Electromagnetic acoustic fingerprint monitoring method and device for IGBT module wire bonding failure state

Abstract

The application provides an electromagnetic acoustic fingerprint monitoring method for a wire bonding failure state of an IGBT module, and relates to the technical field of power module aging monitoring. The method comprises the following steps: selecting an electromagnetic acoustic fingerprint monitoring point in a preset range of a bridge arm to be monitored of the IGBT module; collecting an electromagnetic acoustic fingerprint signal at the electromagnetic acoustic fingerprint monitoring point by using an electromagnetic acoustic fingerprint monitoring device; separating a sudden signal component in the electromagnetic acoustic fingerprint signal by using multi-scale wavelet decomposition, and determining a sudden signal component feature; establishing an electromagnetic acoustic fingerprint reference signal under a wire bonding failure state of the IGBT module, comparing the sudden signal component feature with a reference signal feature, and judging the wire bonding failure state of the IGBT module. The application can realize the monitoring of the wire bonding failure state of the IGBT module without affecting the normal work of the power electronic device. The monitoring method has low invasiveness, is not affected by factors such as junction temperature, and has simple and effective wire bonding failure criteria, which is helpful to improve the reliability of the IGBT module.

Description

Technical Field

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

[0002] Power electronics play a vital role in renewable energy generation, special equipment, rail transit, and other fields, and are key to achieving power conversion. IGBTs, with their high voltage, high current, fast switching speed, and high efficiency, are widely used in power conversion equipment. However, IGBT modules are frequently subjected to repeated thermal and mechanical stresses during operation, which can lead to fatigue damage and pose a serious threat to the safe and stable operation of the system. Therefore, monitoring the damage status of IGBT modules is of great significance.

[0003] Among them, bond wire fatigue failure is a common failure of IGBT modules. Existing methods for monitoring bond wire damage status primarily rely on monitoring electrical quantities, including saturation voltage drop, short-circuit current, and gate voltage overshoot. However, electrical parameter monitoring methods require modifications to the operating circuitry of power electronic devices, making non-invasive monitoring impossible. Furthermore, these methods are susceptible to coupled variables such as temperature, leading to misjudgments. Non-electrical methods such as X-rays and infrared sensors require offline testing of the IGBT module, and the high cost of the testing equipment makes them inadequate for online monitoring. Currently, there is no non-invasive, junction temperature-independent, and highly accurate IGBT module status monitoring method. Summary of the Invention

[0004] The present application aims to solve one of the technical problems in the related art at least to a certain 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 IGBT module bonding wire, which realizes the monitoring of the failure state of the IGBT module bonding wire and provides 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 status of the bonding wires of an IGBT module.

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

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

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

[0010] The mutation signal component is separated from the electromagnetic acoustic fingerprint signal by using multi-scale wavelet decomposition, and the mutation signal component feature is determined.

[0011] The electromagnetic acoustic fingerprint reference signal of the IGBT module in the bond wire failure state is established, and the reference signal feature is extracted.

[0012] The mutation signal component feature is compared with the reference signal feature, and the bond wire failure state of the IGBT module is judged.

[0013] Optionally, in an embodiment of the present application, the electromagnetic acoustic fingerprint monitoring point is selected, comprising:

[0014] The current flow characteristics in the IGBT module when the to-be-tested bridge arm IGBT device is turned on are analyzed.

[0015] The electromagnetic acoustic fingerprint monitoring partition of the to-be-tested bridge arm is demarcated based on the projection of the current flow path to the IGBT module shell when the to-be-tested bridge arm IGBT device is turned on.

[0016] The electromagnetic acoustic fingerprint monitoring position is selected in the electromagnetic acoustic fingerprint monitoring partition, taking the junction of the bond wire and the chip or the anti-parallel diode as the center and considering the installation difficulty of the monitoring probe.

[0017] Optionally, in an embodiment of the present application, it further comprises:

[0018] It is judged whether the total energy of the electromagnetic acoustic fingerprint signal collected by the electromagnetic acoustic fingerprint monitoring device in the frequency band of 500 kHz and above is less than 1% of the total energy of all frequency bands, and if not, the high-frequency band interference signal is filtered out by using an analog low-pass filter.

[0019] Optionally, in an embodiment of the present application, the orthogonal wavelet function is used as the wavelet basis function of the multi-scale wavelet decomposition, the multi-scale wavelet decomposition level is greater than 5, and the mutation signal component in the electromagnetic acoustic fingerprint signal is separated by using the multi-scale wavelet decomposition, comprising:

[0020] The signal mutation point is extracted by using the wavelet coefficient modulus maximum value with the decomposition level greater than 5, and the mutation signal component is reconstructed by using the wavelet coefficient containing the modulus maximum value.

[0021] Optionally, in an embodiment of the present application, the electromagnetic acoustic fingerprint reference signal of the IGBT module in the bond wire failure state is established, comprising:

[0022] The IGBT module without bond wire failure of the same model as the to-be-tested IGBT module is selected, the number i of bond wires of the to-be-tested bridge arm is recorded, and the selected IGBT module is tested on a double-pulse test 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 experiment 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 with no 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 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-to-peak value of the electromagnetic soundprint signal, W(t) is the collected electromagnetic soundprint signal, t0 is the starting time of the transient state, t off is the typical turn-off time of an 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 range of the peak-to-peak value of the electromagnetic soundprint signal of the IGBT module under test. 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 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 under test.

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

[0032] Set a warning threshold for the number of failed nodes. When the number of failed nodes exceeds the warning threshold, an alert 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 and warning unit, and a power supply unit, wherein:

[0034] The data acquisition unit includes: an acoustic emission probe for collecting electromagnetic soundprint signals at the electromagnetic soundprint monitoring location; a preamplifier for amplifying the collected electromagnetic soundprint signals; an analog low-pass filter for filtering out spatial electromagnetic noise coupled to the acoustic emission probe; and an electromagnetic soundprint signal transmission chip for transmitting 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 from the electromagnetic soundprint signals; and a main control chip for calculating the peak-to-peak value characteristics of the electromagnetic soundprint signals, comparing them with the reference values, 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 realizes the monitoring of the failure state of the bonding wires by collecting the transient electromagnetic soundprint signals of the IGBT module when it is turned on and off, and comparing them with the reference electromagnetic soundprint signals. 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 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 flow chart of a method for monitoring electromagnetic soundprints for failure of bonding wires of an IGBT module 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 in this embodiment;

[0044] Figure 3This is a graph showing the peak-to-peak variation of electromagnetic sound patterns 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] The following describes in detail embodiments of the present application, examples of which 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 following describes 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 with reference to the accompanying drawings.

[0048] Figure 1 A flow chart of an electromagnetic soundprint monitoring method for the failure state of an IGBT module bonding wire 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 IGBT module bonding wire includes the following steps:

[0050] Step 101: Select an electromagnetic soundprint monitoring point within a preset range of the 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 IGBT device under test 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 Schematic diagram of the electromagnetic soundprint monitoring zones and monitoring points of the IGBT module in this embodiment. Figure 2 For example, the module to be monitored includes six bridge arms, so the six monitoring regions are divided into R1-R6 as shown in the dashed box. The bridge arm to be tested consists of Q1, D1, and the bond wire between them. The monitoring point P is selected as the center point directly below the bond wire coupling point.

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

[0057] In this embodiment, the total energy of the electromagnetic acoustic fingerprint signals collected by the electromagnetic acoustic fingerprint monitoring device in the frequency band of 500 kHz and above should be less than 1% of the total energy of all frequency bands. If not, 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 abrupt signal component in the electromagnetic acoustic fingerprint signal and determine the abrupt signal component feature;

[0059] In this embodiment, the wavelet basis function used in multi-scale wavelet decomposition includes but is not limited to Haar wavelet, Daubechies wavelet and other orthogonal wavelet functions; the decomposition order of multi-scale wavelet decomposition is at least 5, and the signal abrupt point is extracted using the modulus maximum value of wavelet coefficients with a decomposition order greater than 5; the abrupt signal component is reconstructed using the wavelet coefficients containing the modulus maximum value.

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

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

[0062] In the formula, W(t) is the collected electromagnetic acoustic fingerprint signal, t0 is the start time of the turn-off transient, and t off is the typical turn-off time marked in the IGBT device data sheet.

[0063] Step 104, establishing the electromagnetic acoustic fingerprint reference signal of the IGBT module in the non-bonding wire failure state, and extracting the reference signal feature;

[0064] In this embodiment, the electromagnetic acoustic fingerprint reference signal is constructed, including:

[0065] Using a non-bonding wire failure IGBT module of the same type as the IGBT module to be tested, recording the number of bonding wires i of the bridge arm to be tested, and carrying out testing on the double-pulse test platform;

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

[0067] Using the electromagnetic acoustic fingerprint monitoring device at the same monitoring position as the IGBT module to be tested to collect the electromagnetic acoustic fingerprint signal as the electromagnetic acoustic fingerprint reference signal under the condition of 0 bonding wire failure;

[0068] Cut off the bonding wires of the IGBT module one by one, record the number j of the cut off bonding wires, and collect the electromagnetic acoustic fingerprint signal as the electromagnetic acoustic fingerprint reference signal under the condition of j failed bonding wires, until all the bonding wires are cut off.

[0069] Figure 3 For the peak-to-peak value variation curve of the electromagnetic acoustic fingerprint of the IGBT module with different number of bonding wires in the embodiment, it can be seen that the peak-to-peak value of the electromagnetic acoustic fingerprint increases as the number of bonding wires decreases.

[0070] In step 105, the characteristics of the mutation signal component are compared with the characteristics of the reference signal to determine the failure state of the bonding wires of the IGBT module.

[0071] In the embodiment, determining the failure state of the bonding wires of the IGBT module comprises:

[0072] Determine the reference value interval in which the peak-to-peak value of the electromagnetic acoustic fingerprint signal of the to-be-tested module is located. If the peak-to-peak value of the electromagnetic acoustic fingerprint signal of the to-be-tested module is greater than or equal to the peak-to-peak value of the reference signal corresponding to k failed bonding wires and less than or equal to the peak-to-peak value of the reference signal corresponding to k+1 failed bonding wires, it is determined that the to-be-tested bridge arm of the to-be-tested IGBT module has i failed bonding wires.

[0073] For example, set the monitored peak-to-peak value of the electromagnetic acoustic fingerprint signal to 1.5 V, and compare it with Figure 2 , Figure 3 It can be seen that the R1 bridge arm of the to-be-tested module has 3 failed bonding wires. Figure 3

[0074] In the embodiment, the early warning threshold is set to 1 / 3 of the number of bonding wires of the intact module. If the number of failed bonding wires exceeds the threshold, an early warning is issued.

[0075] The electromagnetic acoustic fingerprint monitoring method for the failure state of the bonding wires of the IGBT module in the embodiment of the application can realize the monitoring of the failure state of the bonding wires by collecting the electromagnetic acoustic fingerprint signal of the IGBT module in the on-off transient state and comparing it with the reference electromagnetic acoustic fingerprint signal. The number of dropped bonding wires of the IGBT module can be monitored and evaluated in real time, and an early warning can be made in time. The monitoring is low in invasion and less affected by temperature. The method criterion is simple, real-time, and highly reliable. The monitoring device is low in cost.

[0076] In order to realize the above-mentioned embodiments, the application further provides an electromagnetic acoustic fingerprint monitoring device for the failure state of the bonding wires of the IGBT module.

[0077] Figure 4 The structure diagram of the electromagnetic acoustic fingerprint monitoring device for the failure state of the bonding wires of the IGBT module provided in the embodiment of the application is shown.

[0078] For example, set the monitored peak-to-peak value of the electromagnetic acoustic fingerprint signal to 1.5 V, and compare it with Figure 4 ​As shown, the electromagnetic acoustic fingerprint monitoring device for the IGBT module wire bonding failure state comprises a data acquisition unit, a data processing unit, a display warning unit and a power supply unit, wherein,

[0079] The data acquisition unit comprises an acoustic emission probe for collecting electromagnetic acoustic fingerprint signals at the electromagnetic acoustic fingerprint monitoring position, a preamplifier for amplifying the collected electromagnetic acoustic fingerprint signals, an analog low-pass filter for filtering out spatial electromagnetic noise coupled to the acoustic emission probe, and an electromagnetic acoustic fingerprint signal transmission chip for transmitting the collected electromagnetic acoustic fingerprint signals to the data processing unit.

[0080] The data processing unit comprises an electromagnetic acoustic fingerprint signal receiving chip for receiving electromagnetic acoustic fingerprint signals, a digital filter chip for filtering out high-frequency noise of the electromagnetic acoustic fingerprint signals, and a master control chip for calculating the peak-to-peak value characteristics of the electromagnetic acoustic fingerprint signals, comparing them with the reference value, judging the wire bonding failure condition, and controlling the display warning unit to issue a warning.

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

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

[0083] Optionally, in an 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 has a gain of at least 40 dB; and the analog low-pass filter has a cutoff frequency of 500 kHz.

[0084] It should be noted that the above description of the electromagnetic acoustic fingerprint monitoring method for the IGBT module wire bonding failure state is also applicable to the electromagnetic acoustic fingerprint monitoring device for the IGBT module wire bonding failure state of the embodiment, which will not be described here.

[0085] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0086] Moreover, the terms "first", "second", "third", etc. are used herein only to describe different steps or categories of steps in a claim for patent purposes, and are not to be construed as indicating or implying relative importance of one step to another or a quantity of steps. Thus, features defined with "first", "second" or "third" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "plurality" is at least two, for example, two, three, etc., unless otherwise explicitly and specifically limited.

[0087] Any process or method descriptions or blocks in flow charts herein, and elsewhere, can be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process, and that the various embodiments of methods or processes can include additional or fewer processes or steps, or can combine two or more processes or steps, than as represented by the figure or described herein, and that the representation in the figure or description is used by those skilled in the art for the specification of the processes or methods being implemented.

[0088] Logic and / or steps represented in flow charts herein, and elsewhere, can be considered as a sequence of executable instructions, and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this specification, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can specifically include a computer storage medium. Examples (non-exhaustive list) of computer storage media include the following: an electronic connection having one or more wires (electronic devices), a portable computer diskette (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for example, by optically scanning the paper or other suitable medium, then electronically converted into a form that can be edited, compiled, or interpreted, or otherwise processed in electronic form into another computer- readable medium.

[0089] It should be understood that parts of the present application can be realized in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be realized as software or firmware stored in a memory and executed by a suitable instruction execution system. As such, if realized in hardware, and in another embodiment, any one or a combination of the following technologies known in the art can be used: discrete logic circuitry having logic gates for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and the like.

[0090] Those skilled in the art can understand that all or part of the steps carried out by the above-mentioned embodiment methods can be completed by programs instructing relevant hardware, and the programs can be stored in a computer readable storage medium, and when the programs are executed, one or a combination of the steps of the method embodiments is included.

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

[0092] The above-mentioned storage medium can 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 should be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-mentioned embodiments within the scope of the present application.

Claims

1. A method for monitoring electromagnetic soundprints of IGBT module bonding wire failure status, characterized in that: include: Select electromagnetic soundprint monitoring points within the preset range of the bridge arm to be monitored of the IGBT module; Using an electromagnetic voiceprint monitoring device to collect electromagnetic voiceprint signals at the electromagnetic voiceprint monitoring point; Using multi-scale wavelet decomposition to separate the mutation signal component in the electromagnetic voiceprint 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; Comparing the mutation signal component characteristics with the reference signal characteristics to determine the failure state of the IGBT module bonding wire; The step of 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 that has no bond wire failure, record the number of bond wires i in the bridge arm to be tested, and test the selected IGBT module on a dual-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 experiment 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 with no 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 bond wire failure are cut in sequence. After each cutting, the number j of bond wires cut is recorded, and the electromagnetic soundprint signal is collected as the electromagnetic soundprint reference signal in the case of j bond wire failures. The mutation signal component features include: in, is the peak-to-peak value of the electromagnetic soundprint signal, is the collected electromagnetic voiceprint signal, is the start time of the transient state, is the typical turn-off time of an IGBT device.

2. The method according to claim 1, wherein Selecting the electromagnetic voiceprint monitoring point includes: Analyze the current flow characteristics inside the IGBT module when the IGBT device under test 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 zone.

3. The method according to claim 1, wherein The method further comprises: 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.

4. The method according to claim 1, wherein An orthogonal wavelet function is used as a wavelet basis function of multi-scale wavelet decomposition, and the multi-scale wavelet decomposition level is greater than 5. The multi-scale wavelet decomposition is used to separate the mutation signal component in the electromagnetic voiceprint signal, including: The signal mutation points are extracted using the modulus maximum of the 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, wherein Comparing the mutation signal component feature with the reference signal feature to determine the failure state of the IGBT module bonding wire includes: Determine the reference value range of the peak-to-peak value of the electromagnetic acoustic 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 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.

6. The method according to claim 5, wherein The method further comprises: Set a warning threshold for the number of failed nodes, and issue a warning when the number of failed nodes exceeds the warning threshold.

7. An electromagnetic soundprint monitoring device for failure status of IGBT module bonding wires, characterized in that: The electromagnetic soundprint monitoring device implements the electromagnetic soundprint monitoring method according to claims 1-6, and the electromagnetic soundprint monitoring device includes a data acquisition unit, a data processing unit, a display and warning unit, and a power supply unit, wherein: The data acquisition unit includes: an acoustic emission probe for collecting electromagnetic soundprint signals at the electromagnetic soundprint monitoring position; a preamplifier for amplifying the collected electromagnetic soundprint signals; an analog low-pass filter for filtering out spatial electromagnetic noise coupled to the acoustic emission probe; and an electromagnetic soundprint signal transmitting chip for transmitting the collected electromagnetic soundprint 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 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 and warning unit is used to display the number of bonding wires and issue a warning signal; a power supply unit, used to supply power to the device; The step of 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 that has no bond wire failure, record the number of bond wires i in the bridge arm to be tested, and test the selected IGBT module on a dual-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 experiment 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 with no 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 bond wire failure are cut in sequence. After each cutting, the number j of bond wires cut is recorded, and the electromagnetic soundprint signal is collected as the electromagnetic soundprint reference signal in the case of j bond wire failures. The mutation signal component features include: in, is the peak-to-peak value of the electromagnetic soundprint signal, is the collected electromagnetic voiceprint signal, is the start time of the transient state, is the typical turn-off time of an IGBT device.

8. The device according to claim 7, wherein 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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