 2 will not change, thereby ensuring the flatness of the top surface of the supporting structure 2, and preventing the top deformation of the supporting structure 2 when the supporting structure 2 is fixed in the first groove 12, which may affect the installation and measurement of the pressure-sensitive element 3.

[0039] As a possible implementation, refer to Figure 2, the surface of the supporting structure 2 in contact with the pressure-sensitive element 3 along the first direction, that is, the dimension of the X direction shown by the arrow in the figure, is smaller than the dimension of 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 a flexible adhesive. In the traditional package, the pressure-sensitive element 3 is directly attached to the metal base, and the electrical insulation is poor, which is easily disturbed by the external environment, thereby affecting the stability of the sensor. First of all, the supporting structure 2 is composed of glass. Glass has good electrical insulation shoes, which can effectively isolate the electrical interference between the pressure-sensitive element 3 and the packaging base 1, which helps 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 a high temperature environment, which means that the supporting structure 2 can not only withstand high temperature curing during the packaging process of the pressure sensor 100, but also maintain stable performance in high temperature application scenarios.

[0040] Furthermore, since the surface of the supporting structure 2 in contact with the pressure-sensitive element 3 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, glue will not be applied to the side of the pressure-sensitive element 3, thereby ensuring the sensitivity of the pressure-sensitive element 3.

[0041] In some embodiments, for example, 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 the 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 the set value means that the thermal expansion coefficient of the supporting structure 2 is close to that of the pressure-sensitive element 3. As a possible implementation, the thermal expansion coefficient of the supporting structure 2 is the same as that of the pressure-sensitive element 3.

[0042] The coefficient of thermal expansion is a parameter that describes the degree to which a material expands when heated or contracts when cooled. If material A and material B have different coefficients of thermal expansion, it means that when the temperature rises, material A may expand faster or more, while material B expands slower or less. On the contrary, when the temperature drops, material A will shrink more, while material B will shrink less. In a packaging structure, if different materials are tightly bonded or fixed together, the inconsistency of material expansion or contraction will be constrained by adjacent materials, resulting in interactive stress. For example, when a material with a larger coefficient of thermal expansion tries to expand, it will be restricted by a material with a smaller coefficient of thermal expansion, which will cause compressive stress in the material with a smaller coefficient of thermal expansion and tensile stress in the material with a larger coefficient of thermal expansion.

[0043] This internal stress caused by inconsistent thermal expansion will have a significant impact on the stability of the structure and the material, especially in multiple temperature cycles or extreme temperature environments, causing material fatigue, performance degradation, or even cracking. For precision devices such as the pressure sensor 100, this thermal stress will cause a slight deformation of the pressure-sensitive element 3, affecting the output of the electrical signal, causing the output signal to drift or become unstable, and reducing the accuracy of the pressure sensor.

[0044] When the thermal expansion coefficient of the supporting structure 2 is the same as that of the pressure-sensitive element 3, when the external temperature changes, the thermal expansion and contraction between the pressure-sensitive element 3 and the supporting structure 2 are synchronized, which can avoid thermal stress caused by the different thermal expansion coefficients between the supporting structure 2 and the pressure-sensitive element 3. 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 hysteresis caused by uneven stress transmission.

[0045] Temperature hysteresis refers to the phenomenon that the output signal of the pressure sensor 100 is inconsistent during the heating and cooling process. Since the hysteresis effect often has nonlinear characteristics, 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-sensitive element 3 as the supporting structure 2, the synchronization of thermal expansion and contraction between the pressure-sensitive element 3 and the supporting structure 2 can be ensured. This matching of thermal expansion coefficients significantly reduces the internal stress generated by the difference in thermal expansion and contraction between different materials, thereby reducing the mechanical deformation of the pressure-sensitive element 3 and reducing the hysteresis effect.

[0046] In some embodiments, for example, Figure 2 As shown. The pressure sensor 100 also includes an air duct 5. The package base 1 includes a second surface 13 opposite to the first surface 11, and the package base 1 includes a second groove 14, and the opening of the second groove 14 faces the second surface 13. The air duct 5 is inserted into the second groove 14 and one end of the air duct 5 is against the bottom 141 of the second groove 14. A first cavity 15 runs through the bottom 141 of the second groove 14 and the bottom of the first groove 12. A second cavity 21 runs through the inside of the supporting structure 2. The air duct 5 is connected to the first cavity 15, and the second cavity 21 is connected to 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 supporting structure 2 is 2-4 mm, the inner diameter is 0.5-1.2 mm, and the depth of the supporting structure 2 is 1-2 mm. There is a gap of 0.1-0.3 mm between the bottom of the fixed supporting structure 2 and the bottom of the first groove 14. The inner diameter of the supporting structure 2 is also the inner diameter of the second cavity 21.

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

[0049] As a possible implementation, Figure 2 As shown, a glass insulator 4 is provided between the side wall of the air duct 5 and the side wall of the second groove 14. The glass insulator 4 is provided between the side wall of the air duct 5 and the side wall of the second groove 14 to ensure the sealing between the air duct 5 and the second groove 14, to ensure that there will be no leakage inside the pressure sensor 100, to prevent pressure release and to prevent external impurities or contaminants from entering the interior of the pressure sensor 100, to ensure the integrity and stability of the pressure transmission path, and thus to improve the reliability and long-term stability of the pressure sensor 100.

[0050] In some embodiments, for example, Figure 3 As shown. The package base 1 includes a third groove 16, which is arranged on the side of the first groove 12 close to the first surface 11, and the bottom of the third groove 16 is connected to the opening of the first groove 12. The pressure sensor 100 also includes a lead post 7, and the package base 1 also includes a lead cavity 17 arranged between the bottom of the third groove 16 and the second surface 13, the lead post 7 is arranged in the lead cavity 17, and one end of the lead post 7 is inserted into the third groove 16, and the other end of the lead post 7 passes through the second surface 13. A glass insulator 4 is arranged around the lead post 7 and between the lead cavity 17.

[0051] As a possible implementation method, the PAD on the pressure sensitive element 3 is electrically connected to the lead post 7 through a wire bonding machine, so that the electrical signal output by the pressure sensitive element 3 can be transmitted to the lead post 7, which greatly enhances the flexibility of the use of the pressure sensor 100.

[0052] In some embodiments, Figure 3 As shown, a ceramic cover 161 is provided inside the third groove 16, and 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 the packaging is completed, the surface of the third groove 16 is sealed by silicone oil, which can effectively prevent the pressure inside the pressure sensor 100 from leaking out. Silicone oil can provide a stable transmission path during the pressure transmission process, help to disperse and absorb the impact of external pressure, avoid the pressure directly impacting the pressure sensitive element 3, thereby protecting the pressure sensitive element 3 and extending the service life of the pressure sensor 100.

[0053] In addition, because 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. In addition, the combination of the ceramic cover 161 and the silicone oil can play a good electrical insulation role, avoiding the influence of external electrical interference on the pressure sensitive element 3, and ensuring the stability and accuracy of the output signal of the pressure sensor 100.

[0054] As a possible implementation, Figure 3 The package base 1 further includes a liquid injection cavity 18, one end of which is connected to the bottom of the third groove 16, and the other end of which penetrates the surface of the package base 1. Incompressible liquid medium is injected through the liquid injection cavity 18, and the injection port is blocked with a steel ball or a pin at the opening where the liquid injection cavity 18 penetrates the surface of the package base 1 to achieve sealing.

[0055] In some embodiments, for example, Figure 4 As shown. The opening of the third groove 16 faces the first surface 11. The pressure sensor 100 also includes a cover structure 80 disposed on one side of the first surface 11 of the package base 1 and connected to the first surface 11. The cover structure 80 includes a corrugated diaphragm 81 and a pressure ring 82, the corrugated diaphragm 81 is connected to the first surface 11, and the pressure ring 82 is disposed 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 a liquid medium.

[0056] The cover structure 80 is disposed on the first surface 11 of the package base 1, and the cover structure 80 includes a corrugated diaphragm 81 and a pressure ring 82, which means that the corrugated diaphragm 81 is located at the top of the pressure sensor 100. When external pressure is applied to the pressure sensor, the corrugated diaphragm 81 is deformed, 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 evenly disperse the pressure applied on the corrugated diaphragm 81 and transmit it to the pressure-sensitive element 3 below. In addition to transmitting pressure, the setting of the cover structure 80 also plays a role of isolation and protection. The cover structure 80 can protect the delicate pressure-sensitive element 3 inside the pressure sensor 100 from mechanical damage or impact of particles, thereby extending the service life of the pressure sensor 100.

[0058] As a possible implementation method, the corrugated diaphragm 81 is connected to the first surface of the package base 1 by laser welding. Since the laser beam has high energy density and local heat input, laser welding can produce small, depth-controlled welds, provide high-quality welding results, and laser welding has high precision and good controllability, and can achieve micron-level weld size and position control, which is suitable for welding small and complex structures. After welding, the cover structure 80 forms a sealed whole with the package base 1, ensuring that the external pressure can be fully transmitted to the pressure-sensitive element, thereby ensuring the accuracy of the pressure sensor 100 measurement.

[0059] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application.

[0060] Finally, it should be noted that the above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A pressure sensor, characterized in that: include: A packaging base, the packaging base comprising a first surface, and a first groove located inside the packaging base, wherein an opening of the first groove faces the first surface; A supporting structure is located in the first groove, and the side wall of the supporting structure is connected to the side wall of the first groove, and there is a gap between the bottom of the supporting structure and the bottom of the first groove; The pressure-sensitive element is arranged on the top of the supporting structure and connected to the supporting structure.

2. The pressure sensor according to claim 1, characterized in that: A glass insulator is disposed between the side wall of the supporting structure and the side wall of the first groove. The glass insulator contacts at least a portion of the side wall of the supporting structure and contacts the side wall of the first groove.

3. The pressure sensor according to claim 2, characterized in that: The first groove comprises a connecting wall connecting the bottom and the side wall of the first groove, and the connecting wall is in a step shape; The connecting wall includes a first transition surface and a second transition surface, the first transition surface is connected to the side wall, the second transition surface is connected to the bottom, and the first transition surface is closer to the first surface than the bottom.

4. The pressure sensor according to claim 3, characterized in that: The glass insulator is also located on the first transition surface of the connecting wall, and at least a portion of the side wall of the supporting structure is in contact with the second transition surface of the connecting wall.

5. The pressure sensor according to claim 2, characterized in that: 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 according to claim 2, characterized in that: The material of the glass insulator includes glass, the material of the supporting structure includes glass, and the melting point of the glass insulator is lower than the melting point of the supporting structure.

7. The pressure sensor according to claim 1, characterized in that: The dimension of the surface of the supporting 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 supporting structure along the first direction; The first direction is parallel to the first surface.

8. The pressure sensor according to claim 1, characterized in that: 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 according to claim 8, characterized in that: The supporting structure has the same thermal expansion coefficient as that of the pressure-sensitive element.

10. The pressure sensor according to claim 1, characterized in that: The pressure sensor also includes an airway; The packaging base includes a second surface opposite to the first surface, and the packaging base includes a second groove, the opening of the second groove faces the second surface; the air guide tube is inserted into the second groove and one end of the air guide tube is against the bottom of the second groove; A first cavity runs through the bottom of the second groove and the bottom of the first groove; a second cavity runs through the inside of the supporting structure; the air duct is connected to the first cavity, and the second cavity is connected to the first cavity.

11. The pressure sensor according to claim 10, characterized in that: A glass insulator is arranged between the side wall of the air guide tube and the side wall of the second groove.

12. The pressure sensor according to claim 10, characterized in that: The packaging base comprises a third groove, the third groove is arranged on a side of the first groove close to the first surface, and the bottom of the third groove is connected to the opening of the first groove; The pressure sensor further includes a lead post, and the package base further includes a lead cavity disposed between the bottom of the third groove and the second surface, the lead post is disposed in the lead cavity, and one end of the lead post is inserted into the third groove, and the other end passes through the second surface; Glass insulators are arranged around the lead post and between the lead cavity.

13. The pressure sensor according to claim 12, characterized in that: The opening of the third groove faces the first surface; The pressure sensor further comprises a cover structure disposed on one side of the first surface of the package base and connected to the first surface; The sealing structure comprises a corrugated diaphragm and a pressure ring, the corrugated diaphragm is connected to the first surface, and the pressure ring is arranged on a 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 according to claim 13, characterized in that: The packaging base further includes 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 thereof penetrates the surface of the packaging base.

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