Method for monitoring packaging aging mode of power module in real time and related device

Abstract

The invention discloses a method for monitoring a packaging aging mode of a power module in real time and a related device, and belongs to the technical field of power electronic devices. According to the method, thermal network models corresponding to different packaging aging modes are established according to the structure of the power module, and frequency separation points corresponding to the different packaging aging modes are found; setting a test frequency, and collecting the conduction voltage drop of the power module and the load current of the inverter circuit; and analyzing the difference of the conduction voltage drop hysteretic curve according to the deviation or rotation of the conduction voltage drop hysteretic curve caused by different aging modes such as bonding wire falling, welding layer fatigue and heat dissipation system aging, and determining the packaging aging mode of the power module. By adopting the method, the packaging aging mode of the power module can be monitored in real time, aging reasons can be effectively distinguished, maintenance measures can be accurately taken, serious faults can be avoided, and the maintenance cost can be reduced; and meanwhile, the reliability and the stability of the whole system can be improved by monitoring and repairing the packaging aging problem in time.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronic devices, and in particular to a method and a related device for real-time monitoring of aging modes of power module packages. Background Art

[0002] Today, power electronic converters have been widely integrated into many cutting-edge fields such as new energy vehicles and renewable energy systems. As its core component, the reliability of the power module plays a vital role in ensuring the stable operation of the entire system.

[0003] The packaging structure of the power module undertakes the electrical connection, isolation protection, and heat dissipation of the insulated gate bipolar transistor (IGBT) and diode chips. During the long-term operation of the converter, the power module will be subject to periodic temperature fluctuations. Since the coefficient of thermal expansion (CTE) between the layers of packaging materials cannot be fully matched, the interconnection interface will be subject to long-term mechanical stress cycles, which will inevitably lead to the gradual degradation of the performance of the power module packaging structure until sudden overstress failure. In view of this, it is particularly important to introduce online monitoring technology to monitor the aging degree of the power module packaging structure in real time, conduct health assessment and proactive operation and maintenance. This can not only reduce the secondary damage caused by the sudden failure of the IGBT module, but also ensure the safe and reliable operation of the converter system.

[0004] In commonly used multi-chip parallel high-power IGBT modules, the main packaging aging modes include bonding wire shedding, solder layer fatigue, and cooling system aging. The bonding wire will gradually fatigue under long-term stress cycles and eventually fall off, causing the device to fail in an open circuit. Inside the IGBT module, the solder layer will have voids or delamination under long-term large temperature fluctuations; outside the module, the cooling system may also suffer from aging in the form of thermal interface material (TIM) drying, flow channel blockage, or fan dust accumulation after long-term operation. The aging of the solder layer and the cooling system will increase the thermal resistance of the device and the junction temperature, eventually leading to severe thermal collapse failure.

[0005] At present, in order to realize the condition monitoring of bonding wire aging, it is usually necessary to identify the changes in characteristic parameters of the power module during operation. Common ones include saturation voltage V CEsat , Miller platform time t GP , Gate peak current I G(peak)The main disadvantages of the existing methods are: they are mostly based on a single characteristic parameter and cannot distinguish complex and diverse aging modes; they are easily disturbed by working conditions and produce erroneous diagnostic results; they change the original control timing and working state, which is not conducive to the safety of the converter; the device switching speed is fast, and online extraction is difficult and costly. Therefore, it is still necessary to conduct in-depth research on the selection of characteristic parameters to characterize the aging of bond wires and their online extraction methods, so as to improve the performance of online monitoring technology in terms of safety, working condition immunity and extraction difficulty, so as to better adapt to complex and changeable field conditions.

[0006] For the aging of solder layer and heat dissipation system, the existing methods are mainly based on the Thermal Sensitive Electrical Parameter (TSEP) method, the steady-state case temperature method or the transient case temperature method. The TSEP method reflects the change of junction-to-ambient thermal resistance, including the junction-to-case thermal resistance of the device and the thermal resistance of the heat dissipation system. Therefore, it is impossible to distinguish whether the aging comes from the solder layer inside the module or the external heat dissipation system, which brings inconvenience to the maintenance and repair of power electronic devices. The steady-state case temperature method requires a certain number of temperature sensors to be placed at the bottom of the substrate of the IGBT module, which may affect the heat dissipation capacity of the device and also increase the cost of the device. The transient case temperature method cannot achieve real-time online monitoring.

[0007] In summary, there is still a lack of a mature solution to monitor the aging of power module packaging structures online and effectively distinguish different aging modes to achieve active operation and maintenance. Therefore, in-depth research on the method of distinguishing different failure modes is still needed to meet the urgent need for reliability of power electronic converters. Summary of the invention

[0008] The purpose of the present invention is to provide a method and related devices for real-time monitoring of the aging mode of power module packaging, so as to overcome the problems in the prior art that the power module status monitoring method cannot distinguish complex and diverse aging modes, online extraction is difficult and costly, and is easily affected by working conditions.

[0009] The present invention solves the above technical problems through the following technical solutions: A method for real-time monitoring of power module package aging mode comprises the following steps: S1. Obtain the structure of the power module, establish the thermal network model corresponding to different package aging modes, draw the amplitude-frequency characteristic curves of the thermal network model respectively, and obtain the frequency separation points corresponding to different package aging modes; S2. According to different frequency separation points, the test frequency of the power module is set, and the conduction voltage drop of the power module and the load current of the inverter circuit in one cycle are collected; S3, with the inverter circuit load current I as the horizontal axis, the conduction voltage drop V CEsatAs the vertical axis, draw the hysteresis curve HC_V of the healthy module CEsat And the hysteresis curve of the on-state voltage drop of the aging module HC_V CEsat * , analyze the differences of the above-mentioned on-state voltage drop hysteresis curves and determine the aging mode of the power module package, including: S31, based on the on-state voltage drop hysteresis curve HC_V CEsat and HC_V CEsat * , calculate the resistance increment △R introduced by the bond wire falling off CE , when the bonding wire falls off, the resistance increment △R CE ≤1%, the bonding wire has not aged; when the bonding wire falls off, the resistance increment △R CE When >1%, the power module package aging mode is bonding wire aging; S32, by subtracting ∆R CE The voltage drop caused by the aging module is corrected. The conduction voltage drop hysteresis curve HC_V CEsat * , and obtain the corrected on-state voltage drop hysteresis curve HC_ CEsat ** Based on this, we can get the junction temperature rising stage point P L_i The area of ​​the closed region enclosed by the horizontal and vertical coordinates is S L and the junction temperature drop stage point P H_i The area of ​​the closed region enclosed by the horizontal and vertical coordinates is S H Calculate the corrected aging module on-state voltage drop hysteresis curve HC_V CEsat ** The closed area S A and S H With S L The average value S B ; S33, calculate the hysteresis curve HC_V of the health module CEsat The closed area S A and S H With S L The average value S B , based on the modified S B and health module S B , calculate the rate of change △S B , when |△S B |≤10%, the power module is considered to be not aged. B |≥10%, based on the corrected S A and health module S A , calculate the rate of change △S A , when △S AWhen △S is less than 15%, the aging mode of the power module package is the aging of the cooling system; A When it is greater than 15%, the power module package aging mode is chip solder layer aging.

[0010] Furthermore, the thermal network model is a Cauer thermal network model.

[0011] Furthermore, the thermal resistance R of the Cauer thermal network model th and heat capacity C th It is obtained from the following formula:

[0012]

[0013] Among them, d, λ, c th , ρ are the thickness, thermal conductivity, specific heat capacity and density of the material respectively, and a is the side length of the equivalent cross section considering the influence of horizontal heat conduction.

[0014] Furthermore, the rate of change △S A Specifically: △S A =

[0015] Rate of change △S B Specifically: △S B = .

[0016] Furthermore, the junction temperature rise stage point P L_i The area of ​​the closed region enclosed by the horizontal and vertical coordinates is S L Specifically:

[0017] Point P during the junction temperature drop phase H_i The area of ​​the closed region enclosed by the horizontal and vertical coordinates is S H Specifically:

[0018] Among them, I H_i , V H_i P H_i The horizontal and vertical coordinates of I L_i , V L_i P L_i The horizontal and vertical coordinates of point P are m and n. H_i and P L_i The number of .

[0019] Furthermore, the on-state voltage drop hysteresis curve HC_V CEsat The closed area S A Specifically:

[0020] S H With S L The average value S B Specifically: .

[0021] Furthermore, the resistance increment △R introduced by the bond wire falling off CE Specifically:

[0022] Among them, I m is the zero temperature coefficient point; V mD For aging module I m The corresponding vertical coordinate; V mH For Health Module I m The corresponding vertical coordinate.

[0023] An electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for real-time monitoring of the aging mode of a power module package is implemented.

[0024] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned method for real-time monitoring of power module package aging mode.

[0025] A computer program product includes a computer program, and when the computer program is executed by a processor, the method for real-time monitoring of the aging mode of a power module package is implemented.

[0026] Compared with the prior art, the positive and progressive effects of the present invention are: The method and related device for real-time monitoring of the aging mode of power module package provided by the present invention establishes corresponding thermal network models under different package aging modes to reflect the heat conduction characteristics inside the module under different aging stages, sets appropriate test frequencies according to the frequency separation point, covers all possible package aging modes, and can more accurately monitor the aging mode of power module package; according to different aging modes such as bonding wire shedding, solder layer fatigue, and aging of the heat dissipation system, the conduction voltage drop hysteresis curve will be offset or rotated, and the difference of the conduction voltage drop hysteresis curve is analyzed to determine the package aging mode of the power module, which is more comprehensive and reliable than traditional single parameter monitoring. Through real-time monitoring, potential package aging problems can be discovered in time, thereby avoiding more serious failures, helping to reduce maintenance costs and improve equipment availability, and improving the reliability and stability of the entire system.

[0027] Furthermore, the Cauer thermal network model can accurately reflect the heat conduction process inside the power module with high estimation accuracy, and can more accurately reflect the temperature distribution inside the power module, thereby improving the accuracy of monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings in the specification are used to provide further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0029] Figure 1 It is the inverter circuit topology diagram; Figure 2 Schematic diagram of the packaging structure of the power module; Figure 3 It is a schematic diagram of the forward output characteristics of the power module in one cycle; Figure 4 It is a schematic diagram of the thermal network model; Figure 5 Bode plot of the thermal network model for cooling system aging; Figure 6 The Bode diagram of the chip solder layer aging thermal network model; Figure 7 It is a schematic diagram of the on-state voltage drop sampling circuit; Figure 8 It is the on-state voltage drop hysteresis curve corresponding to the healthy module; Fig. 9 The schematic diagram of the segmented processing of the hysteresis curve of the on-state voltage drop of the healthy module, where (a) is a schematic diagram of the hysteresis area; (b) is a schematic diagram of the linear area fitting result; Fig.10 The schematic diagram of the power module package aging mode monitoring process. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments, which are intended to explain the present invention rather than to limit it.

[0034] like Figure 1 As shown in FIG. 1 , the inverter circuit built with Infineon FF150R12ME3G power module is used as the test object, including auxiliary modules and the module under test; the package structure of the power module under test is as follows Figure 2 As shown, it includes IGBT chip, chip solder layer, copper layer 1, ceramic substrate, copper layer 2, system solder layer, substrate, thermal conductive silicone grease and peripheral devices. Due to the thermal capacitance effect of the material, there should be a certain phase difference between the junction temperature and loss of the device, and the current and loss have the same phase. Therefore, there should also be a phase difference between the current and the junction temperature in an output cycle. In chronological order, the following sequence can be extracted: P1(I1,T1) -P2(I3,T2) -P3(I4,T3) -P4(I6,T4) -P5(I7,T5) -P6(I8,T6) -P7(I5,T7) -P8(I2,T6) -P9(I1,T5). After marking and connecting the extracted sequence in order on the forward characteristic curve, V CEsat Hysteresis Curves (HC), defined as HC_V CEsat , see Figure 3 , the curve is divided into two parts from the zero temperature coefficient point, the left side is the hysteresis area, and the right side is the linear area. In the hysteresis area, the junction temperature rise stage HC_V CEsat The point is defined as P L_i , the area of ​​the closed area enclosed by the horizontal and vertical coordinates is S L ; The point during the junction temperature drop phase is defined as P H_i , the area of ​​the closed area enclosed by the horizontal and vertical coordinates is S H .

[0035] The reason for the hysteresis phenomenon is that the junction temperature corresponding to the same current is no longer the same during the current rise and fall phases in an output cycle. It can be predicted that when the average value of the junction temperature in a cycle increases, HC_V CEsat Will surround I m (zero temperature coefficient point) counterclockwise; when the fluctuation of junction temperature increases within a cycle, HC_V CEsat The area of ​​the closed area will increase accordingly. It is difficult to distinguish the aging of the solder layer and the heat dissipation system with traditional methods, because both of them will lead to an increase in the junction temperature. However, HC_V CEsatContains information about transient junction temperature changes within a cycle, so HC_V can be used to determine the temperature of the junction under different failure mechanisms. CEsat The difference between the two can be used to determine the aging mode of the power module package.

[0036] Based on the above analysis, a method for real-time monitoring of power module package aging mode is provided, comprising the following steps: S1. Obtain the structure of the power module, establish the thermal network model corresponding to different package aging modes, draw the amplitude-frequency characteristic curves of the thermal network model respectively, and obtain the frequency separation points corresponding to different package aging modes; S2. According to different frequency separation points, the test frequency of the power module is set, and the conduction voltage drop of the power module and the load current of the inverter circuit in one cycle are collected; S3, with the inverter circuit load current I as the horizontal axis, the conduction voltage drop V CEsat As the vertical axis, draw the hysteresis curve HC_V of the healthy module CEsat And the hysteresis curve of the on-state voltage drop of the aging module HC_V CEsat * , analyze the differences in the above-mentioned on-state voltage drop hysteresis curves and determine the aging mode of the power module package.

[0037] In order to obtain the change of transient junction temperature of power module under different failure mechanisms, the corresponding Cauer thermal network model is established. Figure 4 , the thermal resistance of each layer R th and heat capacity C th It can be determined by the following formula

[0038]

[0039] where d, λ, c th , ρ are the thickness, thermal conductivity, specific heat capacity and density of the material layer, respectively, and a is the side length of the equivalent cross section under the influence of horizontal heat conduction. Substituting various parameters of Infineon FF150R12ME3G power module into the calculation, the corresponding thermal network model can be obtained, as shown in Table 1.

[0040]

[0041] like Figures 5 and 6 As shown, according to the established thermal network model, the amplitude-frequency characteristic curves under different aging modes can be drawn. It can be seen that Figure 5 The aging of the cooling system in the main affects the response in the low frequency band. When the frequency exceeds the separation point f sp =0.5Hz, the frequency domain response of the aged IGBT module is similar to that of the healthy module. Figure 6The aging of the chip solder layer in has a similar law, except that the frequency corresponding to the separation point is higher, which is 100Hz.

[0042] It can be seen that for Infineon FF150R12ME3G power module, due to the different frequency separation points, when the output frequency is between 0.5 and 100 Hz, the dynamic thermal characteristics of the two failure mechanisms are different. In order to make the difference obvious enough, the test can be carried out under 1 Hz working condition. Under this working condition, the aging of the cooling system will not affect the junction temperature fluctuation, but only the average junction temperature T jav The aging of the chip solder layer will cause the junction temperature to fluctuate △T j Through this feature, the average junction temperature T can be estimated by monitoring the hysteresis curve of the on-state voltage drop in this area. jav and junction temperature fluctuation △T j and thus distinguish different aging mechanisms.

[0043] The S in one cycle H and S L It is expressed as:

[0044]

[0045] Where: I H_i , V H_i P H_i The horizontal and vertical coordinates of I L_i , V L_i P L_i The horizontal and vertical coordinates of point P are m and n. H_i and P L_i The number of .

[0046] When the average junction temperature T jav When rising, since the current is less than I m Time V CEsat Has a negative temperature coefficient, so S H and S L will decrease; when the junction temperature fluctuates △T j When rising, HC_V CEsat The area of ​​the enclosed area increases, that is, S H and S L In order to correspond to the aging model, S H and S L The relationship is converted into the following formula:

[0047]

[0048] Where: SA HC_V is the on-state voltage drop hysteresis curve CEsat The area of ​​the closed region, used to characterize △T j Changes in S B For S H With S L The average value is used to characterize the average junction temperature T jav Therefore, S A and S B The corresponding relationship with aging types can be summarized as follows: When S B When S A When S increases significantly, it can be judged that the thermal aging comes from the fatigue of the solder layer inside the device; A When it is approximately unchanged, it can be determined that the thermal aging comes from the heat dissipation system outside the device.

[0049] Further, according to S A and S B The state of the power module is judged by the rate of change of △S A Specifically:

[0050] Rate of change △S B for:

[0051] In order to monitor the aging degree of the power module bonding wire, it is necessary to further identify the impact of bonding wire aging on HC_V CEsat As a typical mechanism of package aging, bond wire shedding increases the resistance between the chip and the terminal, so HC_V CEsat will be shifted upward accordingly, which can be expressed as:

[0052] Among them HC_V CEsat * is the on-state voltage drop hysteresis curve of the aging module, HC_V CEsat is the on-state voltage drop hysteresis curve of the healthy module; △R CE The resistance increment introduced by the bond wire detachment can be calculated by the following formula:

[0053] In the formula, I m is the zero temperature coefficient point; V mD For aging module I m The corresponding vertical coordinate; V mH For Health Module I m The corresponding vertical coordinate.

[0054] Therefore, the on-line monitoring of various aging modes of power modules can be realized through the on-voltage drop hysteresis curve. The information to be collected during the monitoring process is the load current and on-voltage drop within a cycle. The on-voltage drop measurement circuit is as follows: Figure 7 As shown, the load current can be measured by the Hall device.

[0055] The healthy Infineon FF150R12ME3G power health module is marked as the tested module A, and it works in the test inverter circuit. The obtained HC_V CEsat like Figure 8 As shown. Limited by temperature sensitivity, I m The hysteresis phenomenon after point I is not as good as m So the on-state voltage drop hysteresis curve can be obtained by I m The points are divided into two regions, namely the hysteresis region and the linear region.

[0056] In a specific embodiment of the present invention, see Fig. 9 (a) Calculation of the S of the healthy module through the hysteresis region A =503.6mV·A and S B =1.43V·A.

[0057] Further obtain the S of the corrected aging module A and S B Then, △S can be obtained according to formulas (7) and (8) A and △S B .

[0058] See also Fig. 9 (b) The linear region can be fitted to obtain the corresponding linear function V CEsat =6.804×(I-40)+1208, where Im=40A is the inherent characteristic of the device, V mH =1208mV, further obtain the fitting function of the aging module in the linear region, and obtain V mD After that, △R can be calculated according to formula (10) CE .

[0059] Based on the above method, the HC_V of module A (healthy module), module B (bonding wire aging module), module C (chip solder layer aging module), and module D (heat dissipation system aging module) are measured respectively. CEsat , the measurement results are shown in Table 2: Table 2 HC_V under different aging modes CEsat Changes

[0060] It can be seen that the bonding wire aging module △R of module B CEobviously increased, while |△S B %|=5.6%, which is less than 10%, indicating that there is no other aging mode; Module C's cooling system aging module|△S B %|=34.3%, greater than 10%, and △S A =9.5%, less than 15%; chip solder layer aging module of module D |△S B %|=18.2%, greater than 10%, and △S A =34.6%, which is greater than 15%, and effectively distinguishes different aging modes of power modules. The above thresholds can be adjusted according to operating conditions and maintenance costs.

[0061] According to the test results, the monitoring process can be obtained as follows Fig.10 As shown, the summary is as follows: Extract (I[i], V CEsat [i]) After the complete sequence, ∆R is calculated CE , when the bonding wire falls off, the resistance increment △R CE When ≤1%, the bonding wire has not aged; When the bonding wire falls off, the resistance increment △R CE >1%, the power module package aging mode is bonding wire aging, and the IGBT module needs to be replaced; By subtracting ∆R CE The voltage drop caused by the aging module is corrected. The conduction voltage drop hysteresis curve HC_V CEsat * , and obtain the corrected on-state voltage drop hysteresis curve HC_ CEsat ** Based on this, we can get the junction temperature rising stage point P L_i The area of ​​the closed region enclosed by the horizontal and vertical coordinates is S L and the junction temperature drop stage point P H_i The area of ​​the closed region enclosed by the horizontal and vertical coordinates is S H Calculate the corrected aging module on-state voltage drop hysteresis curve HC_V CEsat ** The closed area S A and S H With S L The average value S B ; Calculate the hysteresis curve HC_V of the health module CEsat The closed area S A and S H With S L The average value S B , based on the modified S B and health module S B, calculate the rate of change △S B , when |△S B |≤10%, the power module is considered not to have aged and can continue to be used; When |△S B |≥10%, based on the corrected S A and health module S A , calculate the rate of change △S A , when △S A When ≤15%, the power module package aging mode is cooling system aging, and peripheral components such as cooling grease or fans need to be checked. When △S A When it is greater than 15%, the power module package aging mode is chip solder layer aging, and the IGBT module needs to be replaced.

[0062] The above process can be carried out in real-time communication with DSP on the computer or directly on DSP to realize online monitoring and diagnosis of various aging modes of IGBT modules. According to the diagnosis results, corresponding maintenance measures can be taken accordingly. The whole monitoring process is low-cost, high-reliability, high-precision and widely applicable.

[0063] Based on the same inventive concept, an embodiment of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method steps of real-time monitoring of the aging mode of the power module package when executing the computer program, wherein the memory may include a memory, such as a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk memory, etc.; the processor, the network interface, and the memory are interconnected through an internal bus, and the internal bus may be an industrial standard architecture bus, a peripheral component interconnection standard bus, an extended industrial standard structure bus, etc., and the bus may be divided into an address bus, a data bus, a control bus, etc. The memory is used to store programs, and specifically, the program may include a program code, and the program code includes computer operation instructions. The memory may include a memory and a non-volatile memory, and provide instructions and data to the processor.

[0064] Based on the same inventive concept, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method steps for real-time monitoring of the aging mode of the power module package are implemented. Specifically, the computer-readable storage medium includes, but is not limited to, for example, a volatile memory and / or a non-volatile memory. The volatile memory may include a random access memory (RAM) and / or a cache memory (cache), etc. The non-volatile memory may include a read-only memory (ROM), a hard disk, a flash memory, an optical disk, a magnetic disk, etc.

[0065] Based on the same inventive concept, an embodiment of the present application provides a computer program product, which includes a computer program stored on a computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer device, the computer device executes the above-mentioned method steps for real-time monitoring of the aging mode of the power module package.

[0066] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0067] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0068] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0069] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0070] Finally, it should be noted that the above-listed embodiments exist only as one or more specific forms of expression of the technical solution of the present invention. Their purpose is to clearly explain the concept, principle and application of the present invention through specific examples, and it is by no means intended to limit the protection scope of the present invention to these specific embodiments. In fact, the real value of the present invention lies in the technical ideas and innovations it proposes, rather than its form of expression or means of implementation.

[0071] For ordinary technicians in the relevant technical field, after in-depth reading and understanding of the technical solution of the present invention, they are fully capable of making various forms of changes, modifications or equivalent substitutions to the specific implementation methods of the invention based on their own professional knowledge and skills. These changes may include but are not limited to: adjusting the value range of technical parameters, optimizing algorithm processes to improve efficiency, replacing some technical components to achieve better compatibility or reduce costs, etc. As long as these changed technical solutions still substantially maintain the technical features claimed for protection by the original invention, that is, they can still achieve the core functions and effects of the present invention, then these changes should be deemed to fall within the scope of protection of the pending claims of the present invention.

[0072] In addition, with the continuous progress and development of technology, new technical means and methods continue to emerge, which also provides broad space for further improvement and perfection of the present invention. Therefore, the protection scope of the present invention should also include those reasonably foreseeable improvements and extensions based on the existing technology. As long as these improvements and extensions do not deviate from the basic principles and core concepts of the present invention, they should be regarded as equivalents of the present invention and are also protected by patent rights.

Claims

1. A method for real-time monitoring of power module package aging mode, characterized in that: The following steps are involved: S1. Obtain the structure of the power module, establish the thermal network model corresponding to different package aging modes, draw the amplitude-frequency characteristic curves of the thermal network model respectively, and obtain the frequency separation points corresponding to different package aging modes; S2. According to different frequency separation points, the test frequency of the power module is set, and the conduction voltage drop of the power module and the load current of the inverter circuit in one cycle are collected; S3, with the inverter circuit load current I as the horizontal axis, the conduction voltage drop V CEsat As the vertical axis, draw the hysteresis curve HC_V of the healthy module CEsat And the hysteresis curve of the on-state voltage drop of the aging module HC_V CEsat * , analyze the differences of the above-mentioned on-state voltage drop hysteresis curves and determine the aging mode of the power module package, including: S31, based on the on-state voltage drop hysteresis curve HC_V CEsat and HC_V CEsat * , calculate the resistance increment △R introduced by the bond wire falling off CE , when the bonding wire falls off, the resistance increment △R CE ≤1%, the bonding wire has not aged; when the bonding wire falls off, the resistance increment △R CE When >1%, the power module package aging mode is bonding wire aging; S32, by subtracting ∆R CE The voltage drop caused by the aging module is corrected. The conduction voltage drop hysteresis curve HC_V CEsat * , and obtain the corrected on-state voltage drop hysteresis curve HC_ CEsat ** Based on this, we can get the junction temperature rising stage point P L_i The area of ​​the closed region enclosed by the horizontal and vertical coordinates is S L and the junction temperature drop stage point P H_i The area of ​​the closed region enclosed by the horizontal and vertical coordinates is S H Calculate the corrected aging module on-state voltage drop hysteresis curve HC_V CEsat ** The closed area S A and S H With S L The average value S B ; S33, calculate the hysteresis curve HC_V of the health module CEsat The closed area S A and S H With S L The average value S B , based on the modified S B and health module S B , calculate the rate of change △S B , when |△S B |≤10%, the power module is considered to be not aged. B |≥10%, based on the corrected S A and health module S A , calculate the rate of change △S A , when △S A When △S is less than 15%, the aging mode of the power module package is the aging of the cooling system; A When it is greater than 15%, the power module package aging mode is chip solder layer aging.

2. The method for real-time monitoring of power module package aging mode according to claim 1, characterized in that: The thermal network model is a Cauer thermal network model.

3. The method for real-time monitoring of power module package aging mode according to claim 2, characterized in that: Thermal resistance R of Cauer thermal network model th and heat capacity C th It is obtained by the following formula: Among them, d, λ, c th , ρ are the thickness, thermal conductivity, specific heat capacity and density of the material respectively, and a is the side length of the equivalent cross section considering the influence of horizontal heat conduction.

4. The method for real-time monitoring of power module package aging mode according to claim 1, characterized in that: Rate of change △S A Specifically: △S A = Rate of change △S B Specifically: △S B = 5. The method for real-time monitoring of power module package aging mode according to claim 1, characterized in that: Point P during the junction temperature rise phase L_i The area of ​​the closed region enclosed by the horizontal and vertical coordinates is S L Specifically: Point P during the junction temperature drop phase H_i The area of ​​the closed region enclosed by the horizontal and vertical coordinates is S H Specifically: Among them, I H_i , V H_i P H_i The horizontal and vertical coordinates of I L_i , V L_i P L_i The horizontal and vertical coordinates of point P are m and n. H_i and P L_i The number of .

6. The method for real-time monitoring of power module package aging mode according to claim 1, characterized in that: On-state voltage drop hysteresis curve HC_V CEsat The closed area S A Specifically: S H With S L The average value S B Specifically:

7. The method for real-time monitoring of power module package aging mode according to claim 1, characterized in that: Resistance increment △R caused by bond wire detachment CE Specifically: Among them, I m is the zero temperature coefficient point; V mD For aging module I m The corresponding vertical coordinate; V mH For Health Module I m The corresponding vertical coordinate.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the method for real-time monitoring of the aging mode of a power module package as described in any one of claims 1 to 7 is implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for real-time monitoring of the aging mode of a power module package is implemented as claimed in any one of claims 1 to 7.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for real-time monitoring of the aging mode of a power module package is implemented as claimed in any one of claims 1 to 7.

Images