MEMS sensor, wafer, detection system and detection method

Abstract

The invention discloses an MEMS sensor, a wafer, a detection system and a detection method, and the MEMS sensor comprises a substrate, a cover body, an MEMS sensitive structure, and an air tightness detection structure. The substrate comprises a working area and an air tightness detection area. The cover body and the substrate enclose to form an accommodating cavity; the MEMS sensitive structure is located in the working area; the air tightness detection structure comprises a first conductive structure and a second conductive structure, the first conductive structure and the second conductive structure extend from the interior of the accommodating cavity to the exterior of the accommodating cavity, a first interval is formed between the first conductive structure and the second conductive structure on the air tightness detection area, and the first interval is smaller than a preset value. According to the invention, air tightness detection can be immediately carried out after wafer-level packaging is completed, and parallel detection can be carried out on a plurality of MEMS sensors on the wafer, so that the detection efficiency can be remarkably improved, and the problems of detection lag, incapability of full coverage, personal errors and the like in the prior art are solved.

Description

[0001] This application claims priority to the Chinese Patent Application No. 202511422963.5, filed on September 30, 2025, and entitled "MEMS Sensor, Wafer, Detection System and Detection Method", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of micro-electro-mechanical system, and in particular, to a MEMS sensor, a wafer, a detection system and a detection method. BACKGROUND

[0003] Micro-electro-mechanical system (MEMS) chips are widely used in the fields of sensing, communication and automotive electronics, and the internal sensitive structure thereof usually relies on a sealed cavity formed by wafer-level packaging to maintain a stable working environment. Insufficient airtightness will cause moisture or impurities to enter, thereby affecting the performance of the sensitive structure and causing device failure.

[0004] Existing methods for detecting the airtightness of a MEMS sensitive structure mainly include helium mass spectrometry leak detection, infrared interference detection, and gas sensor detection. These methods are usually complex in process, and need to detect or sample inspect each chip after it is separated from the wafer, which is low in detection efficiency and difficult to meet the demand for wafer-level mass detection. SUMMARY

[0005] Embodiments of the present application provide a MEMS sensor, a wafer, a detection system and a detection method, which aim to improve the efficiency of detecting the airtightness of a MEMS sensor.

[0006] To achieve the above-mentioned purpose, according to a first aspect of the present application, a MEMS sensor is provided, comprising: a substrate comprising a working area and an airtightness detection area; a cover body enclosing a containing cavity with the substrate, the working area and the airtightness detection area being located in the containing cavity; a MEMS sensitive structure located in the working area; an airtightness detection structure comprising a first conductive structure and a second conductive structure, and the first conductive structure and the second conductive structure both extend from the containing cavity to the outside of the containing cavity, wherein the first conductive structure and the second conductive structure located on the airtightness detection area have a first spacing therebetween, and the first spacing is less than or equal to a preset value.

[0007] Optionally, the preset value ranges from 1 to 2 microns.

[0008] Optionally, the working area and the hermeticity detection area are arranged on the substrate in a spaced manner, the first conductive structure comprises a first part, the first part is located on the hermeticity detection area, the second conductive structure comprises a second part, the second part is located on the hermeticity detection area.

[0009] Optionally, the first part and the second part are in a spiral structure.

[0010] Optionally, the hermeticity detection area is arranged around the working area, the first conductive structure comprises a first part, the second conductive structure comprises a second part, the first part is located on the hermeticity detection area and arranged around the working area, the second part is located on the hermeticity detection area and arranged around the first part.

[0011] Optionally, the MEMS sensor further comprises a plurality of detection pads, the detection pads are located on the substrate outside the accommodation cavity, the first conductive structure comprises a third part connected with the first part, the second conductive structure comprises a fourth part connected with the second part, the third part and the fourth part are both extended to outside the accommodation cavity and fixedly connected with the corresponding detection pads.

[0012] Optionally, the first conductive structure and the second conductive structure are both metal leads.

[0013] Optionally, the MEMS sensitive structure is an inertial sensor structure.

[0014] Optionally, further comprising a substrate electrode, a signal lead and a signal pad, the MEMS sensitive structure is electrically connected with the substrate electrode, the substrate electrode is electrically connected with the corresponding signal lead, the signal lead is extended to outside the accommodation cavity and fixedly connected with the corresponding signal pad.

[0015] Optionally, the signal lead, the first conductive structure and the second conductive structure are arranged in the same layer.

[0016] According to a second aspect of the present application, a MEMS sensor wafer is provided, comprising an array of the above-mentioned MEMS sensor.

[0017] According to a third aspect of the present application, a detection system is provided for detecting the hermeticity of the above-mentioned MEMS sensor wafer, the detection system comprises: a containing device comprising a detection chamber for containing the wafer and capable of providing a preset environmental condition for the detection chamber; a detection device for acquiring a current signal between the first conductive structure and the second conductive structure of each of the MEMS sensors in the wafer under different preset environmental conditions; The signal processing module is configured to acquire a hermeticity detection result of the MEMS sensor based on the current signal.

[0018] According to a fourth aspect of the present application, a detection method is provided for detecting a wafer including any of the above-mentioned MEMS sensors, the detection system including: In a first environmental condition, detecting a first current signal between the first conductive structure and the second conductive structure of each of the MEMS sensors; In a second environmental condition, detecting a second current signal between the first conductive structure and the second conductive structure of each of the MEMS sensors; For each of the MEMS sensors, acquiring a hermeticity detection result based on the corresponding first current signal and the second current signal.

[0019] Optionally, the first environmental condition includes a first humidity value, and the second environmental condition includes a second humidity value, the first humidity value being less than the second humidity value.

[0020] Optionally, the acquiring of the hermeticity detection result based on the corresponding first current signal and the second current signal for each of the MEMS sensors includes: When the current value of the first current signal is less than the current value of the second current signal, and the difference between the current value of the second current signal and the current value of the first current signal is greater than a current threshold value, the hermeticity detection result is abnormal.

[0021] In the embodiments of the present application, the hermeticity detection structure is partially arranged in the hermeticity detection area of the substrate, and the hermeticity detection structure includes the first conductive structure and the second conductive structure arranged adjacent to each other, and the first distance between the two in the hermeticity detection area is less than a preset value. When the packaging cavity of the MEMS sensor is not airtight enough, external moisture may penetrate into the cavity, causing the humidity in the cavity to change. Under different humidity conditions, the leakage current between the first conductive structure and the second conductive structure will show significant differences. Therefore, by detecting the current signal between the first conductive structure and the second conductive structure, the hermeticity detection result of the corresponding MEMS sensor can be analyzed. The present embodiment can immediately carry out hermeticity detection after wafer-level packaging is completed, and at the same time, multiple MEMS sensors on the wafer can be detected in parallel, thereby significantly improving the detection efficiency and avoiding the problems of detection lag, incomplete coverage, and human error in the prior art. Therefore, the present embodiment not only improves the detection efficiency of the MEMS sensor, but also ensures the simplicity and real-time performance of the detection method, and enhances the reliability and practicality of the detection.

[0022] Other features and advantages of the present application will be described in detail in the following specific embodiments. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0024] Figure 1 This is a schematic diagram of the structure of a MEMS sensor disclosed in an embodiment of this application. Figure 1 ; Figure 2 This is a schematic diagram of the structure of a MEMS sensor disclosed in an embodiment of this application. Figure 2 ; Figure 3 This is a schematic diagram of the structure of a MEMS sensor disclosed in an embodiment of this application. Figure 3 .

[0025] Explanation of reference numerals in the attached figures: 1. Substrate; 111. Working area; 112. Hermeticity testing area; 2. Cover; 21. Receiving cavity; 3. MEMS sensitive structure; 31. Movable mass block; 311. Fixing part; 312. Connecting beam; 313. Connecting part; 314. Movable electrode; 315. Support anchor point; 32. Fixed electrode; 4. Air tightness detection structure; 41. First conductive structure; 411. First part; 412. Third part; 42. Second conductive structure; 421. Second part; 422. Fourth part; 5. Inspect the solder pads; 6. Substrate electrode; 7. Signal leads; 8. Signal pads. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0027] As described in the background, micro-electro-mechanical system (MEMS) chips are widely used in the fields of sensing, communication and automotive electronics, and the internal sensitive structure thereof usually relies on a sealed chamber formed by wafer-level packaging to maintain a stable working environment. Insufficient airtightness can cause moisture or impurities to enter, thereby affecting the performance of the sensitive structure and causing device failure.

[0028] In some embodiments, a detection method for arranging a gas sensor in a packaging chamber of a MEMS sensor is proposed. The method reflects whether the sealing performance of the chamber is normal by monitoring the changes in the concentrations of N2, H2, O2 and other gases in the chamber. Although this method can achieve direct monitoring of the airtightness of the chamber, the integration of the gas sensor inside the packaging chamber of the MEMS sensor makes the preparation process of the MEMS sensor more complex, and the processing cost and manufacturing cycle are significantly increased.

[0029] In other embodiments, an infrared microscope-based airtightness detection method is also proposed. The method detects the MEMS sensor by an infrared microscope, analyzes the data of the finished assembly by combining special control means, to judge the sealing performance thereof. However, since this method relies on the data changes of the finished assembly during use, the leakage defects generated during the production process often need a long time to manifest, thereby existing the problem of detection lag. In addition, this method can only be screened after the preparation of the MEMS sensor is completed, and cannot timely find and correct defects in the early process, thereby existing a large process risk.

[0030] In yet other embodiments, helium leak detection and fluorine oil leak detection are combined to detect airtightness. Specifically, after wafer dicing, helium fine detection and fluorine oil coarse detection are performed on the MEMS sensors selected for sampling, to judge the chamber leak rate thereof. This method belongs to a post-test means, and exists the problems of complicated steps and low detection efficiency, and can only sample part of the chips, and cannot achieve full coverage monitoring of each chip. At the same time, this method relies on manual operation, and is easy to produce human errors and operation mistakes. Moreover, as the chamber volume of the MEMS chip is gradually miniaturized, the traditional leak rate discrimination standard gradually fails, and the reliability of the detection result is further reduced.

[0031] Therefore, in order to improve the defects of the airtightness detection methods in the above embodiments and improve the efficiency of the airtightness detection of the MEMS sensitive structure, an embodiment of the present application provides a MEMS sensor.

[0032] Reference Figure 1 and Figure 2The MEMS sensor disclosed in the embodiment one of the present application comprises a substrate 1, a cover 2, a MEMS sensitive structure 3, and a hermeticity detection structure 4. The substrate 1 comprises a working area 111 and a hermeticity detection area 112. The cover 2 is fixedly connected with the substrate 1, and forms a containing cavity 21 together with the substrate 1. The MEMS sensitive structure 3 is located in the working area 111 and is fixedly connected with the substrate 1. The working area 111 and the hermeticity detection area 112 are both located in the containing cavity 21. The hermeticity detection structure 4 comprises a first conductive structure 41 and a second conductive structure 42. The first conductive structure 41 and the second conductive structure 42 both extend from the containing cavity 21 to the outside of the containing cavity 21. The first conductive structure 41 and the second conductive structure 42 located on the hermeticity detection area 112 have a first spacing therebetween, and the first spacing is less than a preset value.

[0033] It should be noted that, in the embodiment of the present application, the preset value ranges from 1 to 2 μm. In a specific embodiment of the present application, the preset value can be set to 2 μm. In other embodiments, the preset value of the first spacing can also be adjusted according to actual design requirements, for example, it can be set to 1 μm, 1.5 μm or other suitable small spacing, so as to ensure sensitive and reliable hermeticity detection under different device sizes or process conditions. At the same time, for the same MEMS sensor, the first spacing of each adjacent part between the first part 411 and the second part 421 can not be completely equal, as long as it is kept less than or equal to the preset value, which can ensure the detection effect.

[0034] In the embodiment of the present application, the hermeticity detection structure 4 is partially arranged on the hermeticity detection area 112 of the substrate 1, and the hermeticity detection structure 4 comprises the first conductive structure 41 and the second conductive structure 42 arranged adjacently, and the part of the first conductive structure 41 and the second conductive structure 42 located on the hermeticity detection area 112 has a first spacing less than the preset value. When the packaging cavity of the MEMS sensor is not airtight enough, external moisture may penetrate into the cavity, so that the humidity of the cavity environment changes. Under different humidity conditions, the leakage current between the first conductive structure 41 and the second conductive structure 42 will show significant difference. Therefore, by detecting the current signal between the first conductive structure 41 and the second conductive structure 42, the hermeticity detection result of the corresponding MEMS sensor can be analyzed.

[0035] Since the air tightness detection structure 4 is directly integrated in the accommodating cavity 21 and can be formed by only forming a small-interval conductive structure in the air tightness detection area 112, no additional burden is caused to the preparation process of the MEMS sensor. The embodiment can immediately carry out air tightness detection after wafer-level packaging is completed, and can perform parallel detection on multiple MEMS sensors on the wafer, thereby significantly improving the detection efficiency and timely discovering and eliminating air tightness defects in the early process, avoiding the problems of detection lag, incomplete coverage and human error in the prior art. Therefore, the embodiment of the application not only improves the detection efficiency of the MEMS sensor, but also ensures the simplicity and real-time of the detection method, and enhances the reliability and practicality of the detection.

[0036] Further, in the embodiment of the application, the working area 111 and the air tightness detection area 112 are arranged at intervals on the substrate 1. The first conductive structure 41 includes a first part 411 located on the air tightness detection area 112, and the second conductive structure 42 includes a second part 421 located on the air tightness detection area 112. The first part 411 and the second part 421 are in a spiral structure that winds around each other. Each adjacent part of the first part 411 and the second part 421 has a first interval less than a preset value.

[0037] By winding the first part 411 and the second part 421 around each other in a spiral manner, a longer conductive path can be formed in the limited area of the air tightness detection area 112, thereby significantly increasing the effective coupling length between the two. By such arrangement, the current change between the first part 411 and the second part 421 under different humidity conditions is more significant, thereby improving the sensitivity and accuracy of air tightness detection.

[0038] In the embodiment of the application, the substrate 1 further includes a plurality of detection pads 5. The first conductive structure 41 includes a third part 412 connected to the first part 411, and the second conductive structure 42 includes a fourth part 422 connected to the second part 421. The third part 412 and the fourth part 422 both extend to the outside of the accommodating cavity 21 and are fixedly connected to the corresponding detection pads 5.

[0039] By forming a plurality of detection pads 5 on the region of the substrate 1 outside the accommodating cavity 21, the third part 412 in the first conductive structure 41 and the fourth part 422 in the second conductive structure 42 respectively extend to the accommodating cavity 21 and are fixedly connected to the corresponding detection pads 5. Therefore, the MEMS sensor can directly establish electrical connection with the external detection device through the detection pads 5, realizing convenient signal acquisition and transmission. By such arrangement, the MEMS sensor can be compatible with the probe and the detection system, which helps to realize wafer-level automatic batch detection, reduces the interference of human factors, and improves the detection efficiency and process adaptability.

[0040] Furthermore, in this embodiment, the MEMS sensor further includes a substrate electrode 6 and a signal lead 7. The MEMS sensing structure 3 is electrically connected to the substrate electrode 6, and the substrate electrode 6 is electrically connected to the corresponding signal lead 7. The signal lead 7 extends to the accommodating cavity 21. Specifically, the signal lead 7 extends outside the accommodating cavity 21 and connects to the corresponding signal pad 8, enabling the output of the electrical signal from the MEMS sensing structure 3.

[0041] In this embodiment, both the first conductive structure 41 and the second conductive structure 42 are metal leads, and they are located in the same layer as the signal lead 7. The first conductive structure 41 and the second conductive structure 42 can be fabricated simultaneously with the signal lead 7. Therefore, this embodiment can complete the fabrication of the airtightness detection structure 4 without adding any extra process steps, making the overall fabrication process of the MEMS sensor simpler than existing technologies and without imposing additional burden on existing processes.

[0042] In this embodiment, the MEMS sensing structure 3 is an inertial sensor structure. Specifically, the MEMS sensing structure 3 includes a movable mass block 31 and fixed electrodes 32. This application specifically, but not limitingly, proposes an inertial sensor structure, as follows: the movable mass block 31 includes a fixed part 311, a connecting beam 312, a connecting part 313, and movable electrodes 314. The fixed parts 311 are located on both sides of the connecting part 313 in a first direction, and each fixed part 311 is electrically connected to the substrate electrode 6 through a support anchor point 315. The fixed parts 311 and the connecting part 313 are connected by the connecting beam 312, which is a folded beam. Multiple movable electrodes 314 are provided, distributed on both sides of the connecting part 313 in a second direction, and arranged at intervals along the first direction. Each movable electrode 314 is fixedly connected to the connecting part 313. Multiple fixed electrodes 32 are also provided, distributed on both sides of the connecting portion 313 in the second direction, and fixedly connected to the substrate electrode 6 through support anchor points 315. The fixed electrodes 32 are arranged at intervals along the first direction. The fixed electrodes 32 and movable electrodes 314 correspond one-to-one, and the corresponding fixed electrodes 32 and movable electrodes 314 constitute the detection capacitance of the MEMS sensitive structure 3.

[0043] In the embodiments of this application, both the first direction and the second direction are parallel to the plane direction of the substrate 1.

[0044] In some other implementations, the inertial sensor structure can also be a triaxial accelerometer, a triaxial gyroscope, a triaxial magnetometer, etc.

[0045] Embodiment 2 of this application also provides a MEMS sensor, which differs from Embodiment 1 in that the airtightness detection area 112 is arranged around the working area 111. In other words, the airtightness detection area 112 is a ring-shaped region, and the working area 111 is located at the center of the airtightness detection area 112. The first part 411 is located in the airtightness detection area 112 and is arranged around the working area 111, and the second part 421 is located in the airtightness detection area 112 and is arranged around the first part 411.

[0046] Reference Figure 3 In Embodiment 2, by arranging the first part 411 and the second part 421 around the working area 111, the sealing condition within the accommodating cavity 21 can be detected more accurately when the cavity 21 is large. Specifically, when the cavity 21 is large, airtightness defects often first appear at the bonding position between the cover 2 and the substrate 1. By arranging the first part 411 and the second part 421 around the inner wall of the cover 2, potential leakage channels can be effectively covered, enabling rapid detection and response when moisture infiltrates. Furthermore, since the first part 411 and the second part 421 form an encircling layout around the working area 111, all-round detection of the MEMS sensitive structure 3 can be achieved, thereby further improving the sensitivity and accuracy of airtightness detection. At the same time, the surrounding arrangement can also improve space utilization, avoid additional occupation of effective chip area, and has good process compatibility.

[0047] It is worth mentioning that for MEMS devices with small chambers, due to the limited chamber volume, traditional methods such as helium detection or fluorinated oil detection rely on the amount of leaked gas, which often makes it difficult to generate a sufficiently obvious detection signal in such a small volume, resulting in insufficient sensitivity and the risk of missed detection. This embodiment of the application, by arranging adjacent first conductive structures 41 and second conductive structures 42 in the airtightness detection area 112, utilizes the sensitive characteristic of the current between them to humidity changes, enabling a significant current change to be generated even when a small amount of moisture seeps in. Therefore, even in a small chamber structure, this embodiment of the application can still achieve sensitive and reliable airtightness detection, effectively overcoming the shortcomings of insufficient sensitivity in small chamber detection of existing technologies.

[0048] Embodiment 3 of this application also provides a MEMS sensor wafer, including any of the MEMS sensors disclosed above.

[0049] Embodiment 4 of this application also provides a detection system for detecting the hermeticity of the aforementioned MEMS sensor wafer. Specifically, the detection system includes: a housing device, a detection device, and a signal processing module.

[0050] The housing includes a detection chamber for housing the wafer and is capable of providing preset environmental conditions for the detection chamber. The detection device is used to acquire current signals between the first conductive structure 41 and the second conductive structure 42 of each MEMS sensor in the wafer under different preset environmental conditions. The signal processing module is used to acquire the airtightness detection results of the corresponding MEMS sensor based on the current signals.

[0051] In this embodiment, the detection device can be a detection circuit board, which can establish an electrical connection with the detection pads 5 on the wafer via probes, thereby enabling parallel detection of multiple MEMS sensors on the wafer. This approach not only significantly improves the convenience of detection but also allows for the completion of hermeticity testing of MEMS sensors immediately after wafer packaging. This enables the timely detection and elimination of hermeticity defects in early process stages, preventing problems from being delayed until the finished product stage and improving the overall process yield and reliability.

[0052] In this embodiment, the humidity parameters differ under different environmental conditions. By switching between high and low humidity environments, the detection device can acquire the current signal between the first conductive structure 41 and the second conductive structure 42 of each MEMS sensor in the wafer. Since the current signal exhibits a significant response to humidity changes, when a leakage defect exists in the accommodating cavity 21, moisture will seep into the cavity, causing a significant change in current between adjacent conductive structures. By comparing and analyzing the current differences under different humidity conditions, the signal processing module can accurately determine the airtightness of the corresponding MEMS sensor.

[0053] Embodiment 5 of this application also provides a detection method for detecting the hermeticity of the above-mentioned MEMS sensor wafer.

[0054] Specifically, the detection method includes: under a first environmental condition, detecting a first current signal between the first conductive structure 41 and the second conductive structure 42 of each MEMS sensor; under a second environmental condition, detecting a second current signal between the first conductive structure 41 and the second conductive structure 42 of each MEMS sensor; and for each MEMS sensor, obtaining an airtightness detection result based on the corresponding first and second current signals.

[0055] Specifically, in the embodiments of this application, the first environmental condition includes a first humidity value, the second environmental condition includes a second humidity value, and the first humidity value is less than the second humidity value.

[0056] Because the current between conductive structures is sensitive to changes in humidity, when there is an airtightness defect in the housing cavity 21 of the MEMS sensor, leakage occurs between adjacent metal leads. At this time, the current value collected by detecting the detection pad 5 electrically connected to the third part 412 and the fourth part 422 will be significantly increased compared to before the moisture entered, reaching the order of 10E-1pF or higher, thus causing significant differences in the current signal under different humidity conditions.

[0057] The embodiments disclosed in this application can collect current signals from each MEMS sensor under different environmental conditions (such as different humidity conditions) and compare and analyze the difference between the first current signal and the second current signal. Specifically, when the current value of the first current signal is less than the current value of the second current signal, and the difference between the second current signal and the first current signal is greater than a preset current threshold, the airtightness detection result of the MEMS sensor can be determined to be abnormal.

[0058] Meanwhile, the detection method disclosed in this application can detect multiple MEMS sensors on a wafer after wafer-level bonding is completed, before the MEMS sensors are diced. On the one hand, this method utilizes the sensor's own hermeticity detection structure 4 to achieve hermeticity testing, without adding any additional process steps, and can detect MEMS sensors in the early stages of the process, thereby enabling the early detection and elimination of hermeticity defects. On the other hand, this method is applicable to wafer-level inspection, and can simultaneously perform batch testing on multiple MEMS sensors on a wafer, with high detection efficiency, making it suitable for large-scale production applications.

[0059] In the description of this application, 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. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0060] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0061] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0062] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A MEMS sensor, characterized in that, include: The substrate (1) includes a working area (111) and an airtightness detection area (112); The cover (2) and the substrate (1) form a cavity (21), and the working area (111) and the airtightness detection area (112) are both located in the cavity (21); MEMS sensitive structure (3) is located in the working area (111); The airtightness detection structure (4) includes a first conductive structure (41) and a second conductive structure (42), and both the first conductive structure (41) and the second conductive structure (42) extend from inside the accommodating cavity (21) to outside the accommodating cavity (21). There is a first gap between the first conductive structure (41) and the second conductive structure (42) located on the airtightness detection area (112), and the first gap is less than or equal to a preset value.

2. The MEMS sensor according to claim 1, characterized in that, The preset value ranges from [1, 2] μm.

3. The MEMS sensor according to claim 1, characterized in that, The working area (111) and the airtightness detection area (112) are arranged at intervals on the substrate (1). The first conductive structure (41) includes a first part (411) located on the airtightness detection area (112). The second conductive structure (42) includes a second part (421) located on the airtightness detection area (112).

4. The MEMS sensor according to claim 3, characterized in that, The first part (411) and the second part (421) are spiral structures that are intertwined with each other.

5. The MEMS sensor according to claim 1, characterized in that, The airtightness testing area (112) is arranged around the working area (111). The first conductive structure (41) includes a first part (411), and the second conductive structure (42) includes a second part (421). The first part (411) is located in the airtightness testing area (112) and is arranged around the working area (111). The second part (421) is located in the airtightness testing area (112) and is arranged around the first part (411).

6. The MEMS sensor according to claim 5, characterized in that, It also includes multiple detection pads (5), which are located on the substrate (1) outside the accommodating cavity (21). The first conductive structure (41) includes a third part (412) connected to the first part (411), and the second conductive structure (42) includes a fourth part (422) connected to the second part (421). The third part (412) and the fourth part (422) both extend outside the accommodating cavity (21) and are fixedly connected to the corresponding detection pads (5).

7. The MEMS sensor according to any one of claims 1 to 6, characterized in that, Both the first conductive structure (41) and the second conductive structure (42) are metal leads.

8. The MEMS sensor according to claim 1, characterized in that, The MEMS sensitive structure (3) is an inertial sensor structure.

9. The MEMS sensor according to claim 8, characterized in that, It also includes a substrate electrode (6), a signal lead (7) and a signal pad (8). The MEMS sensitive structure (3) is electrically connected to the substrate electrode (6), and the substrate electrode (6) is electrically connected to the corresponding signal lead (7). The signal lead (7) extends outside the accommodating cavity (21) and is fixedly connected to the corresponding signal pad (8).

10. The MEMS sensor according to claim 9, characterized in that, The signal lead (7), the first conductive structure (41), and the second conductive structure (42) are arranged in the same layer.

11. A MEMS sensor wafer, characterized in that, The array includes the MEMS sensor as described in any one of claims 1 to 10.

12. A detection system for detecting the hermeticity of the MEMS sensor wafer of claim 11, characterized in that, include: The housing includes a detection chamber for housing the wafer and is capable of providing preset environmental conditions for the detection chamber; A detection device is used to acquire current signals between the first conductive structure and the second conductive structure of each MEMS sensor in the wafer under different preset environmental conditions. The signal processing module is used to obtain the airtightness detection result of the corresponding MEMS sensor based on the current signal.

13. A detection method for detecting the hermeticity of a MEMS sensor wafer according to claim 11, characterized in that, include: Under a first environmental condition, a first current signal between the first conductive structure and the second conductive structure of each MEMS sensor is detected; Under a second environmental condition, a second current signal is detected between the first conductive structure and the second conductive structure of each MEMS sensor. For each of the aforementioned MEMS sensors, the airtightness detection result is obtained based on the corresponding first current signal and second current signal.

14. The detection method according to claim 13, characterized in that, The first environmental condition includes a first humidity value, the second environmental condition includes a second humidity value, and the first humidity value is less than the second humidity value.

15. The detection method according to claim 14, characterized in that, The step of obtaining the airtightness detection result for each of the MEMS sensors based on the corresponding first current signal and second current signal includes: When the current value of the first current signal is less than the current value of the second current signal, and the difference between the current value of the second current signal and the current value of the first current signal is greater than the current threshold, the airtightness detection result is abnormal.

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