Silicon carbide device bonding wire fatigue state evaluation method, system, equipment, medium and product

Abstract

The invention relates to the technical field of power devices, and discloses a method, a system, equipment, a medium and a product for evaluating the fatigue state of a bonding wire of a silicon carbide device. The method comprises the following steps: determining a voltage oscillation peak increment, a chip junction temperature difference and a turn-on delay time difference according to the voltage oscillation peak value, the chip junction temperature and the turn-on delay during the previous turn-on work, and carrying out per-unit processing on the voltage oscillation peak increment, the chip junction temperature difference and the turn-on delay time difference to obtain a voltage oscillation peak increment per-unit value, a chip junction temperature difference per-unit value and a turn-on delay time difference per-unit value; the bonding wire fatigue index of the target silicon carbide device is obtained by performing weighted calculation on the per unit value of the voltage oscillation peak increment, the per unit value of the chip junction temperature difference and the per unit value of the opening delay time difference, and the bonding wire fatigue state of the target silicon carbide device is determined by using the bonding wire fatigue index, so that the accurate evaluation of the health state of the device is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of power devices, and in particular to a method, system, equipment, medium and product for evaluating the fatigue state of bonding wires of a silicon carbide device. Background Art

[0002] Compared to traditional silicon materials, silicon carbide has a wider energy band gap, higher breakdown field strength, and better thermal conductivity. Traditional silicon devices are difficult to use in environments with temperatures exceeding 200°C due to their high junction temperature and large leakage current. In contrast, silicon carbide power devices have lower intrinsic carrier concentrations and higher breakdown field strengths, making them more suitable for operation under high temperature and high voltage conditions. However, due to the inherent characteristics of silicon carbide materials and harsh operating conditions, the reliability issues of silicon carbide MOSFETs are more serious.

[0003] Silicon carbide MOSFET material degradation can be categorized as die degradation and package-related degradation. Bond wire fatigue is a major reliability issue for packaging. Bond wire fatigue can cause a positive shift in the device's on-resistance. Severe bond wire degradation can not only lead to open-circuit failures but also increase the risk of device overheating. Therefore, online condition monitoring and life prediction of SiC MOSFETs are crucial for power converters to avoid unexpected shutdowns and catastrophic failures.

[0004] Currently, the methods for evaluating the fatigue status of the bond wires of silicon carbide MOSFET devices have poor accuracy and are mostly invasive to the system. They require modifying the system's circuit structure or shutting down the system to monitor the fatigue status of the device's bond wires, affecting the normal operation of the system. Summary of the Invention

[0005] In view of this, the present invention provides a method, system, equipment, medium and product for evaluating the fatigue state of the bonding wires of silicon carbide devices, which solves the technical problems that the bonding wire fatigue state evaluation methods for silicon carbide MOSFET devices have poor accuracy and are mostly invasive to the system, requiring modification of the system's circuit structure or shutdown of the system to monitor the bonding wire fatigue state of the device equipment, thereby affecting the normal operation of the system.

[0006] A first aspect of the present invention provides a method for evaluating the fatigue state of a bonding wire of a silicon carbide device, comprising:

[0007] Obtain the voltage oscillation peak, chip junction temperature, and turn-on delay of the target silicon carbide device when it is turned on through multiple data sources;

[0008] Determine the voltage oscillation peak value increment, the chip junction temperature difference and the turn-on delay time difference according to the voltage oscillation peak value, the chip junction temperature and the turn-on delay during the current turn-on operation, and the voltage oscillation peak value, the chip junction temperature and the turn-on delay during the previous turn-on operation;

[0009] The voltage oscillation peak value increment, the chip junction temperature difference and the turn-on delay time difference are respectively normalized to obtain a per-unit value of the voltage oscillation peak value increment, a per-unit value of the chip junction temperature difference and a per-unit value of the turn-on delay time difference;

[0010] Performing weighted calculation on the voltage oscillation peak increment per unit value, the chip junction temperature difference per unit value, and the turn-on delay time difference per unit value to obtain a bonding wire fatigue index of the target silicon carbide device;

[0011] A bonding wire fatigue state of the target silicon carbide device is determined according to the bonding wire fatigue index.

[0012] Preferably, the method further comprises:

[0013] Filtering and noise reduction processing is performed on the voltage oscillation peak, the chip junction temperature and the turn-on delay respectively.

[0014] Preferably, determining the bonding wire fatigue state of the target silicon carbide device according to the bonding wire fatigue index includes:

[0015] Obtaining a first fatigue index threshold, a second fatigue index threshold, and a third fatigue index threshold for determining a fatigue state of a bonding wire; wherein the values ​​of the first fatigue index threshold, the second fatigue index threshold, and the third fatigue index threshold are arranged in ascending order;

[0016] When the bonding wire fatigue index is less than the first fatigue index threshold, determining that the bonding wire fatigue state of the target silicon carbide device is a healthy state;

[0017] When the bonding wire fatigue index is not less than the first fatigue index threshold and less than the second fatigue index threshold, determining that the bonding wire fatigue state of the target silicon carbide device is a prompt fatigue state;

[0018] When the bonding wire fatigue index is not less than the second fatigue index threshold and less than the third fatigue index threshold, determining that the bonding wire fatigue state of the target silicon carbide device is a fatigue warning state;

[0019] When the bonding wire fatigue index is not less than the third fatigue index threshold, it is determined that the bonding wire fatigue state of the target silicon carbide device is a complete fatigue state.

[0020] Preferably, the method further comprises:

[0021] According to the bonding wire fatigue state of the target silicon carbide device, a maintenance method for the target silicon carbide device is matched in a preset maintenance database; wherein the preset maintenance database includes a mapping relationship between the bonding wire fatigue state and the maintenance method.

[0022] Preferably, the method further comprises: estimating the remaining life of the target silicon carbide device according to the voltage oscillation peak increment, the chip junction temperature difference and the turn-on delay time difference of the target silicon carbide device when the target silicon carbide device is turned on for the current operation;

[0023] The estimating the remaining life of the target silicon carbide device according to the voltage oscillation peak increment, the chip junction temperature difference and the turn-on delay time difference of the target silicon carbide device when the target silicon carbide device is turned on for the current operation includes:

[0024] Obtain historical samples of voltage oscillation peak increment, chip junction temperature difference, turn-on delay time difference, and crack length;

[0025] Perform fitting based on the voltage oscillation peak value increment historical samples, the chip junction temperature difference historical samples, the turn-on delay time difference historical samples, and the crack length historical samples to obtain a crack length fitting relationship;

[0026] Determining an estimated crack length of the target silicon carbide device at the current time based on the crack length fitting relationship and according to the voltage oscillation peak increment, the chip junction temperature difference, and the turn-on delay time difference of the target silicon carbide device when the device is turned on at the current time;

[0027] The remaining power cycle number of the target silicon carbide device is determined according to the crack length estimation value, the drain current effective value, and the critical failure crack length; wherein the remaining power cycle number is used to characterize the remaining life of the target silicon carbide device; wherein the remaining power cycle number is:

[0028]

[0029] Where, is the number of remaining power cycles, is the material parameter, is the critical failure crack length, is the estimated crack length, is the chip junction temperature difference, p and q are load indexes, and m is the crack growth index. is the effective value of the drain current.

[0030] Preferably, the method further comprises:

[0031] Obtaining an actual crack length of the target silicon carbide device, and updating the crack growth index according to an error between the actual crack length and the estimated crack length;

[0032] The remaining number of power cycles is updated according to the updated crack growth index.

[0033] In a second aspect, the present invention further provides a silicon carbide device bonding wire fatigue state assessment system, comprising:

[0034] The first monitoring module is used to obtain the voltage oscillation peak value of the target silicon carbide device when it is turned on;

[0035] The second monitoring module is used to obtain the chip junction temperature of the target silicon carbide device when it is turned on;

[0036] The third monitoring module is used to obtain the activation delay of the target silicon carbide device when it is activated;

[0037] The control operation unit is used to determine the voltage oscillation peak increment, the chip junction temperature difference and the turn-on delay time difference based on the voltage oscillation peak value, the chip junction temperature and the turn-on delay during the current turn-on operation, as well as the voltage oscillation peak value, the chip junction temperature and the turn-on delay during the previous turn-on operation; it is also used to standardize the voltage oscillation peak increment, the chip junction temperature difference and the turn-on delay time difference respectively to obtain the voltage oscillation peak increment standard value, the chip junction temperature difference standard value and the turn-on delay time difference standard value; it is also used to perform weighted calculation on the voltage oscillation peak increment standard value, the chip junction temperature difference standard value and the turn-on delay time difference standard value to obtain the bonding wire fatigue index of the target silicon carbide device; it is also used to determine the bonding wire fatigue state of the target silicon carbide device based on the bonding wire fatigue index.

[0038] In a third aspect, the present invention further provides an electronic device comprising a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the method for evaluating the fatigue state of the bonding wire of a silicon carbide device as described in the first aspect.

[0039] In a fourth aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements the steps of the method for evaluating the fatigue state of a bonding wire of a silicon carbide device as described in the first aspect.

[0040] In a fifth aspect, the present invention further provides a computer program product, comprising a computer program stored on a non-transitory computer-readable storage medium, wherein the computer program comprises program instructions, wherein when the program instructions are executed by a computer, the computer is caused to execute the steps of the method for evaluating the fatigue state of the bonding wire of a silicon carbide device as described in the first aspect.

[0041] It can be seen from the above technical solution that the present invention obtains the voltage oscillation peak value, chip junction temperature and turn-on delay of the target silicon carbide device when it is turned on at the current time, as well as the voltage oscillation peak value, chip junction temperature and turn-on delay when it was turned on for the previous time through multiple data sources, determines the voltage oscillation peak increment, chip junction temperature difference and turn-on delay time difference, and obtains the per-unit value of the voltage oscillation peak increment, the per-unit value of the chip junction temperature difference and the per-unit value of the turn-on delay time difference by standardizing them. By performing weighted calculation on the per-unit value of the voltage oscillation peak increment, the per-unit value of the chip junction temperature difference and the per-unit value of the turn-on delay time difference, the bonding wire fatigue index of the target silicon carbide device is obtained. The bonding wire fatigue state of the target silicon carbide device is determined using the bonding wire fatigue index, thereby achieving accurate assessment of the device health state, providing a reliable basis for subsequent maintenance decisions, ensuring long-term stable operation of the system, and reducing the risk of failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 A diagram illustrating an application environment of a method for evaluating the fatigue state of bonding wires in a silicon carbide device provided by an embodiment of the present invention;

[0044] Figure 2 A schematic diagram of the structure of an equivalent circuit model for transient analysis of a silicon carbide MOSFET switch taking into account parasitic parameters provided by an embodiment of the present invention;

[0045] Figure 3 A flowchart of a method for evaluating the fatigue state of a bonding wire of a silicon carbide device provided in an embodiment of the present invention;

[0046] Figure 4 A schematic structural diagram of a silicon carbide device bonding wire fatigue state assessment system provided by an embodiment of the present invention;

[0047] Figure 5 A schematic structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0049] The method for evaluating the fatigue state of the bonding wire of a silicon carbide device provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown, the terminal 101 communicates with the server 102 via a network. The data storage system can store data that the server 102 needs to process. The data storage system can be integrated on the server 102 or placed on the cloud or other network servers. The terminal 101 or the server 102 obtains the voltage oscillation peak value, the chip junction temperature and the turn-on delay of the target silicon carbide device when it is currently turned on through multiple data sources; determines the voltage oscillation peak value increment, the chip junction temperature difference and the turn-on delay time difference based on the voltage oscillation peak value, the chip junction temperature and the turn-on delay during the current turn-on, as well as the voltage oscillation peak value, the chip junction temperature difference and the turn-on delay during the previous turn-on; respectively normalizes the voltage oscillation peak value increment, the chip junction temperature difference and the turn-on delay time difference to obtain the per-unit value of the voltage oscillation peak value increment, the per-unit value of the chip junction temperature difference and the per-unit value of the turn-on delay time difference; performs weighted calculation on the per-unit value of the voltage oscillation peak value increment, the per-unit value of the chip junction temperature difference and the per-unit value of the turn-on delay time difference to obtain the bonding wire fatigue index of the target silicon carbide device; and determines the bonding wire fatigue state of the target silicon carbide device based on the bonding wire fatigue index.

[0050] The terminal 101 may be, but is not limited to, various personal computers, laptops, smart phones, tablet computers, and the like.

[0051] The server 102 may be an independent physical server, a server cluster or a distributed system composed of multiple physical servers, or a cloud server that provides cloud computing services.

[0052] like Figure 2 As shown in the figure, a switching transient analytical model of multiple devices in parallel is constructed for the switching process of silicon carbide MOSFET devices, and the relationship between the voltage and current of the circuit at each stage of the turn-on process is analyzed. In the current rising stage, the following expression can be obtained by Kirchhoff's law:

[0053]

[0054]

[0055]

[0056]

[0057] Where i d is the drain current, g fs is the device transconductance, u gs is the gate-source voltage, U th is the threshold voltage, i g is the gate current, C gs 、C gd are the gate-source capacitance and gate-drain capacitance respectively, u gd is the gate-drain voltage, U GH is the gate driver voltage, u ds is the drain-source voltage, U DD is the bus voltage, L loop is the sum of the inductance values ​​of the power circuit.

[0058] By combining and deducing, we finally get the relationship between the aging precursor parameters and the various parameters in the device. Since bond wire fatigue will cause the parasitic inductance in the device to increase, and the increased parasitic inductance will cause the voltage oscillation between the drain and source to increase, the voltage oscillation peak can be expressed by the following expression:

[0059]

[0060] Where U peak is the drain-source voltage oscillation peak value, I0 is the instantaneous value of the load current at the moment of turn-on, C oss is the output capacitance of the device.

[0061] Therefore, the voltage oscillation peak can be used to reflect bond wire degradation to a certain extent. However, using only the voltage oscillation peak to monitor bond wire fatigue can lead to poor monitoring stability. Considering that when a bond wire fails, the current density at the failure point increases, Joule heat accumulates, and the local junction temperature increases abnormally. For multi-chip parallel modules, bond wire degradation leads to more uneven current distribution and even more uneven chip temperature distribution.

[0062] At the same time, the source parasitic inductance increases after the bond wire degrades, which will lead to an increase in the device's turn-on delay and turn-off delay. The turn-on delay expression is:

[0063]

[0064] Where, t d(on) For opening delay, C iss is the input capacitance.

[0065] In the embodiment of the present application, the drain-source voltage oscillation peak value, the chip junction temperature and the switching delay time are used together as monitoring parameters for monitoring the fatigue state of the device bonding wire.

[0066] like Figure 3 As shown, the embodiment of the present application provides a method for evaluating the fatigue state of a bonding wire of a silicon carbide device. Figure 1 The terminal 101 or the server 102 in the embodiment is used as an example to illustrate the method, which includes the following steps S1 to S5.

[0067] Step S1: obtaining the voltage oscillation peak value, chip junction temperature and turn-on delay of the target silicon carbide device when it is turned on through multiple data sources.

[0068] Among them, the voltage oscillation peak, chip junction temperature and turn-on delay are obtained at the moment the target SiC device is turned on.

[0069] Data sources can be various sensors, monitoring devices, or data logging systems configured to monitor and record key parameters of SiC devices during operation in real time. For example, voltage oscillation peaks can be acquired using high-precision voltage sensors connected to SiC devices; chip junction temperature can be measured using temperature sensors integrated within the device or infrared thermal imaging equipment; and turn-on delay can be determined by monitoring the device's gate control signal and drain current waveform. These data sources can transmit the collected data to terminal 101 or server 102 in real time or periodically for subsequent processing and analysis. By comprehensively utilizing the information provided by these data sources, accurate assessment of the fatigue state of SiC device bond wires can be achieved.

[0070] Step S2, determining the voltage oscillation peak value increment, the chip junction temperature difference, and the turn-on delay time difference based on the voltage oscillation peak value, the chip junction temperature, and the turn-on delay during the current turn-on operation, as well as the voltage oscillation peak value, the chip junction temperature, and the turn-on delay during the previous turn-on operation;

[0071] The voltage oscillation peak increment is the difference between the current voltage oscillation peak and the previous voltage oscillation peak, the chip junction temperature difference is the difference between the current chip junction temperature and the previous chip junction temperature, and the turn-on delay difference is the difference between the current turn-on delay and the previous turn-on delay. These differences allow for more accurate evaluation.

[0072] Step S3: standardize the voltage oscillation peak value increment, the chip junction temperature difference, and the turn-on delay time difference respectively to obtain the voltage oscillation peak value increment per unit value, the chip junction temperature difference per unit value, and the turn-on delay time difference per unit value.

[0073] The per-unit value of the voltage oscillation peak increment is obtained by dividing the voltage oscillation peak increment by the preset reference value. The per-unit value of the chip junction temperature difference is obtained by dividing the chip junction temperature difference by the maximum junction temperature allowed by the device. The per-unit value of the turn-on delay time difference is obtained by dividing the turn-on delay time difference by the turn-on delay time of a healthy device. All parameters are compared on the same scale.

[0074] Step S4: performing weighted calculation on the per-unit value of the voltage oscillation peak increment, the per-unit value of the chip junction temperature difference, and the per-unit value of the turn-on delay time difference to obtain a bonding wire fatigue index of the target silicon carbide device.

[0075] The embodiment of the present application uses expert experience or entropy weight method to determine the weight of each per-unit value, and comprehensively evaluates it through a weighted summation formula to ensure that the result is objective and accurate. Ultimately, the bond wire fatigue index of the target silicon carbide device is:

[0076]

[0077] Where, ΔU peak is the drain-source voltage oscillation peak increment, U ref is the voltage reference value of the healthy device, ΔT j is the maximum temperature difference of the chip junction temperature, T max is the maximum junction temperature allowed by the device, Δt d(on) is the difference between the turn-on delay time of the current state and the healthy device, t d0 is the turn-on delay time of the healthy device, and α, β, and γ are weight coefficients.

[0078] Among them, the bond wire fatigue index is a key indicator to measure the degree of device performance degradation. The higher the value, the more serious the fatigue, and timely maintenance or replacement is required to ensure stable operation of the system.

[0079] Step S5: Determine the bonding wire fatigue state of the target silicon carbide device according to the bonding wire fatigue index.

[0080] The bond wire fatigue index is compared to a preset threshold. If the index exceeds the threshold, it is determined to be fatigued and appropriate measures must be taken. If it does not exceed the threshold, it is determined to be normal and monitoring continues. This method effectively prevents device failures and extends service life.

[0081] It should be noted that the embodiment of the present application obtains the voltage oscillation peak value, chip junction temperature and turn-on delay of the target silicon carbide device when it is turned on at the current time, as well as the voltage oscillation peak value, chip junction temperature and turn-on delay when it was turned on for the previous time through multiple data sources, determines the voltage oscillation peak increment, chip junction temperature difference and turn-on delay time difference, and obtains the voltage oscillation peak increment per unit value, chip junction temperature difference per unit value and turn-on delay time difference per unit value by standardizing them. By weighted calculation of the voltage oscillation peak increment per unit value, chip junction temperature difference per unit value and turn-on delay time difference per unit value, the bonding wire fatigue index of the target silicon carbide device is obtained. The bonding wire fatigue state of the target silicon carbide device is determined using the bonding wire fatigue index, thereby achieving accurate assessment of the device health state, providing a reliable basis for subsequent maintenance decisions, ensuring long-term stable operation of the system, and reducing the risk of failure.

[0082] In some embodiments, the method further comprises:

[0083] The voltage oscillation peak, chip junction temperature and turn-on delay are filtered and noise reduced respectively.

[0084] In order to improve the accuracy of monitoring parameter sampling and the stability of monitoring results, the sampled data is filtered and denoised. Here, the wavelet transform-singular value decomposition method is selected to perform joint denoising on the parameters:

[0085]

[0086] Where x(t) is the original signal, c j,k is the wavelet packet coefficient, which represents the energy intensity of the signal in frequency subband j and time position k, ψ j,k (t) is the wavelet packet function, which is obtained by scaling and translating the mother wavelet, σ i is a singular value, which represents the energy weight of the signal component, η is an adaptive threshold, which is dynamically adjusted according to the statistical characteristics of the switching transient noise, I(σ i >η) is the indicator function, which filters out the noise component. When σ i >η takes 1, otherwise takes 0.

[0087] This combined noise reduction method effectively improves data quality, ensures the accuracy of the bond wire fatigue index, further enhances the reliability and safety of system operation, reduces the misjudgment rate, extends the actual service life of the device, and reduces maintenance costs.

[0088] In some embodiments, determining a bonding wire fatigue state of a target silicon carbide device according to a bonding wire fatigue index includes:

[0089] Step S501: obtaining a first fatigue index threshold, a second fatigue index threshold, and a third fatigue index threshold for determining a fatigue state of a bonding wire; wherein the values ​​of the first fatigue index threshold, the second fatigue index threshold, and the third fatigue index threshold are in ascending order.

[0090] The first, second, and third fatigue index thresholds correspond to mild, moderate, and severe fatigue states, respectively. By comparing the bond wire fatigue index with these thresholds, the device fatigue level can be determined and appropriate maintenance measures can be taken to ensure stable system operation.

[0091] Step S502: When the bonding wire fatigue index is less than a first fatigue index threshold, it is determined that the bonding wire fatigue state of the target silicon carbide device is a healthy state.

[0092] Among them, the healthy status means that the device bonding wires show no obvious signs of fatigue, no additional maintenance is required, and can continue to be used normally to ensure the efficient operation of the system.

[0093] Step S503: If the bonding wire fatigue index is not less than the first fatigue index threshold and less than the second fatigue index threshold, determining that the bonding wire fatigue state of the target silicon carbide device is a prompt fatigue state;

[0094] Among them, the fatigue state indicates that the device bonding wire shows slight signs of fatigue, which requires regular monitoring and preventive maintenance measures to prevent further deterioration.

[0095] Step S504: if the bonding wire fatigue index is not less than the second fatigue index threshold and less than the third fatigue index threshold, determining that the bonding wire fatigue state of the target silicon carbide device is a fatigue warning state;

[0096] Among them, the fatigue warning state means that the device bonding wire shows obvious signs of fatigue, and maintenance measures must be taken immediately to avoid failures and ensure the safe operation of the system.

[0097] Step S505: If the bonding wire fatigue index is not less than a third fatigue index threshold, it is determined that the bonding wire fatigue state of the target silicon carbide device is a complete fatigue state.

[0098] Full fatigue indicates that the device's bond wires are severely fatigued and require immediate replacement to prevent system crashes and ensure device safety. This hierarchical early warning mechanism effectively extends device life and improves overall system stability.

[0099] It should be noted that, based on actual application requirements, multiple thresholds are set for the bond wire fatigue index, corresponding to different degrees of bond wire fatigue. The measured bond wire fatigue index is compared with the preset thresholds to determine the device's bond wire fatigue aging status. If the monitored value exceeds a certain threshold, a corresponding alarm signal is issued and the current status information is recorded.

[0100] The bond wire fatigue states described above progress from healthy, warning, and fully fatigued, reflecting the full progression of device bond wire fatigue from normal to severe. Each state has clear criteria and countermeasures, ensuring timely intervention at each fatigue stage, maximizing device lifespan and ensuring long-term stable system operation.

[0101] In some embodiments, the method further comprises:

[0102] According to the bonding wire fatigue state of the target silicon carbide device, a maintenance method for the target silicon carbide device is matched in a preset maintenance database; wherein the preset maintenance database includes a mapping relationship between the bonding wire fatigue state and the maintenance method.

[0103] Maintenance methods include, but are not limited to, planned maintenance, power-restricted operation, and immediate shutdown for overhaul. For example, the first, second, and third fatigue index thresholds are set to 0.3, 0.5, and 0.8, respectively. After normalizing the bond wire fatigue index, the normalized bond wire fatigue index is compared with the first, second, and third fatigue index thresholds. When the normalized index is between 0.3 and 0.5, planned maintenance is performed; when it is between 0.5 and 0.8, power operation is restricted; and when it exceeds 0.8, the system is immediately shut down for overhaul to ensure safety. At the same time, once the degree of bond wire fatigue aging is detected to exceed the preset threshold, the system immediately issues an alarm signal, with the LED indicator flashing and the buzzer sounding. At the same time, the system records and stores alarm information, including alarm time, alarm type, etc., for subsequent analysis and processing. Based on the monitoring results, the system can provide corresponding maintenance recommendations, such as replacing SiC MOSFET devices and checking bond wire connections.

[0104] To eliminate the effects of temperature and load current on the monitoring method, double-pulse experiments were conducted under different temperature and load current conditions to obtain corresponding aging precursor parameter values. This data was used to fit a curve that correlated the bond wire fatigue index with temperature and load current, establishing a corresponding relationship between the bond wire fatigue index and temperature and load current. When temperature and load current change, simply updating the lookup table or refitting the mapping function ensures the accuracy of the monitoring results.

[0105] In some embodiments, the method further includes: estimating the remaining life of the target silicon carbide device based on the voltage oscillation peak increment, the chip junction temperature difference and the turn-on delay time difference of the target silicon carbide device when the target silicon carbide device is turned on for the current operation.

[0106] In order to effectively obtain the remaining service life of the silicon carbide MOSFET bonding wire, the mapping relationship between the number of failure cycles and the failure physical quantity is characterized by the power device life model, and the remaining service life of the power device is quantitatively evaluated.

[0107] Specifically, the remaining life of the target silicon carbide device is estimated based on the voltage oscillation peak increment, chip junction temperature difference and turn-on delay time difference of the target silicon carbide device when it is turned on, including:

[0108] Step S601, obtaining voltage oscillation peak value increment history samples, chip junction temperature difference history samples, turn-on delay time difference history samples, and crack length history samples;

[0109] Step S602: fitting the voltage oscillation peak value increment history samples, the chip junction temperature difference history samples, the turn-on delay time difference history samples, and the crack length history samples to obtain a crack length fitting relationship;

[0110] The crack length fitting relationship is established through multivariate regression analysis, comprehensively considering the interactions between various parameters to ensure fitting accuracy. This relationship, combined with real-time monitoring data, dynamically predicts crack growth trends, resulting in an accurate estimate of remaining life.

[0111] In actual applications, the failure of bonding wires is due to the difference in thermal expansion coefficients between the bonding wires and the materials inside the power device. This generates mechanical stress at the bonding wire interface, which leads to cracks. The cracks continue to expand during device operation until the bonding wire separates from the bonding interface, eventually causing bonding wire failure. Therefore, the bonding wire life model generally uses the fatigue crack growth law Paris law:

[0112]

[0113] Where a is the crack length in micrometers, N is the number of power cycles, C is the material constant, m is the crack growth index, and I rms is the effective value of the drain current.

[0114] Considering the collected voltage oscillation peak, chip junction temperature, and turn-on delay, the real-time conversion relationship between electrical parameters and crack length is proposed as follows:

[0115]

[0116] Where, is the crack length estimate, ωi is the weight, Φi is the sensitivity coefficient, obtained through simulation and experiment, X i These are electrical parameters, including voltage oscillation peak, chip junction temperature, and turn-on delay.

[0117] Through simulation and experiments, the mapping expression between electrical parameters and crack length is finally obtained:

[0118]

[0119] Step S603: determining an estimated crack length of the target silicon carbide device at the current time based on the crack length fitting relationship and the voltage oscillation peak increment, the chip junction temperature difference, and the turn-on delay difference of the target silicon carbide device when the device is turned on at the current time;

[0120] Among them, by inputting the voltage oscillation peak increment, chip junction temperature difference and turn-on delay time difference of the target silicon carbide device when it is turned on at the time through the crack length fitting relationship, the estimated value of the crack length of the target silicon carbide device at the time can be obtained.

[0121] Step S604: Determine the remaining power cycle number of the target silicon carbide device based on the estimated crack length, the effective value of the drain current, and the critical failure crack length; wherein the remaining power cycle number is used to characterize the remaining life of the target silicon carbide device; wherein the remaining power cycle number is:

[0122]

[0123] Where, is the number of remaining power cycles, is the material parameter, is the critical failure crack length, is the estimated crack length, is the chip junction temperature difference, p and q are load indices, which are dynamically adjusted with the load spectrum, and m is the crack growth index. is the effective value of the drain current.

[0124] The failure probability of the target silicon carbide device can be obtained by the following formula:

[0125]

[0126] Where, This model allows engineers to monitor device status in real time, provide early warning of potential failure risks, optimize maintenance strategies, extend equipment life, ensure stable system operation, and reduce operation and maintenance costs.

[0127] In some embodiments, the method further comprises:

[0128] Step S61: Acquire the actual crack length of the target silicon carbide device, and update the crack growth index according to the error between the actual crack length and the estimated crack length.

[0129] Among them, when the device is shut down for maintenance, if the error between the actual crack length and the estimated crack length is too large, the sensitivity coefficient of the life prediction can be self-repaired:

[0130]

[0131] Where θ new is the updated crack growth index, θ old is the crack growth index before update, γ is the learning rate, a actual is the actual crack length.

[0132] Step S62: Update the remaining number of power cycles according to the updated crack growth index.

[0133] It can be understood that the embodiment of the present application takes into account the influence of load transformation in the remaining life prediction method. When the error between the prediction result and the actual result is large, the model parameters can be self-corrected to improve the accuracy of life prediction.

[0134] In addition, by periodically inserting monitoring cycles during the operation of the converter, the status monitoring and life prediction of the silicon carbide MOSFET device can be achieved. The monitoring data can be obtained directly during the normal start-up process of the device without modifying the system circuit. It is non-invasive to the device equipment, and the monitoring will not affect the normal operation of the device equipment.

[0135] Based on the same inventive concept, an embodiment of the present application further provides a silicon carbide device bonding wire fatigue state assessment system for implementing the above-mentioned silicon carbide device bonding wire fatigue state assessment method.

[0136] The implementation solution provided by the system to solve the problem is similar to the implementation solution described in the above method. Therefore, the specific limitations in one or more embodiments of the silicon carbide device bonding wire fatigue state assessment system provided below can refer to the limitations of the silicon carbide device bonding wire fatigue state assessment method above, and will not be repeated here.

[0137] like Figure 4 As shown, an embodiment of the present application provides a silicon carbide device bonding wire fatigue state assessment system, comprising:

[0138] The first monitoring module 100 is used to obtain the voltage oscillation peak value of the target silicon carbide device when it is turned on;

[0139] The second monitoring module 200 is used to obtain the chip junction temperature of the target silicon carbide device when it is turned on;

[0140] The third monitoring module 300 is used to obtain the activation delay of the target silicon carbide device during the current activation operation;

[0141] The control operation unit 400 is used to determine the voltage oscillation peak increment, the chip junction temperature difference and the turn-on delay time difference based on the voltage oscillation peak value, the chip junction temperature and the turn-on delay during the current turn-on operation, as well as the voltage oscillation peak value, the chip junction temperature and the turn-on delay during the previous turn-on operation; it is also used to standardize the voltage oscillation peak increment, the chip junction temperature difference and the turn-on delay time difference respectively to obtain the voltage oscillation peak increment standard value, the chip junction temperature difference standard value and the turn-on delay time difference standard value; it is also used to perform weighted calculation on the voltage oscillation peak increment standard value, the chip junction temperature difference standard value and the turn-on delay time difference standard value to obtain the bonding wire fatigue index of the target silicon carbide device; it is also used to determine the bonding wire fatigue state of the target silicon carbide device based on the bonding wire fatigue index.

[0142] In some embodiments, the system also includes an analog-to-digital conversion circuit. Each time the device is turned on, the control unit 100 issues a conversion instruction to the analog-to-digital conversion circuit. The analog-to-digital conversion circuit then converts the captured analog voltage signal (voltage oscillation peak value, chip junction temperature, and turn-on delay) into a digital signal and stores it in the control unit's memory. Finally, the control unit performs preprocessing on the stored digital signal, such as filtering and noise reduction.

[0143] In some embodiments, the system further comprises:

[0144] The noise reduction module is used to filter and reduce noise on the voltage oscillation peak, chip junction temperature and turn-on delay respectively.

[0145] In some embodiments, the control computing unit 400 is configured to:

[0146] Obtaining a first fatigue index threshold, a second fatigue index threshold, and a third fatigue index threshold for determining a fatigue state of a bonding wire; wherein the values ​​of the first fatigue index threshold, the second fatigue index threshold, and the third fatigue index threshold are in ascending order;

[0147] When the bonding wire fatigue index is less than a first fatigue index threshold, determining that the bonding wire fatigue state of the target silicon carbide device is a healthy state;

[0148] When the bonding wire fatigue index is not less than the first fatigue index threshold and less than the second fatigue index threshold, determining that the bonding wire fatigue state of the target silicon carbide device is a prompt fatigue state;

[0149] When the bonding wire fatigue index is not less than the second fatigue index threshold and less than the third fatigue index threshold, it is determined that the bonding wire fatigue state of the target silicon carbide device is a fatigue warning state;

[0150] When the bonding wire fatigue index is not less than the third fatigue index threshold, it is determined that the bonding wire fatigue state of the target silicon carbide device is a complete fatigue state.

[0151] In some embodiments, the system further comprises:

[0152] The maintenance determination module is used to match the maintenance method for the target silicon carbide device in a preset maintenance database according to the fatigue state of the bonding wire of the target silicon carbide device; wherein the preset maintenance database contains a mapping relationship between the fatigue state of the bonding wire and the maintenance method.

[0153] In some embodiments, the system further includes: a lifespan estimation module for estimating the remaining lifespan of the target silicon carbide device based on a voltage oscillation peak increment, a chip junction temperature difference, and a turn-on delay time difference of the target silicon carbide device when the target silicon carbide device is turned on for the current operation;

[0154] Specifically, the lifespan estimation module is used to:

[0155] Obtain historical samples of voltage oscillation peak increment, chip junction temperature difference, turn-on delay time difference, and crack length;

[0156] The crack length fitting relationship is obtained by fitting the historical samples of voltage oscillation peak increment, chip junction temperature difference, turn-on delay time difference and crack length.

[0157] Based on the crack length fitting relationship, the estimated crack length of the target SiC device at the time of turn-on is determined according to the voltage oscillation peak increment, chip junction temperature difference and turn-on delay difference of the target SiC device at the time of turn-on;

[0158] The remaining power cycle number of the target silicon carbide device is determined based on the crack length estimate, the drain current effective value, and the critical failure crack length. The remaining power cycle number is used to characterize the remaining life of the target silicon carbide device. The remaining power cycle number is:

[0159]

[0160] Where, is the number of remaining power cycles, is the material parameter, is the critical failure crack length, is the estimated crack length, is the chip junction temperature difference, p and q are load indexes, and m is the crack growth index. is the effective value of the drain current.

[0161] In some embodiments, the system further includes an update module configured to:

[0162] Obtaining the actual crack length of the target silicon carbide device and updating the crack growth index based on the error between the actual crack length and the estimated crack length;

[0163] The remaining number of power cycles is updated according to the updated crack growth index.

[0164] like Figure 5 As shown, an embodiment of the present application provides an electronic device, the electronic device 10 includes a memory 20 and a processor 30, the memory 20 stores a computer program, and when the computer program is executed by the processor 30, the processor 30 executes the steps of the method for evaluating the fatigue state of the bonding wire of the silicon carbide device as in the above embodiment.

[0165] An embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed, the steps of the method for evaluating the fatigue state of a bonding wire of a silicon carbide device as described in the above embodiment are implemented.

[0166] An embodiment of the present application provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer executes the steps of the method for evaluating the fatigue state of a bonding wire of a silicon carbide device as described in the above embodiment.

[0167] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described systems, electronic devices, computer storage media, and computer program products can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0168] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0169] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0170] In the several embodiments provided by the present invention, it should be understood that the disclosed systems, electronic devices, computer storage media, computer program products and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0171] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0172] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0173] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for executing all or part of the steps of the method described in each embodiment of the present invention via a computer device (which can be a personal computer, server, or network device, etc.). The aforementioned storage medium includes various media that can store program code, such as a USB flash drive, a mobile hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0174] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for evaluating the fatigue state of bonding wires of a silicon carbide device, characterized in that: include: Obtain the voltage oscillation peak, chip junction temperature, and turn-on delay of the target silicon carbide device when it is turned on through multiple data sources; Determine the voltage oscillation peak value increment, the chip junction temperature difference and the turn-on delay time difference according to the voltage oscillation peak value, the chip junction temperature and the turn-on delay during the current turn-on operation, and the voltage oscillation peak value, the chip junction temperature and the turn-on delay during the previous turn-on operation; The voltage oscillation peak value increment, the chip junction temperature difference and the turn-on delay time difference are respectively normalized to obtain a per-unit value of the voltage oscillation peak value increment, a per-unit value of the chip junction temperature difference and a per-unit value of the turn-on delay time difference; Performing weighted calculation on the voltage oscillation peak increment per unit value, the chip junction temperature difference per unit value, and the turn-on delay time difference per unit value to obtain a bonding wire fatigue index of the target silicon carbide device; A bonding wire fatigue state of the target silicon carbide device is determined according to the bonding wire fatigue index.

2. The method for evaluating the fatigue state of bonding wires of silicon carbide devices according to claim 1, wherein: Also includes: Filtering and noise reduction processing is performed on the voltage oscillation peak, the chip junction temperature and the turn-on delay respectively.

3. The method for evaluating the fatigue state of bonding wires of silicon carbide devices according to claim 1, wherein: Determining the bonding wire fatigue state of the target silicon carbide device according to the bonding wire fatigue index includes: Obtaining a first fatigue index threshold, a second fatigue index threshold, and a third fatigue index threshold for determining a fatigue state of a bonding wire; wherein the values ​​of the first fatigue index threshold, the second fatigue index threshold, and the third fatigue index threshold are arranged in ascending order; When the bonding wire fatigue index is less than the first fatigue index threshold, determining that the bonding wire fatigue state of the target silicon carbide device is a healthy state; When the bonding wire fatigue index is not less than the first fatigue index threshold and less than the second fatigue index threshold, determining that the bonding wire fatigue state of the target silicon carbide device is a prompt fatigue state; When the bonding wire fatigue index is not less than the second fatigue index threshold and less than the third fatigue index threshold, determining that the bonding wire fatigue state of the target silicon carbide device is a fatigue warning state; When the bonding wire fatigue index is not less than the third fatigue index threshold, it is determined that the bonding wire fatigue state of the target silicon carbide device is a complete fatigue state.

4. The method for evaluating the fatigue state of bonding wires of silicon carbide devices according to claim 2, wherein: Also includes: According to the bonding wire fatigue state of the target silicon carbide device, a maintenance method for the target silicon carbide device is matched in a preset maintenance database; wherein the preset maintenance database includes a mapping relationship between the bonding wire fatigue state and the maintenance method.

5. The method for evaluating the fatigue state of bonding wires of silicon carbide devices according to claim 1, wherein: Also includes: estimating the remaining life of the target silicon carbide device according to a voltage oscillation peak increment, a chip junction temperature difference, and a turn-on delay time difference of the target silicon carbide device when the target silicon carbide device is turned on for the current operation; The estimating the remaining life of the target silicon carbide device according to the voltage oscillation peak increment, the chip junction temperature difference and the turn-on delay time difference of the target silicon carbide device when the target silicon carbide device is turned on for the current operation includes: Obtain historical samples of voltage oscillation peak increment, chip junction temperature difference, turn-on delay time difference, and crack length; Perform fitting based on the voltage oscillation peak value increment historical samples, the chip junction temperature difference historical samples, the turn-on delay time difference historical samples, and the crack length historical samples to obtain a crack length fitting relationship; Determining an estimated crack length of the target silicon carbide device at the current time based on the crack length fitting relationship and according to the voltage oscillation peak increment, the chip junction temperature difference, and the turn-on delay time difference of the target silicon carbide device when the device is turned on at the current time; The remaining power cycle number of the target silicon carbide device is determined according to the crack length estimation value, the drain current effective value, and the critical failure crack length; wherein the remaining power cycle number is used to characterize the remaining life of the target silicon carbide device; wherein the remaining power cycle number is: Where, is the number of remaining power cycles, is the material parameter, is the critical failure crack length, is the estimated crack length, is the chip junction temperature difference, p and q are load indexes, and m is the crack growth index. is the effective value of the drain current.

6. The method for evaluating the fatigue state of bonding wires of silicon carbide devices according to claim 5, wherein: Also includes: Obtaining an actual crack length of the target silicon carbide device, and updating the crack growth index according to an error between the actual crack length and the estimated crack length; The remaining number of power cycles is updated according to the updated crack growth index.

7. A silicon carbide device bonding wire fatigue state assessment system, characterized in that: include: The first monitoring module is used to obtain the voltage oscillation peak value of the target silicon carbide device when it is turned on; The second monitoring module is used to obtain the chip junction temperature of the target silicon carbide device when it is turned on; The third monitoring module is used to obtain the activation delay of the target silicon carbide device when it is activated; a control calculation unit, configured to determine a voltage oscillation peak value increment, a chip junction temperature difference, and a turn-on delay time difference based on the voltage oscillation peak value, the chip junction temperature, and the turn-on delay during the current turn-on operation, as well as the voltage oscillation peak value, the chip junction temperature, and the turn-on delay during the previous turn-on operation; and further configured to normalize the voltage oscillation peak value increment, the chip junction temperature difference, and the turn-on delay time difference, respectively, to obtain a per-unit value of the voltage oscillation peak value increment, a per-unit value of the chip junction temperature difference, and a per-unit value of the turn-on delay time difference; It is also used to perform weighted calculation on the voltage oscillation peak increment per unit value, the chip junction temperature difference per unit value and the turn-on delay time difference per unit value to obtain the bonding wire fatigue index of the target silicon carbide device; and is also used to determine the bonding wire fatigue state of the target silicon carbide device based on the bonding wire fatigue index.

8. An electronic device, characterized in that: The electronic device includes a memory and a processor, wherein a computer program is stored in the memory. When the computer program is executed by the processor, the processor performs the steps of the method for evaluating fatigue state of bonding wires of a silicon carbide device according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed, the steps of the method for evaluating the fatigue state of a bonding wire of a silicon carbide device according to any one of claims 1 to 6 are implemented.

10. A computer program product, characterized in that The computer program product includes a computer program stored on a non-transitory computer-readable storage medium, wherein the computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer is caused to perform the steps of the method for assessing fatigue status of a bonding wire of a silicon carbide device according to any one of claims 1 to 6.

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