Method of releasing a mems sensor and its sensitive structure

Abstract

This invention provides a MEMS sensor and a method for releasing its sensitive structures. The sensor encapsulates multiple unreleased MEMS sensitive structures. Each unreleased MEMS sensitive structure includes a cantilever beam, a heating electrode and a readout electrode fixed to the cantilever beam, and a mass block suspended on the cantilever beam. The first end of the mass block is connected to the electrode connector of the readout electrode, and the second end of the mass block is rigidly connected to the electrode connector of the heating electrode via a thermally sublimated adhesive droplet. When the sensor is needed, the unreleased MEMS sensitive structures are released. The system continuously monitors whether the released MEMS sensitive structures have failed; if they fail, another unreleased MEMS sensitive structure is selected for release. By encapsulating multiple unreleased MEMS sensitive structures on the sensor and releasing them only when needed, the sensor's shock resistance is enhanced, thus avoiding the simultaneous failure of all MEMS sensitive structures.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a MEMS (Micro-Electro-Mechanical System) sensor and a method for releasing its sensitive structure. Background Technology

[0002] With the development of MEMS technology, sensors based on MEMS processes have also developed rapidly. Most MEMS sensors have internal structures such as movable combs, hinges, and cantilever beams. The fabrication process often employs wet or dry etching processes to remove the sacrificial layer, thus releasing the structure. However, the released structure is often quite fragile and easily broken by external vibrations and impacts.

[0003] Structural fracture is the primary cause of MEMS sensor failure. Besides accidental fractures due to structural manufacturing defects, accelerated overload is the main trigger for structural fractures. Currently, in the design process of MEMS sensors, multiple repeating MEMS sensing structures are used to form redundant structures, thereby strengthening structural rigidity and improving their overload resistance.

[0004] However, current MEMS sensors release the MEMS sensitive structure in advance during the chip manufacturing process. After the MEMS sensor is packaged, its ability to withstand external acceleration impact cannot be changed. Moreover, when multiple MEMS sensitive structures are highly consistent, acceleration overload may cause multiple MEMS sensor sensitive structures to fail simultaneously, thus preventing the redundant structure from playing its due role. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a method for releasing a MEMS sensor and its sensitive structure to solve the problem that premature release of the existing MEMS sensitive structure leads to the MEMS sensitive structure being unable to function properly when the MEMS sensor is damaged or fails.

[0006] To address the above problems, embodiments of the present invention provide the following technical solutions:

[0007] The first aspect of this invention discloses a method for releasing a sensitive structure of a MEMS sensor. The MEMS sensor has multiple unreleased MEMS sensitive structures encapsulated on it. Each unreleased MEMS sensitive structure includes a cantilever beam, a heating electrode and a readout electrode fixed to the cantilever beam, and a mass block suspended on the cantilever beam. A first end of the mass block is connected to the electrode connector of the readout electrode, and a second end of the mass block is rigidly connected to the electrode connector of the heating electrode via a thermal sublimation adhesive droplet. The method includes:

[0008] When using the MEMS sensor, select an unreleased MEMS sensitive structure, perform a release operation, and obtain a released MEMS sensitive structure.

[0009] Real-time detection of whether the currently released MEMS sensitive structure has failed.

[0010] If the currently released MEMS sensitive structure fails, select another unreleased MEMS sensitive structure, perform the release operation, and obtain a new released MEMS sensitive structure.

[0011] The release operation includes:

[0012] A current is applied to the heating electrode on the currently selected unreleased MEMS sensitive structure. The heating electrode heats the thermal sublimation droplet connected to the second end of the mass block, causing the thermal sublimation droplet to sublimate and release the unreleased MEMS sensitive structure, thus obtaining a released MEMS sensitive structure.

[0013] Optionally, the real-time detection of whether the currently released MEMS sensitive structure has failed includes:

[0014] The resistance of the readout electrode on the currently released MEMS sensitive structure is measured in real time. When the resistance of the readout electrode is greater than or equal to a threshold, the currently released MEMS sensitive structure is determined to be faulty.

[0015] Optionally, during the encapsulation of the MEMS sensor, the heating electrode is prepared by silicon doping or metal sputtering, and the relationship between the heating temperature of the heating electrode and the current or voltage applied to the heating electrode is calibrated.

[0016] Optionally, during the encapsulation of the MEMS sensor, a thermally sublimated material dissolved in an organic solvent is sprayed using a piezoelectric inkjet printing process onto a designated position between the second end of the mass block and the electrode connector of the heating electrode.

[0017] Optionally, during the encapsulation of the MEMS sensor, a doped resistor or a metal wire is prepared on the silicon wafer surface to penetrate the MEMS sensitive structure, and the wire is used as a readout electrode.

[0018] Optionally, it also includes heating the thermally sublimated droplets on the unreleased MEMS sensitive structure using laser focusing or arc discharge.

[0019] A second aspect of the present invention discloses a MESM sensor, wherein the MESM sensor is encapsulated with a plurality of unreleased MEMS sensitive structures.

[0020] The MEMS sensing structure includes a cantilever beam, a heating electrode and a readout electrode fixed on the cantilever beam, and a mass block suspended on the cantilever beam.

[0021] The first end of the mass block is connected to the electrode connector of the readout electrode, and the second end of the mass block is rigidly connected to the electrode connector of the heating electrode via a thermal sublimation droplet.

[0022] During the use of the MEMS sensor, the unreleased MEMS sensitive structure in the MEMS sensor is released based on the MESM sensor sensitive structure release method disclosed in the first aspect of the present invention.

[0023] Optionally, the heating electrode includes a platinum heating electrode, which is prepared according to a silicon doping process or a metal sputtering process.

[0024] The relationship between the heating temperature of the platinum heating electrode and the current or voltage on the platinum heating electrode is calibrated during the preparation process.

[0025] Optionally, the sublimation droplets are prepared from a sublimation material dissolved in an organic solvent.

[0026] The organic solvent includes acetone; the thermal sublimation material includes polymethyl methacrylate.

[0027] Optionally, the readout electrode is composed of a doped resistor formed on the silicon wafer surface that runs through the MEMS sensitive structure, or a corresponding wire formed by sputtering and depositing metal.

[0028] Based on the MESM sensor sensitive structure release method provided in the above embodiments of the present invention, the MEMS sensor is encapsulated with multiple unreleased MEMS sensitive structures. Each unreleased MEMS sensitive structure includes a cantilever beam, a heating electrode and a readout electrode fixed to the cantilever beam, and a mass block suspended on the cantilever beam. A first end of the mass block is connected to the electrode connector of the readout electrode, and a second end of the mass block is rigidly connected to the electrode connector of the heating electrode via a thermal sublimation adhesive droplet. The method includes: when using the MEMS sensor, selecting one unreleased MEMS sensitive structure and executing... A release operation is performed to obtain a released MEMS sensitive structure. Then, the failure of the currently released MEMS sensitive structure is detected in real time. If the currently released MEMS sensitive structure fails, another unreleased MEMS sensitive structure is selected, and a release operation is performed to obtain a new released MEMS sensitive structure. The release operation includes: applying current to the heating electrode on the currently selected unreleased MEMS sensitive structure; the heating electrode heats a sublimation droplet connected to the second end of the mass block, causing the sublimation droplet to sublimate and release the unreleased MEMS sensitive structure, thus obtaining a released MEMS sensitive structure. In this embodiment of the invention, when using a MEMS sensor encapsulated with multiple unreleased MEMS sensitive structures, one MEMS sensitive structure is released first. When the released MEMS sensitive structure fails, the remaining unreleased MEMS sensitive structures are released as needed. This avoids the problem of acceleration overload or simultaneous damage and failure of multiple MEMS sensor sensitive structures, which would prevent the redundant structure from functioning properly. This achieves self-repair of the MEMS sensor and ensures its normal operation. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of a MESM sensor provided in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of a structure of a non-released MESM-sensitive structure;

[0032] Figure 3 This is a magnified view of a partially released MESM-sensitive structure.

[0033] Figure 4A flowchart illustrating a method for releasing the sensitive structure of a MESM sensor, provided as an embodiment of the present invention;

[0034] Figure 5 According to Figure 4 A schematic diagram of a structure for releasing MESM-sensitive structures;

[0035] Figure 6 According to Figure 4 A magnified view of a portion of the realized MESM-sensitive structure;

[0036] Figure 7 According to Figure 4 A flowchart illustrating the release of a sensitive structure in a MESM sensor. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0039] Secondly, the present invention will be described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure will be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0040] Regarding the problems with the sensitive structure of MEMS sensors mentioned in the background technology, namely that the sensitive structure of current MEMS sensors is released during the chip manufacturing process, and after the MEMS sensor is packaged, its ability to withstand external acceleration impact becomes a fixed value that cannot be changed, even if multiple redundant MEMS sensitive structures are set to form a redundant structure, if the consistency of multiple MEMS sensitive structures is high, acceleration overload will still cause multiple MEMS sensor sensitive structures to be damaged or fail simultaneously, thus preventing the redundant structure from playing its due role.

[0041] Therefore, this invention provides a method for releasing a MEMS sensor and its sensitive structure, ensuring that the sensitive structure remains in an unreleased state after packaging, and is released only when needed. This avoids the problem of acceleration overload or simultaneous damage and failure of multiple MEMS sensor sensitive structures, preventing the redundant structure from functioning properly. Detailed explanation is provided below.

[0042] like Figure 1 As shown, this embodiment of the invention provides a MEMS sensor, which has multiple unreleased MEMS sensitive structures encapsulated on it.

[0043] That is, at least two unreleased MEMS sensitive structures are encapsulated on the MEMS sensor.

[0044] Specifically, the number of unreleased MEMS sensitive structures can be set according to the requirements of different systems for MEMS sensors.

[0045] like Figure 2 As shown, each of the unreleased MEMS sensitive structures includes a cantilever beam 1, a readout electrode 2, a heating electrode 3, and a mass block 4.

[0046] The cantilever beam 1, the readout electrode 2, the heating electrode 3, and the mass block 4 are all fabricated on a silicon wafer.

[0047] The cantilever beam 1 has a first end and a second end, which are opposite ends.

[0048] The first end of the cantilever beam 1 is fixed with a readout electrode 2, and the electrode connector of the readout electrode 2 is connected to the first end of the mass block 4.

[0049] In one embodiment of the present invention, the readout electrode 2 is formed by fabricating a doped resistor through the MEMS sensitive structure on the surface of a silicon wafer or by making a wire by sputtering deposited metal.

[0050] That is, the readout electrode 2 can be a doped resistor or a metal wire.

[0051] By observing the indicator signal of the readout electrode, such as a change in resistance, it is possible to determine whether the MEMS sensitive structure is damaged or malfunctioning.

[0052] A heating electrode 3 is fixed to the second end of the cantilever beam 1. The electrode connector of the heating electrode 3 is rigidly connected to the second end of the mass block 4 by dripping a heating sublimation adhesive drop 5.

[0053] The thermally sublimated droplet 5 keeps the MEMS sensitive structure in an unreleased state; however, by heating the heating electrode 3 to a certain temperature, the thermally sublimated droplet 5 can be sublimated, thereby releasing the unreleased MEMS sensitive structure.

[0054] In one embodiment of the present invention, the heating electrode 3 may be a platinum heating electrode or a titanium heating electrode. The platinum heating electrode or titanium heating electrode is prepared by silicon doping process or metal sputtering process during the packaging of the MEMS sensor, and the relationship between the heating temperature of the platinum heating electrode or titanium heating electrode and the current or voltage applied thereon is calibrated so that after the MEMS sensor is packaged, the platinum heating electrode or titanium heating electrode can be heated to a preset temperature by applying a certain amount of current or voltage to the platinum heating electrode or titanium heating electrode.

[0055] The mass block 4 is suspended on the cantilever beam 1 through its connection with the readout electrode 2 and the heating electrode 3.

[0056] The mass block 4 has a certain weight, which can be used to improve the sensitivity of the MEMS sensor's sensitive structure to external acceleration, thereby generating a large displacement when an external acceleration impact is applied, and realizing the simulation of MEMS sensor failure in a vibration environment.

[0057] In addition, to improve the working performance of the MEMS sensor's sensitive structure, an array of damping holes can be provided on the mass block 4 to improve the dynamic frequency characteristics of the MEMS sensor's sensitive structure. At the same time, it can also attenuate some stray free vibrations, reduce noise, and improve measurement accuracy.

[0058] In the embodiments provided by this invention, an unreleased MEMS sensitive structure is encapsulated on the MEMS sensor. Each unreleased structure is kept in an unreleased state by dripping a heated sublimation adhesive droplet 5 between the second end of the mass block 4 and the electrode connector of the heating electrode 3. When needed, the MEMS sensitive structure can be released simply by heating the heating electrode 3 of any unreleased MEMS sensitive structure, thereby causing the heated sublimation adhesive droplet 5 to sublimate. This eliminates the need to release the MEMS sensitive structure during the manufacturing process of the MEMS sensor, greatly enhancing the impact resistance of the MEMS sensor and avoiding the problem of multiple MEMS sensor sensitive structures being damaged and failing simultaneously due to external acceleration overload, thus preventing the redundant structure from playing its due role.

[0059] In one embodiment of the present invention, the sublimation adhesive droplets are added during the encapsulation of the MEMS sensor. Specifically, the sublimation material dissolved in an organic solvent is sprayed using a piezoelectric inkjet printing process onto a designated position between the second end of the mass block 4 and the electrode connector of the heating electrode 3. After the organic solvent evaporates, the sublimation material becomes solid, thereby achieving a rigid connection between the mass block 4 and the electrode connector of the heating electrode 3. At this time, the situation between the electrode connector of the heating electrode 3 and the second end of the mass block 4 is as follows: Figure 3 As shown.

[0060] The organic solvent can be acetone; the thermal sublimation material can be polymethyl methacrylate (PMMA). Specifically, by prepolymerizing the MMA before droplet addition, the material is dropped onto a designated position between the second end of the mass block 4 and the electrode connector of the heating electrode 3, and then completely polymerized to become PMMA, thereby completing the droplet addition of the thermal sublimation adhesive droplet 5 to achieve a rigid connection between the second end of the mass block 4 and the heating electrode 3.

[0061] It should be noted that the sublimation droplet 5 does not undergo sublimation within the operating temperature range of the MEMS sensor; it only sublimates when the heating electrode 3 is heated to a certain temperature. After the sublimation droplet 5 sublimates, the mass block 4 is disconnected from the heating electrode 3. Acetone is used as the organic solvent, and polymethyl methacrylate is used as the sublimation material. The sublimation droplet 5 can be sublimated when the electrode junction temperature of the heating electrode 3 reaches 300°C.

[0062] In the embodiments provided by this invention, the MEMS sensitive structure is kept in an unreleased state by dropping a heated sublimation adhesive droplet 5 at a designated position between the second end of the mass block 4 and the electrode connector of the heating electrode 3. Compared to a MEMS sensitive structure that is released during manufacturing, the unreleased MEMS sensitive structure has stronger impact resistance, and is therefore less likely to be damaged or fail when subjected to external impacts.

[0063] Based on the MEMS sensor provided in the above embodiments, combined with Figure 2 The sensitive structure of the MEMS sensor shown is as follows: Figure 4 As shown, this embodiment of the invention also provides a method for releasing the sensitive structure of a MEMS sensor, used to release the MEMS sensitive structure packaged on the MEMS sensor.

[0064] Specifically, when the MEMS sensor needs to be used, releasing the unreleased sensitive structure encapsulated on the MEMS sensor includes the following steps:

[0065] S11: Select an unreleased MEMS sensitive structure and execute S12-S13.

[0066] Steps S12-S13 are release operations.

[0067] The selected unreleased MEMS sensing structure can be any unreleased MEMS sensing structure encapsulated in the MEMS sensor.

[0068] S12: Apply a certain current or voltage to the heating electrode of the currently selected unreleased MEMS sensitive structure to heat the heating electrode.

[0069] The heating electrode has been calibrated during its fabrication process to establish the relationship between its heating temperature and the current or voltage applied to it. To heat the heating electrode to a predetermined temperature, simply apply the corresponding voltage or current to the heating electrode according to the calibrated relationship between its heating temperature and the current or voltage applied to it, and the heating electrode will reach the predetermined temperature.

[0070] S13: The sublimation droplet is heated by the heated electrode to sublimate the droplet and obtain the MEMS sensitive structure.

[0071] The released MEMS sensitive structure, such as Figure 5 As shown.

[0072] Depend on Figure 3 It is understood that the sublimation droplet 5 is placed between the electrode connector of the heating electrode 3 and the second end of the mass block 4. The sublimation droplet 5 is in contact with the electrode connector of the heating electrode 3. When the heating electrode 3 is heated, the sublimation droplet 5 is heated through the electrode connector of the heating electrode 3. When the temperature of the electrode connector of the heating electrode 3 reaches the sublimation temperature of the sublimation droplet 5, the sublimation droplet 5 sublimates. After the sublimation droplet 5 sublimates, the connection between the electrode connector of the heating electrode 3 and the second end of the mass block 4 is broken, that is, the electrode connector of the heating electrode 3 and the second end of the mass block 4 are no longer in contact. At this time, the situation between the electrode connector of the heating electrode 3 and the second end of the mass block 4 is as follows. Figure 6 As shown.

[0073] In one embodiment of the present invention, the heating method of the thermal sublimation droplet can also be: using laser focusing or arc discharge to heat the thermal sublimation droplet on the currently selected unreleased MEMS sensitive structure to the sublimation temperature of the thermal sublimation droplet, so that the thermal sublimation droplet sublimates and thereby releases the currently selected unreleased MEMS sensitive structure.

[0074] S14: Real-time detection of whether the currently released MEMS sensitive structure has failed.

[0075] If the currently released MEMS sensitive structure is subjected to excessive external impact before release, the released MEMS sensitive structure may be damaged or malfunction.

[0076] Alternatively, if the currently released MEMS sensitive structure is subjected to excessive external impact after being obtained, exceeding the withstand capacity of the currently released MEMS sensitive structure, the currently released MEMS sensitive structure will also be damaged or fail.

[0077] Specifically, when the external impact is too great, the acceleration of the mass block of the currently released MEMS sensitive structure is too great, causing irreversible damage or breakage to the readout electrode connected to it, which in turn causes the resistance of the readout electrode to be greater than or equal to the threshold.

[0078] In one embodiment of the present invention, when the resistance of the readout electrode is greater than 1KΩ, it can be determined that the current released MEMS sensitive structure is damaged or failed.

[0079] The peripheral circuit can use an ADC or a resistor divider structure in conjunction with a voltage comparator to read the resistance value of the readout electrode of the currently released MEMS sensitive structure.

[0080] Of course, in addition to the resistance value of the readout electrode, the indicator signal for real-time detection of whether the currently released MEMS sensitive structure has failed can also be: changes in capacitance value, changes in oscillation frequency, self-test failure, etc.

[0081] Therefore, by reading the indication signal of the readout electrode in real time through peripheral circuitry, failure of the currently released MEMS sensitive structure can be detected promptly, thus achieving effective verification of the currently released MEMS sensitive structure. This also achieves effective verification of the subsequently released MEMS sensitive structure.

[0082] The following section will explain the release of four unreleased MEMS sensing structures encapsulated on a MEMS sensor.

[0083] Specifically, one of the four unreleased MEMS sensitive structures is selected, and a certain current or voltage is applied to the heating electrode of the currently selected unreleased MEMS sensitive structure to heat the heating electrode. Since the thermal sublimation droplet is located between the electrode connector of the heating electrode and the second end of the mass block, when the temperature of the heating electrode reaches the sublimation temperature of the thermal sublimation droplet, the thermal sublimation droplet will sublimate, thereby obtaining the first released MEMS sensitive structure.

[0084] The first released MEMS sensitive structure is monitored in real time. If the first released MEMS sensitive structure remains active, no new unreleased MEMS sensitive structure is selected for release. If the first released MEMS sensitive structure is detected to be faulty, one of the remaining three unreleased MEMS sensitive structures is selected for release. Similarly, the release steps are the same as those for the first unreleased MEMS sensitive structure, i.e., a certain current or voltage is applied to the heating electrode of the currently selected unreleased MEMS sensitive structure to heat the heating electrode, causing the thermal sublimation droplet located at a designated position between the electrode connector of the heating electrode and the second end of the mass block to sublimate, thereby obtaining the second released MEMS sensitive structure.

[0085] Similarly, the second released MEMS sensitive structure is monitored in real time. If the second released MEMS sensitive structure remains active, no new unreleased MEMS sensitive structure is selected for release. If the second released MEMS sensitive structure is detected to be ineffective, one of the remaining two unreleased MEMS sensitive structures is selected for release. The release method is still to apply a certain current or voltage to the heating electrode of the currently selected unreleased MEMS sensitive structure to heat the heating electrode, causing the thermal sublimation droplet located at a designated position between the electrode connector of the heating electrode and the second end of the mass block to sublimate, thereby obtaining the third released MEMS sensitive structure.

[0086] The third released MEMS sensitive structure is monitored in real time. If the third released MEMS sensitive structure remains active, no new unreleased MEMS sensitive structures are selected for release. If the third released MEMS sensitive structure fails, the last unreleased MEMS sensitive structure is released, resulting in the fourth released MEMS sensitive structure. This fourth released MEMS sensitive structure is also monitored in real time. If the fourth released MEMS sensitive structure remains active, no new unreleased MEMS sensitive structures are selected for release. If the fourth released MEMS sensitive structure fails, the MEMS sensor is considered completely disabled. Through on-demand release and real-time monitoring of the MEMS sensor's sensitive structures, self-healing of the MEMS sensor is achieved.

[0087] In one embodiment of the present invention, such as Figure 7As shown, the MEMS sensor is in use. At this time, the MEMS sensor includes one released unit (in use) and multiple unreleased units (no output but shock resistant). One released unit represents a released MEMS sensitive structure, which is the released MEMS sensitive structure that the MEMS sensor is currently using; one unreleased unit represents an unreleased MEMS sensitive structure, which is not in use and is in a state of no output but shock resistant.

[0088] When a MEMS sensor is subjected to an external impact, if the released unit fails, the MEMS sensor will then include one failed unit and multiple unreleased units.

[0089] At this point, the peripheral circuit promptly detects that the indicator signal of the readout electrode of the released unit exceeds the threshold, indicating its failure. It then selects one of the multiple unreleased units to release, resulting in the currently released unit. The MEMS sensor then uses this released unit for operation. At this stage, the sensor includes one failed unit, one currently released unit, and multiple unreleased units. Similarly, if the currently released unit fails due to an external impact, it becomes the failed unit, prompting the release of another unreleased unit to ensure that the MEMS sensor has at least one released and usable unit. This process continues until all units in the MEMS sensor become failed under external impact, at which point the MEMS sensor will completely fail.

[0090] In the embodiments provided by the present invention, when the MEMS sensor is subjected to external impact, if the released unit in use fails, the system can read the indication signal of the readout electrode of the released unit through the peripheral circuit, and can promptly detect the failure of the currently used released unit, and then release a new unit as needed to ensure the normal operation of the MEMS sensor. This effectively avoids the situation where all MEMS sensitive structures fail at the same time, causing the entire MEMS sensor to fail.

[0091] It should be noted that, in the description of this application, the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0092] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0093] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of releasing a MEMS sensor sensitive structure, characterized by, The MEMS sensor encapsulates multiple unreleased MEMS sensing structures, each including a cantilever beam, a heating electrode and a readout electrode fixed to the cantilever beam, and a mass block suspended on the cantilever beam. A first end of the mass block is connected to the electrode connector of the readout electrode, and a second end of the mass block is rigidly connected to the electrode connector of the heating electrode via a thermal sublimation adhesive droplet. The method includes: When using the MEMS sensor, select an unreleased MEMS sensitive structure, perform a release operation, and obtain a released MEMS sensitive structure. Real-time detection of whether the currently released MEMS sensitive structure has failed; If the currently released MEMS sensitive structure fails, select another unreleased MEMS sensitive structure, perform the release operation, and obtain a new released MEMS sensitive structure. The release operation includes: A current is applied to the heating electrode on the currently selected unreleased MEMS sensitive structure. The heating electrode heats the thermal sublimation droplet connected to the second end of the mass block, causing the thermal sublimation droplet to sublimate and release the unreleased MEMS sensitive structure, thus obtaining a released MEMS sensitive structure.

2. The method of claim 1, wherein, The real-time detection of whether the currently released MEMS sensitive structure has failed includes: The resistance of the readout electrode on the currently released MEMS sensitive structure is measured in real time. When the resistance of the readout electrode is greater than or equal to a threshold, the currently released MEMS sensitive structure is determined to be faulty.

3. The method according to claim 1, characterized in that, During the packaging of the MEMS sensor, the heating electrode is prepared by silicon doping or metal sputtering, and the relationship between the heating temperature of the heating electrode and the current or voltage applied to the heating electrode is calibrated.

4. The method according to claim 1, characterized in that, During the encapsulation of the MEMS sensor, a thermally sublimated material dissolved in an organic solvent is sprayed using a piezoelectric inkjet printing process onto a designated position between the second end of the mass block and the electrode connector of the heating electrode.

5. The method according to claim 1, characterized in that, During the encapsulation of the MEMS sensor, a doped resistor or a metal wire is fabricated on the silicon wafer surface to penetrate the MEMS sensitive structure, and the wire is used as a readout electrode.

6. The method according to any one of claims 1 to 5, characterized in that, Also includes: The sublimation droplets on the unreleased MEMS sensitive structure are heated using laser focusing or electric arc discharge.

7. A MEMS sensor, characterized in that, The MEMS sensor is packaged with multiple unreleased MEMS sensing structures; The MEMS sensing structure includes a cantilever beam, a heating electrode and a readout electrode fixed on the cantilever beam, and a mass block suspended on the cantilever beam. The first end of the mass block is connected to the electrode connector of the readout electrode, and the second end of the mass block is rigidly connected to the electrode connector of the heating electrode through a thermal sublimation droplet. During the use of the MEMS sensor, the unreleased MEMS sensitive structure in the MEMS sensor is released based on the release method of the MEMS sensor sensitive structure according to any one of claims 1 to 5.

8. The MEMS sensor according to claim 7, characterized in that, The heating electrode includes a platinum heating electrode, which is prepared by silicon doping or metal sputtering process. The relationship between the heating temperature of the platinum heating electrode and the current or voltage on the platinum heating electrode is calibrated during the preparation process.

9. The MEMS sensor according to claim 7, characterized in that, The sublimation droplets are prepared from a sublimation material dissolved in an organic solvent; The organic solvent includes acetone; the thermal sublimation material includes polymethyl methacrylate.

10. The MEMS sensor according to claim 7, characterized in that, The readout electrode is composed of a doped resistor or a wire formed by sputtering and depositing metal to penetrate the MEMS sensitive structure on the silicon wafer surface.

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