A portable multi-discrete power device series acceleration aging experiment platform

Abstract

The application relates to a portable multi-discrete power device series acceleration aging experiment platform, and belongs to the technical field of power device acceleration aging test. The experiment platform comprises a power circuit, a heat dissipation module, a programmable direct current power supply, an upper computer and an acquisition module. The power circuit adopts a U-shaped symmetrical circuit design and comprises n same discrete power devices, 2n test bases, n same drive circuits and 2n voltage test ends. The heat dissipation module is arranged at the intermediate position of two adjacent devices, and the heat dissipation modules are connected in parallel. The acquisition module respectively acquires the conduction voltage drop and temperature of each device, and the online monitoring and experimental data saving are completed through the upper computer. The programmable direct current power supply provides the required current for the experiment platform and communicates with the upper computer, and the output of the programmable direct current power supply is controlled by the upper computer. The experiment platform can significantly improve the temperature fluctuation in the power device acceleration aging test, greatly shorten the experiment time, reduce the volume and reduce the cost.

Description

Technical Field

[0001] This invention belongs to the field of accelerated aging test technology for power devices, and relates to a portable accelerated aging test platform for multiple discrete power devices connected in series. Background Technology

[0002] Discrete power devices (MOSFETs, IGBTs, etc.) are core components in new high-voltage, high-power converter systems for rail transportation, smart grids, aerospace, and other applications. Approximately 38% of power converter failures originate from power device failures. Due to the complex and variable operating conditions and harsh environments in power converter systems, the reliability of power devices has always faced significant challenges. Thermal stress is a major cause of aging failure in power devices; for every 10°C increase in junction temperature, the failure rate doubles. Therefore, the long-term reliability of power devices requires serious attention.

[0003] Currently, accelerated aging testing is an important means of evaluating the long-term reliability of power devices. Common accelerated aging testing methods are divided into power cycling and temperature cycling. Compared with temperature cycling, power cycling testing is closer to the actual aging process of power devices. During accelerated aging, common failure modes of power devices are solder layer failure and bond wire detachment, which are characterized by the increase in thermal resistance and on-state voltage drop of the power device, respectively. However, traditional accelerated aging test platforms for power devices have the following problems: existing accelerated aging tests are mainly conducted on individual power devices, and testing a single device takes several days to several months, resulting in long testing times; power device condition monitoring methods are complex, and the accuracy of online monitoring circuits is poor; accelerated aging test platforms mostly use water-cooling heat dissipation systems, which, although ensuring heat dissipation effect, have high heat dissipation costs, large overall size, and generate a lot of noise; traditional accelerated aging test platforms lack control over the heat dissipation system, which can further amplify temperature fluctuations within each cycle.

[0004] Therefore, there is an urgent need to invent a portable accelerated aging test platform for multiple discrete power devices connected in series, which has a simple structure, improved aging speed, accurate electrical parameter measurement, and reduced size. This platform is of great significance for improving the speed of accelerated aging tests and accurately and conveniently evaluating the failure state of discrete power devices. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a portable accelerated aging test platform for multiple discrete power devices connected in series, which solves the problems of long time consumption, low online monitoring accuracy, large heat dissipation system size and high cost of traditional accelerated aging test platforms for power devices. That is, this invention provides a portable accelerated aging test platform for multiple discrete power devices connected in series with simple structure, improved aging speed, accurate electrical parameter measurement and reduced size.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A portable accelerated aging test platform for multiple discrete power devices connected in series, such as... Figure 1 As shown, it includes a power circuit, a heat dissipation module, a programmable DC power supply, a host computer, and a data acquisition module.

[0008] The power circuit is arranged in a U-shaped symmetrical loop on both sides of the platform PCB board. The PCB traces on both sides of the platform are exactly the same in length and thickness, including n identical discrete power devices (Q1 to Q2). n ), 2n test bases (d1, s1, ..., d n s n d1'、s1'、…、d n '、s n '), n identical drive circuits and 2n voltage test terminals (V) ds1 V ds1 '、…、V dsn V dsn Among them, discrete power devices (Q1~Q) n Each power device is connected in series on the same side of the platform PCB, with one drive circuit connected to each device; voltage test terminal V ds1 and V ds1 '、V ds2 and V ds2 '、…、V dsn-1 and V dsn-1 '、V dsn and V dsn The positions are completely symmetrical on both sides of the platform PCB board. To facilitate the insertion and removal of discrete power devices, identical test bases (d1, s1, d2', s2', ..., d) are installed at corresponding positions on both sides. n s n d n '、s n On the side without the device, a C-type copper strip of the same size as the discrete power device package pins is used to connect the test base d1' and s1', d2' and s2', ..., d1'. n-1 'and s n-1 '、d n 'and s n At this point, the differential method is used to measure the on-state voltage drop of the power device, which is V. ds1 -V ds1 '、V ds2 -V ds2 '、…、V dsn-1 -V dsn-1 '、V dsn -V dsn '.

[0009] The heat dissipation module is located between two adjacent power devices, and the heat dissipation modules are connected in parallel.

[0010] The acquisition module includes a voltage acquisition card and a temperature acquisition card, which respectively acquire the forward voltage drop V between different voltage test terminals of each power device through DuPont wires of the same length. ds1 and V ds1 '、V ds2 and V ds2 '、…、V dsn-1 and V dsn-1 '、V dsn and V dsn ', and the temperatures T1, T2, ..., T are collected by K-type thermocouples. n-1 and T n The experimental data is monitored online and saved via a host computer.

[0011] The programmable DC power supply is configured as a constant current source to provide the required current to the experimental platform, and communicates with the host computer LabVIEW software via TCP / IP protocol. Its output is controlled by the host computer.

[0012] The host computer is a PC with LabVIEW software and NI DAQ driver software installed.

[0013] Furthermore, the drive circuit uses the same drive resistor R. g One end is connected in series with the same external drive, and the other end is connected to the gate of the power device; the drive resistor R g All external drives are connected in parallel and use a unified PWM control signal to ensure that all devices have the same initial output characteristics, thereby ensuring that multiple identical devices operate under the same conditions at the same time.

[0014] Furthermore, the heat dissipation module includes n / 2 identical high-speed air-cooled modules (M1 to M2). n / 2 A current relay K and an identical DC auxiliary power supply, where n is an odd number and rounded up; identical high-speed air-cooled modules (M1~M... n / 2 It is connected in parallel to the normally closed contact of the current relay K and then connected to the DC auxiliary power supply V. DC .

[0015] Along the symmetry axis of the U-shaped PCB board, square slots of appropriate size are etched according to the position of the midpoint of two adjacent components, so that the parallel high-speed air-cooled modules M1 to M2 can be connected in parallel. n / 2(When n is odd, round up, the same applies below) can be embedded so that each device receives the same magnitude and direction of airflow when the air-cooling module is working. Replacing the traditional water-cooling system with an embedded high-speed air-cooling module can significantly reduce the size of the entire accelerated aging test platform, making the designed test platform portable.

[0016] Furthermore, when all power devices are connected to a large current I, the current relay K activates, the normally closed contact opens, and the air-cooled modules (M1~M2) are activated. n / 2 The circuit stops operating, and the device enters the heating phase. When the heating time ends, the current I in the power circuit becomes 0, the normally closed contact of the current relay K closes, and the air-cooled modules (M1~M2) stop operating. n / 2 The device immediately runs at full speed and enters the cooling phase. Based on this design, the air-cooled heat dissipation system shuts down when the device is powered on and turns on when the device is powered off, allowing for significant temperature fluctuations in a short period, thereby significantly accelerating the device's aging process.

[0017] Furthermore, the air-cooled modules (M1 to M2) n / 2 The position is embedded at the midpoint of two adjacent power devices along the axis of symmetry of the U-shaped PCB board.

[0018] Furthermore, the acquisition module uses the differential method to measure the on-state voltage drop of the power device.

[0019] Furthermore, connect the test bases d1' and s1', d2' and s2', ..., d n-1 'and s n-1 '、d n 'and s n The metal strip is made of C-shaped copper.

[0020] Furthermore, the specific operating steps of the accelerated aging test platform of the present invention are as follows:

[0021] 1) At the start of the experiment, set the desired heating current I in the LabVIEW software interface on the host computer. set Heating time t on and cooling time t off And turn on the air cooling. At this time, the heating timer t1 = 0, the cooling timer t2 = 0, and the cycle count cycle = 0.

[0022] 2) Run the LabVIEW software. When the current I in the power circuit is 0, the software displays "open circuit" and stops outputting.

[0023] 3) When the current relay K detects current, its normally closed contact opens, and the air cooling stops working. At this time, I = I setWhen the device is powered on, it enters the heating stage. The acquisition module collects voltage and temperature data in real time and displays them on the LabVIEW software interface of the host computer. Failure judgment is performed based on the collected voltage and temperature signals. If the failure criteria are met, the program stops; otherwise, the heating timer starts.

[0024] 4) When t1 = t on When the device's heating phase ends, the device is powered off and enters the cooling phase; at this time, I=0, the contacts of the current relay K close again, the air cooling is turned on, and the cooling timer begins.

[0025] 5) When t2 = t off When the device cooling phase ends, a heating cycle is completed, t1 and t2 are reset to zero, the cycle count is incremented by 1, and the process jumps to step 3).

[0026] The beneficial effects of this invention are as follows: the experimental platform of this invention can significantly improve the temperature fluctuation in the accelerated aging test of power devices and greatly shorten the experimental time. Taking the TO-247-3 discrete SiC MOSFET device as an example, the case temperature fluctuation can reach 80°C within 1 minute. Compared with the existing accelerated aging experimental platform, it has the advantages of simple structure, improved aging speed, accurate measurement of electrical parameters, reduced size and reduced cost.

[0027] (1) The accelerated aging test platform designed in this invention can simultaneously perform accelerated aging tests on multiple discrete power devices under the same operating conditions, which can greatly shorten the test time.

[0028] (2) The accelerated aging test platform designed in this invention adopts a U-shaped symmetrical circuit design and uses the differential method to measure the on-state voltage drop of power devices. Under large test current conditions, it can eliminate voltage measurement errors introduced by power circuit PCB layout, device test socket and package pins.

[0029] (3) This invention employs an embedded high-speed air-cooling system in the middle of the U-shaped power circuit PCB, and restricts the air-cooling position to be between two adjacent discrete power devices, ensuring that each device receives the same magnitude and direction of airflow when the air-cooling module is working. Compared with water-cooling systems, air-cooling systems can significantly reduce the size and cost of the entire accelerated aging test platform, making the test platform portable.

[0030] (4) Based on the working principle of current relay, this invention provides a wind-cooled heat dissipation system that is turned off when the device is powered on and turned on when the device is powered off, which can achieve greater temperature fluctuation within the same heating and cooling time.

[0031] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0032] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0033] Figure 1 Schematic diagram of an accelerated aging test platform for portable multi-discrete SiC MOSFET devices connected in series;

[0034] Figure 2 Schematic diagram of an accelerated aging test platform for two portable discrete SiC MOSFET devices connected in series;

[0035] Figure 3 A schematic diagram of an accelerated aging test platform for two portable discrete SiC MOSFET devices connected in series.

[0036] Figure 4 Flowchart of the operation of a portable accelerated aging test platform for multiple discrete power devices connected in series;

[0037] Figure 5 This is the LabVIEW user interface for the host computer. Detailed Implementation

[0038] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0039] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0040] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0041] Please see Figures 1-5 The following describes in detail the implementation scheme of the present invention using the TO-247-3 packaged 32mΩ SiC MOSFET B1M032120HC from two basic semiconductor companies as an example.

[0042] like Figure 2 As shown, the portable accelerated aging experimental platform for two discrete SiC MOSFET devices connected in series includes a power circuit, a heat dissipation module, a programmable DC power supply, a host computer, and a data acquisition module. Among them,

[0043] The power circuit includes two discrete SiC MOSFET devices, four test bases, two drive circuits, two external drives, and eight voltage test terminals.

[0044] The heat dissipation module includes a 4000r / min air-cooled module, a current relay with a range of 0-50A, and a 12V DC auxiliary power supply.

[0045] The programmable DC power supply is set to output a constant current source, providing the required current I=20A in the accelerated aging test platform, and communicates with the host computer LabVIEW software via TCP / IP protocol. Its output is controlled by the host computer.

[0046] The host computer is a PC with LabVIEW software and NI DAQ driver software installed.

[0047] The data acquisition module uses a voltage and temperature acquisition card from NI, and acquires the forward voltage drop V between the different voltage test terminals of the two devices via 30cm long DuPont wires. ds1 and V ds1 '、V ds2 and V ds2 '、V ds3 and V ds3 '、V ds4 and V ds4The system collects temperatures T1 and T2 using a K-type thermocouple, communicates with the host computer's LabVIEW via the NI DAQ plugin, and performs online monitoring and saves experimental data.

[0048] As a preferred embodiment, the accelerated aging test platform adopts a U-shaped symmetrical circuit design, with PCB traces on both sides of the platform having identical length and thickness, and the voltage test terminal V... ds1 and V ds1 '、V ds2 and V ds2 '、V ds3 and V ds3 '、V ds4 and V ds4 The positions are completely symmetrical on both sides. To facilitate the insertion and removal of discrete power devices, identical test bases are installed at corresponding positions on both sides. On the side without devices, C-shaped copper strips of the same size as the discrete power device package pins are used to connect d1' and s1', d2' and s2', d3' and s3', and d4' and s4'. At this time, the differential method is used to measure the on-state voltage drop of the power devices, which are V. ds1 -V ds1 '、V ds2 -V ds2 '、V ds3 -V ds3 '、V ds4 -V ds4 '.

[0049] Two identical discrete SiC MOSFET devices, Q1 and Q2, are connected in series on the same side of the power circuit, and each device uses the same drive resistor R in its drive circuit section. g =5Ω and the same external drive, where the external drive is the output voltage V g =+20V / -5V 1CD0214T17, two external drivers are connected in parallel to the +15V drive power supply and use the same 5V PWM control signal to ensure the uniformity of the drive voltage of all device drive circuits, thereby ensuring that the two SiCMOSFET devices operate under the same conditions at the same time.

[0050] like Figure 3 As shown, along the symmetry axis of the U-shaped PCB power board, appropriately sized square slots are etched according to the midpoints of adjacent components, allowing the high-speed air-cooling module M1 to be embedded within them. This ensures that each component receives the same magnitude and direction of airflow during operation. The air-cooling module measures 120mm × 120mm × 38mm, and the power board measures 129mm × 188mm. These dimensions demonstrate that replacing the traditional water-cooling system with an embedded high-speed air-cooling module significantly reduces the overall size of the accelerated aging test platform, making it portable.

[0051] The high-speed air-cooled module M1 is connected to the normally closed contact of the current relay K, and then connected to a DC power supply V. DC When all power devices are connected to a large current I, the current relay K trips, its normally closed contact opens, M1 stops running, and the devices enter the heating phase. When the heating time ends, the current I in the power circuit becomes 0, the normally closed contact of relay K closes, M1 immediately runs at full speed, and the devices enter the cooling phase. Based on this design, the air-cooled heat dissipation system, which shuts off when the devices are powered on and turns on when the devices are powered off, can achieve large temperature fluctuations in a short period of time, thereby significantly improving the aging speed of the devices.

[0052] like Figure 4 As shown, the specific operating steps of the portable accelerated aging test platform with two discrete SiC MOSFET devices connected in series are as follows:

[0053] 1) At the start of the experiment, set the desired heating current I in the LabVIEW software interface on the host computer. set =20A, heating time t on =25s and cooldown time t off =35s, and turn on air cooling. At this time, heating timer t1=0, cooling timer t2=0, and cycle number cycle=0;

[0054] 2) Run the LabVIEW software. When the current I in the power circuit is 0, the software displays "open circuit" and stops outputting.

[0055] 3) When the current sensor K detects current, its normally closed contact opens, and the air cooling stops working. At this time, I = I set Once the device is powered on, it enters the heating phase. The acquisition module collects voltage and temperature data in real time and displays them on the LabVIEW software interface of the host computer. Failure is determined based on the collected voltage and temperature signals; if the failure criteria are met, the program stops; otherwise, heating timing begins.

[0056] 4) When t1 = t on At this point, the heating phase of the device ends, the device is powered off, and it enters the cooling phase. At this time, I = 0, the contacts of the current relay K close again, the air cooling is activated, and the cooling timer begins.

[0057] 5) When t2 = t off When the device cooling phase ends, a heating cycle is completed, t1 and t2 are reset to zero, the cycle count is incremented by 1, and the process jumps to step 3).

[0058] like Figure 5As shown, an accelerated aging test platform using two portable discrete SiC MOSFET devices connected in series can achieve a case temperature fluctuation of 80°C within 1 minute. Compared with existing accelerated aging test platforms, it has the advantages of simple structure, improved aging speed, accurate measurement of electrical parameters, reduced size and lower cost.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A portable platform for accelerated aging test of multiple discrete power devices in series, comprising a direct current power supply, an acquisition module, characterized in that, It also includes power loop, heat dissipation module and host computer; The power circuit adopts U-shaped symmetrical loop arrangement on both sides of the platform PCB board, including n same discrete power devices (Q1~Q n ), 2n test bases (d1, s1, …, d n , s n , d1', s1', …, d n ' and s n '), n same drive circuits and 2n voltage test ends ( V ds1 、 V ds1 '、…、 V dsn 、 V dsn ');Wherein, the discrete power devices (Q1~Q n ) are connected in series on the same side of the platform PCB board, and each power device is connected with one drive circuit; the voltage test ends V ds1 and V ds1 '、 V ds2 and V ds2 '、…、 V dsn-1 and V dsn-1 '、 V dsn and V dsn ' positions are completely symmetrical on both sides of the platform, and the same test bases (d1, s1, d2', s2', …, d n , s n , d n ' and s n ') are installed at the corresponding positions on both sides, and the same size metal strips as the discrete power device package pins are used to connect the test bases d1' and s1', d2' and s2', …, d n-1 ' and s n-1 ', d n ' and s n ' on the side without devices, at this time, the on-state voltage drop of the power device is respectively V ds1 - V ds1 '、 V ds2 - V ds2 '、…、 V dsn-1 - V dsn-1 '、 V dsn .- V dsn '； The heat dissipation module is arranged at the middle position between two adjacent power devices, and each heat dissipation module is connected in parallel; the heat dissipation module comprises n / 2 same air-cooled modules (M1~M n / 2 ), a current relay K and a same DC auxiliary power supply, wherein n is an odd number and is rounded up; the same high-speed air-cooled modules (M1~M n / 2 ) are connected in parallel, connected with the normally closed contact of the current relay K and connected with the DC auxiliary power supply V DC ; The acquisition module includes a voltage acquisition card and a temperature acquisition card, and uses a differential method to respectively acquire the on-voltage drop between different voltage test ends of each power device V ds1 and V ds1 '、 V ds2 and V ds2 '、…、 V dsn-1 and V dsn-1 '、 V dsn and V dsn ' and temperature T 1、 T 2、…、 T n-1 and T n , and the upper computer is used for completing online monitoring and saving experimental data; The direct current power supply provides required current for the experiment platform and communicates with the host computer, and the output is controlled by the host computer.

2. The accelerated aging test platform of claim 1, wherein, The driving circuit adopts the same driving resistance R g One end is connected with the same external drive in series, and the other end is connected with the gate of the power device; the driving resistance R g All external drives are connected in parallel and adopt a unified PWM control signal, so that all devices have the same initial output characteristics, thereby ensuring that multiple same devices operate in the same working condition at the same time.

3. The accelerated aging test platform of claim 1, wherein, When all the power devices are connected to large current I , the current relay K acts, the normally closed contact opens, the air-cooled module (M1~M n / 2 ) stops running, and the device enters the heating stage; when the heating time ends, the current in the power loop I becomes 0, the normally closed contact of the current relay K closes, the air-cooled module (M1~M n / 2 ) immediately runs at full speed, and the device enters the cooling stage.

4. The accelerated aging test platform of claim 1, wherein, The air-cooling module (M1~M n / 2 ) is embedded in the position of the midpoint of the adjacent two power devices along the symmetry axis of the PCB board of the U-shaped layout.

5. The accelerated aging test platform of claim 1, wherein, The metal strips of the connection test bases d1' and s1', d2' and s2',..., d n-1 ' and s n-1 ' and s n ' and s n The metal strips of the connection test bases d1' and s1', d2' and s2',..., d 6. The accelerated aging test platform of claim 1, wherein, The direct current power supply is a programmable direct current power supply, which is set as a constant current source output, provides required current for the experiment platform, and communicates with the host computer, and the output is controlled by the host computer.

7. The accelerated aging test platform according to any one of claims 1 to 6, characterized in that The specific operation steps of the experiment platform are as follows: 1) At the beginning of the experiment, set the desired heating current in the host computer software operation interface I set , heating time t on and cooling time t off , and start the air cooling at this time, heating timing t 1=0, cooling timing t 2=0, cycle number cycle=0; 2) Run software, when current in power loop is 0, software displays "open circuit" and stops output. I 2) Run software, when current in power loop is 0, software displays "open circuit" and stops output. 3) When the current relay K detects the current, its normally closed contact is disconnected, and the air cooling stops working. At this time I = I set , the device is powered on, enters the heating stage, and the acquisition module collects the voltage and temperature in real time and displays it on the LabVIEW software operation interface of the host computer; According to the collected voltage and temperature signals, the failure is judged, and if the failure criterion is met, the program is stopped, otherwise the heating timing starts; 4) when t 1= t on the device heating phase ends, the device is de-energized and enters the cooling phase; at this time I= 0, the contacts of the current relay K are reclosed, the air cooling is turned on and the cooling timing is started; 5) when t 2= t off the device cooling phase is finished, a heating cycle is completed, t 1、 t 2 is reset to zero, the cycle number is cycle+1 and the routine jumps to step 3) run.

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