Device performance evaluation method, device, equipment, system and storage medium

Abstract

The present application discloses a device performance evaluation method, apparatus, equipment, system and storage medium. The device performance evaluation method includes: obtaining a first thermal spectrum of the device to be evaluated and a second thermal spectrum of several standard devices, wherein the first thermal spectrum and each second thermal spectrum are collected when the device to be evaluated and each standard device work at the same power; determining the parameters of the crack in the device to be evaluated based on the temperature difference of each pixel point in the first thermal spectrum and each second thermal spectrum; determining the performance parameters of the device to be evaluated based on the parameters of the crack in the device to be evaluated. The above scheme can realize the determination of the performance evaluation of the device.

Description

Technical Field

[0001] The present application relates to the field of computers, and in particular to a device performance evaluation method, apparatus, device, system and storage medium. Background Art

[0002] With the continuous development of the power electronics industry, more and more companies and customers have begun to pay attention to the long-term reliability of power electronic modules, which is often referred to as the "lifespan" of electronic products and components, in order to evaluate the long-term reliability of electronic products in daily applications. Among them, the typical aging failure mode of electronic product SMD components is that the solder cracks under long-term changing stress, and the cracks intensify as the stress continues, causing the aging of electronic products to intensify and eventually fail. The source of these cracks may be the formation of voids inside the solder during welding, or the gradual generation of new cracks in daily applications.

[0003] However, currently, whether an electronic product can still work normally can only be determined through its working parameters. If it is necessary to quantitatively analyze the aging of the soldering layer in the electronic product, the electronic product can only be sliced ​​and then the cracks in the soldering layer can be observed. However, this analysis method will cause damage to the electronic product and is not conducive to the use of the electronic product. Summary of the invention

[0004] The present application at least provides a device performance evaluation method, apparatus, device, system and storage medium.

[0005] The present application provides a device performance evaluation method, comprising: obtaining a first thermal spectrum of a device to be evaluated and second thermal spectrums of several standard devices, wherein the first thermal spectrum and each second thermal spectrum are collected when the device to be evaluated and each standard device are operating at the same power; determining parameters of a crack in the device to be evaluated based on a temperature difference between each pixel point in the first thermal spectrum and each second thermal spectrum; and determining performance parameters of the device to be evaluated based on the parameters of the crack in the device to be evaluated.

[0006] In the above scheme, if there is a crack in the device to be evaluated, it will cause the temperature of some areas of the device to be evaluated to be higher. By obtaining the thermal spectra of the device to be evaluated and the standard device working at the same power, and analyzing the difference between the thermal spectra of the device to be evaluated and the thermal spectra of the standard device, the parameters of the crack in the device to be evaluated can be determined. Because the crack parameters are determined, the performance parameters such as the equivalent life or residual life of the device to be evaluated can be further determined.

[0007] In some embodiments, based on the temperature difference between each pixel in the first thermal spectrum and each second thermal spectrum, the parameters of the crack in the device to be evaluated are determined, including: for each pixel in the first thermal spectrum, obtaining the temperature difference between the temperature of the pixel in the first thermal spectrum and the temperature statistical value of the pixel in each second thermal spectrum; based on the temperature difference of each pixel and the working power of the device to be evaluated, predicting the thermal resistance value-added of the device to be evaluated; based on the thermal resistance value-added, obtaining the parameters of the crack.

[0008] In the above scheme, since the working power of the device to be evaluated is different, the electrical stress on the device to be evaluated may be different. Therefore, when determining the crack parameters, referring to the working power of the device to be evaluated can make the determined crack parameters more accurate.

[0009] In some embodiments, the device to be evaluated includes a welding layer, the parameters of the crack include parameters of the crack generated by the welding layer, and based on the temperature difference of each pixel point and the working power of the device to be evaluated, the thermal resistance appreciation of the device to be evaluated is predicted, including: taking the maximum temperature difference among the temperature differences as the target temperature difference; taking the ratio between the target temperature difference and the power as the thermal resistance appreciation; based on the thermal resistance appreciation, obtaining the parameters of the crack, including: obtaining the parameters of the crack based on the product of the thermal resistance appreciation and the thermal conductivity of the welding material used for the welding layer.

[0010] In the above scheme, by using the maximum temperature difference to determine the thermal resistance increment, the determined thermal resistance increment can be made the maximum value, and the performance parameters of the device to be evaluated are relatively conservative, which can better guarantee the subsequent use of the device to be evaluated.

[0011] In some embodiments, the device to be evaluated includes a welding layer, and the parameters of the crack include the height of the crack generated in the welding layer. Based on the parameters of the crack in the device to be evaluated, the performance parameters of the device to be evaluated are determined, including: determining the fatigue strength of the device to be evaluated based on the height of the crack and the crack height-fatigue strength relationship; determining the performance parameters of the device to be evaluated based on the fatigue strength of the device to be evaluated.

[0012] In the above scheme, the crack height and fatigue strength are generally related to the welding material, that is, when the welding material is fixed, the relationship between the crack height and the fatigue strength is also fixed. Therefore, this relationship can be used in different devices to determine the fatigue strength at a specific crack height, thereby improving the versatility of the device performance evaluation method.

[0013] In some embodiments, the performance parameters of the device to be evaluated include the residual life of the device to be evaluated. Based on the fatigue strength of the device to be evaluated, the performance parameters of the device to be evaluated are determined, including: using the fatigue strength of the device to be evaluated to query the attenuation relationship of the fatigue strength over time to obtain the equivalent life of the device to be evaluated; and using the difference between the preset maximum life of the device to be evaluated working under power and the equivalent life as the residual life of the device to be evaluated.

[0014] In the above solution, by predetermining the attenuation relationship of fatigue strength over time, the equivalent life of the device to be evaluated can be more conveniently obtained, thereby determining the residual life of the device to be evaluated.

[0015] In some embodiments, based on the temperature difference between each pixel in the first thermal spectrum and each second thermal spectrum, the parameters of the crack in the device to be evaluated are determined, including: for each pixel in the first thermal spectrum, obtaining the temperature difference between the temperature of the pixel in the first thermal spectrum and the temperature statistical value of the pixel in each second thermal spectrum; based on the temperature difference of each pixel and the working power of the device to be evaluated, determining the equivalent impedance of the device to be evaluated; obtaining the impedance difference between the equivalent impedance and the calibrated impedance of the device to be evaluated and obtaining the parameters of the crack based on the impedance difference.

[0016] In the above scheme, the temperature rise caused by the internal crack of the device to be evaluated is due to the increase in the internal impedance of the device caused by the crack, thereby causing the device to heat up. Therefore, by obtaining the difference between the equivalent impedance evaluated during the operation of the device to be evaluated and the calibrated impedance, the parameters of the crack in the device to be evaluated can be determined.

[0017] In some embodiments, the parameters of the crack include the crack area of ​​the fracture surface in the device to be evaluated and the crack area ratio. The impedance difference between the equivalent impedance and the calibrated impedance of the device to be evaluated is obtained and the parameters of the crack are obtained based on the impedance difference, including: obtaining the ratio between the impedance difference and the equivalent impedance, and using the ratio as the crack area ratio; and using the product of the ratio and the initial area of ​​the fracture surface as the crack area.

[0018] In the above solution, by obtaining the ratio between the impedance difference and the equivalent impedance, the crack area ratio can be determined, thereby determining the crack area on the fracture surface in the device to be evaluated.

[0019] In some embodiments, the device performance evaluation method further includes: predicting the performance parameters of the device to be evaluated when operating at other powers based on the performance parameters of the device to be evaluated and a preset stress model.

[0020] In the above scheme, by combining the Arrhenius model and the preset stress model, the performance parameters of the device to be evaluated under a specified stress can be predicted.

[0021] The present application provides a device performance evaluation apparatus, comprising: a thermal spectrum acquisition module, a crack parameter determination module and a performance evaluation module; the thermal spectrum acquisition module is used to acquire a first thermal spectrum of a device to be evaluated and a second thermal spectrum of several standard devices, the first thermal spectrum and each second thermal spectrum are collected when the device to be evaluated and each standard device work at the same power; the crack parameter determination module is used to determine the parameters of the crack in the device to be evaluated based on the temperature difference of each pixel point in the first thermal spectrum and each second thermal spectrum; the performance evaluation module is used to determine the performance parameters of the device to be evaluated based on the parameters of the crack in the device to be evaluated.

[0022] The present application provides an electronic device, including a memory and a processor, wherein the processor is used to execute program instructions stored in the memory to implement the performance evaluation method of the above-mentioned device.

[0023] The present application provides a device performance evaluation system, including the above-mentioned electronic device and a thermal spectrum acquisition device communicatively connected to the electronic device, the thermal spectrum acquisition device can acquire thermal spectra, and the electronic device cooperates with the thermal spectrum acquisition device to implement any of the above-mentioned device performance evaluation methods.

[0024] In some embodiments, the device performance evaluation system further includes a test bench, the placement plane of the test bench is used to place the device to be evaluated, and the projection plane of the thermal spectrum acquisition device is parallel to the placement plane of the test bench.

[0025] In the above solution, the placement plane of the test bench and the projection plane of the thermal spectrum acquisition device enable the thermal spectrum map to better acquire the thermal spectrum map of the device to be evaluated.

[0026] The present application provides a computer-readable storage medium having program instructions stored thereon, and when the program instructions are executed by a processor, any of the above-mentioned device performance evaluation methods is implemented.

[0027] In the above scheme, if there is a crack in the device to be evaluated, it will cause the temperature of some areas of the device to be evaluated to be higher. By obtaining the thermal spectra of the device to be evaluated and the standard device working at the same power, and analyzing the difference between the thermal spectra of the device to be evaluated and the thermal spectra of the standard device, the parameters of the crack in the device to be evaluated can be determined. Because the crack parameters are determined, the performance parameters such as the equivalent life or residual life of the device to be evaluated can be further determined.

[0028] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings herein are incorporated into the specification and constitute a part of the specification. These drawings illustrate embodiments consistent with the present application and are used together with the specification to illustrate the technical solution of the present application.

[0030] Figure 1 is a flow chart of an embodiment of a method for evaluating device performance provided by some embodiments;

[0031] Figure 2 The internal structure of the device to be evaluated provided in some embodiments is shown in FIG. Figure 1 ;

[0032] Figure 3 The internal structure of the device to be evaluated provided in some embodiments is shown in FIG. Figure 2 ;

[0033] Figure 4 Some embodiments provide Figure 1 Schematic diagram of the sub-process of step S12;

[0034] Figure 5 is a schematic diagram of cracks in a welding layer provided by some embodiments;

[0035] Figure 6 is a schematic diagram of the relationship between crack height and fatigue strength provided by some embodiments;

[0036] Figure 7 is a schematic diagram of the attenuation relationship of fatigue strength of a device to be evaluated over time provided by some embodiments;

[0037] Figure 8 Some embodiments provide Figure 1 Another sub-process diagram of step S12;

[0038] Fig. 9 is a schematic structural diagram of a device performance evaluation apparatus provided in some embodiments;

[0039] Fig.10 is a schematic diagram of the structure of an electronic device provided by some embodiments;

[0040] Fig.11 is a schematic diagram of the structure of a performance evaluation system for a device provided in some embodiments;

[0041] Fig.12 It is a schematic diagram of the structure of a computer-readable storage medium provided in some embodiments. DETAILED DESCRIPTION

[0042] The scheme of the embodiment of the present application is described in detail below in conjunction with the drawings of the specification.

[0043] In the following description, for the purpose of explanation rather than limitation, specific details such as specific subsystem structures, interfaces, and technologies are provided to facilitate a thorough understanding of the present application.

[0044] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the objects associated before and after are in an "or" relationship. In addition, "many" in this article means two or more than two. In addition, the term "at least one" in this article means any combination of at least two of any one or more of a plurality of, for example, including at least one of A, B, and C, can mean including any one or more elements selected from the set consisting of A, B, and C.

[0045] The aging assessment of the soldering layer of chips or other SMD components is very important for the use of chips or devices. The chips or devices should not only be qualitatively analyzed from the perspective of whether the operation of the chips or devices is normal, but the aging of the soldering layer should be quantitatively analyzed to facilitate the formulation of usage plans for the chips or other devices in the future.

[0046] However, currently, quantitative analysis of the soldering layer of a chip or other device requires slicing the chip or device, and then performing quantitative analysis based on the cross section of the slice. This method causes great damage to the chip or other device, which is not conducive to the future use of the chip or other device.

[0047] In order to solve this problem, the present application provides a device performance evaluation method. Considering that if there is a crack in the device to be evaluated, it will cause the temperature of some areas of the device to be evaluated to be higher. By obtaining the thermal spectrum of the device to be evaluated and the standard device working at the same power, and analyzing the difference between the thermal spectrum of the device to be evaluated and the thermal spectrum of the standard device, the parameters of the crack in the device to be evaluated can be determined. Because the crack parameters are determined, the performance parameters such as the equivalent life or residual life of the device to be evaluated can be further determined.

[0048] See also Figure 1 , the performance evaluation method of the device provided in the present application may include the contents of the following steps S11 to S14. Step S11: Obtain a first thermal spectrum of the device to be evaluated and a second thermal spectrum of several standard devices. The first thermal spectrum and each second thermal spectrum are collected when the device to be evaluated and each standard device are working at the same power. Step S12: Determine the parameters of the crack in the device to be evaluated based on the temperature difference of each pixel point in the first thermal spectrum and each second thermal spectrum. Step S13: Determine the performance parameters of the device to be evaluated based on the parameters of the crack in the device to be evaluated.

[0049] The device to be evaluated can be a chip or other SMD components. For example, the device to be evaluated can be a packaged chip, which includes a chip layer and a welding layer. For example, the internal structure of the device to be evaluated can be as follows: Figure 2 and Figure 3 As shown, the chip layer is connected to the welding layer and can be connected to other chips through bonding wires. Or the device to be evaluated can also be a conventional component, such as a device packaged in ceramics, injection molding, etc. A thermogram is an image generated by infrared imaging technology, which shows the temperature distribution on the surface of an object. Specifically, it can be a thermal distribution diagram of the surface temperature of the device to be evaluated when it is working. In the thermogram, different colors or grayscales can be used to represent different temperatures. Several can be one or more. The standard device can be a newly produced device or a device that has not been actually used. Of course, if the performance parameters of the device to be evaluated need to be evaluated, then the standard device needs to be a device of the same type as the device to be evaluated. For example, if the device to be evaluated is a Class B chip produced by manufacturer A, then the standard device is also a Class B chip produced by manufacturer A, which ensures the accuracy of the performance evaluation results of the device to be evaluated. Of course, if the performance evaluation results of the device to be evaluated are not required, the Class B chip produced by manufacturer C can also be used. The parameters of the crack may include but are not limited to one or more of the following: the height of the crack, the area of ​​the crack, and the length of the crack. This application takes the device to be evaluated as a chip, and the crack parameters including the crack height of the chip welding layer as an example. Figure 2 and Figure 3 Figure 2 shows two types of cracks that may occur in the solder layer connected to the chip layer in the device to be evaluated. One type of crack, a, and the other type of crack, b, originate from the edge of the solder layer and extend along the inside of the chip. The other type of crack, c, originates from the middle of the chip and extends along the edge of the chip. Figure 2 If the crack starts from the edge, the temperature of the relatively low temperature chip area will increase, while the maximum temperature in the center of the chip remains unchanged. Figure 3 The maximum temperature in the center of the chip will increase rapidly, and after reaching a certain temperature, it will spread to the surrounding area. This positive feedback cycle will accelerate the fatigue progress of the entire interface solder layer, thereby reducing the life of the power module. The height of the crack can also be understood as the width of the crack, that is, the distance between the two interfaces of the crack. Figure 2 and Figure 3For example, the direction of collecting the thermal spectrum of the image to be evaluated can be collected from top to bottom or from bottom to top, that is, the collection direction of the thermal spectrum can be perpendicular to the interface where the welding layer contacts the chip layer, so as to better observe the crack situation of the entire interface of the welding layer. The implementation method of the above step S12 can be to first obtain the difference between the temperature of each pixel point in the first thermal spectrum and each second thermal spectrum respectively, and the position of the crack in the device to be evaluated can be determined according to the temperature difference, and the height or area of ​​the crack can be evaluated according to the size of the temperature difference. Parameters, or the difference between the equivalent impedance of the device to be evaluated and the calibrated impedance of the device to be evaluated can be determined according to the temperature difference, and then the parameters of the crack are determined according to the difference. The implementation method of the above step S13 may include but is not limited to: 1. Presetting the corresponding relationship between the parameters of different cracks and the performance parameters of the device to be evaluated, and the performance parameters of the device to be evaluated can be determined by querying the relationship; 2. It can also be determined according to the parameters of the crack The fatigue strength of the welding layer of the device to be evaluated is determined, and the performance parameters of the device to be evaluated are determined according to the fatigue strength.

[0050] In the above scheme, if there is a crack in the device to be evaluated, it will cause the temperature of some areas of the device to be evaluated to be higher. By obtaining the thermal spectra of the device to be evaluated and the standard device working at the same power, and analyzing the difference between the thermal spectra of the device to be evaluated and the thermal spectra of the standard device, the parameters of the crack in the device to be evaluated can be determined. Because the crack parameters are determined, the performance parameters such as the equivalent life or residual life of the device to be evaluated can be further determined.

[0051] In some embodiments, see Figure 4 , the above step S12 may include the following steps: Step S121: for each pixel point in the first thermal spectrum, obtain the temperature difference between the temperature of the pixel point in the first thermal spectrum and the temperature statistical value of the pixel point in each second thermal spectrum. Step S122: based on the temperature difference of each pixel point and the working power of the device to be evaluated, predict the thermal resistance increment of the device to be evaluated. Step S123: based on the thermal resistance increment, obtain the parameters of the crack.

[0052] Each pixel in the first thermal spectrum has a corresponding pixel in the second thermal spectrum. Optionally, the pixels at the same position in the first thermal spectrum and the second thermal spectrum are collected from the same position of the device to be evaluated. The temperature statistics may include but are not limited to the maximum value, minimum value, mean, median, mode, etc. In this embodiment, the temperature statistics are the average value after removing the abnormal value, for example, the average value after removing the maximum value and minimum value of the pixel in each second thermal spectrum. That is, there is a temperature difference for each pixel in the first thermal spectrum. In some embodiments, before executing the above step S122, the following steps may also be performed: determine whether there is an abnormal temperature difference in each temperature difference, the abnormal temperature difference may be a temperature difference in which the temperature difference is greater than or equal to a preset temperature difference, for example, the preset temperature difference may be a temperature difference that characterizes the presence of cracks in the device to be evaluated, that is, as long as there is an abnormal temperature difference in the temperature difference corresponding to each pixel in the first thermal spectrum, it means that there is a crack in the device to be evaluated, and step S122 may be performed, otherwise step S122 may not be performed on the device to be evaluated. The above-mentioned method of predicting the value-added thermal resistance of the device to be evaluated based on the temperature difference of each pixel point and the working power of the device to be evaluated may be: counting the temperature differences to obtain the temperature difference statistics, and then predicting the value-added thermal resistance of the device based on the temperature difference statistics and the working power of the device to be evaluated, for example, directly using the maximum temperature difference or the average temperature difference as the temperature difference statistics. In the case where the device to be evaluated includes a welding layer, the method of obtaining the parameters of the crack based on the value-added thermal resistance may be: obtaining the parameters of the crack based on the product of the value-added thermal resistance and the thermal conductivity of the welding material used for the welding layer. In the case where the device to be evaluated is a device packaged by ceramics, injection molding, etc., the above-mentioned method of obtaining the parameters of the crack based on the value-added thermal resistance may be: obtaining the parameters of the crack based on the ratio between the value-added thermal resistance and the calibrated resistance of the device to be evaluated.

[0053] In the above scheme, since the working power of the device to be evaluated is different, the electrical stress on the device to be evaluated may be different. Therefore, when determining the crack parameters, referring to the working power of the device to be evaluated can make the determined crack parameters more accurate.

[0054] In some embodiments, the device to be evaluated includes a welding layer, and the parameters of the crack include parameters of the crack generated by the welding layer. The above-mentioned method of predicting the thermal resistance increment of the device to be evaluated based on the temperature difference of each pixel point and the power of the device to be evaluated may include: taking the maximum temperature difference among the temperature differences as the target temperature difference; taking the ratio between the target temperature difference and the power as the thermal resistance increment. The above-mentioned method of obtaining the parameters of the crack based on the thermal resistance increment may include: obtaining the parameters of the crack based on the product of the thermal resistance increment and the thermal conductivity of the welding material used in the welding layer.

[0055] The method of obtaining the temperature difference of each pixel can refer to formula (1):

[0056] Formula (1);

[0057] in, Represents the temperature difference of the pixel. represents the temperature in the first thermogram, The statistical value representing the temperature of the pixel in each second thermal spectrum map may be, for example, the average temperature obtained after removing the abnormal temperature of the pixel in each second thermal spectrum map. The abnormal temperature may be an outlier in each temperature. As the target temperature difference. In other embodiments, the mean value of the temperature difference or other statistical values ​​may be selected as the target temperature difference. Optionally, the implementation of the above step S122 may refer to formula (2):

[0058] Formula (2);

[0059] Among them, in formula (2) represents the target temperature difference, Indicates the power at which the device to be evaluated operates. Indicates the thermal resistance of the solder used in the soldering layer, that is, the solder thermal resistance. Indicates the thermal resistance increment, in formula (2) known, P known, Known, can be obtained .

[0060] The crack parameters can include the crack height (also called height), and the material thermal resistance can be calculated by the thermal conductivity of the material. ,thickness And area A, in this scheme, the temperature difference is analyzed with a single pixel point, then area A can be equal to 1, because the thermal resistance of the material , so the height of the crack is obtained in this scheme The method can refer to formula (3):

[0061] Formula (3);

[0062] That is, the height of the crack in this application can be considered to be the width of the crack at a single pixel in the first thermal spectrum. To better understand the difference between crack height and length, please refer to Figure 5 , the crack d in the welding layer extends from left to right, and the height of a certain pixel is .

[0063] In the above scheme, by using the maximum temperature difference to determine the thermal resistance increment, the determined thermal resistance increment can be made the maximum value, and the performance parameters of the device to be evaluated are relatively conservative, which can better guarantee the subsequent use of the device to be evaluated.

[0064] In other embodiments, the length of the crack can also be determined based on each temperature difference. For example, temperature differences greater than or equal to a preset temperature difference are determined as abnormal temperature differences, and then the pixel points corresponding to each abnormal temperature difference in the first thermal spectrum are taken as abnormal pixel points, and the connecting line between the abnormal pixel points is taken as the length of the crack.

[0065] In some embodiments, the device to be evaluated includes a welding layer, and the crack parameters include the height of the crack generated by the welding layer. The above-mentioned method of determining the performance parameters of the device to be evaluated based on the crack parameters in the device to be evaluated may include: determining the fatigue strength of the device to be evaluated based on the crack height and the crack height-fatigue strength relationship; determining the performance parameters of the device to be evaluated based on the fatigue strength of the device to be evaluated.

[0066] Among them, the crack height-fatigue strength relationship can be obtained through mechanical stress testing or stress simulation fitting. The crack height-fatigue strength relationship can be characterized as: , where N represents fatigue strength, f represents the relationship between crack height and fatigue strength, h represents crack height, and C is the relationship constant and fitting parameter, which has no practical meaning. The crack height-fatigue strength relationship of each solder is unique. For example, f is a curve, which can be specifically referred to Figure 6 By querying the relationship curve between fatigue strength N and crack height h, the fatigue strength Nth of the device to be evaluated is obtained. Figure 6 Where N0 represents the initial fatigue strength, Figure 6 The horizontal axis represents the inverse of the crack height, and the vertical axis represents the fatigue strength. Based on the fatigue strength of the device to be evaluated, the method of determining the performance parameters of the device to be evaluated may include but is not limited to: pre-establishing a correlation between the fatigue strength and the performance parameters of the device to be evaluated, and then determining the performance parameters of the device to be evaluated based on the correlation and the determined fatigue strength of the device to be evaluated.

[0067] In the above scheme, the crack height and fatigue strength are generally related to the welding material, that is, when the welding material is fixed, the relationship between the crack height and the fatigue strength is also fixed. Therefore, this relationship can be used in different devices to determine the fatigue strength at a specific crack height, thereby improving the versatility of the device performance evaluation method.

[0068] In some embodiments, the performance parameters of the device to be evaluated include the residual life of the device to be evaluated. The above-mentioned method of determining the performance parameters of the device to be evaluated based on the fatigue strength of the device to be evaluated may include: using the fatigue strength of the device to be evaluated, querying the decay relationship of the fatigue strength over time, and obtaining the equivalent life of the device to be evaluated; and taking the difference between the preset maximum life of the device to be evaluated working at power and the equivalent life as the residual life of the device to be evaluated.

[0069] The attenuation relationship of the fatigue strength of the device to be evaluated over time can be obtained from solder manufacturers or through experiments. For example, the attenuation relationship can refer to Figure 7 , Figure 7 The horizontal axis represents the equivalent life, the vertical axis represents the fatigue strength, and t0 represents the calibrated life, which is the preset maximum life of the device to be evaluated. Based on the fatigue strength attenuation curve of the solder used in the welding layer of the device to be evaluated and the fatigue strength Nth of the device to be evaluated obtained above, the equivalent life under the current aging state can be obtained by querying , and the equivalent life of the device to be evaluated can be obtained by analyzing the temperature difference between the first thermal spectrum and each second thermal spectrum. Determine the residual life The way can be: .

[0070] In the above solution, by predetermining the attenuation relationship of fatigue strength over time, the equivalent life of the device to be evaluated can be more conveniently obtained, thereby determining the residual life of the device to be evaluated.

[0071] In some embodiments, see Figure 8 , the above step S12 may include the following steps: Step S124: For each pixel point in the first thermal spectrum, obtain the temperature difference between the temperature of the pixel point in the first thermal spectrum and the temperature statistics of the pixel point in each second thermal spectrum. Step S125: Based on the temperature difference of each pixel point and the working power of the device to be evaluated, determine the equivalent impedance of the device to be evaluated. Step S126: Obtain the impedance difference between the equivalent impedance and the calibrated impedance of the device to be evaluated and obtain the crack parameters based on the impedance difference.

[0072] Each pixel in the first thermal spectrum has a corresponding pixel in the second thermal spectrum. Optionally, the pixels at the same position in the first thermal spectrum and the second thermal spectrum are collected from the same position of the device to be evaluated. The temperature statistics may include but are not limited to the maximum value, minimum value, mean, median, mode, etc. In this embodiment, the temperature statistics are the average value after removing the abnormal value, for example, the average value after removing the maximum value and minimum value of the pixel in each second thermal spectrum. That is, there is a temperature difference for each pixel in the first thermal spectrum. In some embodiments, before executing the above step S125, the following steps may also be performed: determine whether there is an abnormal temperature difference in each temperature difference, the abnormal temperature difference may be a temperature difference in which the temperature difference is greater than or equal to a preset temperature difference, for example, the preset temperature difference may be a temperature difference that characterizes the presence of cracks in the device to be evaluated, that is, as long as there is an abnormal temperature difference in the temperature difference corresponding to each pixel in the first thermal spectrum, it means that there is a crack in the device to be evaluated, and step S125 may be performed, otherwise step S125 may not be performed on the device to be evaluated. Based on the temperature difference of each pixel point and the working power of the device to be evaluated, the method of determining the equivalent impedance of the device to be evaluated can be to select the maximum temperature difference from each temperature difference as the target temperature difference, and then determine the equivalent impedance of the device to be evaluated based on the target temperature difference and the working power of the device to be evaluated.

[0073] For example, the equivalent impedance is calculated The way can be: , represents the target temperature difference, Indicates the material quality of the device to be evaluated, such as the quality of the ceramic packaging layer or injection molding packaging layer in the device to be evaluated. Represents the specific heat capacity, which can be obtained by querying the device material. is the current, t is the time from the start of detection to reaching thermal equilibrium, Represents equivalent impedance.

[0074] The above-mentioned method of obtaining the impedance difference between the equivalent impedance and the calibrated impedance of the device to be evaluated and obtaining crack parameters based on the impedance difference may be: determining parameters such as the crack height or the crack area according to the size of the impedance difference.

[0075] In the above scheme, the temperature rise caused by the internal crack of the device to be evaluated is due to the increase in the internal impedance of the device caused by the crack, thereby causing the device to heat up. Therefore, by obtaining the difference between the equivalent impedance evaluated during the operation of the device to be evaluated and the calibrated impedance, the parameters of the crack in the device to be evaluated can be determined.

[0076] In some embodiments, the parameters of the crack include the crack area of ​​the fracture surface in the device to be evaluated and the crack area ratio. The impedance difference between the equivalent impedance and the calibrated impedance of the device to be evaluated is obtained and the parameters of the crack are obtained based on the impedance difference, including: obtaining the ratio between the impedance difference and the equivalent impedance, and using the ratio as the crack area ratio; and using the product of the ratio and the initial area of ​​the fracture surface as the crack area.

[0077] From the Holland formula, it can be seen that the impedance is inversely proportional to the contact area, so the crack area can be calculated The formula can refer to formula (4):

[0078] Formula (4);

[0079] in, represents the initial contact area, that is, the initial cross-sectional area of ​​the device fracture surface. In formula (4), R is the initial impedance of the device, that is, the device calibration impedance. Represents equivalent impedance, and the impedance difference is .

[0080] Calculation of crack area ratio The method can be referred to formula (5):

[0081] = Formula (5);

[0082] Crack area The area ratio η is used as a reference value for evaluating the degree of device damage. In addition to the contact area, the change in impedance is also affected by factors such as temperature and material properties. The crack area obtained by this method is the reference area.

[0083] In the above solution, by obtaining the ratio between the impedance difference and the equivalent impedance, the crack area ratio can be determined, thereby determining the crack area on the fracture surface in the device to be evaluated.

[0084] In some embodiments, the device performance evaluation method further includes: predicting the performance parameters of the device to be evaluated when operating at other powers based on the performance parameters of the device to be evaluated and a preset stress model.

[0085] The preset stress model may include the Arrhenius model. The stress to be evaluated on the device may include mechanical stress, temperature stress, humidity stress, etc. A corresponding stress model may be preset for each stress factor. The equivalent life and residual life obtained above are obtained under specific stress (for example, power of a specific operation). The equivalent life under other stress conditions can be equivalently calculated by the adopted stress acceleration model (such as Arrhenius). Figure 7The attenuation curve shown in the figure represents the fatigue strength attenuation of solder caused by cracks or voids. The slope of the curve represents the attenuation rate. This attenuation is a positive feedback. The appearance of cracks will accelerate the fatigue attenuation of the solder.

[0086] In the above scheme, by combining the Arrhenius model and the preset stress model, the performance parameters of the device to be evaluated under a specified stress can be predicted.

[0087] In some embodiments, in daily applications or stress acceleration tests, due to the material differences of the chip, solder and substrate (PCB), their thermal expansion coefficients are different. Therefore, the high stress generated causes the solder to crack under repeated action, forming a solder interface fracture; the fracture of the solder interface increases the local thermal resistance of the corresponding chip area, thereby causing the chip temperature to increase locally. The present application provides a device performance evaluation method. According to the temperature difference at the same point in the thermal spectrum of the device to be evaluated and the standard device, the thermal resistance value-added of the chip solder layer is calculated, and the crack (or void) height is calculated from the thermal resistance value-added. The current fatigue strength is obtained on the inverse relationship curve of fatigue strength-crack height, and the instantaneous solder layer fatigue degree of the chip is quantitatively analyzed. It can be understood that the fatigue strength of the device to be evaluated and the fatigue strength of the solder layer can be the same concept, that is, the fatigue strength of the device to be evaluated in this solution is equal to the fatigue strength of the solder layer.

[0088] In addition, the equivalent aging time can be further obtained based on the fatigue strength-aging time curve, so as to obtain the current used life and residual life of the evaluation sample, and then the equivalent life under other stresses can be equivalently calculated by combining the Arrhenius model, thereby reducing the exponential growth of test time and test cost caused by the increase of equivalent life.

[0089] By calculating the solder fatigue strength of the chip after a certain degree of aging, combined with the degradation curve of the solder, the aging degree (i.e., equivalent life) of various SMD devices such as IGBT and chips can be accurately evaluated. The residual life under the same stress can also be predicted, and the complete life of the device under a certain stress can be obtained. That is, the performance evaluation method of the device provided by this solution requires a certain length of accelerated aging test to predict the complete life of the product under a certain stress.

[0090] In addition, for common components, according to the mechanism of the internal cracks of the components changing the impedance of the components, the algorithm is changed, and the crack (or void) area is calculated by the electrothermal formula and the Dutch formula (also known as the Holland formula), so as to quantify the internal crack defect or fault degree of the components. That is, through the thermal spectrum analysis method, the reference area of ​​the internal cracks of the components (generally referring to ceramics) is equivalently calculated, so as to evaluate the defect degree of the internal cracks of the components, and non-destructively judge the potential fault severity of the components and the probability of failure in the later stage, which replaces the existing destructive device slice analysis method and reduces the cost and difficulty of conducting internal defect analysis of the device.

[0091] Specifically, taking the device to be evaluated as a chip as an example, the device performance evaluation method may include the following steps:

[0092] First, the thermal spectra are collected and the internal state is preliminarily analyzed. The chip to be evaluated and the standard chip both work at the same power below the rated power. High-definition images of the thermal spectra of the chip to be evaluated and the standard chip are scanned and collected respectively. The thermal spectra (P1, P2...Pn) collected from the standard device are preprocessed and compared with each other to eliminate the thermal spectra with obvious differences in temperature distribution and temperature values ​​from other thermal spectra. The remaining thermal spectra are superimposed and the temperature values ​​of the thermal spectra pixels are "averaged" as the standard reference spectrum P0. Then, the thermal spectrum of the sample to be evaluated under the rated working state is obtained, and the spectrum is compared with the thermal spectrum of the standard part of the same product to analyze the temperature distribution difference between the thermal spectra. If the distribution difference is more obvious, it means that there are cracks or voids inside, and the temperature difference is obtained. The way is: , represents the temperature of the pixel in the thermal spectrum Pt of the device to be evaluated, Indicates the temperature of the pixel in the standard reference spectrum P0. Specifically, the temperature difference between the thermal spectrum Pt of the device to be evaluated and the temperature value of the same pixel in the standard reference spectrum P0 is compared and analyzed. If there is an obvious temperature difference point on the thermal spectrum, it means that there are cracks or voids inside the chip.

[0093] Secondly, the maximum temperature difference between the same point or area on the thermal spectrum of the sample and the standard part is analyzed and used as the point data for subsequent evaluation and calculation.

[0094] Then, by querying the chip specification and solder parameter table, the thermal resistance R1, R2 and operating power P of the chip and solder are obtained, and the thermal resistance increment R0 of the sample to be evaluated is calculated, and then the crack height / spacing h (or void height) at that point can be calculated. The thermal resistance R1 of the chip material and the thermal resistance R2 of the solder are obtained through the chip specification and solder specification, and the design power of the chip is obtained (this power refers to the actual operating power of the chip in this product, which may be reduced relative to the rated power). The data processing module is output through the interactive module, and the chip junction temperature is calculated by the formula: .

[0095] From this we can see that:

[0096] ;

[0097] In the above formula Indicates the target temperature difference (maximum temperature difference), is the junction temperature of the chip to be evaluated, is the junction temperature of the standard chip. In the above formula, the thermal resistance R1 from the chip surface to the internal junction temperature is constant, and the chip power is the actual operating power P.

[0098] From the internal bonding structure of the chip, we know that the rise in chip aging temperature is mainly caused by the change in thermal resistance of the solder layer at the bottom of the chip. The increase in thermal resistance hinders the heat conduction and heat dissipation of the chip. Assuming that the thermal resistance value added by the crack is R0, the relationship between the chip temperature rise and thermal resistance is as follows: Then according to , and obtain the crack height.

[0099] Then, through mechanical stress simulation, it can be known that the fatigue strength of the solder is positively correlated with the inverse of the crack height h. By querying the simulation curve relationship between the fatigue strength N and the crack height h, the fatigue strength Nth at this time is obtained.

[0100] Next, based on the fatigue strength Nth value obtained above, query the fatigue life at this time in Nt (fatigue strength attenuation curve) , and the residual life under this fatigue strength can be obtained simultaneously.

[0101] In other embodiments, the device to be evaluated is a conventional component (generally ceramic, injection molding, etc.) as an example. When ceramic components (resistors, chips, etc.) are subjected to cyclic mechanical stress or temperature stress, aging cracks will appear inside the device. The mechanism of thermal spectrum analysis is applied to analyze the potential damage inside the device as follows:

[0102] By comparing the thermal spectra of the evaluation sample and the standard part, the point with the maximum temperature difference at the same point is obtained, and the maximum temperature difference value is obtained. .

[0103] From the heat power consumption and temperature rise formula:

[0104] ;

[0105] ;

[0106] available: ;

[0107] in, represents the target temperature difference, Indicates the material quality of the device to be evaluated, such as the quality of the ceramic packaging layer or injection molding packaging layer in the device to be evaluated. Represents the specific heat capacity, which can be obtained by querying the device material. is the current, t is the time from the start of detection to reaching thermal equilibrium, Represents equivalent impedance.

[0108] From the Holland formula, it can be seen that the impedance is inversely proportional to the contact area, so the crack area can be calculated The formula can be:

[0109] ;

[0110] in, It represents the initial contact area, that is, the initial cross-sectional area of ​​the device fracture surface. In this formula, R is the initial impedance of the device, that is, the device calibration impedance. Represents equivalent impedance, and the impedance difference is .

[0111] Calculation of crack area ratio The method can be referred to:

[0112] = ;

[0113] Crack area The area ratio η is used as a reference value for evaluating the degree of device damage. In addition to the contact area, the change in impedance is also affected by factors such as temperature and material properties. The crack area obtained by this method is the reference area.

[0114] In the above solution, by obtaining the ratio between the impedance difference and the equivalent impedance, the crack area ratio can be determined, thereby determining the crack area on the fracture surface in the device to be evaluated.

[0115] See also Fig. 9The device performance evaluation device 30 provided in the present application includes a thermal spectrum acquisition module 31, a crack parameter determination module 32 and a performance evaluation module 33; the thermal spectrum acquisition module 31 is used to obtain a first thermal spectrum of the device to be evaluated and a second thermal spectrum of several standard devices, the first thermal spectrum and each second thermal spectrum are collected when the device to be evaluated and each standard device work at the same power; the crack parameter determination module 32 is used to determine the parameters of the crack in the device to be evaluated based on the temperature difference of each pixel point in the first thermal spectrum and each second thermal spectrum; the performance evaluation module 33 is used to determine the performance parameters of the device to be evaluated based on the parameters of the crack in the device to be evaluated.

[0116] In the above scheme, if there is a crack in the device to be evaluated, it will cause the temperature of some areas of the device to be evaluated to be higher. By obtaining the thermal spectra of the device to be evaluated and the standard device working at the same power, and analyzing the difference between the thermal spectra of the device to be evaluated and the thermal spectra of the standard device, the parameters of the crack in the device to be evaluated can be determined. Because the crack parameters are determined, the performance parameters such as the equivalent life or residual life of the device to be evaluated can be further determined.

[0117] In some embodiments, the crack parameter determination module 32 determines the parameters of the crack in the device to be evaluated based on the temperature difference between each pixel point in the first thermal spectrum and each second thermal spectrum, including: for each pixel point in the first thermal spectrum, obtaining the temperature difference between the temperature of the pixel point in the first thermal spectrum and the temperature statistical value of the pixel point in each second thermal spectrum; based on the temperature difference of each pixel point and the working power of the device to be evaluated, predicting the thermal resistance value-added of the device to be evaluated; based on the thermal resistance value-added, obtaining the parameters of the crack.

[0118] In the above scheme, since the working power of the device to be evaluated is different, the electrical stress on the device to be evaluated may be different. Therefore, when determining the crack parameters, referring to the working power of the device to be evaluated can make the determined crack parameters more accurate.

[0119] In some embodiments, the device to be evaluated includes a welding layer, and the parameters of the crack include parameters of the crack generated by the welding layer. The crack parameter determination module 32 predicts the thermal resistance appreciation of the device to be evaluated based on the temperature difference of each pixel point and the working power of the device to be evaluated, including: taking the maximum temperature difference among the temperature differences as the target temperature difference; taking the ratio between the target temperature difference and the power as the thermal resistance appreciation; obtaining the parameters of the crack based on the thermal resistance appreciation, including: obtaining the parameters of the crack based on the product of the thermal resistance appreciation and the thermal conductivity of the welding material used for the welding layer.

[0120] In the above scheme, by using the maximum temperature difference to determine the thermal resistance increment, the determined thermal resistance increment can be made the maximum value, and the performance parameters of the device to be evaluated are relatively conservative, which can better guarantee the subsequent use of the device to be evaluated.

[0121] In some embodiments, the device to be evaluated includes a welding layer, and the parameters of the crack include the height of the crack generated in the welding layer. The performance evaluation module 33 determines the performance parameters of the device to be evaluated based on the parameters of the crack in the device to be evaluated, including: determining the fatigue strength of the device to be evaluated based on the height of the crack and the crack height-fatigue strength relationship; determining the performance parameters of the device to be evaluated based on the fatigue strength of the device to be evaluated.

[0122] In the above scheme, the crack height and fatigue strength are generally related to the welding material, that is, when the welding material is fixed, the relationship between the crack height and the fatigue strength is also fixed. Therefore, this relationship can be used in different devices to determine the fatigue strength at a specific crack height, thereby improving the versatility of the device performance evaluation method.

[0123] In some embodiments, the performance parameters of the device to be evaluated include the residual life of the device to be evaluated. The performance evaluation module 33 determines the performance parameters of the device to be evaluated based on the fatigue strength of the device to be evaluated, including: using the fatigue strength of the device to be evaluated to query the attenuation relationship of the fatigue strength over time to obtain the equivalent life of the device to be evaluated; and taking the difference between the preset maximum life of the device to be evaluated working under power and the equivalent life as the residual life of the device to be evaluated.

[0124] In the above solution, by predetermining the attenuation relationship of fatigue strength over time, the equivalent life of the device to be evaluated can be more conveniently obtained, thereby determining the residual life of the device to be evaluated.

[0125] In some embodiments, the crack parameter determination module 32 determines the parameters of the crack in the device to be evaluated based on the temperature difference between each pixel point in the first thermal spectrum and each second thermal spectrum, including: for each pixel point in the first thermal spectrum, obtaining the temperature difference between the temperature of the pixel point in the first thermal spectrum and the temperature statistical value of the pixel point in each second thermal spectrum; determining the equivalent impedance of the device to be evaluated based on the temperature difference of each pixel point and the working power of the device to be evaluated; obtaining the impedance difference between the equivalent impedance and the calibrated impedance of the device to be evaluated and obtaining the parameters of the crack based on the impedance difference.

[0126] In the above scheme, the temperature rise caused by the internal crack of the device to be evaluated is due to the increase in the internal impedance of the device caused by the crack, thereby causing the device to heat up. Therefore, by obtaining the difference between the equivalent impedance evaluated during the operation of the device to be evaluated and the calibrated impedance, the parameters of the crack in the device to be evaluated can be determined.

[0127] In some embodiments, the parameters of the crack include the crack area of ​​the fracture surface in the device to be evaluated and the crack area ratio. The crack parameter determination module 32 obtains the impedance difference between the equivalent impedance and the calibrated impedance of the device to be evaluated and obtains the parameters of the crack based on the impedance difference, including: obtaining the ratio between the impedance difference and the equivalent impedance, and using the ratio as the crack area ratio; and using the product of the ratio and the initial area of ​​the fracture surface as the crack area.

[0128] In the above solution, by obtaining the ratio between the impedance difference and the equivalent impedance, the crack area ratio can be determined, thereby determining the crack area on the fracture surface in the device to be evaluated.

[0129] In some embodiments, the performance evaluation module 33 is further used to predict the performance parameters of the device to be evaluated when operating at other powers based on the performance parameters of the device to be evaluated and a preset stress model.

[0130] In the above scheme, by combining the Arrhenius model and the preset stress model, the performance parameters of the device to be evaluated under a specified stress can be predicted.

[0131] See also Fig.10 The electronic device 40 provided in the embodiment of the present application includes a memory 41 and a processor 42. The processor 42 is used to execute the program instructions stored in the memory 41 to implement the steps in the embodiment of the performance evaluation method of any device described above. In a specific implementation scenario, the electronic device 40 may include, but is not limited to: a monitoring device, a microcomputer, and a server. In addition, the electronic device 40 may also include a carrier device such as a laptop computer and a tablet computer, which is not limited here.

[0132] Specifically, the processor 42 is used to control itself and the memory 41 to implement the steps in the performance evaluation method embodiment of any of the above-mentioned devices. The processor 42 can also be called a CPU (Central Processing Unit). The processor 42 may be an integrated circuit chip with signal processing capabilities. The processor 42 can also be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field-programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. In addition, the processor 42 can be implemented by an integrated circuit chip.

[0133] See also Fig.11 The device performance evaluation system 10 provided in the embodiment of the present application includes the above-mentioned electronic device 40 and a thermal spectrum acquisition device 50 that is communicatively connected to the electronic device 40. The thermal spectrum acquisition device 50 is capable of acquiring thermal spectra. The electronic device 40 cooperates with the thermal spectrum acquisition device 50 to implement any of the above-mentioned device performance evaluation methods.

[0134] In some application scenarios, the thermal spectrum acquisition device 50 and the electronic device 40 can be integrated into one device, and the thermal spectrum acquisition device 50 and the electronic device 40 can be communicated with each other through a communication circuit integrated inside the device, or the thermal spectrum acquisition device 50 and the electronic device 40 can be independently set up and the two can establish a communication connection wirelessly or wiredly.

[0135] In some embodiments, the device performance evaluation system 10 further includes a test bench 60 , a placement plane (not shown) of the test bench 60 is used to place the device to be evaluated, and the projection plane of the thermal spectrum acquisition device 50 is parallel to the placement plane of the test bench 60 .

[0136] In the above solution, the placement plane of the test bench and the projection plane of the thermal spectrum acquisition device enable the thermal spectrum map to better acquire the thermal spectrum map of the device to be evaluated.

[0137] See also Fig.12 , Fig.12 The computer-readable storage medium 70 has program instructions 71 stored thereon, and when the program instructions 71 are executed by a processor, the steps in any of the above-mentioned device performance evaluation method embodiments are implemented.

[0138] In some embodiments, the functions or modules included in the device provided by the embodiments of the present disclosure can be used to execute the method described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0139] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0140] In the several embodiments provided in the present application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device implementation described above is only schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation. For example, units or components can be combined or integrated into another system, or some features can be ignored or not executed. In another image position, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0141] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit. If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or part of the contribution to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor (processor) to perform all or part of the steps of each implementation method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.

Claims

1. A method for evaluating device performance, characterized in that: include: Obtaining a first thermal spectrum of the device to be evaluated and second thermal spectrums of several standard devices, wherein the first thermal spectrum and each of the second thermal spectrums are collected when the device to be evaluated and each of the standard devices operate at the same power; Determining parameters of a crack in the device to be evaluated based on a temperature difference between each pixel point in the first thermal spectrum and each of the second thermal spectrums; Determining performance parameters of the device to be evaluated based on parameters of the crack in the device to be evaluated; The method of determining the parameters of the crack in the device to be evaluated based on the temperature difference between each pixel in the first thermal spectrum and each pixel in the second thermal spectrum includes: for each pixel in the first thermal spectrum, obtaining the temperature difference between the temperature of the pixel in the first thermal spectrum and the temperature statistical value of the pixel in each pixel in the second thermal spectrum; predicting the thermal resistance increment of the device to be evaluated based on the temperature difference of each pixel and the working power of the device to be evaluated; and obtaining the parameters of the crack based on the thermal resistance increment; Or, determining the parameters of the crack in the device to be evaluated based on the temperature difference between each pixel point in the first thermal spectrum and each of the second thermal spectrums includes: for each of the pixel points in the first thermal spectrum, obtaining the temperature difference between the temperature of the pixel point in the first thermal spectrum and the temperature statistical value of the pixel point in each of the second thermal spectrums; determining the equivalent impedance of the device to be evaluated based on the temperature difference of each of the pixel points and the working power of the device to be evaluated; obtaining the impedance difference between the equivalent impedance and the calibrated impedance of the device to be evaluated and obtaining the parameters of the crack based on the impedance difference.

2. The device performance evaluation method according to claim 1, characterized in that: The device to be evaluated includes a welding layer, the crack parameters include parameters of cracks generated by the welding layer, and the thermal resistance increment of the device to be evaluated is predicted based on the temperature difference of each pixel point and the working power of the device to be evaluated, including: The maximum temperature difference among the temperature differences is taken as the target temperature difference; Taking the ratio between the target temperature difference and the power as the thermal resistance increment; The step of obtaining the crack parameters based on the thermal resistance increment includes: The parameters of the crack are obtained based on the product of the thermal resistance increment and the thermal conductivity of the welding material used in the welding layer.

3. The device performance evaluation method according to claim 1 or 2, characterized in that: The device to be evaluated includes a welding layer, the crack parameter includes a height of a crack generated in the welding layer, and the determining the performance parameter of the device to be evaluated based on the crack parameter in the device to be evaluated includes: Determining the fatigue strength of the device to be evaluated based on the height of the crack and the crack height-fatigue strength relationship; Based on the fatigue strength of the device to be evaluated, a performance parameter of the device to be evaluated is determined.

4. The device performance evaluation method according to claim 3, characterized in that: The performance parameter of the device to be evaluated includes the residual life of the device to be evaluated, and determining the performance parameter of the device to be evaluated based on the fatigue strength of the device to be evaluated includes: Using the fatigue strength of the device to be evaluated, querying the decay relationship of the fatigue strength over time, and obtaining the equivalent life of the device to be evaluated; The difference between the preset maximum lifetime of the device to be evaluated when operating at the power and the equivalent lifetime is used as the residual lifetime of the device to be evaluated.

5. The device performance evaluation method according to claim 1, characterized in that: The crack parameters include a crack area and a crack area ratio of a fracture surface in the device to be evaluated. The step of obtaining an impedance difference between the equivalent impedance and a calibrated impedance of the device to be evaluated and obtaining the crack parameters based on the impedance difference includes: Obtaining a ratio between the impedance difference and the equivalent impedance, and using the ratio as the crack area ratio; The product of the ratio and the initial cross-sectional area of ​​the fracture surface is taken as the crack area.

6. The device performance evaluation method according to any one of claims 1, 2 and 5, characterized in that: The performance evaluation method of the device also includes: Based on the performance parameters of the device to be evaluated and a preset stress model, the performance parameters of the device to be evaluated when operating at other powers are predicted.

7. A device performance evaluation apparatus, characterized in that: include: A thermal spectrum acquisition module, used to acquire a first thermal spectrum of the device to be evaluated and second thermal spectrums of a plurality of standard devices, wherein the first thermal spectrum and each of the second thermal spectrums are acquired when the device to be evaluated and each of the standard devices operate at the same power; A crack parameter determination module, used to determine the parameters of the crack in the device to be evaluated based on the temperature difference between each pixel point in the first thermal spectrum and each of the second thermal spectrums; A performance evaluation module, used to determine the performance parameters of the device to be evaluated based on the parameters of the crack in the device to be evaluated; The crack parameter determination module determines the parameters of the crack in the device to be evaluated based on the temperature difference between each pixel in the first thermal spectrum and each of the second thermal spectrums in a manner including: for each pixel in the first thermal spectrum, obtaining the temperature difference between the temperature of the pixel in the first thermal spectrum and the temperature statistical value of the pixel in each of the second thermal spectrums; predicting the thermal resistance increment of the device to be evaluated based on the temperature difference of each pixel and the working power of the device to be evaluated; and obtaining the parameters of the crack based on the thermal resistance increment; Alternatively, the crack parameter determination module determines the parameters of the crack in the device to be evaluated based on the temperature difference between each pixel point in the first thermal spectrum and each of the second thermal spectrums in a manner including: for each pixel point in the first thermal spectrum, obtaining the temperature difference between the temperature of the pixel point in the first thermal spectrum and the temperature statistical value of the pixel point in each of the second thermal spectrums; determining the equivalent impedance of the device to be evaluated based on the temperature difference of each of the pixel points and the working power of the device to be evaluated; obtaining the impedance difference between the equivalent impedance and the calibrated impedance of the device to be evaluated and obtaining the parameters of the crack based on the impedance difference.

8. An electronic device, characterized in that: The device comprises a memory and a processor, wherein the processor is used to execute program instructions stored in the memory to implement the performance evaluation method of the device according to any one of claims 1 to 6.

9. A device performance evaluation system, characterized in that: It comprises the electronic device as claimed in claim 8 and a thermal spectrum acquisition device communicatively connected to the electronic device, the thermal spectrum acquisition device is capable of acquiring thermal spectra, and the electronic device cooperates with the thermal spectrum acquisition device to implement the performance evaluation method of the device as described in any one of claims 1 to 6.

10. The device performance evaluation system according to claim 9, characterized in that: The device performance evaluation system further comprises a test bench, a placement plane of the test bench is used to place the device to be evaluated, and a projection plane of the thermal spectrum acquisition device is parallel to the placement plane of the test bench.

11. A computer-readable storage medium having program instructions stored thereon, characterized in that: When the program instructions are executed by a processor, the performance evaluation method of the device according to any one of claims 1 to 6 is implemented.

Images