MEMS accelerometer life evaluation method, device and equipment

Abstract

The invention provides an MEMS accelerometer life evaluation method, device and equipment, and relates to the field of MEMS accelerometers. According to the method, core stress is applied in a stepping mode, all performance parameters are monitored, and a core stress limit range is obtained; in a core stress limit range, constructing a core stress combination test scheme, and carrying out a constant acceleration life test on the MEMS accelerometer; analyzing the performance parameter degradation amount according to the constant acceleration life test data and the performance parameter degradation model to obtain pseudo life estimation values of the plurality of performance parameters under different stress levels; and establishing a multi-stress accelerated life evaluation model among the MEMS accelerometer, temperature, impact, electric stress and working time according to the core stress of the MEMS accelerometer based on the pseudo life estimation values of the plurality of performance parameters under different stress levels. The problem that the reliability life cannot be accurately evaluated due to the fact that the life evaluation of the existing MEMS accelerometer is generally assessed based on an accelerated life test of a single stress and a single failure mode is solved.

Description

Technical Field

[0001] This document relates to the field of MEMS accelerometers, and in particular to a method, device and equipment for evaluating the life of a MEMS accelerometer. Background Art

[0002] Due to the complexity of the working principle and structure of the Micro-Electro-Mechanical System (MEMS) accelerometer, its reliability problem limits the industrial development of the product. MEMS accelerometer can measure acceleration and is mainly used in the fields of aviation, aerospace and military industry. For semiconductor integrated circuits, temperature and electrical stress are important factors that induce device failure, so these stresses are often used for life tests. However, for MEMS accelerometers, the structure is complex and has a movable mechanical structure. In actual use, it is often accompanied by complex stresses such as high temperature, high impact, and overload, causing microstructural fractures, performance parameters (such as zero bias, temperature drift, bias stability) out of tolerance, fractures and pull-in caused by electrical stress, etc. At present, the life assessment of MEMS accelerometers is mostly carried out through accelerated life tests based on a single stress and a single failure mode, and it is impossible to accurately assess the reliability life.

[0003] Therefore, a life assessment method is urgently needed to solve the problem that the existing MEMS accelerometer life assessment is usually based on accelerated life tests with a single stress and a single failure mode, and cannot accurately assess the reliability life. Summary of the invention

[0004] This specification provides a MEMS accelerometer life assessment method, device and equipment, which are used to solve the problem that the existing MEMS accelerometer life assessment is usually based on accelerated life testing with a single stress and a single failure mode, and cannot accurately assess the reliability life.

[0005] In a first aspect, this specification provides a method for evaluating the life of a MEMS accelerometer, comprising:

[0006] According to the application environment and working conditions, the core stress is applied step by step, various performance parameters are monitored, the main failure modes and weak links are determined, and the core stress limit range is obtained; wherein the performance parameters include zero bias, scale factor, nonlinearity, and frequency response;

[0007] Within the core stress limit range, a core stress combination test plan is constructed, and based on the given reliability and confidence, the number of test samples and the number of failures of the constant accelerated life are determined, and a constant accelerated life test is performed on the MEMS accelerometer;

[0008] Based on the constant acceleration life test data, the variation law of performance parameters over time is obtained, and the performance parameter degradation amount is analyzed according to the performance parameter degradation model, and the pseudo-lifetime estimation values ​​of the performance parameters of multiple MEMS accelerometers under different stress levels are obtained;

[0009] Based on the pseudo-lifetime estimation values ​​of the performance parameters of multiple MEMS accelerometers under different stress levels and according to the core stress of the MEMS accelerometer, a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time is established.

[0010] Optionally, the core stress is applied step by step based on a preset strengthening test scheme, the zero bias, scaling factor, nonlinearity, and frequency response performance parameters are monitored, the main failure modes and weak links are determined, and the core stress limit range is obtained, including:

[0011] According to the application environment and working conditions, based on the enhanced test plan, step high temperature test, step electrical stress test and step impact test are adopted, and performance test comparison and failure analysis are carried out after the test;

[0012] According to the strengthening test results, the core stresses affecting the MEMS accelerometer are clearly identified, and the limit range and main failure modes of the core stress are obtained.

[0013] Optionally, the core stress includes: temperature, impact, and electrical stress.

[0014] Optionally, the core stress combination test scheme includes: constant acceleration test under the same temperature stress, different impacts and electrical stresses; constant acceleration test under the same impact stress, different temperatures and electrical stresses; constant acceleration test under the same electrical stress, different temperatures and impact stresses; multiple groups of constant acceleration test schemes under different electrical stresses and the same temperature and impact stress.

[0015] Optionally, for the same stress level, take the minimum pseudo life value of the MEMS accelerometer.

[0016] Optionally, the performance parameter degradation model includes: a linear parameter regression model, specifically:

[0017] f(t)=f(0)+bt+δ (1)

[0018] Where f(t) is the test value of the performance parameter, f(0) is the initial value of the performance parameter, b is the degradation model parameter, and δ is the model error.

[0019] Optionally, the multi-stress accelerated life evaluation model includes:

[0020]

[0021] Where t is the average life, f(F) is the relative impact force function, gI) is the inverse power law model function, g(I) = C·I -D ; Among them, A, B, C, D, E, G are unknown constants, k is the Boltzmann constant, parameter T represents temperature stress, F represents impact force, and I represents electrical stress.

[0022] Optionally, the main failure modes include degradation of key parameters such as zero bias, scale factor, nonlinearity, frequency response, wire bonding failure, pull-in short circuit, sensitive structure fracture, mechanical defects such as cracks, and degradation of sealing performance;

[0023] The application environment includes: temperature, humidity, electrical stress, vibration shock and magnetic field.

[0024] In a second aspect, the present specification provides a MEMS accelerometer life assessment device, including: a core stress limit range determination module, a constant acceleration life test module, a pseudo life estimation value determination module, and a multi-stress accelerated life assessment model construction module, wherein:

[0025] The core stress limit range determination module is used to apply the core stress step by step according to the application environment and working conditions, monitor various performance parameters, determine the main failure mode and weak links, and obtain the core stress limit range; wherein the performance parameters include zero bias, scale factor, nonlinearity, and frequency response;

[0026] The constant acceleration life test module is used to construct a core stress combination test plan within the core stress limit range, and determine the number of test samples and failures of the constant acceleration life according to the given reliability and confidence level, and perform a constant acceleration life test on the MEMS accelerometer;

[0027] The pseudo-lifetime estimation value determination module is used to obtain the variation law of the performance parameters over time according to the constant acceleration life test data, and analyze the performance parameter degradation amount according to the performance parameter degradation model to obtain the pseudo-lifetime estimation values ​​of the performance parameters of multiple MEMS accelerometers under different stress levels;

[0028] The multi-stress accelerated life evaluation model building module is used to establish a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time based on the pseudo-life estimation values ​​of the performance parameters of the multiple MEMS accelerometers under the different stress levels and according to the MEMS accelerometer core stress.

[0029] In a third aspect, this specification also provides an electronic device, including: a communication interface, a processor, and a memory;

[0030] The processor calls the program instructions in the memory to perform the following actions:

[0031] According to the application environment and working conditions, the core stress is applied step by step, various performance parameters are monitored, the main failure modes and weak links are determined, and the core stress limit range is obtained; wherein the performance parameters include zero bias, scale factor, nonlinearity, and frequency response;

[0032] Within the core stress limit range, a core stress combination test plan is constructed, and based on the given reliability and confidence, the number of test samples and the number of failures of the constant accelerated life are determined, and a constant accelerated life test is performed on the MEMS accelerometer;

[0033] Based on the constant acceleration life test data, the variation law of performance parameters over time is obtained, and the performance parameter degradation amount is analyzed according to the performance parameter degradation model, and the pseudo-lifetime estimation values ​​of the performance parameters of multiple MEMS accelerometers under different stress levels are obtained;

[0034] Based on the pseudo-lifetime estimation values ​​of the performance parameters of multiple MEMS accelerometers under different stress levels and according to the core stress of the MEMS accelerometer, a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time is established.

[0035] The beneficial effects of the present invention are as follows:

[0036] This specification provides a method, device and equipment for evaluating the life of a MEMS accelerometer. The method applies core stress stepwise, monitors various performance parameters, and obtains the core stress limit range; within the core stress limit range, a core stress combination test scheme is constructed to perform a constant acceleration life test on the MEMS accelerometer; the performance parameter degradation amount is analyzed according to the constant acceleration life test data and the performance parameter degradation model to obtain pseudo life estimates of multiple performance parameters under different stress levels; based on the pseudo life estimates of multiple performance parameters under different stress levels, according to the core stress of the MEMS accelerometer, a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time is established. This method combines the actual application environment of the device, proposes to couple multiple stresses such as temperature, vibration shock, and electrical stress together, and conducts an accelerated life test of the MEMS accelerometer. The principle that the failure mechanism of the accelerometer remains unchanged under normal stress and accelerated stress levels is used to realize the life evaluation of the MEMS accelerometer, which can greatly shorten the time required for normal stress life test. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of this specification and constitute a part of this specification. The illustrative embodiments and descriptions of this specification are used to explain this specification and do not constitute an improper limitation on this specification. In the drawings:

[0038] Figure 1 is a schematic diagram of a MEMS accelerometer life assessment method provided in an embodiment of this specification;

[0039] Figure 2 is a schematic diagram of a MEMS accelerometer life assessment device provided in an embodiment of this specification;

[0040] Figure 3 It is a schematic diagram of an electronic device structure provided in an embodiment of this specification. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of this specification clearer, the technical solutions of this application will be clearly and completely described below in conjunction with the specific embodiments of this application and their corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this specification, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this document.

[0042] The technical solutions provided by the embodiments of this specification are described in detail below in conjunction with the accompanying drawings. Specific embodiment one:

[0044] This embodiment provides a method for evaluating the life of a MEMS accelerometer. Figure 1 , specifically including the following steps:

[0045] Step 102: According to the application environment and working conditions, the core stress is applied step by step, various performance parameters are monitored, the main failure modes and weak links are determined, and the core stress limit range is obtained; wherein the performance parameters include zero bias, scaling factor, nonlinearity, and frequency response;

[0046] The core stresses include temperature, impact, and electrical stress.

[0047] Specifically, a specific implementation of step 102 may be:

[0048] S21. According to the application environment and working conditions, based on the enhanced test plan, step high temperature test, step electrical stress test and step impact test are adopted, and performance test comparison and failure analysis are carried out after the test;

[0049] The application environment includes: temperature, humidity, electrical stress, vibration shock and magnetic field.

[0050] S22. According to the strengthening test results, the core stresses affecting the MEMS accelerometer are clearly identified, and the limit range and main failure modes of the core stress are obtained.

[0051] Among them, the main failure modes include degradation of key parameters such as zero bias, scale factor, nonlinearity, frequency response, wire bonding failure, pull-in short circuit, sensitive structure fracture, mechanical defects such as cracks, and degradation of sealing performance;

[0052] Based on this, by determining the limit ranges of multiple core stresses, a scope basis is provided for subsequent combination tests.

[0053] Step 104: construct a core stress combination test plan within the core stress limit range, and determine the number of test samples and the number of failures of the constant accelerated life according to the given reliability and confidence level, and perform a constant accelerated life test on the MEMS accelerometer;

[0054] It should be noted that the core stress combination test scheme includes: constant acceleration test under the same temperature stress, different impacts and electrical stresses; constant acceleration test under the same impact stress, different temperatures and electrical stresses; constant acceleration test under the same electrical stress, different temperatures and impact stresses; and multiple groups of constant acceleration test schemes under different electrical stresses and the same temperature and impact stress.

[0055] Among them, for the same stress level, the minimum pseudo life value of the MEMS accelerometer is taken.

[0056] According to the given reliability R and confidence φ, the method to determine the number of test samples m and the number of failures n of the constant accelerated life is:

[0057]

[0058] in, is the probability coefficient;

[0059] It should be further explained that the constant acceleration life test is conducted within the core stress limit range and based on the core stress combination test scheme, which provides batch test data under the same stress level for subsequent accelerometer life evaluation.

[0060] Step 106: obtaining the variation law of the performance parameters over time according to the constant acceleration life test data, and analyzing the performance parameter degradation amount according to the performance parameter degradation model to obtain the performance parameter pseudo-life estimation values ​​of multiple MEMS accelerometers under different stress levels;

[0061] Wherein, the performance parameter degradation model includes: a linear parameter regression model, see formula (1);

[0062] It should be noted that a suitable mathematical model is selected according to the variation law of the accelerometer test parameters over time, and the mathematical model includes but is not limited to a linear parameter regression model;

[0063] Specifically,

[0064]

[0065] Among them, f(t) i，j，k is the jth accelerometer at the kth time t under the i-th stress i，j，k The obtained parameter values; i = 1, 2, ..., p; j = 1, 2, ..., q i ; k = 1, 2, ..., m ij .

[0066] Then, according to the failure threshold of the performance parameters, the pseudo-lifetime estimation values ​​of the performance parameters of multiple MEMS accelerometer samples under different stress levels are obtained by combining the accelerated life test data with the above two equations. For the same stress level, the minimum pseudo life value of the MEMS accelerometer is taken.

[0067] Step 108: Based on the pseudo-lifetime estimates of the performance parameters of the multiple MEMS accelerometers at the different stress levels and according to the core stress of the MEMS accelerometer, a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time is established.

[0068] Wherein, the multi-stress accelerated life evaluation model is shown in formula (2);

[0069] Specifically, the pseudo life estimates of the performance parameters of the multiple MEMS accelerometers at different stress levels obtained in step 106 are Substituting into formula (2), the specific values ​​of A, B, C, D, E, and G are obtained through approximate estimation, and then the life evaluation model of the MEMS accelerometer under the reliability R and confidence φ is determined. The life evaluation model is a function of temperature stress T, impact force F, and electrical stress I;

[0070] Furthermore, using formula (2), the actual application environment of the MEMS accelerometer is input, including temperature stress T, impact stress F, and electrical stress I, to evaluate the life of the MEMS accelerometer in the current application environment.

[0071] The life assessment method provided in this embodiment is applicable to a variety of MEMS accelerometers, including but not limited to MEMS capacitive accelerometers, MEMS piezoresistive accelerometers, MEMS vacuum packaged accelerometers, etc.

[0072] In summary, this embodiment applies core stress in steps and monitors various performance parameters to obtain the core stress limit range; within the core stress limit range, a core stress combination test scheme is constructed to perform a constant acceleration life test on the MEMS accelerometer; the performance parameter degradation amount is analyzed according to the constant acceleration life test data and the performance parameter degradation model to obtain pseudo life estimates of multiple performance parameters at different stress levels; based on the pseudo life estimates of multiple performance parameters at different stress levels, a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time is established according to the core stress of the MEMS accelerometer. In combination with the actual application environment of the device, this embodiment proposes to couple multiple stresses such as temperature, vibration shock, and electrical stress together to carry out an accelerated life test of the MEMS accelerometer, and utilizes the principle that the failure mechanism of the accelerometer remains unchanged under normal stress and accelerated stress levels to realize the life evaluation of the MEMS accelerometer, which can greatly shorten the time required for the normal stress life test. Specific embodiment 2:

[0074] A method for evaluating the life of a MEMS accelerometer proposed in this embodiment is as follows:

[0075] Step 1. MEMS accelerometer performance test and structural analysis;

[0076] Before the experiment, the performance of all devices was tested and two were selected for structural analysis.

[0077] Step 2. MEMS accelerometer reinforcement test;

[0078] Step 2.1 Design a strengthening test plan based on the application environment and working conditions such as temperature, humidity, electrical stress, vibration shock and magnetic field, and use tests such as step high temperature test, step electrical stress test and step shock test. After the test, perform performance test comparison and failure analysis;

[0079] Step 2.2: Based on the results of the strengthening test, the main environmental stresses that affect the MEMS accelerometer, such as temperature, shock, and electrical stress, are identified, and the limit ranges and main failure modes of these stresses are obtained.

[0080] Step 3. Accelerated life test

[0081] Step 3.1 Design a stress combination test plan within the above limit range, and determine the number of test samples m and the number of failures n of the constant accelerated life according to the given reliability R and confidence φ, and conduct a constant accelerated life test on the MEMS accelerometer;

[0082]

[0083] Step 3.2: Analyze the performance parameter degradation based on the accelerated life test data and the mathematical model to obtain the pseudo life value.

[0084] More specifically, a degradation model is established by selecting a suitable mathematical model (including but not limited to a linear parameter regression model) based on the variation pattern of the accelerometer test parameters over time, such as the performance parameter degradation model established based on the linear parameter regression model in the present invention, see formula (1);

[0085]

[0086] Among them, f(t) i，j，k is the jth accelerometer at the kth time t under the i-th stress i，j，k The obtained parameter values ​​are: i=1,2,...,p;j=1,2,...,q i ; k = 1, 2, ..., m ij .

[0087] Then, according to the failure threshold of the performance parameters, the pseudo-lifetime estimation values ​​of the performance parameters of multiple MEMS accelerometer samples under different stress levels are obtained by combining the accelerated life test data with the above two equations. For the same stress level, the minimum pseudo life value of the MEMS accelerometer is taken.

[0088] Step 4. Establish a multi-stress acceleration model and determine the model parameters

[0089] A multi-stress accelerated life evaluation model between MEMS accelerometer and temperature, shock, electrical stress and working time is established.

[0090] The multi-stress accelerated life evaluation model established in this embodiment is shown in formula (2);

[0091] Where A, B, C, D, E, G are constants to be determined, and k is the Boltzmann constant.

[0092] Finally, the pseudo-lifetime data obtained in step 3 and formula (2) are combined to obtain the accelerated life model of the MEMS accelerometer under the reliability R and confidence φ.

[0093] In summary, this embodiment applies core stress in steps and monitors various performance parameters to obtain the core stress limit range; within the core stress limit range, a core stress combination test scheme is constructed to perform a constant acceleration life test on the MEMS accelerometer; the performance parameter degradation amount is analyzed according to the constant acceleration life test data and the performance parameter degradation model to obtain pseudo life estimates of multiple performance parameters at different stress levels; based on the pseudo life estimates of multiple performance parameters at different stress levels, a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time is established according to the core stress of the MEMS accelerometer. In combination with the actual application environment of the device, this embodiment proposes to couple multiple stresses such as temperature, vibration shock, and electrical stress together to carry out an accelerated life test of the MEMS accelerometer, and utilizes the principle that the failure mechanism of the accelerometer remains unchanged under normal stress and accelerated stress levels to realize the life evaluation of the MEMS accelerometer, which can greatly shorten the time required for the normal stress life test. Specific embodiment three:

[0095] This embodiment provides a MEMS accelerometer life assessment device, see Figure 2 , including: a core stress limit range determination module 201, a constant accelerated life test module 202, a pseudo life estimation value determination module 203, and a multi-stress accelerated life evaluation model construction module 204, wherein:

[0096] The core stress limit range determination module 201 is used to apply the core stress step by step according to the application environment and working conditions, monitor various performance parameters, determine the main failure mode and weak links, and obtain the core stress limit range; wherein the performance parameters include but are not limited to zero bias, scale factor, nonlinearity, and frequency response;

[0097] The constant acceleration life test module 202 is used to construct a core stress combination test scheme within the core stress limit range, and determine the number of test samples and failures of the constant acceleration life according to the given reliability and confidence level, and perform a constant acceleration life test on the MEMS accelerometer;

[0098] The pseudo-lifetime estimation value determination module 203 is used to obtain the variation law of the performance parameters over time according to the constant acceleration life test data, and analyze the performance parameter degradation amount according to the performance parameter degradation model to obtain the pseudo-lifetime estimation values ​​of the performance parameters of multiple MEMS accelerometers under different stress levels;

[0099] The multi-stress accelerated life evaluation model building module 204 is used to establish a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time based on the pseudo-life estimation values ​​of the performance parameters of the multiple MEMS accelerometers under the different stress levels and according to the MEMS accelerometer core stress.

[0100] Optionally, the core stress limit range determination module 201 is specifically used to:

[0101] According to the application environment and working conditions, based on the enhanced test plan, step high temperature test, step electrical stress test and step impact test are adopted, and performance test comparison and failure analysis are carried out after the test;

[0102] According to the strengthening test results, the core stresses affecting the MEMS accelerometer are clearly identified, and the limit range and main failure modes of the core stress are obtained.

[0103] Optionally, the core stress includes: temperature, impact, and electrical stress.

[0104] Optionally, the core stress combination test scheme includes: constant acceleration test under the same temperature stress, different impacts and electrical stresses, constant acceleration test under the same impact stress, different temperatures and electrical stresses, constant acceleration test under the same electrical stress, different temperatures and impact stresses, and constant acceleration test under different electrical stresses and the same temperature and impact stress.

[0105] Optionally, for the same stress level, take the minimum pseudo life value of the MEMS accelerometer.

[0106] Optionally, the performance parameter degradation model includes: a linear parameter regression model, specifically:

[0107] f(t)=f(0)+bt+δ (1)

[0108] Where f(t) is the test value of the performance parameter, f(0) is the initial value of the performance parameter, b is the degradation model parameter, and δ is the model error.

[0109] Optionally, the multi-stress accelerated life evaluation model includes:

[0110]

[0111] Where t is the average life, f(F) is the relative impact force function, g(I) is the inverse power law model function, g(I) = C·I -D ; Where A, B, C, D, E, G are unknown constants, k is the Boltzmann constant, parameter T represents temperature stress, F represents impact force, and I represents electrical stress;

[0112] Optionally, the main failure modes include degradation of key parameters such as zero bias, scale factor, nonlinearity, frequency response, wire bonding failure, pull-in short circuit, sensitive structure fracture, mechanical defects such as cracks, and degradation of sealing performance;

[0113] The application environment includes: temperature, humidity, electrical stress, vibration shock and magnetic field.

[0114] In summary, this embodiment applies core stress in steps and monitors various performance parameters to obtain the core stress limit range; within the core stress limit range, a core stress combination test scheme is constructed to perform a constant acceleration life test on the MEMS accelerometer; the performance parameter degradation amount is analyzed according to the constant acceleration life test data and the performance parameter degradation model to obtain pseudo life estimates of multiple performance parameters at different stress levels; based on the pseudo life estimates of multiple performance parameters at different stress levels, a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time is established according to the core stress of the MEMS accelerometer. In combination with the actual application environment of the device, this embodiment proposes to couple multiple stresses such as temperature, vibration shock, and electrical stress together to carry out an accelerated life test of the MEMS accelerometer, and utilizes the principle that the failure mechanism of the accelerometer remains unchanged under normal stress and accelerated stress levels to realize the life evaluation of the MEMS accelerometer, which can greatly shorten the time required for the normal stress life test. Specific embodiment four:

[0116] This manual also provides an electronic device, see Figure 3 , the electronic device can implement the details of the method described in the above embodiment and achieve the same effect. Figure 3 As shown, the electronic device 300 includes: a processor 301, a transceiver 302, a memory 303, a user interface 304 and a bus interface, wherein:

[0117] In the embodiment of this specification, the electronic device 300 further includes: a computer program stored in the memory 303 and executable by the processor 301, and the computer program is executed by the processor 301 to implement the following steps:

[0118] According to the application environment and working conditions, the core stress is applied step by step, various performance parameters are monitored, the main failure modes and weak links are determined, and the core stress limit range is obtained; wherein the performance parameters include zero bias, scale factor, nonlinearity, and frequency response;

[0119] Within the core stress limit range, a core stress combination test plan is constructed, and based on the given reliability and confidence, the number of test samples and the number of failures of the constant accelerated life are determined, and a constant accelerated life test is performed on the MEMS accelerometer;

[0120] Based on the constant acceleration life test data, the variation law of performance parameters over time is obtained, and the performance parameter degradation amount is analyzed according to the performance parameter degradation model, and the pseudo-lifetime estimation values ​​of the performance parameters of multiple MEMS accelerometers under different stress levels are obtained;

[0121] Based on the pseudo-lifetime estimation values ​​of the performance parameters of multiple MEMS accelerometers under different stress levels and according to the core stress of the MEMS accelerometer, a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time is established.

[0122] exist Figure 3 In the embodiment, the bus framework may include any number of interconnected buses and bridges, specifically one or more processors represented by processor 401 and various circuits of memory represented by memory 303 are linked together. The bus framework may also link together various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore not further described in this document. The bus interface provides an interface. The transceiver 402 may be a plurality of components, namely, a transmitter and a receiver, providing a unit for communicating with various other devices on a transmission medium. For different user devices, the user interface 304 may also be an interface capable of externally and internally connecting required devices, and the connected devices include but are not limited to a keypad, a display, a speaker, a microphone, a joystick, and the like.

[0123] The processor 301 manages the bus architecture and the usual processing, and the memory 303 can store data used by the processor 301 when performing operations. Optionally, when the computer program is executed by the processor 301, the following steps can also be implemented:

[0124] Optionally, the core stress is applied step by step based on a preset strengthening test scheme, the zero bias, scaling factor, nonlinearity, and frequency response performance parameters are monitored, the main failure modes and weak links are determined, and the core stress limit range is obtained, including:

[0125] According to the application environment and working conditions, based on the enhanced test plan, step high temperature test, step electrical stress test and step impact test are adopted, and performance test comparison and failure analysis are carried out after the test;

[0126] According to the strengthening test results, the core stresses affecting the MEMS accelerometer are clearly identified, and the limit range and main failure modes of the core stress are obtained.

[0127] Optionally, the core stress includes: temperature, impact, and electrical stress.

[0128] Optionally, the core stress combination test scheme includes: constant acceleration test of the same temperature stress, different impact and electrical stress,

[0129] Multiple groups of schemes include constant acceleration test under the same impact stress, different temperatures and electrical stresses, constant acceleration test under the same electrical stress, different temperatures and impact stresses, and constant acceleration test under different electrical stresses, the same temperature and impact stress.

[0130] Optionally, for the same stress level, take the minimum pseudo life value of the MEMS accelerometer.

[0131] Optionally, the performance parameter degradation model includes: a linear parameter regression model, specifically:

[0132] f(t)=f(0)+bt+δ (1)

[0133] Where f(t) is the test value of the performance parameter, f(0) is the initial value of the performance parameter, b is the degradation model parameter, and δ is the model error.

[0134] Optionally, the multi-stress accelerated life evaluation model includes:

[0135]

[0136] Where t is the average life, f(F) is the relative impact force function, gI) is the inverse power law model function, g(I) = C·I -D ; where A, B, C, D, E, G are constants, and k is the Boltzmann constant.

[0137] Optionally, the main failure modes include degradation of key parameters such as zero bias, scale factor, nonlinearity, frequency response, wire bonding failure, pull-in short circuit, sensitive structure fracture, mechanical defects such as cracks, and degradation of sealing performance;

[0138] The application environment includes: temperature, humidity, electrical stress, vibration shock and magnetic field.

[0139] In summary, this embodiment applies core stress in steps and monitors various performance parameters to obtain the core stress limit range; within the core stress limit range, a core stress combination test scheme is constructed to perform a constant acceleration life test on the MEMS accelerometer; the performance parameter degradation amount is analyzed according to the constant acceleration life test data and the performance parameter degradation model to obtain pseudo life estimates of multiple performance parameters at different stress levels; based on the pseudo life estimates of multiple performance parameters at different stress levels, a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time is established according to the core stress of the MEMS accelerometer. In combination with the actual application environment of the device, this embodiment proposes to couple multiple stresses such as temperature, vibration shock, and electrical stress together to carry out an accelerated life test of the MEMS accelerometer, and utilizes the principle that the failure mechanism of the accelerometer remains unchanged under normal stress and accelerated stress levels to realize the life evaluation of the MEMS accelerometer, which can greatly shorten the time required for the normal stress life test.

[0140] The above description is only a preferred embodiment of this specification and is not intended to limit this specification. For those skilled in the art, this specification may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this specification shall be included in the protection scope of this specification.

Claims

1. A method for evaluating the life of a MEMS accelerometer, characterized in that: include: According to the application environment and working conditions, the core stress is applied step by step, and various performance parameters are monitored to determine the main failure modes and weak links, and obtain the core stress limit range; The performance parameters include zero bias, scale factor, nonlinearity, and frequency response; Within the core stress limit range, a core stress combination test plan is constructed, and based on the given reliability and confidence, the number of test samples and failures of the constant accelerated life are determined, and a constant accelerated life test is performed on the MEMS accelerometer; Based on the constant acceleration life test data, the variation law of performance parameters over time is obtained, and the performance parameter degradation amount is analyzed according to the performance parameter degradation model, and the pseudo-lifetime estimation values ​​of the performance parameters of multiple MEMS accelerometers under different stress levels are obtained; Based on the pseudo-lifetime estimation values ​​of the performance parameters of multiple MEMS accelerometers under different stress levels and according to the core stress of the MEMS accelerometer, a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time is established.

2. The method according to claim 1, characterized in that Based on the preset strengthening test scheme, the core stress is applied step by step, the zero bias, scale factor, nonlinearity, and frequency response performance parameters are monitored, the main failure modes and weak links are determined, and the core stress limit range is obtained, including: According to the application environment and working conditions, based on the enhanced test plan, step high temperature test, step electrical stress test and step impact test are adopted, and performance test comparison and failure analysis are carried out after the test; According to the strengthening test results, the core stresses affecting the MEMS accelerometer are clearly identified, and the limit range and main failure modes of the core stress are obtained.

3. The method according to claim 1 or 2, characterized in that: The core stress includes: temperature, impact, and electrical stress.

4. The method according to claim 3, characterized in that: The core stress combination test scheme includes: constant acceleration test under the same temperature stress, different impacts and electrical stresses; constant acceleration test under the same impact stress, different temperatures and electrical stresses; constant acceleration test under the same electrical stress, different temperatures and impact stresses; and multiple groups of constant acceleration test schemes under different electrical stresses, the same temperature and impact stress.

5. The method according to claim 4, characterized in that For the same stress level, take the minimum pseudo life value of the MEMS accelerometer.

6. The method according to claim 5, characterized in that The performance parameter degradation model includes: a linear parameter regression model, specifically: f(t)=f(0)+bt+δ (1) Where f(t) is the test value of the performance parameter, f(0) is the initial value of the performance parameter, b is the degradation model parameter, and δ is the model error.

7. The method according to claim 6, characterized in that The multi-stress accelerated life evaluation model includes: Where t is the average life, f(F) is the relative impact force function, gI) is the inverse power law model function, g(I) = C·I -D ; Among them, A, B, C, D, E, G are unknown constants, k is the Boltzmann constant, parameter T represents temperature stress, F represents impact force, and I represents electrical stress.

8. The method according to claim 7, characterized in that The main failure modes include degradation of key parameters such as zero bias, scale factor, nonlinearity, frequency response, wire bonding failure, pull-in short circuit, sensitive structure fracture, mechanical defects such as cracks, and degradation of sealing performance; The application environment includes: temperature, humidity, electrical stress, vibration shock and magnetic field.

9. A MEMS accelerometer life assessment device, used to implement the method according to any one of claims 1 to 8, characterized in that: include: Core stress limit range determination module, constant accelerated life test module, pseudo life estimation value determination module, multi-stress accelerated life evaluation model construction module, including: The core stress limit range determination module is used to apply the core stress step by step according to the application environment and working conditions, monitor various performance parameters, determine the main failure mode and weak links, and obtain the core stress limit range; wherein the performance parameters include zero bias, scale factor, nonlinearity, and frequency response; The constant acceleration life test module is used to construct a core stress combination test plan within the core stress limit range, and determine the number of test samples and failures of the constant acceleration life according to the given reliability and confidence level, and perform a constant acceleration life test on the MEMS accelerometer; The pseudo life estimation value determination module is used to obtain the variation law of the performance parameters over time according to the constant acceleration life test data, and analyze the performance parameter degradation amount according to the performance parameter degradation model to obtain the pseudo life estimation values ​​of multiple performance parameters under different stress levels; The multi-stress accelerated life evaluation model building module is used to establish a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, impact, electrical stress and working time based on the pseudo-life estimation values ​​of multiple performance parameters under the different stress levels and according to the MEMS accelerometer core stress.

10. An electronic device, characterized in that: include: Communications interface, processor and memory; The processor calls the program instructions in the memory to perform the following actions: According to the application environment and working conditions, the core stress is applied step by step, various performance parameters are monitored, the main failure modes and weak links are determined, and the core stress limit range is obtained; wherein the performance parameters include zero bias, scale factor, nonlinearity, and frequency response; Within the core stress limit range, a core stress combination test plan is constructed, and based on the given reliability and confidence, the number of test samples and the number of failures of the constant accelerated life are determined, and a constant accelerated life test is performed on the MEMS accelerometer; Based on the constant accelerated life test data, the variation law of performance parameters over time is obtained, and the performance parameter degradation amount is analyzed according to the performance parameter degradation model to obtain the pseudo life estimation values ​​of multiple performance parameters under different stress levels; Based on the pseudo-lifetime estimation values ​​of multiple performance parameters under different stress levels and according to the core stress of the MEMS accelerometer, a multi-stress accelerated lifetime evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time is established.

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