A test fixture for DBC components of welding IGBT modules

Abstract

The present invention discloses a test fixture for a DBC component of a welded IGBT module, comprising: an upper cover assembly, a base plate assembly, and a latch assembly; the base plate assembly includes a base plate, on which is provided a receiving compartment suitable for receiving a DBC component to be tested; the upper cover assembly is adapted to be fastened to the base plate assembly and adapted to surround the receiving compartment from the sides and top when fastened; one side of the upper cover assembly is adapted to be connected to the base plate assembly and the other side is adapted to be fastened to the base plate assembly via the latch assembly; the upper cover assembly also includes an electrode group adapted to electrically contact corresponding electrodes of the DBC component to be tested when the upper cover assembly is fastened to the base plate assembly. The test fixture for the DBC component of a welded IGBT module of the present invention can be used to verify whether there are defects in the DBC component design and welding process, complete the screening of the DBC component before packaging, and improve the yield rate and reliability of the IGBT module.

Description

Technical Field

[0001] The present invention relates to the field of power device testing, and in particular to a testing tool for a DBC component of a welding type IGBT module. Background Art

[0002] High-voltage, high-power IGBT modules, as power electronic devices, are widely used in industrial inverters, household appliances, electric traction, flexible direct current transmission, and photovoltaic access projects. Due to their large capacity, high-voltage, high-power IGBT modules are typically packaged with multiple IGBT chips (insulated-gate bipolar transistors) and freewheeling diodes (FWDs) connected via a specific circuit bridge. In a typical soldered IGBT module, the IGBT and FWD chips are soldered to a DBC substrate using solder tabs before the IGBT module is encapsulated. The DBC assembly is then bonded (the DBC substrate with the IGBT and FWD chips bonded is called a DBC assembly), and then the housing assembly is soldered to form the complete IGBT module. The IGBT module production and research process requires extensive testing. If testing is performed after the IGBT module is soldered, accurate DBC assembly parameters may not be obtained during some tests. Therefore, a series of tests are performed at the DBC assembly stage to detect defects in the DBC assembly and prevent them from causing overall IGBT module failure. Summary of the Invention

[0003] In view of the above problems, the present invention provides a DBC component testing tool for a welding-type IGBT module, so as to test the DBC component before welding to form the IGBT module.

[0004] The present invention provides a test fixture for a DBC component of a welding-type IGBT module, comprising: an upper cover assembly, a base plate assembly and a locking assembly; the base plate assembly comprises a base plate, on which is provided a accommodating chamber suitable for accommodating a DBC component to be tested; the upper cover assembly is suitable for being fastened to the base plate assembly, and is suitable for surrounding the accommodating chamber from the side and top when fastened; one side of the upper cover assembly is suitable for being connected to the base plate assembly, and the other side is suitable for being fastened to the base plate assembly through the locking assembly; the upper cover assembly also comprises a lead-out electrode group, which is suitable for electrically contacting corresponding electrodes of the DBC component to be tested when the upper cover assembly is fastened to the base plate assembly.

[0005] Optionally, the upper cover assembly includes a frame, the frame includes side walls extending downward, the side walls of the frame are closed-loop connected to form a space, and the side walls of the frame are suitable for surrounding the outer surface of the side walls of the accommodating bin when the upper cover assembly is buckled on the base plate assembly; a rotating shaft perforation seat is provided on one side of the frame, which is suitable for the rotating shaft to pass through; a torsion spring sleeve is provided on one outer wall of the accommodating bin, which protrudes laterally from the outer wall surface, is suitable for accommodating a connecting torsion spring, and is provided with a perforation suitable for the rotating shaft to pass through; the rotating shaft is suitable for passing through the perforation of the torsion spring sleeve and the rotating shaft perforation of the frame, so that the frame is connected to the accommodating bin; the connecting torsion spring is suitable for the rotating shaft to pass through the perforation and is sleeved on the rotating shaft when the rotating shaft passes through the perforation.

[0006] Optionally, a locking groove is provided on the side wall of the frame on the side opposite to the side where the rotating shaft perforated seat is located; the locking assembly includes a locking groove and a lock provided on the bottom plate; the lock includes a buckling part and a fixing part, the fixing part is fixedly connected to the bottom plate, the buckling part is rotatably connected to the fixing part, and the buckling part is suitable for buckling into the locking groove when the frame is buckled into the accommodating bin, so that the upper cover assembly and the bottom plate assembly are buckled and fastened.

[0007] Optionally, the upper cover assembly also includes: an electrode lead-out plate and an electrode support plate; the lower surface of the electrode lead-out plate has a plurality of electrode lead-out grooves, and each electrode lead-out groove is provided with an electrode lead-out seam that penetrates the electrode lead-out plate in the thickness direction; the electrode support plate is provided with a plurality of electrode access grooves and a plurality of electrode access holes; the electrode group is arranged between the electrode lead-out plate and the electrode support plate, and each electrode in the electrode group is respectively arranged in each electrode lead-out groove, and extends out of the surface of the electrode lead-out plate through the electrode lead-out seam in the corresponding electrode lead-out groove and is fastened to the upper surface of the electrode lead-out plate; the electrode support plate is installed on the upper surface of the frame; each electrode in the electrode group is electrically connected to the corresponding electrode on the DBC assembly to be tested through each electrode access groove or electrode access hole.

[0008] Optionally, the electrode lead-out groove includes a collector electrode lead-out groove, an emitter electrode lead-out groove and a gate electrode lead-out groove, and the emitter electrode lead-out groove is located between the gate electrode lead-out groove and the collector electrode lead-out groove; the electrode group includes a collector electrode, a gate electrode and an emitter electrode; the collector electrode is suitable for being embedded in the collector electrode lead-out groove, the emitter electrode is suitable for being embedded in the emitter electrode lead-out groove, and the gate electrode is suitable for being embedded in the gate electrode lead-out groove; the position of each electrode access groove on the electrode support plate corresponds to the position of each collector electrode lead-out groove on the electrode lead-out plate or the position of each emitter electrode lead-out groove on the electrode lead-out plate; the position of each electrode access hole on the electrode support plate corresponds to the position of each gate electrode lead-out groove on the electrode lead-out plate.

[0009] Optionally, the collector electrode includes a collector electrode main external lead, an auxiliary collector electrode external lead and a collector electrode internal connection portion connected to the collector electrode main external lead and the collector electrode auxiliary external lead; the emitter electrode includes an emitter electrode main external lead, an auxiliary emitter electrode external lead and an emitter electrode internal connection portion connected to the emitter electrode main external lead and the emitter electrode auxiliary external lead; the gate electrode includes a gate electrode external lead, a gate electrode internal connection portion and a gate electrode internal connection portion connected to the gate electrode external lead and the gate electrode internal connection portion; a protrusion is provided on the upper surface of the electrode lead-out plate, and the collector electrode main external lead and the emitter electrode main external lead respectively extend from the top surface of the protrusion to the upper surface of the electrode lead-out plate and are buckled to the upper surface of the electrode lead-out plate; the collector electrode auxiliary external lead, the emitter electrode auxiliary external lead and the gate electrode external lead respectively extend from the side of the side wall of the protrusion and are buckled to the upper surface of the electrode lead-out plate.

[0010] Optionally, the shape of the collector electrode main external lead and the collector electrode auxiliary external lead is a U-shaped bending structure, the arc tops of the two U-shaped bending structures are facing the same direction, and the collector internal connection part connects the same side wall of the two U-shaped bending structures; the shape of the emitter electrode main external lead and the emitter electrode auxiliary external lead is a U-shaped bending structure, the arc tops of the two U-shaped bending structures are facing the same direction, and the emitter internal connection part connects the same side wall of the two U-shaped bending structures.

[0011] Optionally, the collector electrode auxiliary lead-in terminal, the emitter electrode auxiliary lead-in terminal and the gate electrode lead-in terminal are arranged in a direction parallel to one side of the electrode lead-out plate.

[0012] Optionally, the pole electrode, the gate electrode and the emitter electrode are electrically connected to the DBC component to be tested through electrode connectors respectively; the electrode connector includes an auxiliary electrode probe and a compression spring; and the compression spring is a bow-shaped structure.

[0013] Optionally, the number of the containing chambers is two, the number of the electrode groups is two, and the lead-out directions of the electrodes in the two electrode groups are symmetrically arranged relative to the center of the electrode lead-out plate.

[0014] Optionally, an accommodating bin air inlet is provided on one side wall of the accommodating bin, and a frame air inlet is provided at a corresponding position on the frame; and a vent hole is provided on the partition wall between the two accommodating bins.

[0015] Optionally, a ridge is provided between the collector electrode lead-out groove and the collector electrode lead-out groove; a spacing groove is also provided on the electrode support plate, the shape of the spacing groove matches the shape of the ridge and is suitable for the ridge to be embedded; the position of the spacing groove on the electrode support plate corresponds to the position of the ridge on the electrode lead-out plate.

[0016] Optionally, the upper cover assembly further includes a sealing ring, and a sealing groove is provided around the top end of the side wall of the accommodating chamber. The sealing ring is suitable for filling the sealing groove when the upper cover assembly is buckled onto the bottom plate assembly to achieve sealing of the accommodating chamber.

[0017] Optionally, the length and width of the test fixture are 190 mm × 140 mm, the height is 35 mm to 50 mm, and the height of the accommodating chamber is 21 mm to 33 mm.

[0018] The beneficial effects of the present invention are:

[0019] The test fixture for the DBC assembly of a welded IGBT module of the present invention, through the corresponding arrangement of the upper cover assembly, the bottom plate assembly, and the locking assembly, allows the DBC assembly to be placed in a receiving chamber before the DBC assembly is welded into a complete IGBT module. The test fixture itself is used to replace the welded IGBT module packaging frame for testing. The test fixture is used to detect and verify whether there are defects in the DBC assembly design and welding process, completing the screening of the DBC assembly before packaging, which can improve the yield and reliability of the IGBT module. At the same time, it can avoid the waste caused by testing after welding to form a complete IGBT module. After the test is completed, the locking assembly is opened to remove the DBC assembly to be tested, and the test fixture and the DBC assembly to be tested can continue to be used.

[0020] The present invention's test fixture for DBC components of welded IGBT modules has dimensions consistent with the dimensions of the IGBT module to be welded after the DBC components are tested. This fixture meets various test conditions for DBC welded components, such as temperature and dynamic and static testing. It is suitable for testing the dynamic and static electrical parameters of various high-voltage, high-power welded IGBT modules, eliminating the need to reconfigure specialized test fixtures based on the test equipment.

[0021] The test fixture of the DBC component of the welded IGBT module of the present invention has a U-shaped bending structure arrangement of the collector electrode main external lead, the collector electrode auxiliary external lead, the emitter electrode main external lead and the emitter electrode auxiliary external lead, as well as a bow-shaped structure arrangement of the compression spring, so that the electrical connection path of each electrode is short, and all the external lead structures are consistent with the connection structure of the electrodes of a conventional welded IGBT module. Therefore, the parasitic inductance introduced into the test loop is low, which is conducive to improving the test accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a schematic diagram of the three-dimensional structure of a test fixture for a DBC assembly of a welding-type IGBT module according to an embodiment of the present invention when the upper cover assembly and the bottom plate assembly are fastened together;

[0024] Figure 2 An exploded view of a test fixture for a DBC assembly of a welded IGBT module according to an embodiment of the present invention;

[0025] Figure 3 This is a structural schematic diagram of a test fixture for a DBC component of a welding-type IGBT module according to an embodiment of the invention when the DBC component is provided;

[0026] Figure 4 This is a structural schematic diagram of an upper cover assembly of a test fixture for a DBC assembly of a welding-type IGBT module according to an embodiment of the present invention;

[0027] Figure 5 This is an exploded view of an upper cover assembly of a test fixture for a DBC assembly of a welded IGBT module according to an embodiment of the present invention;

[0028] Figure 6 A front view of the upper cover assembly of a test fixture for a DBC assembly of a welded IGBT module according to an embodiment of the present invention

[0029] Figure 7 for Figure 6 Section view at the mid-section line;

[0030] Figure 8 A schematic structural diagram showing the lower surface of an electrode lead-out plate of a test fixture for a DBC assembly of a welding-type IGBT module according to an embodiment of the present invention;

[0031] Figure 9 This is a structural schematic diagram of a frame of a test fixture for a DBC assembly of a welding-type IGBT module according to an embodiment of the present invention;

[0032] Figure 10 A bottom view of an electrode support plate of a test fixture for a DBC assembly of a welded IGBT module according to an embodiment of the present invention;

[0033] Figure 11 A top view of an electrode support plate of a test fixture for a DBC assembly of a welded IGBT module according to an embodiment of the present invention;

[0034] Figure 12 This is a schematic structural diagram of each electrode in an electrode group of a test fixture for a DBC assembly of a welding-type IGBT module according to an embodiment of the present invention;

[0035] Figure 13 This is a schematic structural diagram of an electrode connector of a test fixture for a DBC assembly of a welding-type IGBT module according to an embodiment of the present invention;

[0036] Figure 14This is a structural schematic diagram of a base plate assembly equipped with a locking assembly of a test fixture for a DBC assembly of a welding-type IGBT module according to an embodiment of the present invention;

[0037] Figure 15 This is a schematic structural diagram of a base plate assembly without a locking assembly installed in a test fixture for a DBC assembly of a welding-type IGBT module according to an embodiment of the present invention;

[0038] Figure 16 A front view of a base plate assembly of a test fixture for a DBC assembly of a welding-type IGBT module according to an embodiment of the present invention;

[0039] Figure 17 for Figure 16 A cross-sectional view of the hatching line in ;

[0040] Figure 18 A top view of a test fixture for a DBC assembly of a welding-type IGBT module according to an embodiment of the invention, showing a bottom plate assembly on which a DBC assembly to be tested is installed. DETAILED DESCRIPTION

[0041] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying 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 direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.

[0043] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] Example 1

[0045] refer to Figures 1-18 The present invention provides a test fixture for the DBC assembly of a welding type IGBT module. The test fixture includes: an upper cover assembly 1, a bottom plate assembly 2 and a locking assembly.

[0046] The bottom plate assembly 2 includes a bottom plate 2-1, on which a receiving compartment 2-1-2 is provided for receiving the DBC component to be tested. A component setting table 2-1-3 is provided at the center bottom of the receiving compartment 2-1-2 for setting the DBC component 5 to be tested.

[0047] The upper cover assembly 1 is adapted to snap onto the bottom plate assembly 2-1 and, when engaged, to enclose the housing compartment 2-1-2 from the sides and top. One side of the upper cover assembly 1 is adapted to connect to the bottom plate assembly 2, while the other side is adapted to be secured to the bottom plate assembly 2 via a latch assembly. The upper cover assembly also includes an electrode assembly, adapted to electrically contact corresponding electrodes of the DBC assembly 5 under test when the upper cover assembly 1 is snapped onto the bottom plate assembly 2.

[0048] The test fixture for the DBC assembly of the welded IGBT module of this embodiment, through the corresponding arrangement of the upper cover assembly 1, the bottom plate assembly 2, and the locking assembly, allows the DBC assembly 5 to be placed in the accommodating chamber 2-1-2 before the DBC assembly is welded into a complete IGBT module. The test fixture itself is used to replace the welded IGBT module packaging frame for testing. The test fixture is used to detect and verify whether there are defects in the DBC assembly design and welding process, completing the screening of the DBC assembly before packaging, which can improve the yield and reliability of the IGBT module. At the same time, it can avoid the waste caused by testing after welding into a complete IGBT module. After the test is completed, the locking assembly is opened to remove the DBC assembly 5 to be tested, and the test fixture and the DBC assembly 5 to be tested can continue to be used.

[0049] In one embodiment, the length and width of the test tool are 190mm×140mm, and the height is 35mm to 50mm, for example, it can be 35mm, 38mm, 40mm, 42mm, 45mm, 48mm, and 50mm. The height of the accommodating chamber 2-1-2 is 21mm to 33mm, for example, it can be 21mm, 24mm, 27mm, 30mm, and 33mm. With such dimensions, the size of the test tool can be consistent with the size of the IGBT module to be welded after the test of the DBC component is completed. For example, the height of the IGBT module of the 1700V and 3300V specifications is 38mm, and the height of the IGBT module of the 4500V and 6500V specifications is 48mm. For IGBT modules of other specifications, other test tool sizes can be used. Therefore, the size of the test fixture is within the above range, which can ensure that the DBC component being tested in the test fixture has basically the same appearance as the IGBT module to be welded, meeting the requirements of various test conditions such as temperature or dynamic and static conditions for DBC welding components. It is suitable for dynamic and static electrical parameter testing of various high-voltage and high-power welded IGBT modules, and there is no need to reconfigure special test fixtures according to the test equipment.

[0050] Furthermore, the upper cover assembly 1 includes a frame 1-2, which includes side walls extending downward. The side walls of the frame 1-2 are connected in a closed loop to form a space. The side walls of the frame 1-2 are suitable for surrounding the outer surface of the side walls of the accommodating chamber 2-1-2 when the upper cover assembly 1 is buckled onto the base plate assembly 2. A rotating shaft perforation seat 1-2-2 is provided on one side of the frame 1-2, suitable for the rotating shaft to pass through. A torsion spring sleeve 2-2 is provided on one side of the outer wall of the accommodating chamber 2-1-2, which protrudes laterally from the outer wall surface, suitable for accommodating the connecting torsion spring 3, and is provided with a perforation suitable for the rotating shaft 4 to pass through. The rotating shaft 4 is suitable for passing through the perforation of the torsion spring sleeve 2-2 and the rotating shaft perforation of the frame 1-2, so that the frame 1-2 is connected to the accommodating chamber 2-1-2. The connecting torsion spring 3 is suitable for the rotating shaft 4 to pass through the perforation and is sleeved on the rotating shaft 4 when the rotating shaft perforation is passed through.

[0051] The test fixture of the DBC component of the welding type IGBT module of this embodiment, through the arrangement of the shaft perforated seat 1-2-2 on the frame 1-2 and the torsion spring sleeve 2-2 on the outer wall of the accommodating chamber, allows the shaft 4 to be passed through it to realize the connection between the upper cover assembly 1 and the base plate assembly 2, and cooperates with the locking assembly to realize the snap-fit ​​covering of the upper cover assembly 1 on the accommodating chamber 2-1-2 on the base plate assembly 2.

[0052] Furthermore, the frame 1-2 is provided with a lock groove (not numbered in the figure) on the side wall on the side opposite to the side where the rotating shaft perforated seat 1-2-2 is located. The lock assembly includes a lock groove and a lock provided on the base plate 2-1. The lock includes a buckle portion 2-4 and a fixed portion 2-3, the fixed portion 2-3 is fixedly connected to the base plate 2-1, the buckle portion 2-4 is rotatably connected to the fixed portion 2-3, and the buckle portion 2-4 is suitable for buckling into the lock groove when the frame 1-2 is buckled into the accommodating chamber 2-1-2, so that the upper cover assembly 1 and the base plate assembly 2 are buckled and fastened. When it needs to be opened, the buckle portion 2-4 is rotated to disengage it from the lock groove, and the upper cover assembly can be opened. And in conjunction with the connecting torsion spring 3 and the rotating shaft 4, it can be opened naturally after unlocking.

[0053] Furthermore, the upper cover assembly 1 also includes: an electrode lead-out plate 1-1 and an electrode support plate 1-3. The lower surface of the electrode lead-out plate 1-1 has a plurality of electrode lead-out grooves, and each electrode lead-out groove is provided with an electrode lead-out slit that penetrates the electrode lead-out plate in the thickness direction. The electrode support plate 1-3 is provided with a plurality of electrode access grooves 1-3-3 and a plurality of electrode access holes 1-3-2. The electrode group is arranged between the electrode lead-out plate 1-1 and the electrode support plate 1-3, and each electrode in the electrode group is respectively arranged in each electrode lead-out groove, and extends out of the surface of the electrode lead-out plate through the electrode lead-out slit in the corresponding electrode lead-out groove and is buckled to the upper surface of the electrode lead-out plate. The electrode support plate 1-3 is installed on the upper surface of the frame. Specifically, a mounting groove 1-2-1 is provided on the upper inner side of the frame 1-2, and the electrode support plate 1-3 is installed in the mounting groove 1-2-1. Each electrode in the electrode group is electrically connected to a corresponding electrode on the DBC component 5 to be tested through each electrode access groove 1-3-3 or electrode access hole 1-3-2.

[0054] Specifically, the electrode lead-out groove includes a collector electrode lead-out groove 1-1-1, an emitter electrode lead-out groove 1-1-2 and a gate electrode lead-out groove 1-1-3, and the emitter electrode lead-out groove 1-1-2 is located between the gate electrode lead-out groove 1-1-3 and the collector electrode lead-out groove 1-1-1. The electrode group includes a collector electrode 1-4, a gate electrode 1-6 and an emitter electrode 1-5. The collector electrode 1-4 is suitable for being embedded in the collector electrode lead-out groove 1-1-1, the emitter electrode 1-5 is suitable for being embedded in the emitter electrode lead-out groove 1-1-2, and the gate electrode 1-6 is suitable for being embedded in the gate electrode lead-out groove 1-1-3. The positions of each electrode access groove 1-3-3 on the electrode support plate 1-3 correspond to the positions of each collector electrode lead-out groove 1-1-1 on the electrode lead-out plate 1-1 or the positions of each emitter electrode lead-out groove 1-1-2 on the electrode lead-out plate. The positions of the electrode access holes 1-3-2 on the electrode support plate correspond to the positions of the gate electrode lead-out grooves 1-1-3 on the electrode lead-out plate.

[0055] The test fixture for the DBC assembly of a welded IGBT module of this embodiment utilizes electrode lead-out slots to position each electrode during installation. The electrode lead-out plate, electrode support plate, and electrode assembly facilitate the lead-out of each electrode on the DBC assembly under test, enabling appropriate testing.

[0056] In this embodiment, the collector electrode 1-4, the gate electrode 1-6, and the emitter electrode 1-5 are made of a T2 copper plate with a nickel plating surface. The copper plate may be 0.5 mm to 1 mm thick, for example, 0.5 mm, 0.8 mm, or 1 mm, and may have two nickel plating layers.

[0057] Furthermore, the collector electrode 1-4 includes a main collector electrode lead 1-4-1, an auxiliary collector electrode lead 1-4-2, and a collector electrode interconnector 1-4-3 connecting the main collector electrode lead 1-4-1 and the auxiliary collector electrode lead 1-4-2. The emitter electrode 1-5 includes a main emitter electrode lead 1-5-1, an auxiliary emitter electrode lead 1-5-2, and an emitter electrode interconnector 1-5-3 connecting the main emitter electrode lead 1-5-1 and the auxiliary emitter electrode lead 1-5-2. The gate electrode 1-6 includes a gate electrode lead 1-6-1, a gate electrode interconnector 1-6-2, and a gate electrode interconnector (not numbered in the figure) connecting the gate electrode lead 1-6-1 and the gate electrode interconnector 1-6-2. The top surface of the electrode lead plate is provided with a protrusion. The collector electrode main lead 1-4-1 and the emitter electrode main lead 1-5-1 extend from the top surface of the protrusion and snap onto the top surface of the electrode lead plate 1-1. The collector electrode auxiliary lead 1-4-2, the emitter electrode auxiliary lead 1-5-2, and the gate electrode lead 1-6-1 extend from the sidewalls of the protrusion and snap onto the top surface of the electrode lead plate 1-1. In this embodiment, the collector electrode auxiliary lead 1-4-2, the emitter electrode auxiliary lead 1-5-2, and the gate electrode lead 1-6-1 are arranged parallel to one side of the electrode lead plate 1-1.

[0058] The collector electrode main external lead 1-4-1 and the collector electrode auxiliary external lead 1-4-2 are in the shape of a U-shaped bending structure, the arc tops of the two U-shaped bending structures face the same direction, and the collector internal connection part 1-4-3 connects the same side wall of the two U-shaped bending structures.

[0059] The main external lead end 1-5-1 of the emitting electrode and the auxiliary external lead end 1-5-2 of the emitting electrode are in the shape of a U-shaped bending structure, the arc tops of the two U-shaped bending structures face the same direction, and the internal connecting part 1-5-3 of the emitting electrode connects the same side wall of the two U-shaped bending structures.

[0060] Each electrode is electrically connected to the DBC component 5 to be tested through an electrode connector. The electrode connector includes an auxiliary electrode probe 1-7 and a compression spring 1-8. The auxiliary electrode probe 1-7 is installed in the electrode access hole 1-3-2, and the compression spring 1-8 is installed in the electrode access groove 1-3-3. The electrode access hole 1-3-2 and the electrode access groove 1-3-3 are both holes or grooves that step down inward and are hollowed out in the center, and the lower surface of the electrode support plate 1-3 protrudes below. The auxiliary electrode probe 1-7 can be a T-shaped spring probe with a gold-plated surface. The thickness of the gold plating on the surface of the T-shaped spring probe can be 1μm to 9μm, for example, 1μm, 3μm, 5μm, 7μm, and 9μm. The compression spring 1-8 can be a bow-shaped structure with a thickness of 0.1mm to 0.9mm, for example, 0.1mm, 0.3mm, 0.5mm, 0.7mm, and 0.9mm. The material of the compression spring 1 - 8 may be T2 copper, and the surface may be silver-plated. The thickness of the silver plating may be 5 μm to 15 μm, for example, 5 μm, 10 μm, or 15 μm.

[0061] The test fixture of the DBC assembly of the welded IGBT module of this embodiment has a U-shaped bending structure of the collector electrode main external lead, the collector electrode auxiliary external lead, the emitter electrode main external lead, and the emitter electrode auxiliary external lead, as well as the bow-shaped structure of the compression spring, so that the electrical connection path of each electrode is short, and all the external lead structures are consistent with the connection structure of the electrodes of the conventional welded IGBT module. Therefore, the parasitic inductance introduced into the test loop is low, which is conducive to improving the test accuracy. In this embodiment, the number of accommodating chambers 2-1-2 is two, the number of electrode groups is two, and the lead directions of each electrode in the two electrode groups are symmetrically arranged relative to the center of the electrode lead plate (reference Figure 5 ).

[0062] By arranging two receiving chambers and two sets of electrode groups in a centrally symmetrical manner, two DBC components (5-1 and 5-2) can be accommodated at one time. After one test is completed (for example, 5-1), the plane can be rotated 180° to immediately test the next DBC component (for example, 5-2). This is more efficient than testing one DBC component at a time.

[0063] Furthermore, a storage bin air inlet 2-1-4 is provided on one side wall of the storage bin 2-1-2, and a frame body air inlet 1-2-3 is provided at a corresponding position on the frame body 1-2. A vent 2-1-5 is provided on the partition wall between the two storage bins 2-1-2. The diameters of the storage bin air inlet 2-1-4 and the frame body air inlet 1-2-3 can be 2mm to 10mm, for example, 2mm, 5mm, 8mm, or 10mm. There can be multiple vents 2-1-5, for example, two. The diameter of the vent 2-1-5 can be 1mm to 5mm, for example, 1mm, 2mm, 3mm, 4mm, or 5mm. The position of the vent 2-1-5 can be slightly higher than the position of the storage bin air inlet 2-1-4, and can be 2mm to 4mm higher, for example, 2mm, 3mm, or 4mm. By configuring the chamber air inlet 2-1-4, the frame air inlet 1-2-3, and the vent 2-1-5, an external air supply system can be connected to fill the chamber with gas, such as nitrogen or other inert gas, as needed to control the atmosphere within the DBC component test fixture. In other embodiments, a liquid supply system can also be connected to fill the chamber with liquid, such as fluorinated oil, as needed to meet the insulation requirements of the DBC component.

[0064] In addition, a ridge 1-1-4 is provided between the collector electrode lead-out groove 1-1-1 and the emitter electrode lead-out groove 1-1-2, and a spacing groove 1-3-4 is provided on the electrode support plate 1-3. The shape of the spacing groove 1-3-4 matches the shape of the ridge 1-1-4, allowing the ridge 1-1-4 to be embedded therein. The position of the spacing groove 1-3-4 on the electrode support plate 1-3 corresponds to the position of the ridge 1-1-4 on the electrode lead-out plate 1-1. The provision of the ridge 1-1-4 and the spacing groove 1-3-4 allows a spacing to be provided between the collector electrode 1-4 and the emitter electrode 1-5, thereby increasing the creepage distance between the electrodes and providing a positioning function during the installation of the electrode lead-out plate 1-1 and the electrode support plate 1-3.

[0065] The upper cover assembly 1 also includes a sealing ring 1-9. A sealing groove 2-1-6 is provided around the top of the side wall of the receiving chamber 2-1-2. The sealing ring 1-9 is adapted to fit into the sealing groove 2-1-6 when the upper cover assembly 1 is fastened to the base assembly 2, thereby sealing the receiving chamber 2-1-2. The sealing ring 1-9 may be made of polytetrafluoroethylene.

[0066] The base plate 2-1, the torsion spring sleeve 2-2, the fixing portion 2-3 and the buckling portion 2-4 of the lock are all metal parts, for example, aluminum alloy with nickel plating on the surface, especially 6061 aluminum alloy, with a nickel plating thickness of 15 μm.

[0067] The technical solutions disclosed in the present invention have been described above through the use of embodiments. It is believed that those skilled in the art will be able to understand the present invention through the description of the above embodiments. Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A test fixture for the DBC assembly of a welding IGBT module, characterized in that: include: Upper cover assembly, bottom plate assembly and lock assembly; The base plate assembly includes a base plate, and a receiving compartment suitable for receiving a DBC component to be tested is provided on the base plate; A component placement platform is provided at the center bottom of the storage chamber for placing the DBC component to be tested; the upper cover assembly is adapted to be buckled onto the bottom plate assembly and adapted to surround the storage chamber from the sides and top when buckled; one side of the upper cover assembly is adapted to be connected to the bottom plate assembly, and the other side is adapted to be fastened to the bottom plate assembly via the locking assembly; the upper cover assembly further comprises an electrode group for lead-out, the electrode group being adapted to electrically contact corresponding electrodes of the DBC component to be tested when the upper cover assembly is buckled onto the bottom plate assembly; The electrode group includes a collector electrode, a gate electrode and an emitter electrode; The collector electrode includes a collector electrode main external lead, a collector electrode auxiliary external lead, and a collector electrode internal connection portion connecting the collector electrode main external lead and the collector electrode auxiliary external lead; The emitting electrode includes an emitting electrode main external lead-in terminal, an emitting electrode auxiliary external lead-in terminal, and an emitting electrode internal connection portion connecting the emitting electrode main external lead-in terminal and the emitting electrode auxiliary external lead-in terminal; The gate electrode includes a gate electrode external lead end, a gate electrode internal connection end, and a gate electrode internal connection portion connecting the gate electrode external lead end and the gate electrode internal connection end; The upper cover assembly includes an electrode lead-out plate; a protrusion is provided on the upper surface of the electrode lead-out plate, and the collector electrode main external lead and the emitter electrode main external lead respectively extend from the top surface of the protrusion to the upper surface of the electrode lead-out plate and are buckled to the upper surface of the electrode lead-out plate; the collector electrode auxiliary external lead, the emitter electrode auxiliary external lead and the gate electrode external lead respectively extend from the side of the side wall of the protrusion to the upper surface of the electrode lead-out plate and are buckled to the upper surface of the electrode lead-out plate.

2. The test fixture for the DBC assembly of the welding type IGBT module according to claim 1, characterized in that: The upper cover assembly includes a frame, the frame including side walls extending downward, the side walls of the frame being connected in a closed loop to form a space, and the side walls of the frame are adapted to surround the outer surface of the side walls of the accommodating compartment when the upper cover assembly is buckled onto the bottom plate assembly; a rotating shaft perforated seat is provided on one side of the frame, adapted for the rotating shaft to pass through; A torsion spring sleeve is provided on one side of the outer wall of the accommodating chamber and protrudes laterally from the outer wall surface, suitable for accommodating the connecting torsion spring and provided with a through hole suitable for the rotation shaft to pass through; The rotating shaft is suitable for passing through the through hole of the torsion spring sleeve and the rotating shaft through hole of the frame body, so that the frame body is connected to the accommodating chamber; the connecting torsion spring is suitable for being sleeved on the rotating shaft when the rotating shaft passes through the through hole and the rotating shaft through hole.

3. The test fixture for the DBC assembly of the welding type IGBT module according to claim 2, characterized in that: The frame is provided with a locking groove on the side wall opposite to the side where the rotating shaft perforated seat is located; The lock assembly includes the lock slot and a lock provided on the bottom plate; The lock includes a buckling portion and a fixing portion, the fixing portion is fixedly connected to the base plate, the buckling portion is rotatably connected to the fixing portion, and the buckling portion is suitable for buckling into the lock slot when the frame is buckled into the accommodating bin, so that the upper cover assembly and the base plate assembly are buckled and fastened.

4. The test fixture for the DBC assembly of the welding type IGBT module according to claim 2, characterized in that: The upper cover assembly further includes: an electrode support plate; The lower surface of the electrode lead-out plate is provided with a plurality of electrode lead-out grooves, each of which is provided with an electrode lead-out seam that penetrates the electrode lead-out plate in the thickness direction; the electrode support plate is provided with a plurality of electrode access grooves and a plurality of electrode access holes; The electrode group is arranged between the electrode lead-out plate and the electrode support plate, and each electrode in the electrode group is respectively arranged in each electrode lead-out groove, and extends out of the surface of the electrode lead-out plate through the electrode lead-out slit in the corresponding electrode lead-out groove and is buckled with the upper surface of the electrode lead-out plate; the electrode support plate is mounted on the upper surface of the frame; Each electrode in the electrode group is electrically connected to a corresponding electrode on the DBC component to be tested through each electrode access groove or electrode access hole.

5. The test fixture for the DBC assembly of the welding type IGBT module according to claim 4, characterized in that: The electrode lead-out groove includes a collector electrode lead-out groove, an emitter electrode lead-out groove and a gate electrode lead-out groove, and the emitter electrode lead-out groove is located between the gate electrode lead-out groove and the collector electrode lead-out groove; The collector electrode is adapted to be embedded in the collector electrode lead-out groove, the emitter electrode is adapted to be embedded in the emitter electrode lead-out groove, and the gate electrode is adapted to be embedded in the gate electrode lead-out groove; The positions of the electrode access grooves on the electrode support plate respectively correspond to the positions of the collector electrode lead-out grooves on the electrode lead-out plate or the positions of the emitter electrode lead-out grooves on the electrode lead-out plate; the positions of the electrode access holes on the electrode support plate respectively correspond to the positions of the gate electrode lead-out grooves on the electrode lead-out plate.

6. The test fixture for the DBC assembly of the welding type IGBT module according to claim 5, characterized in that: The collector electrode main external lead and the collector electrode auxiliary external lead are in the shape of a U-shaped bent structure, the arc tops of the two U-shaped bent structures face the same direction, and the collector electrode internal connection portion connects the same side wall of the two U-shaped bent structures; The main external lead of the emitting electrode and the auxiliary external lead of the emitting electrode are in the shape of a U-shaped bending structure, the arc tops of the two U-shaped bending structures face the same direction, and the internal connecting portion of the emitting electrode connects the same side wall of the two U-shaped bending structures.

7. The test fixture for the DBC assembly of the welding type IGBT module according to claim 5, characterized in that: The collector electrode auxiliary lead-out terminal, the emitter electrode auxiliary lead-out terminal, and the gate electrode lead-out terminal are arranged in a direction parallel to one side of the electrode lead-out plate.

8. The test fixture for the DBC assembly of the welding type IGBT module according to claim 5, characterized in that: The pole electrode, the gate electrode and the emitter electrode are electrically connected to the DBC component to be tested through electrode connectors respectively; the electrode connectors include auxiliary electrode probes and compression springs; the compression springs are of bow-shaped structure.

9. The test fixture for the DBC assembly of the welding type IGBT module according to claim 5, characterized in that: There are two containing chambers and two electrode groups, and the lead-out directions of the electrodes in the two electrode groups are symmetrically arranged relative to the center of the electrode lead-out plate.

10. The test fixture for the DBC assembly of the welding type IGBT module according to claim 9, characterized in that: An air inlet hole is provided on one side wall of the storage bin, and a frame air inlet hole is provided at a corresponding position on the frame; and a vent hole is provided on the partition wall between the two storage bins.

11. The test fixture for the DBC assembly of the welding type IGBT module according to claim 5, characterized in that: A convex ridge is further provided between the collector electrode lead-out groove and the collector electrode lead-out groove; The electrode support plate is further provided with a spacing groove, the shape of which matches the shape of the ridge and is suitable for the ridge to be embedded; the position of the spacing groove on the electrode support plate corresponds to the position of the ridge on the electrode lead-out plate.

12. The test fixture for the DBC assembly of the welding type IGBT module according to claim 5, characterized in that: The upper cover assembly also includes a sealing ring. A sealing groove is provided around the top of the side wall of the accommodating chamber. The sealing ring is suitable for filling the sealing groove when the upper cover assembly is buckled onto the bottom plate assembly to achieve sealing of the accommodating chamber.

13. The test fixture for the DBC assembly of the welding type IGBT module according to claim 1, characterized in that: The length and width of the test tool are 190 mm×140 mm, the height is 35 mm to 50 mm, and the height of the containing chamber is 21 mm to 33 mm.

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