Test platform and method for failure short circuit resistance of crimp package power device

Abstract

This invention relates to a test platform and method for the short-circuit withstand capability of press-fit packaged power devices, belonging to the field of power device testing technology. The test platform includes a voltage regulator module, an impulse capacitor bank, a pressure clamp structure integrating voltage and current sensors, and a control and acquisition module. The impulse capacitor bank includes multiple capacitors connected in series and parallel. The pressure clamp structure integrating voltage and current sensors includes a high-precision voltage probe, a high-precision current probe, and a pressure clamp. The pressure clamp includes an arc-coupling pressure bolt contact structure, a heatsink guide rail structure, a disc spring guide rod structure, and a special insulation isolation structure. The high-precision current and voltage sensors integrated into the pressure clamp are used to monitor characteristic parameters such as collector current, collector-emitter voltage, and gate-emitter voltage of the device in real time. This invention has advantages such as wide applicability, accurate measurement of characteristic parameters, and uniform pressure loading.

Description

Technical Field

[0001] This invention belongs to the field of power device testing technology, and relates to a platform and experimental method suitable for testing the short-circuit withstand capability of press-fit packaged power devices in the event of failure. Background Technology

[0002] Compared to welded packaged power devices, press-fit packaged power devices offer advantages such as double-sided heat dissipation, high power density, and fault tolerance during short circuits, making them fundamental core components of flexible DC transmission systems. Due to the complex and variable operating conditions of flexible DC transmission systems, press-fit packaged power devices used in flexible DC transmission equipment must withstand occasional short-circuit current surges. Obtaining the short-circuit tolerance of these devices is fundamental to setting protection system parameters and is a crucial guarantee for the reliability of flexible DC transmission equipment. However, device failure under short-circuit current surges is an occasional overstress failure, which differs significantly from the long-term fatigue and strain accumulation failures mainly focused on in existing research. Therefore, the evaluation of the fault tolerance during short circuits of press-fit packaged power devices requires serious attention.

[0003] Currently, short-circuit withstand capability testing is an important means of evaluating the short-term reliability of power devices. However, traditional short-circuit withstand capability testing platforms have the following problems: Traditional platforms mainly rely on low-precision current probes to monitor device characteristic parameters in real time, resulting in a limited number of monitored parameters and low measurement accuracy. Press-packed power devices have various power levels, and traditional platforms, primarily based on constant voltage power supplies and custom capacitors, can only perform short-circuit withstand capability tests on devices of specific power levels, limiting their applicability. Furthermore, the characteristics of press-packed power devices are greatly affected by pressure distribution. Traditional platforms lack consideration for pressure uniformity in the pressure clamps, easily leading to uneven pressure loading that affects device characteristics and results in inaccurate test results. Therefore, inventing a short-circuit withstand capability testing method and platform suitable for press-packed power devices, with a wide applicability, accurate characteristic parameter measurement, and uniform pressure loading, is of great significance for accurately evaluating the short-circuit withstand capability of press-packed power devices. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a test platform and method for failure short-circuit withstand capability of press-fit packaged power devices, so as to solve the problems of narrow adaptability, low measurement accuracy and uneven pressure loading of traditional failure short-circuit withstand capability test platforms.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] Option 1: A test platform for the failure short-circuit withstand capability of a press-fit packaged power device includes a voltage regulator module, an impact capacitor bank, a pressure clamp structure with integrated voltage and current sensors, and a control and acquisition module;

[0007] The voltage regulation module includes a controllable high-voltage DC power supply and a voltage-regulating capacitor bank; the controllable high-voltage DC power supply maintains a constant conduction state during the test, and the voltage-regulating capacitor bank is connected in parallel across the controllable high-voltage DC power supply to maintain the voltage stability of the device under test.

[0008] The impact capacitor bank is connected in parallel with the voltage stabilizing capacitor bank, and includes multiple capacitors connected in series and parallel.

[0009] The pressure clamp structure with integrated voltage and current sensors includes a high-precision voltage probe, a high-precision current probe, and a pressure clamp.

[0010] The control and acquisition module includes a drive circuit and a data acquisition card. The drive circuit controls the device under test to conduct, and the device conduction is used as a trigger signal. The data acquisition card synchronously acquires characteristic parameters of the device under test, such as collector-emitter voltage, gate-emitter voltage, and collector current, to complete online monitoring and save experimental data.

[0011] Furthermore, the impact capacitor bank adopts a detachable design, which can change the series and parallel connection method and number of capacitors according to the power level of the device under test. This design enables the test platform to quickly match the test requirements of devices with different power levels, greatly improving the adaptability of the experimental test platform.

[0012] Furthermore, the pressure clamp adopts a design with an arc-coupling pressure bolt contact structure 8, that is, the tail of the pressure bolt 7 adopts a convex arc surface design, and the top of the pressure sensor 9 in contact with it adopts a concave arc surface design. The pressure sensor 9 is mounted on the surface of the heat sink 1 on the collector side of the device under test. This structural design can ensure that the pressure direction applied by the pressure bolt is perpendicular to the surface of the press-packed power device, thereby ensuring the uniformity of the pressure distribution on the chip surface in the press-packed power device.

[0013] Furthermore, the heat sink 1 is mounted on the upper surface of the collector and the lower surface of the emitter of the device under test.

[0014] Furthermore, the pressure clamp adopts a heat sink guide rail structure 2 design, that is, a (thermoplastic resin) heat sink guide 3 with a through hole at the end is installed on the side of the heat sink 1. The through hole at the end of the heat sink guide 3 is nested with the heat sink guide rail 4. This structural design can ensure the lateral stability of the heat sink during the pressurization process, thereby ensuring the uniformity of the pressure distribution on the chip surface in the press-packed power device.

[0015] Furthermore, the pressure clamp adopts a disc spring guide rod structure 15 design, that is, a through hole is provided in the center of the bottom flange 16 of the pressure clamp, and the disc spring guide rod 13 adopts a boss structure design, including a support base and a guide rod. The disc spring 14 is nested in the disc spring guide rod 13, and the end of the disc spring guide rod 13 is inserted into the center through hole of the bottom flange 16. This structure design can ensure the verticality of the bottom support during the pressurization process, thereby ensuring the uniformity of pressure distribution on the surface of the press-packed power device chip.

[0016] Furthermore, the pressure fixture is designed with a special insulation isolation structure 6, which includes a (thermoplastic resin) radiator guide 3 made of insulating material and an (epoxy glass cloth) insulating plate 5 installed on the top of the upper radiator 1 and the bottom of the lower radiator 1. This structural design can ensure the insulation of the main structure of the fixture during the test, thereby ensuring the safety of the test personnel.

[0017] Option 2: A method for testing the failure short-circuit withstand capability of a press-fit packaged power device, specifically including the following steps:

[0018] S1: Before testing, determine the series and parallel connection method and quantity of capacitors in the impulse capacitor group according to the power level of the device under test, and apply the rated pressure to the press-packed power device using a pressure clamp.

[0019] S2: Start the controllable high-voltage DC power supply and set the output voltage according to the voltage level of the device under test;

[0020] S3: The drive circuit controls the device to conduct, triggering the data acquisition card to synchronously acquire the collector-emitter voltage V. CE Gate-emitter voltage V GE and collector current I C Characteristic parameters are measured, and the short-circuit energy E of the press-fit packaged power device is calculated in real time. SC :

[0021]

[0022] Where t0 is the device turn-on time, and t is the calculation time; the failure criterion is that the collector current exceeds the device's short-circuit saturation current limit and rises sharply, and the failure time t is recorded. F And the short-circuit energy E of the device at the time of failure CR .

[0023] The beneficial effects of this invention are as follows:

[0024] 1) The short-circuit withstand capability test platform designed in this invention adopts a detachable design for the impact capacitor group. The series and parallel connection method and quantity of capacitors can be changed according to the power level of the device under test, so as to quickly complete the experimental adaptation and adjustment of press-packed power devices of different power levels, greatly improving the adaptability range of the experimental test platform.

[0025] 2) The failure short-circuit withstand capability test platform designed in this invention uses a high-precision voltage probe and a high-precision current probe integrated in the pressure fixture to monitor the collector-emitter voltage, gate-emitter voltage and collector current during the short-circuit current impact process, increasing the types of characteristic parameters monitored and effectively improving the measurement accuracy of characteristic parameters.

[0026] 3) The failure short-circuit withstand capability testing platform designed in this invention employs an arc-coupling pressure bolt contact structure, a heat sink guide rail structure, and a disc spring guide rod structure in the pressure clamp, ensuring uniform pressure distribution on the surface of the press-fit packaged power device chip. Simultaneously, the pressure clamp utilizes a special insulation isolation structure to guarantee the safety of experimental personnel.

[0027] 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

[0028] 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:

[0029] Figure 1 This is a schematic diagram of the experimental method for the failure short-circuit withstand capability of press-fit packaged power devices according to the present invention.

[0030] Figure 2 This is a structural diagram of the pressure clamp designed for this invention, wherein, Figure 2 (a) is a front view of the overall structure of the pressure clamp. Figure 2 (b) is a side cross-sectional view of the pressure clamp;

[0031] Figure 3 This is a schematic diagram of the overall structure of the pressure clamp designed for this invention;

[0032] Figure 4 Flowchart for short-circuit withstand capability testing of press-fit packaged power devices;

[0033] Reference numerals: 1-Radiator; 2-Radiator guide rail structure; 3-(Thermoplastic resin) Radiator guide component; 4-Radiator guide rail; 5-(Epoxy glass cloth) Insulation board; 6-Special insulation isolation structure; 7-Pressure bolt; 8-Arc-surface coupling pressure bolt contact structure; 9-Pressure sensor; 10-Voltage sensor slot; 11-Current sensor slot; 13-Disc spring guide rod; 14-Disc spring; 15-Disc spring guide rod structure; 16-Bottom flange. Detailed Implementation

[0034] 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.

[0035] 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.

[0036] 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.

[0037] Please see Figures 1-4 The following describes the implementation scheme of the present invention in detail, taking the 3300V / 50A press-fit IGBT device DG50N3300 produced by State Grid Smart Grid Research Institute Co., Ltd. as an example.

[0038] like Figure 1 As shown, the short-circuit withstand capability test platform for press-fit IGBT devices includes a voltage regulator module, an impact capacitor bank, a pressure fixture structure integrating voltage and current sensors, and a control and acquisition module.

[0039] The voltage regulator module includes one HSPY2K high-voltage DC power supply and one 2000V / 1.0μF capacitor connected in parallel across the power supply.

[0040] The surge capacitor bank consists of eight 450V / 1000μF capacitors. First, the capacitors are connected in series in pairs to form a small group, then the two small groups are connected in parallel to form a large group, and finally the two large groups are connected in series to form a capacitor bank with a capacitance of 1800V / 500μF.

[0041] The integrated voltage and current sensor pressure clamp fixture includes a high-precision current probe with a range of 1200A, a high-precision voltage probe with a range of 1500V, and a pressure clamp with a maximum load capacity of 10000N.

[0042] The control and acquisition module includes one drive circuit and one data acquisition card. The drive circuit controls the device under test to conduct, and the device conduction is used as a trigger signal. Based on the data acquisition card, characteristic parameters such as collector-emitter voltage, gate-emitter voltage and collector current are collected synchronously to complete online monitoring and save experimental data.

[0043] like Figure 1 As shown, the impact capacitor bank in the designed test platform adopts a detachable design, which can change the series and parallel connection method and number of capacitors according to the power level of the device under test. This design enables the experimental test platform to quickly match the test requirements of devices with different power levels, greatly improving the adaptability of the test platform.

[0044] like Figure 2 As shown, the pressure fixture in the test platform adopts a design with an arc-coupling pressure bolt contact structure 8, that is, the tail of the pressure bolt 7 adopts a convex arc surface design, and the top of the pressure sensor 9 in contact with it adopts a concave arc surface design. The pressure sensor 9 with a range of 10000N is mounted on the surface of the collector-side heat sink 1. This structural design can ensure that the pressure direction applied by the pressure bolt is perpendicular to the surface of the press-fit IGBT device, thereby ensuring the uniformity of pressure distribution on the surface of the IGBT chip in the press-fit IGBT device.

[0045] The heat sink 1 is installed on the upper surface of the collector and the lower surface of the emitter of the device under test.

[0046] A 1500V high-precision voltage probe is installed in voltage sensor slot 10, and a 1200A high-precision current probe is nested in sensor slot 11.

[0047] like Figures 2-3 As shown, the pressure fixture in the test platform adopts the heat sink guide rail structure 2 design, that is, a heat sink guide 3 with a through hole at the end is installed on the side of the heat sink 1. The through hole at the end of the heat sink guide 3 is nested with the heat sink guide rail 4. This structure design can ensure the lateral stability of the heat sink during the pressurization process, thereby ensuring the uniformity of the pressure distribution on the chip surface in the pressurized IGBT device.

[0048] like Figure 2As shown, the pressure fixture in the test platform adopts a disc spring guide rod structure 15 design, that is, a through hole is provided in the center of the bottom flange 16 of the pressure fixture, and the disc spring guide rod 13 adopts a boss structure design, including a support base and a guide rod. The disc spring 14 is nested in the disc spring guide rod 13, and the end of the disc spring guide rod 1 is inserted into the center through hole of the bottom flange 16. This structure design can ensure the verticality of the bottom support during the pressurization process, thereby ensuring the uniformity of the pressure distribution on the surface of the press-fit IGBT device chip.

[0049] like Figure 2 As shown, the pressure fixture in the test platform adopts a special insulation and isolation structure design. The special insulation and isolation structure includes a (thermoplastic resin) radiator guide 3 made of thermoplastic resin and an (epoxy glass cloth) insulation plate 5 installed on the top of the upper radiator 1 and the bottom of the lower radiator 1. This structure design can ensure the insulation of the main structure of the fixture during the test, thereby ensuring the safety of the test personnel.

[0050] like Figure 4 As shown, a test method for a fault short-circuit withstand capability test platform suitable for press-fit power devices is described, and the specific operation steps are as follows:

[0051] 1) Before the experiment, based on the power rating of the 3300V / 50A press-fit IGBT device under test, a customized impact capacitor assembly scheme was developed, consisting of eight 450V / 1000μF capacitors connected in series and parallel to form an 1800V / 500μF capacitor bank. A pressure of 1200N was applied to the press-fit IGBT device using a pressure clamp.

[0052] 2) Start the high-voltage DC power supply. Based on the voltage level of the device under test and the actual application conditions, set the output of the high-voltage DC power supply to 1500V.

[0053] 3) A 5V step signal is input to the drive circuit via a signal generator. The controller turns on the IGBT device under test, and the rising edge of the step signal triggers the data acquisition card to synchronously acquire the collector-emitter voltage V of the IGBT device under test. CE Gate-emitter voltage V GE and collector current I C Characteristic parameters are measured, and the short-circuit energy E of the press-fit IGBT device is calculated in real time. SC :

[0054]

[0055] Where t0 is the device turn-on time, and t is the calculation time; the failure criterion is that the collector current exceeds the device's short-circuit saturation current limit and rises sharply, and the failure time t is recorded. F And the short-circuit energy E of the device at the time of failure CR .

[0056] As can be seen from the above, the fault short-circuit withstand capability test platform designed in this invention for press-fit packaged power devices can quickly match the testing requirements of devices with different power levels, significantly enhance the testing accuracy of fault short-circuit withstand capability for press-fit packaged power devices, and quickly match the testing requirements of devices with different power levels by increasing or decreasing the number of series and parallel capacitors, greatly expanding the adaptability of the test platform, while effectively avoiding test result deviations caused by uneven pressure loading. The test platform of this invention can quickly and accurately complete the fault short-circuit withstand capability test of press-fit packaged power devices, and compared with existing fault short-circuit withstand capability test platforms, it has the characteristics of wide adaptability, accurate measurement of characteristic parameters, and uniform pressure loading.

[0057] 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 test platform for the failure short-circuit withstand capability of press-fit packaged power devices, characterized in that, The test platform includes a voltage regulator module, an impact capacitor bank, a pressure clamp structure with integrated voltage and current sensors, and a control and acquisition module. The voltage regulation module includes a controllable high-voltage DC power supply and a voltage-regulating capacitor bank; the controllable high-voltage DC power supply maintains a constant conduction state during the test, and the voltage-regulating capacitor bank is connected in parallel across the controllable high-voltage DC power supply to maintain the voltage stability of the device under test. The impact capacitor bank is connected in parallel with the voltage stabilizing capacitor bank, and includes multiple capacitors connected in series and parallel. The pressure clamp structure of the integrated voltage and current sensor includes a high-precision voltage probe, a high-precision current probe and a pressure clamp; the pressure clamp adopts a design with an arc-coupling pressure bolt contact structure (8), that is, the tail of the pressure bolt (7) adopts a convex arc surface design, and the top of the pressure sensor (9) in contact with it adopts a concave arc surface design. The pressure sensor (9) is mounted on the surface of the heat sink (1) on the collector side of the device under test. The control and acquisition module includes a drive circuit and a data acquisition card. The drive circuit controls the device under test to conduct, and the device conduction is used as a trigger signal. The data acquisition card synchronously acquires the collector-emitter voltage, gate-emitter voltage and collector current of the device under test, and completes online monitoring and saves experimental data.

2. The failure short-circuit withstand capability test platform according to claim 1, characterized in that, The impact capacitor bank adopts a detachable design, and the series and parallel connection method and number of capacitors can be changed according to the power level of the device under test.

3. The failure short-circuit withstand capability test platform according to claim 1, characterized in that, The heat sink (1) is installed on the upper surface of the collector and the lower surface of the emitter of the device under test.

4. The failure short-circuit withstand capability test platform according to claim 1 or 3, characterized in that, The pressure clamp adopts a radiator guide rail structure (2) design, that is, a radiator guide (3) with a through hole at the end is installed on the side of the radiator (1), and the through hole at the end of the radiator guide (3) is nested with the radiator guide rail (4).

5. The failure short-circuit withstand capability test platform according to claim 1, characterized in that, The pressure clamp adopts a disc spring guide rod structure (15) design, that is, a through hole is provided in the center of the bottom flange (16) of the pressure clamp, and the disc spring guide rod (13) adopts a boss structure design, including a support base and a guide rod. The disc spring (14) is nested in the disc spring guide rod (13), and the end of the disc spring guide rod (13) is inserted into the center through hole of the bottom flange (16).

6. The failure short-circuit withstand capability test platform according to claim 1, characterized in that, The pressure clamp is designed with a special insulation isolation structure (6), which includes a radiator guide (3) made of insulating material and an insulating plate (5) installed on the top of the upper radiator (1) and the bottom of the lower radiator (1).

7. A test method applicable to the failure short-circuit withstand capability test platform according to any one of claims 1 to 6, characterized in that, The method specifically includes the following steps: S1: Before testing, determine the series and parallel connection method and quantity of capacitors in the impulse capacitor group according to the power level of the device under test, and apply the rated pressure to the press-packed power device using a pressure clamp. S2: Start the controllable high-voltage DC power supply and set the output voltage according to the voltage level of the device under test; S3: The drive circuit controller turns on, triggering the data acquisition card to synchronously acquire the collector-emitter voltage. V CE Gate-emitter voltage V GE and collector current I C It also calculates the short-circuit energy of press-fit packaged power devices in real time. E SC : in, t 0 represents the device's on-time. t The failure time is calculated based on the sudden increase in collector current exceeding the device's short-circuit saturation current limit. t F And the short-circuit energy of the device at the time of failure E CR .

Images