Silicon carbide power device thermal resistance and power cycle test system, method and product

Abstract

The invention provides a silicon carbide power device thermal resistance and power cycle test system, method and product, and relates to the technical field of power device test. The system comprises an upper computer, a temperature measuring device and at least one cooling loop, the cooling loop is used for cooling the to-be-tested power device; the temperature measuring device is used for collecting the temperature of the power device to be measured and sending the temperature to the upper computer to calculate a test result; the cooling loop has a flow and flow speed adjusting function, and the upper computer is further used for controlling cooling parameters of the cooling loop through the flow and flow speed adjusting function. According to the invention, the problem that the reliability and the service life of the power device under real conditions cannot be accurately evaluated because the thermal resistance or power cycle test of the traditional power device is greatly different from the actual application scene can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power device testing, and in particular to a thermal resistance and power cycle testing system, method and product for a silicon carbide power device. Background Art

[0002] With the vigorous development of new energy, power electronics and other fields, power devices have gradually become core components due to their high power density and high temperature resistance.

[0003] Thermal resistance testing and power cycling testing are important methods for evaluating the performance and reliability of power devices. However, in laboratory environments, traditional thermal resistance and power cycling testing of power devices has significant limitations. Because the cold plates used in testing are often large metal plates, parameters such as the flow rate and flow velocity of the cooling medium are usually fixed to ensure the reliability, stability, and consistency of the test results. These parameters are also designed for rapid heat dissipation. This results in significant differences between test conditions and actual application scenarios, and the resulting test results are often idealized and unable to accurately assess the reliability and lifespan of power devices under real-world conditions. Furthermore, for overall equipment reliability considerations, power devices are often significantly derated based on test data during actual use, leaving a large safety margin. While this approach ensures safety, it prevents power devices from fully utilizing their high power advantages, resulting in efficiency losses and waste of resources. Summary of the Invention

[0004] Embodiments of the present invention provide a system, method, and product for testing the thermal resistance and power cycle of silicon carbide power devices to address the problem that traditional thermal resistance or power cycle testing of power devices differs significantly from actual application scenarios and cannot accurately assess the reliability and life of power devices under real conditions.

[0005] In a first aspect, an embodiment of the present invention provides a thermal resistance and power cycle testing system for a silicon carbide power device, comprising: a host computer, a temperature measuring device, and at least one cooling circuit;

[0006] The cooling circuit is used to cool the power device to be tested;

[0007] The temperature measuring device is used to collect the temperature of the power device to be tested and send it to the host computer to calculate the thermal resistance or power cycle test results;

[0008] The cooling circuit has a flow rate and flow velocity adjustment function, and the host computer is further used to control the cooling parameters of the cooling circuit through the flow rate and flow velocity adjustment function.

[0009] In a possible implementation, the cooling circuit is connected to a chiller and cools the power device to be tested via a cold plate;

[0010] The flow rate and velocity regulation function is achieved through the following structure:

[0011] The water outlet valve of the chiller and the flow area regulating valve of the cold plate.

[0012] In a possible implementation, the power device testing system further includes:

[0013] pressure devices and pressure gauges;

[0014] The pressure device is used to press the power device to be tested onto the cold plate;

[0015] The pressure gauge is used to collect the actual pressure value of the pressure device;

[0016] The host computer is connected to the pressure device and the pressure gauge, and is used for feedback-adjusting the pressure of the pressure device according to a pre-input target pressure value and the actual pressure value.

[0017] In a possible implementation, a flow rate sensor is installed on the cooling circuit;

[0018] The flow rate and flow velocity sensor is used to collect the flow rate and flow velocity of the cooling circuit, obtain the actual value of the cooling parameter of the cooling circuit, and send it to the host computer;

[0019] The host computer is further configured to feedback-adjust the cooling parameters of the cooling circuit through the flow rate and flow velocity adjustment function according to the pre-input cooling parameter target value and the actual value of the cooling parameter.

[0020] In a possible implementation, the temperature measuring device includes at least one of the following: an electrical temperature measuring device and an optical temperature measuring device.

[0021] In a possible implementation, the power device testing system further includes: a voltage-sharing protection plate disposed between the pressure device and the power device to be tested.

[0022] In a possible implementation, the middle position of the pressure balancing protection plate has an opening;

[0023] The opening is used to perform optical temperature measurement on the power device to be measured; the opening is smaller than the power device to be measured, and the pressure device presses the edge of the voltage-sharing protection plate.

[0024] In a possible implementation, the cold plate is equipped with a quick-change interface; and switching valves are provided on the cooling circuits on both sides of the cold plate.

[0025] In a second aspect, an embodiment of the present invention provides a method for testing thermal resistance and power cycling of a silicon carbide power device, which is applied to a host computer as described in the first aspect or any possible implementation of the first aspect.

[0026] The method comprises:

[0027] Obtaining cooling parameter target values and actual cooling parameter values of the cooling circuit;

[0028] controlling the cooling parameter of the cooling circuit according to the cooling parameter target value and the cooling parameter actual value;

[0029] Under the current cooling parameters, the temperature of the power device to be tested during the thermal resistance or power cycling test is collected, and the results of the thermal resistance or power cycling test are calculated.

[0030] In a third aspect, an embodiment of the present invention provides a computer program product, including a computer program, which implements the method of the second aspect when executed by a processor.

[0031] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0032] The present invention utilizes a host computer to control the flow rate and flow rate regulation function, thereby controlling the cooling parameters in the cooling circuit. This allows for adjusting the thermal resistance or heat dissipation conditions of the power device under test during power cycling tests based on actual operating conditions, simulating the device's actual operating state and accurately assessing its reliability and lifespan under real-world conditions. Furthermore, test results for different usage scenarios can provide an accurate reference for the actual use of power devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the structure of the thermal resistance and power cycle testing system for silicon carbide power devices provided by an embodiment of the present invention;

[0034] Figure 2 Schematic diagram of the structure of the cold plate provided by an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the structure of the pressure device and the pressure equalizing protection plate provided by the embodiment of the present invention. Figure 1 ;

[0036] Figure 4 This is a schematic diagram of the structure of the pressure device and the pressure equalizing protection plate provided by the embodiment of the present invention. Figure 2 ;

[0037] Figure 5 1 is a schematic diagram of the implementation flow of the thermal resistance and power cycle testing method of a silicon carbide power device provided by an embodiment of the present invention;

[0038] Figure 6 It is a structural diagram of the host computer provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] The purpose of thermal resistance testing is to determine the thermal resistance of power devices from the chip to the heat dissipation surface, fluid or environment, so as to evaluate the heat dissipation performance of the device during operation, ensure that it operates within the normal operating temperature range, and avoid performance degradation or failure due to overheating.

[0041] Power cycling testing is an accelerated life test method that simulates the repeated power fluctuations experienced by power devices in real-world applications. Its purpose is to evaluate the reliability of power devices subjected to long-term, cyclical switching cycles. It detects potential internal issues such as thermal fatigue, wire bond failure, and packaging material aging, ensuring device stability and lifespan in real-world environments.

[0042] Due to their high power consumption, high-power devices require optimal water cooling in practical use. For example, in confined environments such as automotive electronics and aviation, to reduce overall device mass and component size, water cooling for power devices requires a low flow rate and high velocity of the cooling medium to achieve rapid heat dissipation. Due to the differences between laboratory environments and actual application environments, current thermal resistance tests and power cycling tests cannot simulate the actual operating environment of power devices, making it difficult to accurately assess their actual reliability and lifespan.

[0043] In view of this, an embodiment of the present invention provides a thermal resistance and power cycle testing system for silicon carbide power devices, which can simulate the actual working conditions of power devices through variable cooling conditions when performing thermal resistance or power cycle tests on power devices, thereby achieving accurate evaluation of the reliability and life of power devices.

[0044] See also Figure 1 , which shows a schematic structural diagram of a thermal resistance and power cycle test system for a silicon carbide power device provided by an embodiment of the present invention, including: a host computer, a temperature measuring device and at least one cooling circuit ( Figure 1 Take three as an example).

[0045] The cooling circuit is used to cool the power device under test G. The power device under test G here is generally a high-power power device, and its actual use needs to be simulated to accurately assess the quality and reliability of the device chip and package.

[0046] For example, the cooling circuit can be connected to a chiller, and the cooling medium is injected into the cooling circuit through the chiller. Figure 1The cold plate (a heat dissipating component typically made of a material with good thermal conductivity, such as metal) shown in the figure cools the power device under test. During power device testing, a cooling circuit removes heat generated by the device through the cold plate, thereby reducing its temperature and ensuring that the device is tested at the appropriate case temperature.

[0047] The temperature measuring device is used to monitor the junction temperature change of the power device under test during the thermal resistance or power cycle test. Exemplarily, the temperature measuring device may include: an electrical thermometer and an optical thermometer.

[0048] For some power device products with stable temperature coefficients or temperature-sensitive sensors, such as parasitic body diodes and built-in thermistors, accurate temperature measurement can be achieved through electrical methods. Some products contain special components whose electrical characteristics show a stable pattern as the temperature changes. The electrical method uses the specific relationship between the electrical parameters (such as resistance and voltage) of these components and temperature to measure temperature. Because the temperature coefficients of these components are stable (that is, when the temperature changes, the change of their electrical parameters follows a fixed pattern), by measuring their electrical parameters and then based on the predetermined relationship between temperature and electrical parameters (for example, for thermistors, their resistance value has a specific functional relationship with temperature), the temperature of these products can be accurately determined.

[0049] For power devices other than those listed above, the device can be unsealed to expose the chip and then tested for temperature changes using optical methods. For example, infrared optical methods utilize the principle that an object radiates infrared light, and the intensity of this radiation is correlated with the object's temperature. Once the chip is exposed, infrared temperature measurement equipment can detect the radiation emitted by the chip and analyze the temperature changes.

[0050] The host computer has a built-in data acquisition and control system, which is connected to the temperature measuring device. It calculates the results of thermal resistance or power cycle test by receiving the temperature changes of the power device to be tested.

[0051] The host computer can also control the cooling parameters of the cooling circuit through the flow rate and flow velocity adjustment function. For example, based on standards, customer requirements or actual working conditions of power devices (such as cooling medium temperature 25°C, water flow 8L / min, flow velocity 1m / s), determine the cooling conditions of the thermal resistance or power cycle test, that is, the cooling parameter target value, including flow rate and flow velocity. When the flow rate and flow velocity are larger than the target value, the flow rate and flow velocity of the cooling circuit are reduced. When the flow rate and flow velocity are smaller than the set value, the flow rate and flow velocity of the cooling circuit are increased. Furthermore, a flow rate and flow velocity sensor can be installed on the cooling circuit. The flow rate and flow velocity sensor is used to collect the flow rate and flow velocity of the cooling circuit, obtain the actual value of the cooling parameter of the cooling circuit, and send it to the host computer. During the thermal resistance or power cycle test stage, the host computer adjusts the cooling parameters of the cooling circuit through the flow rate and flow velocity adjustment function according to the cooling parameter target value and the actual value of the cooling parameter, thereby ensuring the stability of the flow rate and flow velocity and the stable cooling conditions.

[0052] In some embodiments, the flow rate regulation function of the cooling circuit is achieved by the following structure:

[0053] (1) The water outlet valve of the chiller.

[0054] The chiller's outlet valve is installed at the chiller's water outlet. By changing the valve's opening (e.g., fully open, half-open, etc.), the flow of cooling medium out of the chiller can be controlled, thereby affecting the flow rate and flow velocity of the entire cooling circuit. When the valve is wide open, more cooling medium flows out, and the flow rate is high. Given fixed pipe dimensions, the flow velocity will also vary accordingly. When the valve is narrowed, less cooling medium flows out, and both the flow rate and flow velocity are reduced.

[0055] (2) Flow area regulating valve of cold plate.

[0056] The cold plate is a component in the cooling circuit that contacts the power device to be cooled and is used to remove heat. For example, the structure of the cold plate can be as follows: Figure 2 As shown, the flow area control valve (moving block) is installed in the cooling medium channel of the cold plate. The moving block adjusts the flow area of the cooling medium channel within the cold plate. When the channel flow area increases, the flow rate of the cooling medium within the cold plate decreases (assuming a constant flow rate); when the channel flow area decreases, the flow rate increases. By adjusting the flow area within the cold plate, the flow rate and flow rate of the entire cooling circuit can be controlled.

[0057] The principle of flow rate regulation is:

[0058] Q=vA

[0059] Among them, Q represents flow rate; v represents flow velocity; A represents flow area. When the flow area A remains unchanged, the greater the flow rate Q, the greater the flow velocity v, and the smaller the flow rate Q, the smaller the flow velocity v.

[0060] Based on this principle, flow rate and velocity regulation methods may include:

[0061] ① Keep the flow area of the cooling medium channel in the cold plate unchanged, increase / decrease the flow rate, so that the flow rate and flow velocity increase / decrease synchronously;

[0062] ② The chiller input flow remains unchanged, and the heat dissipation flow rate is increased / decreased by reducing / increasing the flow area of the cooling medium channel directly below the cold plate;

[0063] ③ Simultaneously change the chiller input flow and the flow area of the cooling medium channel to achieve simultaneous changes in flow and flow velocity.

[0064] In some embodiments, to ensure the reliability of test results during thermal resistance or power cycling tests, the clamping force between the power device under test and the cold plate should also be considered. This can be achieved by securing the device to the cold plate using a suitable pressure device, supplemented by a pressure gauge or other means to ensure consistent clamping force. During testing, the host computer can provide feedback and adjust the pressure of the pressure device based on the pre-entered target pressure value and the actual pressure value.

[0065] In some embodiments, to avoid damaging power devices, a pressure-equalizing plate can be installed between the pressure device and the power device under test. This plate is a device that evenly distributes pressure. Placing the plate between the pressure device and the power device under test utilizes its properties to make the pressure on the power device more uniform during operation, thereby reducing potential damage to the power device due to uneven pressure distribution and protecting the power device.

[0066] For example, for power devices that can be directly tested using electrical methods, the pressure device and the voltage-sharing protection board can refer to Figure 3 shown.

[0067] For power devices that need to be tested using optical methods, you can consider using Figure 4 The voltage-equalizing protection plate shown in the figure has an opening in the middle of the plate that is smaller than the power device under test. A pressure device can compress the edge of the voltage-equalizing protection plate, allowing an optical thermometer to measure the temperature of the power device under test through the opening.

[0068] In some embodiments, to accurately measure the refrigerant flow rate, a cooling medium with a certain viscosity or conductivity can be selected based on the characteristics of the flow rate sensor. If necessary, the actual flow rate of the cooling medium can be corrected through calibration to ensure accurate cooling of the cold plate.

[0069] In some embodiments, the cold plate can be equipped with quick-change interfaces, such as pagoda connectors, quick-connect connectors, adapters for different pipe diameters, etc. Switch valves are provided on the cooling circuits on both sides of the cold plate to improve replacement efficiency when replacing the cold plate and achieve the purpose of rapid cold plate replacement.

[0070] In combination with the above embodiments, the present invention has the following advantages:

[0071] (1) It can solve the problem of fixed cooling conditions in thermal resistance or power cycle tests, simulate the actual use scenarios of power devices through variable cooling conditions, and accurately assess the device life and reliability;

[0072] (2) Taking into account the fact that some power devices have no temperature-sensitive parameters or the temperature-sensitive parameters are unavailable, both electrical and optical methods are used to accurately monitor the temperature of power devices;

[0073] (3) When using high-power devices in the fields of automotive electronics, power systems, etc., improve their use conditions, obtain higher efficiency, and provide data support;

[0074] (4) The cooling conditions can be changed by means of interchangeable cold plates and flow rate control. The system is simple and easy to build and has broad application prospects.

[0075] Figure 5 The present invention provides a schematic diagram of the implementation process of the thermal resistance and power cycle testing method for silicon carbide power devices. The method is applied to the host computer in the thermal resistance and power cycle testing system for silicon carbide power devices.

[0076] The method includes:

[0077] Step S501, obtaining a cooling parameter target value and an actual value of the cooling parameter of the cooling circuit;

[0078] Step S502, controlling the cooling parameters of the cooling circuit according to the cooling parameter target value and the cooling parameter actual value;

[0079] Step S503 : Under the current cooling parameters, the temperature of the power device to be tested during the thermal resistance or power cycle test is collected, and the result of the thermal resistance or power cycle test is calculated.

[0080] This method simulates the actual working environment of the power device during thermal resistance or power cycle testing by controlling the cooling parameters of the cooling loop, thereby achieving the purpose of accurately evaluating the actual reliability and life of the power device.

[0081] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0082] Figure 6 Schematic diagram of the host computer provided by the embodiment of the present invention. Figure 6 As shown, the host computer 6 of this embodiment includes: a processor 60 and a memory 61. The memory 61 stores a computer program 62. When the processor 60 executes the computer program 62, the steps of the above-mentioned various method embodiments are implemented.

[0083] For example, the computer program 62 may be divided into one or more modules / units, which are stored in the memory 61 and executed by the processor 60 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program 62 in the host computer 6.

[0084] The host computer 6 may include, but is not limited to, a processor 60 and a memory 61. Those skilled in the art will appreciate that Figure 6 It is only an example of the host computer 6 and does not constitute a limitation of the host computer 6. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the host computer 6 may also include input and output devices, network access devices, buses, etc.

[0085] The processor 60 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0086] The memory 61 can be an internal storage unit of the host computer 6, such as a hard disk or memory of the host computer 6. The memory 61 can also be an external storage device of the host computer 6, such as a plug-in hard disk, a SmartMedia Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. equipped on the host computer 6. Furthermore, the memory 61 can also include both an internal storage unit of the host computer 6 and an external storage device. The memory 61 is used to store the computer program 62 and other programs and data required by the host computer 6. The memory 61 can also be used to temporarily store data that has been output or is about to be output.

[0087] For the sake of convenience and brevity, the division of the above functional modules / units is only used as an example. In actual applications, the above functions can be assigned to different functional modules / units as needed. The above modules / units can be implemented in the form of hardware, software, or a combination of hardware and software.

[0088] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the methods in the above-mentioned method embodiments.

[0089] An embodiment of the present invention further provides a computer program product, including a computer program, which, when executed by a processor, implements the methods in the above-mentioned method embodiments.

[0090] The computer program includes computer program code, which may be in source code form, object code form, executable file, or some intermediate form. Computer-readable media may include any entity or device capable of carrying computer program code, recording media, USB flash drives, mobile hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunications signals, and software distribution media.

[0091] In the above embodiments, the descriptions of each embodiment have their own focus. For parts not described or recorded in detail in one embodiment, please refer to the relevant descriptions of other embodiments. Unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other. The technical features of different embodiments can be combined to form new embodiments based on their inherent logical relationships.

[0092] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A silicon carbide power device thermal resistance and power cycle testing system, characterized in that: include: Host computer, temperature measuring device and at least one cooling circuit; The cooling circuit is used to cool the power device to be tested; The temperature measuring device is used to collect the temperature of the power device to be tested and send it to the host computer to calculate the thermal resistance or power cycle test results; The cooling circuit has a flow rate and flow velocity adjustment function, and the host computer is further used to control the cooling parameters of the cooling circuit through the flow rate and flow velocity adjustment function.

2. The silicon carbide power device thermal resistance and power cycle testing system according to claim 1, characterized in that: The cooling circuit is connected to a water chiller and cools the power device to be tested through a cold plate; The flow rate and velocity regulation function is achieved through the following structure: The water outlet valve of the chiller and the flow area regulating valve of the cold plate.

3. The silicon carbide power device thermal resistance and power cycle testing system according to claim 2, characterized in that: Also includes: pressure devices and pressure gauges; The pressure device is used to press the power device to be tested onto the cold plate; The pressure gauge is used to collect the actual pressure value of the pressure device; The host computer is connected to the pressure device and the pressure gauge, and is used for feedback-adjusting the pressure of the pressure device according to a pre-input target pressure value and the actual pressure value.

4. The silicon carbide power device thermal resistance and power cycle testing system according to claim 1, characterized in that: A flow rate sensor is installed on the cooling circuit; The flow rate and flow velocity sensor is used to collect the flow rate and flow velocity of the cooling circuit, obtain the actual value of the cooling parameter of the cooling circuit, and send it to the host computer; The host computer is further configured to feedback-adjust the cooling parameters of the cooling circuit through the flow rate and flow velocity adjustment function according to the pre-input cooling parameter target value and the actual value of the cooling parameter.

5. The silicon carbide power device thermal resistance and power cycle testing system according to claim 1, characterized in that: The temperature measuring device includes at least one of the following: an electrical temperature measuring device and an optical temperature measuring device.

6. The silicon carbide power device thermal resistance and power cycle testing system according to claim 3, characterized in that: Also includes: A voltage-sharing protection plate is provided between the pressure device and the power device to be tested.

7. The silicon carbide power device thermal resistance and power cycle testing system according to claim 6, characterized in that: The middle position of the pressure equalizing protection plate has an opening; The opening is used to perform optical temperature measurement on the power device to be measured; The opening is smaller than the power device to be tested, and the pressure device presses the edge of the voltage-sharing protection plate.

8. The silicon carbide power device thermal resistance and power cycle testing system according to claim 3, characterized in that: The cold plate is equipped with a quick-change interface; and switch valves are provided on the cooling circuits on both sides of the cold plate.

9. A method for testing thermal resistance and power cycle of silicon carbide power devices, characterized in that: A host computer used in a power device testing system according to any one of claims 1 to 8; The method comprises: Obtaining cooling parameter target values and actual cooling parameter values of the cooling circuit; controlling the cooling parameter of the cooling circuit according to the cooling parameter target value and the cooling parameter actual value; Under the current cooling parameters, the temperature of the power device to be tested during the thermal resistance test or the power cycling test is collected, and the results of the thermal resistance or power cycling test are calculated.

10. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to claim 9 when being executed by a processor.

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