Method and device for determining service life of power module and storage medium

Abstract

The invention provides a method and device for determining the service life of a power module and a storage medium, the power module comprises a shell, a power semiconductor chip located in the shell and a heat conductor, the heat conductor located in the shell is in contact with the power semiconductor chip, and the method comprises the steps of obtaining a first temperature and a first function, the first temperature is the temperature of the heat conductor, and the first function is a relational expression of the first temperature, the material thermal resistance of the heat conductor, the environment temperature of the power module and the power loss of the power module and the heat conduction temperature difference of the heat conductor; calculating the junction temperature of the power module according to the first temperature and the first function; the transient thermal resistance of the power module is calculated at least according to the first temperature, the power loss and a second temperature, and the second temperature is the temperature of the shell; and determining the service life of the power module at least according to the transient thermal resistance, the junction temperature, the second temperature, the environment temperature and the power loss of the power module. The method solves the technical problem of inaccurate life estimation of the power module.

Description

Technical Field

[0001] The present application relates to the field of power modules, and in particular, to a method for determining the life of a power module, a device for determining the life of a power module, and a computer-readable storage medium. Background Art

[0002] With the continuous development of power electronics technology, power modules, as key components in power electronics devices, have evolved from single components to integrated intelligent power modules (IPMs). The life of power modules is crucial to the normal operation of equipment. Temperature is an important factor affecting the life of power modules. Therefore, timely and accurate monitoring of power module temperature is of great significance.

[0003] Therefore, a method is urgently needed to solve the problem of inaccurate life estimation of power modules in the prior art. Summary of the invention

[0004] The main purpose of the present application is to provide a method for determining the life of a power module, a device for determining the life of a power module, and a computer-readable storage medium, so as to at least solve the problem of inaccurate life estimation of a power module in the prior art.

[0005] According to one aspect of the present application, a method for determining the life of a power module is provided, wherein the power module comprises a shell, a power semiconductor chip located in the shell, and a heat conductor, wherein a portion of the heat conductor is located outside the shell, and another portion is located in the shell, and the heat conductor located in the shell is in contact with the power semiconductor chip. The method comprises: obtaining a first temperature and a first function, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal conductivity temperature difference of the heat conductor; calculating the junction temperature of the power module according to the first temperature and the first function; obtaining a second temperature and the power loss of the power module, and calculating the transient thermal resistance of the power module according to at least the first temperature, the power loss and the second temperature, wherein the second temperature is the temperature of the shell; determining the life of the power module according to at least the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature and the power loss of the power module.

[0006] Optionally, obtaining the first function includes: according to formula F 1 =-a×R c +b×T R -c×T E +d×P, calculate the first function F1 , where R c is the thermal resistance of the thermal conductor material, T R is the first temperature, T E is the ambient temperature, P is the power loss, and a, b, c, and d are pre-set coefficients greater than 0.

[0007] Optionally, calculating the junction temperature of the power module according to the first temperature and the first function includes: calculating the sum of the first temperature and the function value of the first function at the same moment to obtain the junction temperature.

[0008] Optionally, the power module also includes a heat sink, which is located on one side of the shell. The transient thermal resistance of the power module is calculated based on at least the first temperature, the power loss and the second temperature, including: obtaining the heat transfer efficiency of the power module in a predetermined direction, the predetermined direction being the direction in which the power semiconductor chip points to the heat sink; calculating the product of the heat transfer efficiency and the power loss to obtain a first value; the difference between the first temperature and the second temperature to obtain a second value; and calculating the ratio of the second value to the first value to obtain the transient thermal resistance.

[0009] Optionally, determining the life of the power module at least according to the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature and the power loss of the power module includes: obtaining the steady-state thermal resistance of the power module, the temperature gradient and the heat conduction time difference of the power module, wherein the temperature gradient is used to characterize the degree of temperature reduction of the power module in the heat conduction direction, the heat conduction time difference is the time difference corresponding to when the temperatures of the heat conductor and the shell are the same or the time difference between the start time of the predetermined time of the heat conductor and the start time of the predetermined time period of the shell, the predetermined time period is the time period corresponding to when the temperature of the heat conductor or the shell remains unchanged, and the duration of the predetermined time of the heat conductor is equal to the duration of the predetermined time period of the shell; calculating the life of the power module according to the transient thermal resistance, the steady-state thermal resistance, the junction temperature, the second temperature, the ambient temperature, the temperature gradient and the heat conduction time difference.

[0010] Optionally, obtaining the thermal conduction time difference includes: a first obtaining step of sequentially obtaining a plurality of first temperatures and a plurality of second temperatures, wherein the plurality of first temperatures are arranged in chronological order, and the plurality of second temperatures are arranged in chronological order; a first calculating step of calculating a change rate of each of the first temperatures within a unit time to obtain a plurality of first change rates; a second calculating step of calculating a change rate of each of the second temperatures within the unit time to obtain a plurality of second change rates; a first determining step of determining whether the first change rate and the second change rate corresponding to the same moment meet a preset condition; and a second determining step of determining whether the second change rate meets the preset condition if the first change rate and the second change rate corresponding to the same moment meet the preset condition. whether the first change rate is 0, wherein the preset condition is that the signs of the first change rate and the second change rate are the same or the first change rate is 0; a second acquisition step, when the second change rate is 0, acquiring the moment corresponding to the second change rate to obtain the second moment; a third determination step, when the first change rate and the second change rate corresponding to the same moment do not meet the preset condition, determining whether the second change rate is equal to the first change rate, and a third acquisition step, when the second change rate is equal to the first change rate, acquiring the moment corresponding to the first change rate to obtain the first moment; a third calculation step, calculating the difference between the second moment and the first moment to obtain the heat conduction time difference.

[0011] Optionally, after the first determination step, the method further includes: when the second change rate is not 0 or the second change rate is not equal to the first change rate, repeating the first acquisition step, the first calculation step, the second calculation step, the first determination step, the second determination step, the second acquisition step, the third determination step, the third acquisition step and the calculation step at least once in sequence until a predetermined number of repetitions is reached.

[0012] Optionally, calculating the life of the power module according to the transient thermal resistance, the steady-state thermal resistance, the junction temperature, the second temperature, the ambient temperature, the temperature gradient and the heat conduction time difference comprises: calculating the life of the power module according to formula F 2 =-e×(RR b )-f×(T J -T C )-g×(T J -T E )-h×ki×t, calculate the life of the power module F 2 , where R is the transient thermal resistance, R b is the steady-state thermal resistance, T J is the junction temperature, T C is the second temperature, T Eis the ambient temperature, k is the temperature gradient, t is the heat conduction time difference, and e, f, g, h, and i are pre-set coefficients greater than 0.

[0013] According to another aspect of the present application, a device for determining the life of a power module is provided, the power module comprising a shell, a power semiconductor chip located in the shell, and a heat conductor, a portion of the heat conductor being located outside the shell, and another portion being located in the shell, the heat conductor located in the shell being in contact with the power semiconductor chip, the device comprising: an acquisition unit, for acquiring a first temperature and a first function, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal conductivity temperature difference of the heat conductor; a first calculation unit, for calculating the junction temperature of the power module according to the first temperature and the first function; a second calculation unit, for acquiring a second temperature and the power loss of the power module, and calculating the transient thermal resistance of the power module according to at least the first temperature, the power loss and the second temperature, wherein the second temperature is the temperature of the shell; a determination unit, for determining the life of the power module according to at least the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature and the power loss of the power module.

[0014] According to another aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute any one of the methods described.

[0015] By applying the technical solution of the present application, a method for determining the life of a power module is provided. The power module includes a shell, a power semiconductor chip located in the shell, and a heat conductor, wherein the heat conductor located in the shell is in contact with the power semiconductor chip. First, a first temperature and a first function are obtained, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal temperature difference of the heat conductor; then, based on the first temperature and the first function, the junction temperature of the power module is calculated; then, based on at least the first temperature, the power loss, and the second temperature, the transient thermal resistance of the power module is calculated, wherein the second temperature is the temperature of the shell; finally, based on at least the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature, and the power loss of the power module, the life of the power module is determined. The temperature of the power semiconductor chip, i.e., the first temperature, is obtained through the heat conductor. Due to the good thermal conductivity of the heat conductor itself, the actual temperature of the power semiconductor chip can be obtained. The first function representing the influence of the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module on the thermal conductivity of the heat conductor can be used to calculate the accurate junction temperature. At the same time, the temperature of the power device housing, i.e., the second temperature, is obtained. The accurate transient thermal resistance value can be calculated by combining the first temperature and the power loss of the power module. Finally, the accurate life of the power module can be determined based on the transient thermal resistance, junction temperature, the second temperature, the ambient temperature, and the power loss of the power module, thereby solving the technical problem of inaccurate life estimation of the power module in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0017] Figure 1 A hardware structure block diagram of a mobile terminal for executing a method for determining the life of a power module provided in an embodiment of the present application is shown;

[0018] Figure 2 A schematic diagram of the structure of a power module provided according to an embodiment of the present application is shown;

[0019] Figure 3 A schematic flow chart of a method for determining the life of a power module provided in accordance with an embodiment of the present application is shown;

[0020] Figure 4 A schematic diagram of the internal structure of a power module provided in an embodiment of the present application is shown;

[0021] Figure 5A specific flow chart of a method for determining the life of a power module provided in an embodiment of the present application is shown;

[0022] Figure 6 A structural block diagram of a device for determining the life of a power module provided according to an embodiment of the present application is shown.

[0023] The above drawings include the following reference numerals:

[0024] 102, processor; 104, memory; 106, transmission device; 108, input / output device; 302, housing; 304, power semiconductor chip; 306, heat conductor; 308, heat dissipation device; 310, first connection part; 312, second connection part; 314, infrared temperature sensor; 316, packaging layer; 318, substrate layer; 320, thermistor. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising 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.

[0028] As introduced in the background technology, the life estimation of the power module in the prior art is inaccurate. To solve the above problem, the embodiments of the present application provide a method for determining the life of a power module, a device for determining the life of a power module, and a computer-readable storage medium.

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0030] The method embodiments provided in the embodiments of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Taking running on a mobile terminal as an example, Figure 1 FIG. 1 is a hardware structure block diagram of a mobile terminal of a method for determining the life of a power module according to an embodiment of the present invention. Figure 1 As shown, the mobile terminal may include one or more ( Figure 1 Only one is shown in the figure) a processor 102 (the processor 102 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA) and a memory 104 for storing data, wherein the mobile terminal may also include a transmission device 106 and an input / output device 108 for communication functions. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the mobile terminal. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations are shown.

[0031] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the method for determining the life of the power module in the embodiment of the present invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, the above method is implemented. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the above-mentioned network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof. The transmission device 106 is used to receive or send data via a network. The above-mentioned specific examples of the network may include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0032] In this embodiment, a method for determining the life of a power module running on a mobile terminal, a computer terminal or a similar computing device is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0033] like Figure 2 As shown, the power module includes a shell 302, a power semiconductor chip 304 located in the shell 302, and a heat conductor 306, a portion of the heat conductor 306 is located outside the shell 302, and another portion is located in the shell 302, and the heat conductor 306 located in the shell 302 is in contact with the power semiconductor chip 304. Figure 3 FIG. 1 is a flow chart of a method for determining the life of a power module according to an embodiment of the present application. Figure 3 As shown, the method comprises the following steps:

[0034] Step S201, obtaining a first temperature and a first function, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal conductivity temperature difference of the heat conductor;

[0035] Specifically, the temperature of the heat conductor can be measured using a non-contact device, such as a copper busbar, which can use the good thermal conductivity of the copper material itself to quickly transfer the heat of the chip inside the power module through heat conduction. Due to the characteristics of the copper material itself, it can be regarded as a heat spreader, which can then be monitored by a sensor to obtain the above-mentioned first temperature.

[0036] Step S202, calculating the junction temperature of the power module according to the first temperature and the first function;

[0037] Specifically, the junction temperature of a power module generally refers to the temperature of the chip "junction" area in a semiconductor device, and is an important parameter for measuring the operating temperature of a power module. The junction temperature directly affects the stability, life and reliability of the power module.

[0038] Step S203, obtaining a second temperature and a power loss of the power module, and calculating a transient thermal resistance of the power module at least based on the first temperature, the power loss and the second temperature, wherein the second temperature is a temperature of the housing;

[0039] Specifically, the second temperature can be obtained by a contact temperature measuring instrument, such as a thermistor. The temperature rise of the power module is mainly caused by the heat caused by the power loss of the power module during operation. The power loss of the power module mainly comes from the conduction and shutdown losses of the power semiconductor.

[0040] Step S204 , determining the life of the power module at least according to the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature, and the power loss of the power module.

[0041] Specifically, the life of the power module is affected by many factors, among which temperature is one of the key factors. Combining transient thermal resistance, junction temperature, housing temperature, ambient temperature and power loss of the power module, the accurate power of the power module can be calculated.

[0042] Through this embodiment, a method for determining the life of a power module is provided. The power module includes a shell, a power semiconductor chip located in the shell, and a heat conductor, wherein the heat conductor located in the shell is in contact with the power semiconductor chip. First, a first temperature and a first function are obtained, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal temperature difference of the heat conductor; then, according to the first temperature and the first function, the junction temperature of the power module is calculated; then, according to at least the first temperature, the power loss, and the second temperature, the transient thermal resistance of the power module is calculated, wherein the second temperature is the temperature of the shell; finally, according to at least the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature, and the power loss of the power module, the life of the power module is determined. The temperature of the power semiconductor chip, i.e., the first temperature, is obtained through the heat conductor. Due to the good thermal conductivity of the heat conductor itself, the actual temperature of the power semiconductor chip can be obtained. The first function representing the influence of the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module on the thermal conductivity of the heat conductor can be used to calculate the accurate junction temperature. At the same time, the temperature of the power device housing, i.e., the second temperature, is obtained. The accurate transient thermal resistance value can be calculated by combining the first temperature and the power loss of the power module. Finally, the accurate life of the power module can be determined based on the transient thermal resistance, junction temperature, the second temperature, the ambient temperature, and the power loss of the power module, thereby solving the technical problem of inaccurate life estimation of the power module in the prior art.

[0043] In the specific implementation process, the above step S201 can be implemented by the following steps: Step S2011, according to formula F 1 =-a×R c +b×T R -c×T E +d×P, calculate the first function F 1, where R c is the thermal resistance of the material of the above-mentioned thermal conductor, T R is the first temperature mentioned above, T E is the above-mentioned ambient temperature, P is the above-mentioned power loss, and a, b, c, d are pre-set coefficients greater than 0. This method can further accurately calculate the above-mentioned first function.

[0044] Specifically, the first function value is inversely proportional to the thermal resistance of the material of the heat conductor. The smaller the thermal resistance of the material of the heat conductor, the larger the first function value. The first function value is proportional to the temperature of the heat conductor. The smaller the temperature of the heat conductor, the smaller the first function value. The first function value is inversely proportional to the ambient temperature. The smaller the ambient temperature, the larger the first function value. The first function value is related to power loss. The smaller the power loss, the smaller the first function value. In addition, the values ​​of a, b, c, and d can be set by calibration, or those skilled in the art can set them based on experience. This application does not impose any specific restrictions.

[0045] In order to further improve the accuracy of calculating the above-mentioned junction temperature, the above-mentioned step S202 of the present application can be implemented by the following steps: Step S2021, calculate the sum of the above-mentioned first temperature and the function value of the above-mentioned first function at the same time to obtain the above-mentioned junction temperature.

[0046] In practical applications, although the heat conductor has good thermal conductivity, there is heat loss in the heat transfer process. The temperature difference can be obtained by calculating the first function value through the relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, the power loss of the power module and the thermal conductivity temperature difference of the heat conductor, i.e., the first function. The accurate junction temperature of the power module can be obtained by calculating the sum of the first temperature and the first function value.

[0047] like Figure 2 As shown, the power module also includes a heat sink 308, and the heat sink 308 is located on one side of the housing 302. The step S203 can also be implemented in other ways, for example: step S2031, obtaining the heat transfer efficiency of the power module in a predetermined direction, the predetermined direction is the direction in which the power semiconductor chip points to the heat sink; step S2032, calculating the product of the heat transfer efficiency and the power loss to obtain a first value; step S2033, calculating the difference between the first temperature and the second temperature to obtain a second value; step S2034, calculating the ratio of the second value to the first value to obtain the transient thermal resistance. This method can further improve the calculation accuracy of the transient thermal resistance.

[0048] Specifically, the detection principle diagram of the first temperature and the second temperature is as follows: Figure 4As shown. The temperature rise of the power module is mainly caused by the heat caused by the power loss of the power semiconductor chip 304 during operation. The power module is monitored timely, accurately and effectively by arranging the infrared temperature sensor 314 and the thermistor 320 at the position of the heat conductor 306 led out from the shell 302 of the power module and the position of the shell 302 near the heat dissipation device 308. The upper part of the power semiconductor chip 304 is connected to the first connection part 310 through the second connection part 312, and the lower part is connected to the substrate layer 318 through the second connection part 312 and the packaging layer 316. The substrate layer 318 is arranged on the shell 302 of the power module. The other directions of the power semiconductor chip 304 are sealed by insulating and heat-resistant materials. Since the first connection part 310 and the shell 302 are isolated by insulating and heat-resistant materials, and the upper first connection part 310, the heat conductor 306 and the lower packaging layer 316 and substrate layer 318 are all good thermal conductive materials, the heat transfer direction of the power semiconductor chip 304 is mainly in the upper and lower directions.

[0049] In some embodiments, the above step S204 can be specifically implemented by the following steps: step S2041, obtaining the steady-state thermal resistance, temperature gradient and heat conduction time difference of the above power module, wherein the above temperature gradient is used to characterize the degree of temperature reduction of the above power module in the heat conduction direction, the above heat conduction time difference is the time difference corresponding to the temperature of the above heat conductor and the above shell being the same, or the time difference between the start time of the predetermined time of the above heat conductor and the start time of the predetermined time period of the above shell, the above predetermined time period is the time period corresponding to the temperature of the above heat conductor or the above shell being constant, and the duration of the predetermined time of the above heat conductor is equal to the duration of the predetermined time period of the above shell; step S2042, calculating the life of the above power module according to the above transient thermal resistance, the above steady-state thermal resistance, the above junction temperature, the above second temperature, the above ambient temperature, the above temperature gradient and the above heat conduction time difference. According to the transient thermal resistance, the steady-state thermal resistance, the junction temperature, the second temperature, the ambient temperature, the temperature gradient and the heat conduction time difference, the method can further improve the calculation accuracy of the life of the above power module.

[0050] Specifically, transient thermal resistance is the resistance encountered by heat passing through a material under non-steady-state or transient conditions, that is, when the heat input is not constant but varies with time. Transient thermal resistance is used to describe the thermal response of semiconductor devices under pulsed power conditions, such as switching operations or load changes. Steady-state thermal resistance is the resistance encountered by heat passing through a material under steady-state or long-term constant heat load conditions. In this case, the flow of heat reaches a state of equilibrium and the temperature distribution no longer varies with time. Steady-state thermal resistance is a fixed value that can be calculated using a simple heat conduction equation, which is the ratio between the temperature difference between the two ends of an object and the power of the heat source.

[0051] The above step S2041 can be implemented by the following steps: step S20411, a first acquisition step, sequentially acquiring a plurality of first temperatures and a plurality of second temperatures, wherein the plurality of first temperatures are arranged in chronological order, and the plurality of second temperatures are arranged in chronological order; step S20412, a first calculation step, calculating the change rate of each of the above first temperatures within a unit time, and obtaining a plurality of first change rates; step S20413, a second calculation step, calculating the change rate of each of the above second temperatures within the above unit time, and obtaining a plurality of second change rates; step S20414, a first determination step, determining whether the above first change rate and the above second change rate corresponding to the same moment meet a preset condition; step S20415, a second determination step, determining whether the above first change rate and the above second change rate corresponding to the same moment meet the above preset condition if the above first change rate and the above second change rate meet the above preset condition. Whether the second change rate is 0, wherein the preset condition is that the signs of the first change rate and the second change rate are the same or the first change rate is 0; step S20416, a second acquisition step, when the second change rate is 0, acquiring the moment corresponding to the second change rate, and obtaining the second moment; step S20417, a third determination step, when the first change rate and the second change rate corresponding to the same moment do not meet the preset condition, determining whether the second change rate is equal to the first change rate, step S20418, a third acquisition step, when the second change rate is equal to the first change rate, acquiring the moment corresponding to the first change rate, and obtaining the first moment; step S20419, a third calculation step, calculating the difference between the second moment and the first moment, and obtaining the thermal conduction time difference. This method can further quickly obtain the thermal conduction time difference.

[0052] In practical applications, the calculation program logic scheme of the above steps is as follows Figure 5 As shown, after the software initialization configuration is completed, the temperature data of the infrared temperature sensor and thermistor (Negative Temperature Coefficient, referred to as NTC) are sampled and read through the analog-to-digital converter (ADC), and each temperature value T1, T2 and the corresponding time t1, t2 are recorded. The temperature data processing interrupt is triggered by the set time interrupt to calculate the thermal resistance R and thermal conduction time t of the power module. In the data processing module, the thermal resistance R of the power module is first calculated by the temperature difference T1 and T2 inside and outside the power module at the same time, combined with the current power loss P and heat transfer efficiency n, and the average thermal resistance of the power module is obtained by averaging. At the same time, the thermal conduction time difference t of the module is calculated by the temperature change rate k1 of T1 and the temperature change rate k2 of T2.

[0053] After step S20414, the method further includes step S204141, in which, when the second rate of change is not 0 or the second rate of change is not equal to the first rate of change, the first acquisition step, the first calculation step, the second calculation step, the first determination step, the second determination step, the second acquisition step, the third determination step, the third acquisition step and the calculation step are sequentially repeated at least once until a predetermined number of repetitions is reached. The method can further quickly calculate the thermal conduction time difference when the second rate of change is not 0 or the second rate of change is not equal to the first rate of change.

[0054] Specifically, when the second change rate is not 0 or the second change rate is not equal to the first change rate, new sensor data can be acquired in real time by repeatedly acquiring sensor data, and subsequent calculation of the thermal conduction time difference can be performed.

[0055] In the specific implementation process, step S2042 can also be implemented by the following steps: Step S20421, according to formula F 2 =-e×(RR b )-f×(T J -T C )-g×(T J -T E )-h×ki×t, calculate the life of the above power module F 2 , where R is the transient thermal resistance mentioned above, R b is the above steady-state thermal resistance, T J is the junction temperature above, T C is the second temperature, T E is the above-mentioned ambient temperature, k is the above-mentioned temperature gradient, t is the above-mentioned heat conduction time difference, and e, f, g, h, and i are pre-set coefficients greater than 0. This method can further accurately calculate the life of the above-mentioned power module.

[0056] Specifically, the life of the power module is the function value of the second function, and the second function is the relationship between the transient thermal resistance, the steady-state thermal resistance, the junction temperature, the second temperature, the ambient temperature, the temperature gradient, the heat conduction time difference and the life of the power module. The life of the power module is inversely proportional to the difference between the transient thermal resistance and the steady-state thermal resistance. The smaller the difference between the transient thermal resistance and the steady-state thermal resistance, the longer the life of the power module. The life of the power module is inversely proportional to the difference between the junction temperature and the temperature of the shell. The smaller the difference between the junction temperature and the temperature of the shell, the longer the life of the power module. The life of the power module is inversely proportional to the difference between the junction temperature and the ambient temperature. The smaller the difference between the junction temperature and the ambient temperature, the longer the life of the power module. The life of the power module is inversely proportional to the degree of temperature reduction of the power module in the heat conduction direction. The smaller the temperature gradient, the longer the life of the power module. The life of the power module is inversely proportional to the heat conduction time difference. The smaller the heat conduction time difference, the longer the life of the power module. In addition, the values ​​of e, f, g, h, and i can be set by calibration, or can be set by those skilled in the art based on experience, and this application does not impose any specific limitations.

[0057] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the implementation process of the method for determining the life of a power module of the present application will be described in detail below in conjunction with specific embodiments.

[0058] The embodiment of the present application also provides a device for determining the life of a power module. It should be noted that the device for determining the life of a power module in the embodiment of the present application can be used to execute the method for determining the life of a power module provided in the embodiment of the present application. The device is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made will not be repeated. As used below, the term "module" can implement a combination of software and / or hardware for a predetermined function. Although the device described in the following embodiments is preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0059] The following is an introduction to a device for determining the life of a power module provided in an embodiment of the present application.

[0060] like Figure 2 As shown, the power module includes a shell 302, a power semiconductor chip 304 located in the shell 302, and a heat conductor 306, a portion of the heat conductor 306 is located outside the shell 302, and another portion is located in the shell 302, and the heat conductor 306 located in the shell 302 is in contact with the power semiconductor chip 304. Figure 6 is a schematic diagram of the structure of a device for determining the life of a power module according to an embodiment of the present application. Figure 6 As shown, including:

[0061] An acquisition unit 10 is used to acquire a first temperature and a first function, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal conductivity temperature difference of the heat conductor;

[0062] Specifically, the temperature of the heat conductor can be measured using a non-contact device, such as a copper busbar, which can use the good thermal conductivity of the copper material itself to quickly transfer the heat of the chip inside the power module through heat conduction. Due to the characteristics of the copper material itself, it can be regarded as a heat spreader, which can then be monitored by a sensor to obtain the above-mentioned first temperature.

[0063] A first calculation unit 20, configured to calculate a junction temperature of the power module according to the first temperature and the first function;

[0064] Specifically, the junction temperature of a power module generally refers to the temperature of the chip "junction" area in a semiconductor device, and is an important parameter for measuring the operating temperature of a power module. The junction temperature directly affects the stability, life and reliability of the power module.

[0065] A second calculation unit 30 is used to obtain a second temperature and a power loss of the power module, and calculate a transient thermal resistance of the power module at least according to the first temperature, the power loss and the second temperature, wherein the second temperature is a temperature of the housing;

[0066] Specifically, the second temperature can be obtained by a contact temperature measuring instrument, such as a thermistor. The temperature rise of the power module is mainly caused by the heat caused by the power loss of the power module during operation. The power loss of the power module mainly comes from the conduction and shutdown losses of the power semiconductor.

[0067] The determination unit 40 is configured to determine the life of the power module at least according to the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature, and the power loss of the power module.

[0068] Specifically, the life of the power module is affected by many factors, among which temperature is one of the key factors. Combining transient thermal resistance, junction temperature, housing temperature, ambient temperature and power loss of the power module, the accurate power of the power module can be calculated.

[0069] Through this embodiment, a device for determining the life of a power module is provided. The power module includes a shell, a power semiconductor chip located in the shell, and a heat conductor, the heat conductor located in the shell is in contact with the power semiconductor chip, an acquisition unit acquires a first temperature and a first function, the first temperature is the temperature of the heat conductor, the first function is the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and a relationship between the power loss of the power module and the thermal temperature difference of the heat conductor; the first calculation unit calculates the junction temperature of the power module according to the first temperature and the first function; the second calculation unit calculates the transient thermal resistance of the power module according to at least the first temperature, the power loss and the second temperature, the second temperature being the temperature of the shell; the determination unit determines the life of the power module according to at least the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature and the power loss of the power module. The temperature of the power semiconductor chip, i.e., the first temperature, is obtained through the heat conductor. Due to the good thermal conductivity of the heat conductor itself, the actual temperature of the power semiconductor chip can be obtained. The first function representing the influence of the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module on the thermal conductivity of the heat conductor can be used to calculate the accurate junction temperature. At the same time, the temperature of the power device housing, i.e., the second temperature, is obtained. The accurate transient thermal resistance value can be calculated by combining the first temperature and the power loss of the power module. Finally, the accurate life of the power module can be determined based on the transient thermal resistance, junction temperature, the second temperature, the ambient temperature, and the power loss of the power module, thereby solving the technical problem of inaccurate life estimation of the power module in the prior art.

[0070] In the specific implementation process, the acquisition unit includes a first calculation module for calculating the value of 1 =-a×R c +b×T R -c×T E +d×P, calculate the first function F 1 , where R c is the thermal resistance of the material of the above-mentioned thermal conductor, T R is the first temperature mentioned above, T E is the above-mentioned ambient temperature, P is the above-mentioned power loss, and a, b, c, d are pre-set coefficients greater than 0. The device can further accurately calculate the above-mentioned first function.

[0071] Specifically, the first function value is inversely proportional to the thermal resistance of the material of the heat conductor. The smaller the thermal resistance of the material of the heat conductor, the larger the first function value. The first function value is proportional to the temperature of the heat conductor. The smaller the temperature of the heat conductor, the smaller the first function value. The first function value is inversely proportional to the ambient temperature. The smaller the ambient temperature, the larger the first function value. The first function value is related to power loss. The smaller the power loss, the smaller the first function value. In addition, the values ​​of a, b, c, and d can be set by calibration, or those skilled in the art can set them based on experience. This application does not impose any specific restrictions.

[0072] In order to further improve the accuracy of calculating the above-mentioned junction temperature, the above-mentioned first calculation unit of the present application includes a second calculation module, which is used to calculate the sum of the above-mentioned first temperature and the function value of the above-mentioned first function at the same time to obtain the above-mentioned junction temperature.

[0073] In practical applications, although the heat conductor has good thermal conductivity, there is heat loss in the heat transfer process. The temperature difference can be obtained by calculating the first function value through the relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, the power loss of the power module and the thermal conductivity temperature difference of the heat conductor, i.e., the first function. The accurate junction temperature of the power module can be obtained by calculating the sum of the first temperature and the first function value.

[0074] like Figure 2 As shown, the power module further includes a heat sink 308, which is located on one side of the housing 302. The second calculation unit includes a first acquisition module, a third calculation module, a fourth calculation module and a fifth calculation module, wherein the first acquisition module is used to acquire the heat transfer efficiency of the power module in a predetermined direction, and the predetermined direction is the direction in which the power semiconductor chip points to the heat sink; the third calculation module is used to calculate the product of the heat transfer efficiency and the power loss to obtain a first value; the fourth calculation module is used to calculate the difference between the first temperature and the second temperature to obtain a second value; the fifth calculation module is used to calculate the ratio of the second value to the first value to obtain the transient thermal resistance. This device can further improve the calculation accuracy of the transient thermal resistance.

[0075] Specifically, the detection principle diagram of the first temperature and the second temperature is as follows: Figure 4As shown. The temperature rise of the power module is mainly caused by the heat caused by the power loss of the power semiconductor chip 304 during operation. The power module is monitored timely, accurately and effectively by arranging the infrared temperature sensor 314 and the thermistor 320 at the position of the heat conductor 306 led out from the shell 302 of the power module and the position of the shell 302 near the heat dissipation device 308. The upper part of the power semiconductor chip 304 is connected to the first connection part 310 through the second connection part 312, and the lower part is connected to the substrate layer 318 through the second connection part 312 and the packaging layer 316. The substrate layer 318 is arranged on the shell 302 of the power module. The other directions of the power semiconductor chip 304 are sealed by insulating and heat-resistant materials. Since the first connection part 310 and the shell 302 are isolated by insulating and heat-resistant materials, and the upper first connection part 310, the heat conductor 306 and the lower packaging layer 316 and substrate layer 318 are all good thermal conductive materials, the heat transfer direction of the power semiconductor chip 304 is mainly in the upper and lower directions.

[0076] In some embodiments, the determination unit includes a second acquisition module and a sixth calculation module, wherein the second acquisition module is used to acquire the steady-state thermal resistance, temperature gradient and heat conduction time difference of the power module, wherein the temperature gradient is used to characterize the degree of temperature reduction of the power module in the heat conduction direction, the heat conduction time difference is the time difference corresponding to the temperature of the heat conductor and the shell being the same, or the time difference between the start time of the predetermined time of the heat conductor and the start time of the predetermined time period of the shell, the predetermined time period is the time period corresponding to the temperature of the heat conductor or the shell being constant, and the length of the predetermined time of the heat conductor is equal to the length of the predetermined time period of the shell; the sixth calculation module is used to calculate the life of the power module according to the transient thermal resistance, the steady-state thermal resistance, the junction temperature, the second temperature, the ambient temperature, the temperature gradient and the heat conduction time difference. According to the transient thermal resistance, the steady-state thermal resistance, the junction temperature, the second temperature, the ambient temperature, the temperature gradient and the heat conduction time difference, the device can further improve the calculation accuracy of the life of the power module.

[0077] Specifically, transient thermal resistance is the resistance encountered by heat passing through a material under non-steady-state or transient conditions, that is, when the heat input is not constant but varies with time. Transient thermal resistance is used to describe the thermal response of semiconductor devices under pulsed power conditions, such as switching operations or load changes. Steady-state thermal resistance is the resistance encountered by heat passing through a material under steady-state or long-term constant heat load conditions. In this case, the flow of heat reaches a state of equilibrium and the temperature distribution no longer varies with time. Steady-state thermal resistance is a fixed value that can be calculated using a simple heat conduction equation, which is the ratio between the temperature difference between the two ends of an object and the power of the heat source.

[0078] The above-mentioned second acquisition module includes a first acquisition submodule, a first calculation submodule, a second calculation submodule, a first determination submodule, a second determination submodule, a second acquisition submodule, a third determination submodule, a third acquisition submodule and a third calculation submodule, wherein the first acquisition submodule is used in the first acquisition step to sequentially acquire multiple first temperatures and multiple second temperatures, wherein the multiple first temperatures are arranged in chronological order, and the multiple second temperatures are arranged in chronological order; the first calculation submodule is used in the first calculation step to calculate the change rate of each of the above-mentioned first temperatures within the unit time to obtain multiple first change rates; the second calculation submodule is used in the second calculation step to calculate the change rate of each of the above-mentioned second temperatures within the unit time to obtain multiple second change rates; the first determination submodule is used in the first determination step to determine whether the above-mentioned first change rate and the above-mentioned second change rate corresponding to the same time meet the preset conditions; the second determination submodule is used in the second determination step to determine whether the above-mentioned first change rate and the above-mentioned second change rate corresponding to the same time meet the preset conditions. When the first change rate and the second change rate corresponding to the moment meet the preset condition, determine whether the second change rate is 0, wherein the preset condition is that the signs of the first change rate and the second change rate are the same or the first change rate is 0; the second acquisition submodule is used for the second acquisition step, when the second change rate is 0, acquire the moment corresponding to the second change rate to obtain the second moment; the third determination submodule is used for the third determination step, when the first change rate and the second change rate corresponding to the same moment do not meet the preset condition, determine whether the second change rate is equal to the first change rate, the third acquisition submodule is used for the third acquisition step, when the second change rate is equal to the first change rate, acquire the moment corresponding to the first change rate to obtain the first moment; the third calculation submodule is used for the calculation step, calculates the difference between the second moment and the first moment, and obtains the thermal conduction time difference. The device can further quickly obtain the thermal conduction time difference.

[0079] In practical applications, the calculation program logic scheme of the above steps is as follows Figure 5As shown, after the software initialization configuration is completed, the temperature data of the infrared temperature sensor and thermistor (Negative Temperature Coefficient, referred to as NTC) are sampled and read through the analog-to-digital converter (ADC), and each temperature value T1, T2 and the corresponding time t1, t2 are recorded. The temperature data processing interrupt is triggered by the set time interrupt to calculate the thermal resistance R and thermal conduction time t of the power module. In the data processing module, the thermal resistance R of the power module is first calculated by the temperature difference T1 and T2 inside and outside the power module at the same time, combined with the current power loss P and heat transfer efficiency n, and the average thermal resistance of the power module is obtained by averaging. At the same time, the thermal conduction time difference t of the module is calculated by the temperature change rate k1 of T1 and the temperature change rate k2 of T2.

[0080] The device further includes a repeating submodule, which is used to repeat the first acquisition step, the first calculation step, the second calculation step, the first determination step, the second determination step, the second acquisition step, the third determination step, the third acquisition step and the calculation step at least once in sequence, until a predetermined number of repetitions is reached, when the second change rate is not 0 or the second change rate is not equal to the first change rate. The device can further quickly calculate the thermal conduction time difference when the second change rate is not 0 or the second change rate is not equal to the first change rate.

[0081] Specifically, when the second change rate is not 0 or the second change rate is not equal to the first change rate, new sensor data can be acquired in real time by repeatedly acquiring sensor data, and subsequent calculation of the thermal conduction time difference can be performed.

[0082] In the specific implementation process, the sixth calculation module includes a fourth calculation submodule, which is used to calculate the value of the formula F according to the formula 2 =-e×(RR b )-f×(T J -T C )-g×(T J -T E )-h×ki×t, calculate the life of the above power module F 2 , where R is the transient thermal resistance mentioned above, R b is the above steady-state thermal resistance, T J is the junction temperature above, T C is the second temperature, T E is the above-mentioned ambient temperature, k is the above-mentioned temperature gradient, t is the above-mentioned heat conduction time difference, and e, f, g, h, and i are pre-set coefficients greater than 0. The device can further accurately calculate the life of the above-mentioned power module.

[0083] Specifically, the life of the power module is the function value of the second function, and the second function is the relationship between the transient thermal resistance, the steady-state thermal resistance, the junction temperature, the second temperature, the ambient temperature, the temperature gradient, the heat conduction time difference and the life of the power module. The life of the power module is inversely proportional to the difference between the transient thermal resistance and the steady-state thermal resistance. The smaller the difference between the transient thermal resistance and the steady-state thermal resistance, the longer the life of the power module. The life of the power module is inversely proportional to the difference between the junction temperature and the temperature of the shell. The smaller the difference between the junction temperature and the temperature of the shell, the longer the life of the power module. The life of the power module is inversely proportional to the difference between the junction temperature and the ambient temperature. The smaller the difference between the junction temperature and the ambient temperature, the longer the life of the power module. The life of the power module is inversely proportional to the degree of temperature reduction of the power module in the heat conduction direction. The smaller the temperature gradient, the longer the life of the power module. The life of the power module is inversely proportional to the heat conduction time difference. The smaller the heat conduction time difference, the longer the life of the power module. In addition, the values ​​of e, f, g, h, and i can be set by calibration, or can be set by those skilled in the art based on experience, and this application does not impose any specific limitations.

[0084] The apparatus for determining the life of the power module includes a processor and a memory. The acquisition unit, the first calculation unit, the second calculation unit, and the determination unit are all stored in the memory as program units, and the processor executes the program units stored in the memory to implement corresponding functions. The modules are all located in the same processor; or, the modules are located in different processors in any combination.

[0085] The processor includes a kernel, which calls the corresponding program unit from the memory. One or more kernels can be set, and the life of the power module can be determined by adjusting the kernel parameters.

[0086] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0087] An embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium includes a stored program, wherein when the program is executed, a device where the computer-readable storage medium is located is controlled to execute the method for determining the life of the power module.

[0088] Specifically, the method for determining the life of the power module includes:

[0089] Step S201, obtaining a first temperature and a first function, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal conductivity temperature difference of the heat conductor;

[0090] Specifically, the temperature of the heat conductor can be measured using a non-contact device, such as a copper busbar, which can use the good thermal conductivity of the copper material itself to quickly transfer the heat of the chip inside the power module through heat conduction. Due to the characteristics of the copper material itself, it can be regarded as a heat spreader, which can then be monitored by a sensor to obtain the above-mentioned first temperature.

[0091] Step S202, calculating the junction temperature of the power module according to the first temperature and the first function;

[0092] Specifically, the junction temperature of a power module generally refers to the temperature of the chip "junction" area in a semiconductor device, and is an important parameter for measuring the operating temperature of a power module. The junction temperature directly affects the stability, life and reliability of the power module.

[0093] Step S203, obtaining a second temperature and a power loss of the power module, and calculating a transient thermal resistance of the power module at least based on the first temperature, the power loss and the second temperature, wherein the second temperature is a temperature of the housing;

[0094] Specifically, the second temperature can be obtained by a contact temperature measuring instrument, such as a thermistor. The temperature rise of the power module is mainly caused by the heat caused by the power loss of the power module during operation. The power loss of the power module mainly comes from the conduction and shutdown losses of the power semiconductor.

[0095] Step S204 , determining the life of the power module at least according to the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature, and the power loss of the power module.

[0096] Specifically, the life of the power module is affected by many factors, among which temperature is one of the key factors. Combining transient thermal resistance, junction temperature, housing temperature, ambient temperature and power loss of the power module, the accurate power of the power module can be calculated.

[0097] An embodiment of the present invention provides a processor, and the processor is used to run a program, wherein the method for determining the life of the power module is executed when the program is run.

[0098] Specifically, the method for determining the life of the power module includes:

[0099] Step S201, obtaining a first temperature and a first function, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal conductivity temperature difference of the heat conductor;

[0100] Specifically, the temperature of the heat conductor can be measured using a non-contact device, such as a copper busbar, which can use the good thermal conductivity of the copper material itself to quickly transfer the heat of the chip inside the power module through heat conduction. Due to the characteristics of the copper material itself, it can be regarded as a heat spreader, which can then be monitored by a sensor to obtain the above-mentioned first temperature.

[0101] Step S202, calculating the junction temperature of the power module according to the first temperature and the first function;

[0102] Specifically, the junction temperature of a power module generally refers to the temperature of the chip "junction" area in a semiconductor device, and is an important parameter for measuring the operating temperature of a power module. The junction temperature directly affects the stability, life and reliability of the power module.

[0103] Step S203, obtaining a second temperature and a power loss of the power module, and calculating a transient thermal resistance of the power module at least based on the first temperature, the power loss and the second temperature, wherein the second temperature is a temperature of the housing;

[0104] Specifically, the second temperature can be obtained by a contact temperature measuring instrument, such as a thermistor. The temperature rise of the power module is mainly caused by the heat caused by the power loss of the power module during operation. The power loss of the power module mainly comes from the conduction and shutdown losses of the power semiconductor.

[0105] Step S204 , determining the life of the power module at least according to the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature, and the power loss of the power module.

[0106] Specifically, the life of the power module is affected by many factors, among which temperature is one of the key factors. Combining transient thermal resistance, junction temperature, housing temperature, ambient temperature and power loss of the power module, the accurate power of the power module can be calculated.

[0107] An embodiment of the present invention provides a device, the device including a processor, a memory, and a program stored in the memory and executable on the processor, and when the processor executes the program, at least the following steps are implemented:

[0108] Step S201, obtaining a first temperature and a first function, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal conductivity temperature difference of the heat conductor;

[0109] Step S202, calculating the junction temperature of the power module according to the first temperature and the first function;

[0110] Step S203, obtaining a second temperature and a power loss of the power module, and calculating a transient thermal resistance of the power module at least based on the first temperature, the power loss and the second temperature, wherein the second temperature is a temperature of the housing;

[0111] Step S204 , determining the life of the power module at least according to the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature, and the power loss of the power module.

[0112] The devices in this article can be servers, PCs, PADs, mobile phones, etc.

[0113] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing a program for initializing at least the following method steps:

[0114] Step S201, obtaining a first temperature and a first function, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal conductivity temperature difference of the heat conductor;

[0115] Step S202, calculating the junction temperature of the power module according to the first temperature and the first function;

[0116] Step S203, obtaining a second temperature and a power loss of the power module, and calculating a transient thermal resistance of the power module at least based on the first temperature, the power loss and the second temperature, wherein the second temperature is a temperature of the housing;

[0117] Step S204 , determining the life of the power module at least according to the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature, and the power loss of the power module.

[0118] Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be executed in a different order than here, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

[0119] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0120] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes 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 generate 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.

[0121] 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.

[0122] 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 in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0123] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0124] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0125] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0126] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0127] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0128] 1) A method for determining the life of a power module of the present application, wherein the power module comprises a shell, a power semiconductor chip located in the shell, and a heat conductor, wherein the heat conductor located in the shell is in contact with the power semiconductor chip. First, a first temperature and a first function are obtained, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal temperature difference of the heat conductor; then, based on the first temperature and the first function, the junction temperature of the power module is calculated; then, based on at least the first temperature, the power loss, and the second temperature, the transient thermal resistance of the power module is calculated, wherein the second temperature is the temperature of the shell; finally, based on at least the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature, and the power loss of the power module, the life of the power module is determined. The temperature of the power semiconductor chip, i.e., the first temperature, is obtained through the heat conductor. Due to the good thermal conductivity of the heat conductor itself, the actual temperature of the power semiconductor chip can be obtained. The first function representing the influence of the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module on the thermal conductivity of the heat conductor can be used to calculate the accurate junction temperature. At the same time, the temperature of the power device housing, i.e., the second temperature, is obtained. The accurate transient thermal resistance value can be calculated by combining the first temperature and the power loss of the power module. Finally, the accurate life of the power module can be determined based on the transient thermal resistance, junction temperature, the second temperature, the ambient temperature, and the power loss of the power module, thereby solving the technical problem of inaccurate life estimation of the power module in the prior art.

[0129] 2) A device for determining the life of a power module of the present application, wherein the power module comprises a shell, a power semiconductor chip located in the shell, and a heat conductor, wherein the heat conductor located in the shell is in contact with the power semiconductor chip, an acquisition unit acquires a first temperature and a first function, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal temperature difference of the heat conductor; a first calculation unit calculates the junction temperature of the power module based on the first temperature and the first function; a second calculation unit calculates the transient thermal resistance of the power module based on at least the first temperature, the power loss, and the second temperature, wherein the second temperature is the temperature of the shell; a determination unit determines the life of the power module based on at least the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature, and the power loss of the power module. The temperature of the power semiconductor chip, i.e., the first temperature, is obtained through the heat conductor. Due to the good thermal conductivity of the heat conductor itself, the actual temperature of the power semiconductor chip can be obtained. The first function representing the influence of the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module on the thermal conductivity of the heat conductor can be used to calculate the accurate junction temperature. At the same time, the temperature of the power device housing, i.e., the second temperature, is obtained. The accurate transient thermal resistance value can be calculated by combining the first temperature and the power loss of the power module. Finally, the accurate life of the power module can be determined based on the transient thermal resistance, junction temperature, the second temperature, the ambient temperature, and the power loss of the power module, thereby solving the technical problem of inaccurate life estimation of the power module in the prior art.

[0130] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for determining the life of a power module, characterized in that: The power module comprises a housing, a power semiconductor chip located in the housing, and a heat conductor, a portion of the heat conductor is located outside the housing, and another portion is located inside the housing, the heat conductor located inside the housing is in contact with the power semiconductor chip, and the method comprises: Acquire a first temperature and a first function, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal conductivity temperature difference of the heat conductor; Calculating a junction temperature of the power module according to the first temperature and the first function; Acquire a second temperature and a power loss of the power module, and calculate a transient thermal resistance of the power module at least based on the first temperature, the power loss, and the second temperature, wherein the second temperature is a temperature of the housing; The life of the power module is determined based on at least the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature, and the power loss of the power module.

2. The method according to claim 1, characterized in that Get the first function, including: According to the formula F1 = -a × R c +b×T R -c×T E +d×P, calculate the first function F1, where R c is the thermal resistance of the thermal conductor material, T R is the first temperature, T E is the ambient temperature, P is the power loss, and a, b, c, and d are pre-set coefficients greater than 0.

3. The method according to claim 1, characterized in that Calculating the junction temperature of the power module according to the first temperature and the first function includes: The junction temperature is obtained by calculating the sum of the first temperature and the function value of the first function at the same time.

4. The method according to claim 1, characterized in that The power module further includes a heat sink, which is located at one side of the housing. The transient thermal resistance of the power module is calculated based on at least the first temperature, the power loss and the second temperature, including: Acquiring the heat transfer efficiency of the power module in a predetermined direction, where the predetermined direction is the direction in which the power semiconductor chip points to the heat dissipation device; Calculating the product of the heat transfer efficiency and the power loss to obtain a first value; Calculating the difference between the first temperature and the second temperature to obtain a second value; The ratio of the second value to the first value is calculated to obtain the transient thermal resistance.

5. The method according to claim 1, characterized in that Determining the life of the power module at least according to the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature, and the power loss of the power module includes: Obtaining a steady-state thermal resistance, a temperature gradient, and a heat conduction time difference of the power module, wherein the temperature gradient is used to characterize the degree of temperature reduction of the power module in the heat conduction direction, and the heat conduction time difference is a time difference corresponding to when the temperatures of the heat conductor and the shell are the same, or a time difference between a start time of the predetermined time of the heat conductor and a start time of a predetermined time period of the shell, wherein the predetermined time period is a time period corresponding to when the temperature of the heat conductor or the shell remains unchanged, and the duration of the predetermined time of the heat conductor is equal to the duration of the predetermined time period of the shell; The life of the power module is calculated according to the transient thermal resistance, the steady-state thermal resistance, the junction temperature, the second temperature, the ambient temperature, the temperature gradient, and the heat conduction time difference.

6. The method according to claim 5, characterized in that Obtaining the heat conduction time difference includes: A first acquisition step of sequentially acquiring a plurality of first temperatures and a plurality of second temperatures, wherein the plurality of first temperatures are arranged in chronological order, and the plurality of second temperatures are arranged in chronological order; A first calculation step is to calculate the change rate of each of the first temperatures in a unit time to obtain a plurality of first change rates; A second calculation step, calculating a change rate of each of the second temperatures within the unit time to obtain a plurality of second change rates; A first determination step is to determine whether the first change rate and the second change rate corresponding to the same moment meet a preset condition; A second determination step, in which, when the first change rate and the second change rate corresponding to the same time point meet the preset condition, determining whether the second change rate is 0, wherein the preset condition is that the first change rate and the second change rate have the same sign or the first change rate is 0; A second acquisition step, when the second change rate is 0, acquiring a moment corresponding to the second change rate to obtain a second moment; The third determination step is to determine whether the second change rate is equal to the first change rate when the first change rate and the second change rate corresponding to the same time do not meet the preset condition. A third acquisition step, when the second change rate is equal to the first change rate, acquiring a moment corresponding to the first change rate to obtain a first moment; The third calculation step is to calculate the difference between the second moment and the first moment to obtain the heat conduction time difference.

7. The method according to claim 6, characterized in that After the first determining step, the method further comprises: When the second change rate is not 0 or the second change rate is not equal to the first change rate, the first acquisition step, the first calculation step, the second calculation step, the first determination step, the second determination step, the second acquisition step, the third determination step, the third acquisition step and the calculation step are repeated in sequence at least once until a predetermined number of repetitions is reached.

8. The method according to claim 5, characterized in that Calculating the life of the power module according to the transient thermal resistance, the steady-state thermal resistance, the junction temperature, the second temperature, the ambient temperature, the temperature gradient, and the heat conduction time difference includes: According to the formula F2 = -e × (RR b )-f×(T J -T C )-g×(T J -T E )-h×ki×t, calculate the life F2 of the power module, where R is the transient thermal resistance, R b is the steady-state thermal resistance, T J is the junction temperature, T C is the second temperature, T E is the ambient temperature, k is the temperature gradient, t is the heat conduction time difference, and e, f, g, h, and i are pre-set coefficients greater than 0.

9. A device for determining the life of a power module, characterized in that: The power module comprises a housing, a power semiconductor chip located in the housing, and a heat conductor, a portion of the heat conductor is located outside the housing, and another portion is located inside the housing, the heat conductor located inside the housing is in contact with the power semiconductor chip, and the device comprises: an acquisition unit, configured to acquire a first temperature and a first function, wherein the first temperature is the temperature of the heat conductor, and the first function is a relationship between the first temperature, the material thermal resistance of the heat conductor, the ambient temperature of the power module, and the power loss of the power module and the thermal conductivity temperature difference of the heat conductor; a first calculation unit, configured to calculate a junction temperature of the power module according to the first temperature and the first function; a second calculation unit, configured to obtain a second temperature and a power loss of the power module, and calculate a transient thermal resistance of the power module at least based on the first temperature, the power loss and the second temperature, wherein the second temperature is a temperature of the housing; A determination unit is used to determine the life of the power module at least according to the transient thermal resistance, the junction temperature, the second temperature, the ambient temperature and the power loss of the power module.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 8.

Images