Electromagnetic voiceprint monitoring method and device for failure state of bonding wire of IGBT (Insulated Gate Bipolar Translator) module

Abstract

The invention provides an electromagnetic voiceprint monitoring method for an IGBT module bonding wire failure state, and relates to the technical field of power module aging monitoring, and the method comprises the steps: selecting an electromagnetic voiceprint monitoring point in a preset range of a to-be-monitored bridge arm of an IGBT module; collecting electromagnetic voiceprint signals at the electromagnetic voiceprint monitoring points by using an electromagnetic voiceprint monitoring device; separating abrupt change signal components in the electromagnetic voiceprint signals by using multi-scale wavelet decomposition, and determining abrupt change signal component features; and establishing an electromagnetic voiceprint reference signal of the IGBT module in a bonding wire failure-free state, extracting reference signal characteristics, comparing abrupt change signal component characteristics with the reference signal characteristics, and judging a bonding wire failure state of the IGBT module. By the adoption of the scheme, monitoring of the failure state of the bonding wire of the IGBT module is achieved under the condition that normal work of a power electronic device is not affected; the monitoring method is low in invasiveness and is not influenced by factors such as junction temperature, the bonding wire failure criterion is simple and effective, and the reliability of the IGBT module can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of power module aging monitoring, and in particular to an electromagnetic acoustic print monitoring method and device for the failure state of bonding wires of an IGBT module. Background Art

[0002] Power electronic devices play an important role in the fields of renewable energy power generation, special equipment, rail transportation, etc., and are the key to achieving power conversion. IGBT has the characteristics of high voltage, large current, fast switching speed and high efficiency, and is widely used in power conversion equipment. However, when working, IGBT modules need to frequently withstand the repeated effects of thermal stress and mechanical stress, which leads to fatigue damage, posing a serious threat to the safe and stable operation of the system. Therefore, the damage status monitoring of IGBT modules is of great significance.

[0003] Among them, bonding wire fatigue failure is one of the common failures of IGBT modules. Existing methods for monitoring the damage status of bonding wires mainly monitor electrical quantities, including saturation voltage drop, short-circuit current, and gate voltage overshoot. However, the electrical parameter monitoring method requires changing the working circuit of the power electronic device, which cannot achieve non-invasive monitoring and is easily affected by coupled variables such as temperature, resulting in misjudgment. Non-electrical methods such as X-rays and infrared require the IGBT module to be tested offline, and the detection equipment is expensive and cannot meet the needs of online monitoring. At present, there is no non-invasive IGBT module status monitoring method that is not affected by junction temperature and has a high failure judgment accuracy. Summary of the invention

[0004] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0005] To this end, the first purpose of this application is to propose an electromagnetic soundprint monitoring method for the failure state of the bonding wire of the IGBT module, thereby realizing the monitoring of the failure state of the bonding wire of the IGBT module and providing technical support for the safe operation of new energy power generation, special equipment, rail transit, etc.

[0006] The second objective of the present application is to provide an electromagnetic soundprint monitoring device for the failure state of the bonding wire of an IGBT module.

[0007] To achieve the above-mentioned purpose, the first embodiment of the present application proposes an electromagnetic soundprint monitoring method for the failure state of the bonding wire of an IGBT module, comprising:

[0008] Selecting electromagnetic soundprint monitoring points within the preset range of the bridge arm to be monitored of the IGBT module;

[0009] Using an electromagnetic soundprint monitoring device to collect electromagnetic soundprint signals at an electromagnetic soundprint monitoring point;

[0010] Use multi-scale wavelet decomposition to separate the mutation signal components in the electromagnetic soundprint signal and determine the characteristics of the mutation signal components;

[0011] Establish the electromagnetic soundprint reference signal of the IGBT module without bond wire failure and extract the reference signal features;

[0012] The characteristics of the mutation signal component are compared with the reference signal characteristics to determine the failure state of the IGBT module bonding wire.

[0013] Optionally, in one embodiment of the present application, selecting electromagnetic soundprint monitoring points includes:

[0014] Analyze the current flow characteristics inside the IGBT module when the bridge arm IGBT device to be tested is turned on;

[0015] The electromagnetic soundprint monitoring zone of the bridge arm to be tested is delineated based on the projection of the current flow path to the IGBT module housing when the IGBT device of the bridge arm to be tested is turned on;

[0016] Taking the junction point of the bonding wire and the chip or the anti-parallel diode as the center and considering the difficulty of installing the monitoring probe, the electromagnetic soundprint monitoring position is selected within the electromagnetic soundprint monitoring zone.

[0017] Optionally, in one embodiment of the present application, it further includes:

[0018] Determine whether the total energy of the electromagnetic soundprint signal collected by the electromagnetic soundprint monitoring device in the frequency band of 500kHz and above is less than 1% of the total energy of all frequency bands. If not, use an analog low-pass filter to filter out high-frequency interference signals.

[0019] Optionally, in one embodiment of the present application, an orthogonal wavelet function is used as a wavelet basis function of multiscale wavelet decomposition, the multiscale wavelet decomposition level is greater than 5, and the multiscale wavelet decomposition is used to separate the mutation signal component in the electromagnetic soundprint signal, including:

[0020] The signal mutation points are extracted using the modulus maximum of wavelet coefficients with a decomposition level greater than 5, and the mutation signal components are reconstructed using the wavelet coefficients containing the modulus maximum.

[0021] Optionally, in one embodiment of the present application, establishing an electromagnetic soundprint reference signal of an IGBT module in a bonding wire failure state includes:

[0022] Select an IGBT module of the same model as the IGBT module to be tested and without bond wire failure, record the number of bond wires i of the bridge arm to be tested, and test the selected IGBT module on the double pulse experimental platform;

[0023] During the test, the bus voltage and turn-off current of the IGBT module under actual working conditions are taken into consideration, and the bus voltage and pulse length of the double pulse test are adjusted to ensure that the bus voltage and turn-off current are the same as those under actual working conditions.

[0024] During the test, the electromagnetic soundprint signal at the monitoring position corresponding to the IGBT module without bond wire failure is collected as the electromagnetic soundprint reference signal in the case of zero bond wire failure;

[0025] During the test, the bonding wires of the IGBT modules without bonding wire failure are cut one by one. After each cutting, the number j of the cut bonding wires is recorded, and the electromagnetic soundprint signal is collected as the electromagnetic soundprint reference signal in the case of j bonding wire failures.

[0026] Optionally, in one embodiment of the present application, the mutation signal component features include:

[0027] V app =max(W(t)-min(W(t))),t0≤t≤t0+10t off

[0028] Among them, V app is the peak value of the electromagnetic soundprint signal, W(t) is the collected electromagnetic soundprint signal, t0 is the start time of the transient state, t off is the typical turn-off time of the IGBT device.

[0029] Optionally, in one embodiment of the present application, comparing the mutation signal component feature with the reference signal feature to determine the failure state of the IGBT module bonding wire includes:

[0030] Determine the reference value interval of the peak-to-peak value of the electromagnetic soundprint signal of the IGBT module to be tested. If the peak-to-peak value of the signal is greater than or equal to the peak-to-peak value of the reference signal corresponding to the failure of k bonding wires, and is less than or equal to the peak-to-peak value of the reference signal corresponding to the failure of k+1 bonding wires, it is determined that there are k bonding wire failures in the IGBT module to be tested.

[0031] Optionally, in one embodiment of the present application, it further includes:

[0032] Set a warning threshold for the number of failed roots. When the number of failed roots exceeds the warning threshold, a warning is issued.

[0033] To achieve the above purpose, the second embodiment of the present invention proposes an electromagnetic soundprint monitoring device for the failure state of the bonding wire of an IGBT module, which implements the above electromagnetic soundprint monitoring method. The device includes a data acquisition unit, a data processing unit, a display warning unit and a power supply unit, wherein:

[0034] The data acquisition unit includes: an acoustic emission probe, which is used to collect electromagnetic soundprint signals at the electromagnetic soundprint monitoring position; a preamplifier, which is used to amplify the collected electromagnetic soundprint signals; an analog low-pass filter, which is used to filter out the spatial electromagnetic noise coupled to the acoustic emission probe; and an electromagnetic soundprint signal sending chip, which is used to send the collected electromagnetic soundprint signals to the data processing unit;

[0035] The data processing unit includes: an electromagnetic soundprint signal receiving chip for receiving electromagnetic soundprint signals; a digital filter chip for filtering out high-frequency noise of electromagnetic soundprint signals; a main control chip for calculating the peak-to-peak value characteristics of electromagnetic soundprint signals, comparing the peak-to-peak value characteristics with the reference value, determining the failure of the bonding wire, and controlling the display warning unit to issue a warning;

[0036] The display warning unit is used to display the number of bonding wires and issue a warning signal.

[0037] A power supply unit is used to supply power to the device.

[0038] Optionally, in one embodiment of the present application, the acoustic emission probe is a differential acoustic emission probe with a sensitivity of at least 65 dB; the preamplifier gain is at least 40 dB; and the analog low-pass filter cutoff frequency is 500 kHz.

[0039] The electromagnetic soundprint monitoring method for the failure state of the bonding wires of the IGBT module in the embodiment of the present application collects the electromagnetic soundprint signals of the transient on and off states of the IGBT module and compares them with the reference electromagnetic soundprint signals to achieve the monitoring of the failure state of the bonding wires. The method can monitor and evaluate the number of detached bonding wires of the IGBT module in real time and issue early warnings in time. The monitoring is less invasive and less affected by temperature. The method has simple criteria, good real-time performance and higher reliability. The monitoring device has low cost.

[0040] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0042] Figure 1 A schematic flow chart of an electromagnetic soundprint monitoring method for a failure state of an IGBT module bonding wire provided in the first embodiment of the present application;

[0043] Figure 2 This is a schematic diagram of the electromagnetic soundprint monitoring zones and monitoring points of the IGBT module of this embodiment;

[0044] Figure 3This is a graph showing the peak-to-peak variation of electromagnetic acoustic prints for IGBT modules with different numbers of bonding wires according to an embodiment of the present application.

[0045] Figure 4 A schematic structural diagram of an electromagnetic soundprint monitoring device for the failure state of an IGBT module bonding wire provided in an embodiment of the present application. DETAILED DESCRIPTION

[0046] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0047] The electromagnetic soundprint monitoring method and device for the failure state of the bonding wire of the IGBT module according to the embodiment of the present application are described below with reference to the accompanying drawings.

[0048] Figure 1 A schematic flow chart of an electromagnetic soundprint monitoring method for the failure state of bonding wires of an IGBT module provided in the first embodiment of the present application.

[0049] like Figure 1 As shown, the electromagnetic soundprint monitoring method for the failure state of the bonding wire of the IGBT module includes the following steps:

[0050] Step 101, selecting an electromagnetic soundprint monitoring point within a preset range of a bridge arm to be monitored of the IGBT module;

[0051] In this embodiment, the monitoring positions of the electromagnetic soundprint are selected, including:

[0052] Analyze the current flow characteristics inside the IGBT module when the bridge arm IGBT device to be tested is turned on;

[0053] The electromagnetic soundprint monitoring zone of the bridge arm to be tested is delineated based on the projection of the current flow path to the IGBT module housing when the IGBT device of the bridge arm to be tested is turned on;

[0054] Taking the junction of the bonding wire and the chip or the anti-parallel diode as the center and considering the difficulty of installing the monitoring probe, the electromagnetic soundprint monitoring position is determined near the center point.

[0055] Figure 2 FIG. 1 is a schematic diagram of the electromagnetic sound pattern monitoring partitions and monitoring points of the IGBT module of this embodiment. Figure 2 For example, the module to be monitored includes 6 bridge arms, so it is divided into 6 monitoring areas R1-R6 as shown in the dashed box. The bridge arm to be tested consists of Q1, D1 and the bonding wire in the middle, and the monitoring point P is selected as the center point directly below the bonding wire coupling point.

[0056] Step 102, using an electromagnetic soundprint monitoring device to collect electromagnetic soundprint signals at an electromagnetic soundprint monitoring point;

[0057] In this embodiment, the total energy of the electromagnetic soundprint signal collected by the electromagnetic soundprint monitoring device in the frequency band of 500kHz and above should be less than 1% of the total energy of all frequency bands. If it does not meet the requirement, a digital low-pass filter should be used to filter out high-frequency interference signals first.

[0058] Step 103, using multi-scale wavelet decomposition to separate the mutation signal component in the electromagnetic soundprint signal, and determine the characteristics of the mutation signal component;

[0059] In this embodiment, the wavelet basis functions used in the multi-scale wavelet decomposition include but are not limited to orthogonal wavelet functions such as Haar wavelet and Daubechies wavelet; the multi-scale wavelet decomposition level is at least 5, and the signal mutation points are extracted using the modulus maximum of the wavelet coefficients with a decomposition level greater than 5; the mutation signal components are reconstructed using the wavelet coefficients containing the modulus maximum.

[0060] In this embodiment, the extracted electromagnetic soundprint signal features include but are not limited to the peak-to-peak value V app , which is expressed as follows:

[0061] V app =max(W(t)-min(W(t))),t0≤t≤t0+10t off

[0062] Where W(t) is the collected electromagnetic soundprint signal, t0 is the start time of the shutdown transient, and t off This is the typical turn-off time specified in the IGBT device data sheet.

[0063] Step 104, establishing an electromagnetic soundprint reference signal of the IGBT module in a non-bond wire failure state, and extracting reference signal features;

[0064] In this embodiment, constructing an electromagnetic soundprint reference signal includes:

[0065] Use an IGBT module with no bond wire failure of the same model as the IGBT module to be tested, record the number of bond wires i of the bridge arm to be tested, and conduct the test on the double pulse experimental platform;

[0066] Considering the actual working condition bus voltage and shutoff current of the IGBT module to be tested, adjust the bus voltage and pulse length of the double pulse test to ensure that the bus voltage and shutoff current are the same as the actual working condition;

[0067] An electromagnetic soundprint monitoring device is used to collect electromagnetic soundprint signals at the same monitoring position as the IGBT module to be tested, as electromagnetic soundprint reference signals in the case of zero bonding wire failure;

[0068] The bonding wires of the IGBT module without bonding wire failure are cut one by one, and the number j of the cut bonding wires is recorded. Similarly, the electromagnetic soundprint signal is collected as the electromagnetic soundprint reference signal when j bonding wires fail, until all the bonding wires are cut.

[0069] Figure 3 This is a curve diagram of the peak-to-peak value of the electromagnetic soundprint of the IGBT module with different numbers of bonding wires in this embodiment. It can be seen that as the number of bonding wires decreases, the peak-to-peak value of the electromagnetic soundprint increases.

[0070] Step 105 , comparing the sudden change signal component characteristics with the reference signal characteristics to determine the failure state of the bonding wire of the IGBT module.

[0071] In this embodiment, determining the failure state of the bonding wire of the IGBT module includes:

[0072] Determine the reference value interval of the peak-to-peak value of the electromagnetic soundprint signal of the module under test. If the peak-to-peak value of the electromagnetic soundprint signal of the module under test is greater than or equal to the peak-to-peak value of the reference signal corresponding to the failure of k bonding wires, and is less than or equal to the peak-to-peak value of the reference signal corresponding to the failure of k+1 bonding wires, it is determined that there is a failure of i bonding wires in the bridge arm of the IGBT module under test.

[0073] by Figure 2 , Figure 3 For example, the peak value of the electromagnetic soundprint signal detected is set to 1.5V. Figure 3 It can be seen that there are three failed bonding wires in the R1 bridge arm of the module under test.

[0074] In this embodiment, the warning threshold is set to 1 / 3 of the number of intact module bonding wires, and a warning is issued when the number of failed wires exceeds the threshold.

[0075] The electromagnetic soundprint monitoring method for the failure state of the bonding wires of the IGBT module in the embodiment of the present application collects the electromagnetic soundprint signals of the transient on and off states of the IGBT module and compares them with the reference electromagnetic soundprint signals to achieve the monitoring of the failure state of the bonding wires. The method can monitor and evaluate the number of detached bonding wires of the IGBT module in real time and issue early warnings in time. The monitoring is less invasive and less affected by temperature. The method has simple criteria, good real-time performance and higher reliability. The monitoring device has low cost.

[0076] In order to implement the above-mentioned embodiment, the present application also proposes an electromagnetic soundprint monitoring device for the failure state of bonding wires of an IGBT module.

[0077] Figure 4 A schematic structural diagram of an electromagnetic soundprint monitoring device for the failure state of an IGBT module bonding wire provided in an embodiment of the present application.

[0078] like Figure 4As shown, the electromagnetic soundprint monitoring device for the failure state of the bonding wire of the IGBT module includes a data acquisition unit, a data processing unit, a display and early warning unit and a power supply unit, wherein:

[0079] The data acquisition unit includes: an acoustic emission probe, which is used to collect electromagnetic soundprint signals at the electromagnetic soundprint monitoring position; a preamplifier, which is used to amplify the collected electromagnetic soundprint signals; an analog low-pass filter, which is used to filter out the spatial electromagnetic noise coupled to the acoustic emission probe; and an electromagnetic soundprint signal sending chip, which is used to send the collected electromagnetic soundprint signals to the data processing unit;

[0080] The data processing unit includes: an electromagnetic soundprint signal receiving chip for receiving electromagnetic soundprint signals; a digital filter chip for filtering out high-frequency noise of electromagnetic soundprint signals; a main control chip for calculating the peak-to-peak value characteristics of electromagnetic soundprint signals, comparing the peak-to-peak value characteristics with the reference value, determining the failure of the bonding wire, and controlling the display warning unit to issue a warning;

[0081] The display warning unit is used to display the number of bonding wires and issue a warning signal.

[0082] A power supply unit is used to supply power to the device.

[0083] Optionally, in one embodiment of the present application, the acoustic emission probe is a differential acoustic emission probe with a sensitivity of at least 65 dB; the preamplifier gain is at least 40 dB; and the analog low-pass filter cutoff frequency is 500 kHz.

[0084] It should be noted that the aforementioned explanation of the electromagnetic soundprint monitoring method for the failure state of the bonding wire of the IGBT module in the embodiment is also applicable to the electromagnetic soundprint monitoring device for the failure state of the bonding wire of the IGBT module in this embodiment, and will not be repeated here.

[0085] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0086] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0087] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0088] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0089] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0090] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0091] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0092] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. An electromagnetic soundprint monitoring method for the failure state of an IGBT module bonding wire, characterized in that: include: Selecting electromagnetic soundprint monitoring points within the preset range of the bridge arm to be monitored of the IGBT module; Using an electromagnetic soundprint monitoring device to collect electromagnetic soundprint signals at the electromagnetic soundprint monitoring point; Using multi-scale wavelet decomposition to separate the mutation signal component in the electromagnetic soundprint signal, and determine the characteristics of the mutation signal component; Establishing an electromagnetic soundprint reference signal of the IGBT module in a non-bond wire failure state, and extracting reference signal features; The mutation signal component feature is compared with the reference signal feature to determine the failure state of the bonding wire of the IGBT module.

2. The method according to claim 1, characterized in that Selecting the electromagnetic soundprint monitoring point includes: Analyze the current flow characteristics inside the IGBT module when the bridge arm IGBT device to be tested is turned on; The electromagnetic soundprint monitoring zone of the bridge arm to be tested is delineated based on the projection of the current flow path to the IGBT module housing when the IGBT device of the bridge arm to be tested is turned on; Taking the junction point of the bonding wire and the chip or the anti-parallel diode as the center and considering the difficulty of installing the monitoring probe, an electromagnetic soundprint monitoring position is selected within the electromagnetic soundprint monitoring partition.

3. The method according to claim 1, characterized in that The method further comprises: It is determined whether the total energy of the electromagnetic soundprint signal collected by the electromagnetic soundprint monitoring device in the frequency band of 500kHz and above is less than 1% of the total energy of all frequency bands. If not, an analog low-pass filter is used to filter out high-frequency interference signals.

4. The method according to claim 1, characterized in that An orthogonal wavelet function is used as a wavelet basis function of multiscale wavelet decomposition, the multiscale wavelet decomposition level is greater than 5, and the multiscale wavelet decomposition is used to separate the mutation signal component in the electromagnetic soundprint signal, including: The signal mutation points are extracted using the modulus maximum of wavelet coefficients with a decomposition level greater than 5, and the mutation signal components are reconstructed using the wavelet coefficients containing the modulus maximum.

5. The method according to claim 1, characterized in that Establishing an electromagnetic soundprint reference signal of the IGBT module in a bonding wire failure state includes: Select an IGBT module of the same model as the IGBT module to be tested and without bond wire failure, record the number of bond wires i of the bridge arm to be tested, and test the selected IGBT module on the double pulse experimental platform; During the test, the bus voltage and turn-off current of the IGBT module under actual working conditions are taken into consideration, and the bus voltage and pulse length of the double pulse test are adjusted to ensure that the bus voltage and turn-off current are the same as those under actual working conditions. During the test, the electromagnetic soundprint signal at the monitoring position corresponding to the IGBT module without bond wire failure is collected as the electromagnetic soundprint reference signal in the case of zero bond wire failure; During the test, the bonding wires of the IGBT modules without bonding wire failure are cut one by one. After each cutting, the number j of the cut bonding wires is recorded, and the electromagnetic soundprint signal is collected as the electromagnetic soundprint reference signal in the case of j bonding wire failures.

6. The method according to claim 1, characterized in that The mutation signal component features include: V app =max(W(t)-min(W(t))),t0≤t≤t0+10t off Among them, V app is the peak value of the electromagnetic soundprint signal, W(t) is the collected electromagnetic soundprint signal, t0 is the start time of the transient state, t off is the typical turn-off time of the IGBT device.

7. The method according to any one of claims 5 or 6, characterized in that: Comparing the mutation signal component feature with the reference signal feature to determine the failure state of the bonding wire of the IGBT module includes: Determine the reference value interval of the peak-to-peak value of the electromagnetic sound print signal of the IGBT module to be tested. If the peak-to-peak value of the signal is greater than or equal to the peak-to-peak value of the reference signal corresponding to the failure of k bonding wires, and is less than or equal to the peak-to-peak value of the reference signal corresponding to the failure of k+1 bonding wires, it is determined that the IGBT module to be tested has k bonding wire failures.

8. The method according to claim 7, characterized in that The method further comprises: A warning threshold for the number of failed roots is set, and a warning is issued when the number of failed roots exceeds the warning threshold.

9. An electromagnetic soundprint monitoring device for failure status of bonding wires of an IGBT module, characterized in that: The battery soundprint monitoring device implements the electromagnetic soundprint monitoring method according to claims 1-7, and the battery soundprint monitoring device includes a data acquisition unit, a data processing unit, a display warning unit and a power supply unit, wherein: The data acquisition unit includes: an acoustic emission probe, used to collect electromagnetic sound print signals at the electromagnetic sound print monitoring position; a preamplifier, used to amplify the collected electromagnetic sound print signals; an analog low-pass filter, used to filter out the spatial electromagnetic noise coupled to the acoustic emission probe; an electromagnetic sound print signal sending chip, used to send the collected electromagnetic sound print signals to the data processing unit; The data processing unit includes: an electromagnetic soundprint signal receiving chip for receiving the electromagnetic soundprint signal; a digital filter chip for filtering out the high-frequency noise of the electromagnetic soundprint signal; a main control chip for calculating the peak-to-peak value characteristics of the electromagnetic soundprint signal, comparing the peak-to-peak value characteristics with the reference value, determining the failure of the bonding wire, and controlling the display warning unit to issue a warning; The display warning unit is used to display the number of bonding wires and send out a warning signal. A power supply unit is used to supply power to the device.

10. The device according to claim 9, characterized in that The acoustic emission probe is a differential acoustic emission probe with a sensitivity of at least 65dB; the preamplifier gain is at least 40dB; and the analog low-pass filter cutoff frequency is 500kHz.

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