A low-inductance device for low-temperature testing of silicon carbide double pulses

Abstract

The present application relates to a low-inductance device for double-pulse low-temperature testing of silicon carbide, which includes a cooling box. A module to be tested is arranged inside the cooling box, and a sealing plate is arranged outside the cooling box at a position corresponding to the module to be tested. The sealing plate can seal the cooling box, and the sealing plate integrates a driving plate and a main power connection plate; the driving plate on the sealing plate is arranged corresponding to the module to be tested; a hot air channel is arranged outside the cooling box at a position corresponding to the sealing plate, and the hot air channel is in mutual abutment with the upper surface of the sealing plate. The present application has the effect that even in a low-temperature environment, the main circuit and the signal circuit to be tested of the silicon carbide module can still maintain low inductance, thereby ensuring the test accuracy.

Description

Technical Field

[0001] The present application relates to the field of cryogenic detection, and in particular to a low stray inductance device for double-pulse cryogenic testing of silicon carbide. Background Art

[0002] In the current silicon carbide test platform, due to the switching characteristics of silicon carbide, the rising and falling speeds of the current are very fast. The measuring device should have a small enough stray inductance in the main circuit / signal circuit to ensure that the silicon carbide module can be accurately tested over the full range during testing. With the increasing testing requirements, cryogenic testing is increasingly needed by customers.

[0003] Regarding the above related technologies, the inventor believes that cryogenic testing requires placing the module in a cryogenic chamber for testing to ensure that the silicon carbide module under test reaches -40°C. However, at the same time, it is necessary to lead out the connection wires of the main circuit and the signal circuit, which will increase the stray inductance of the main circuit and the signal circuit. It can be seen that cryogenic testing and low stray inductance of silicon carbide are contradictory to each other. Summary of the Utility Model

[0004] In order to enable the silicon carbide module under test to maintain low stray inductance in the main circuit and the signal circuit even in a low-temperature environment, thereby ensuring the testing accuracy, the present application provides a low stray inductance device for double-pulse cryogenic testing of silicon carbide.

[0005] The low stray inductance device for double-pulse cryogenic testing of silicon carbide provided by the present application adopts the following technical solutions:

[0006] A low stray inductance device for double-pulse cryogenic testing of silicon carbide includes a cooling box. A module under test is arranged inside the cooling box. A sealing plate is arranged outside the cooling box at a position corresponding to the module under test. The sealing plate can seal the cooling box and integrates a driving board and a main power connection board; the driving board on the sealing plate is arranged corresponding to the module under test; a hot air pipeline is arranged outside the cooling box at a position corresponding to the sealing plate, and the hot air pipeline is in contact with the upper surface of the sealing plate.

[0007] By adopting the above technical solutions, the module under test is placed inside the cooling box, and the driving board and the main power connection board on the sealing plate are arranged in a constant temperature chamber, ensuring the state with the lowest stray inductance in the driving circuit and the best driving waveform; since the lower surface of the sealing plate is in a constant temperature chamber at minus 40 degrees, while the upper surface is at normal temperature, there is a temperature difference between the upper and lower surfaces, thus inevitably generating the phenomenon of condensation. Through the hot air pipeline, heat conduction is carried out on the upper surface of the sealing tank to solve the condensation problem on the upper surface.

[0008] Optionally, the sealing plate adopts a multi-layer stacked PCB structure; the sealing plate is connected to the bus bar through copper columns, and the stray inductance of the copper columns = 4 nh; the sealing plate is a PCB board with a thickness of 3 mm.

[0009] By adopting the above technical solution, the positive and negative electrodes of the main power connection board are connected to the main circuit board and the external bus capacitor through copper columns, which can reduce the stray inductance of the overall circuit, minimize the stray inductance of the signal loop, and obtain the best driving waveform. The sealing board uses a multi-layer stacked PCB structure to further reduce the stray inductance. The driving board is arranged directly opposite the module under test, so that the signal of the module under test can be conducted to the driving board in the shortest time.

[0010] Optionally, a locking groove is provided at the position of the cooling box corresponding to the sealing board. The locking groove is a key groove. A locking block is provided at the position of the cooling box corresponding to the locking groove. The locking block abuts against the sealing board. A guiding inclined surface is provided at one end of the locking block close to the sealing board. The guiding inclined surface starts from the lower end of the locking block and slopes upward towards the side close to the sealing board. An elastic member for pushing the locking block to abut against the sealing board is provided above the locking block. A vertically arranged guiding rod is provided in the locking block. A guiding groove is provided at the position of the locking block corresponding to the guiding rod. The guiding rod can be slidably connected in the guiding groove.

[0011] By adopting the above technical solution, when the cooling box detects the module under test, the temperature difference between the front and back of the sealing board is large, which is likely to cause deformation of the sealing board. The elastic member pushes the locking block to move in the vertical direction. The guiding rod and the guiding groove cooperate with each other to limit the sliding direction of the locking block. The elastic member pushes the locking block to seal the sealing board.

[0012] Optionally, fixing bolts are provided at the position of the cooling box corresponding to the sealing board. A plastic housing is provided at the position of the cooling box body corresponding to the fixing bolts. The plastic housing can be threadedly connected with the fixing bolts. Positioning holes are provided at the position of the sealing board corresponding to the plastic housing. The fixing bolts can be inserted into the positioning holes.

[0013] By adopting the above technical solution, the sealing board is sealed by the fixing bolts. The relative position of the sealing board is fixed by inserting the fixing bolts into the positioning holes. The plastic housing arranged in the cooling box body reduces the heat conduction of the outside air to the inside of the cooling box by the fixing bolts, resulting in a change in the temperature inside the box and thus a poor detection effect of the module under test.

[0014] Optionally, a water bag is provided between the hot air duct and the sealing board. A thermometer is provided on the water bag. The thermometer can detect the temperature of the water bag. The constant temperature water bag abuts against the outside air and the water bag abuts against the sealing board.

[0015] Optionally, a refrigerator is provided in the cooling box. A heat conduction pipe is provided between the exchange port of the refrigerator and the hot air duct. An air compressor is provided outside the heat conduction pipe. A gas one-way valve is provided inside the heat conduction pipe.

[0016] By adopting the above technical solution, the heat generated by the refrigerator is sent to the hot air duct through the air compressor, increasing the utilization rate of gas thermal energy. Subsequently, a gas check valve is used to prevent the gas in the hot air duct from flowing back. The water bag is observed through a temperature machine, and the temperature is conducted through the water bag. Since the specific heat capacity of water is greater than that of air, the probability of sudden temperature change of the sealing plate is reduced through the water bag, preventing damage to the sealing plate caused by sudden temperature change.

[0017] Optionally, a plurality of reset grooves are provided on the locking groove, and adjacent reset grooves are parallel to each other. A reset spring is arranged in the reset groove, and a reset block is slidably connected in the reset groove. The reset spring can push the reset block to slide in a direction away from the cooling box. A rotating rod that moves synchronously is arranged on the reset block, and a rotating wheel that moves synchronously and rotates synchronously is arranged on the rotating rod. The rotating direction of the rotating wheel is the same as the pushing direction of the sealing plate; a pressing plate is fixedly connected to the cooling box corresponding to the position of the clamping groove, and the gap between the pressing plate and the clamping groove is the same as the thickness of the sealing plate.

[0018] By adopting the above technical solution, when the sealing plate slides to close the cooling box, the sealing plate abuts against the rotating wheel, and the upper surface of the sealing plate abuts against the pressing plate, enabling the sealing plate to abut against the locking groove. And when the sealing plate slides, the pressing plate limits the sliding direction of the sealing plate. When the sealing plate slides, the outer peripheral surface of the sealing plate abuts against the rotating plate, thereby driving the rotating rod and the rotating wheel to rotate synchronously. When the sealing plate abuts against the pressing plate, the sealing plate pushes the rotating wheel and the reset block to slide along the direction of the reset groove; the reset spring is compressed, and the reset spring has a force to push the rotating wheel to reset.

[0019] In summary, the present application includes at least one of the following beneficial technical effects:

[0020] 1. The heat module is placed in the cooling box, and the driving plate and the main power connection plate on the sealing plate are arranged in the greenhouse, ensuring the state with the lowest stray inductance in the driving circuit and the best driving waveform; since the lower surface of the sealing plate is in a constant temperature room of minus 40 degrees, while the upper surface is at room temperature, there is a temperature difference between the upper and lower surfaces, and thus the phenomenon of condensation inevitably occurs. Through the hot air duct, heat conduction is carried out on the upper surface of the sealing plate to solve the condensation problem on the upper surface;

[0021] 2. When the cooling box detects the module under test, the temperature difference between the front and back of the sealing plate is large, which is likely to cause deformation of the sealing plate. The elastic member pushes the locking block to move in the vertical direction, and the guide rod and the guide groove cooperate with each other to limit the sliding direction of the locking block. The elastic member pushes the locking block to seal the sealing plate;

[0022] 3. When the sealing plate slides to close the cooling box, the sealing plate abuts against the rotating wheel, the upper surface of the sealing plate abuts against the pressing plate, so that the sealing plate can abut against the locking groove. And when the sealing plate slides, the pressing plate limits the sliding direction of the sealing plate. When the sealing plate slides, the sealing plate abuts against the outer peripheral surface of the rotating plate, thereby driving the rotating rod and the rotating wheel to rotate synchronously. When the sealing plate abuts against the pressing plate, the sealing plate pushes the rotating wheel and the reset block to slide along the direction of the reset groove; the reset spring is compressed, and the reset spring has a force to push the rotating wheel to reset. Description of the Drawings

[0023] Figure 1 is an overall schematic diagram of a silicon carbide double-pulse low-temperature test low-inductance device in this embodiment.

[0024] Figure 2 is a partial schematic diagram highlighting the sealing plate of a silicon carbide double-pulse low-temperature test low-inductance device in this embodiment.

[0025] Figure 3 is an overall schematic diagram highlighting the cooling box of a silicon carbide double-pulse low-temperature test low-inductance device in this embodiment.

[0026] Figure 4 is a partial schematic diagram highlighting the spring frame of a silicon carbide double-pulse low-temperature test low-inductance device in this embodiment.

[0027] Figure 5 is a cross-sectional schematic diagram highlighting the elastic member of a silicon carbide double-pulse low-temperature test low-inductance device in this embodiment.

[0028] Figure 6 is a partial schematic diagram highlighting the reset assembly of a silicon carbide double-pulse low-temperature test low-inductance device in this embodiment.

[0029] Figure 7 is a partial schematic diagram highlighting the hot air duct of a silicon carbide double-pulse low-temperature test low-inductance device in this embodiment.

[0030] Description of the Reference Numerals: 1, cooling box; 11, clamping groove; 12, locking groove; 13, sealing plate; 14, module under test; 15, busbar; 16, copper column; 2, spring frame; 21, elastic member; 22, locking block; 23, guide rod; 24, guide groove; 25, guide inclined surface; 3, reset assembly; 31, reset groove; 32, reset spring; 33, reset block; 34, rotating rod; 35, rotating wheel; 36, pressing plate; 4, fixing bolt; 41, plastic housing; 42, positioning hole; 5, hot air duct; 51, hot air blower; 52, refrigerator; 53, heat conduction pipe; 54, gas one-way valve; 55, water bag; 56, thermometer. Detailed Embodiment

[0031] The following further elaborates on this application in conjunction with the attached drawings. Figure 1-7 A further detailed description of this application will be given below.

[0032] An embodiment of this application discloses a low stray inductance device for double - pulse low - temperature testing of silicon carbide.

[0033] Referring to Figure 1 and Figure 2 , a low stray inductance device for double - pulse low - temperature testing of silicon carbide includes a cooling box 1. A clamping groove 11 is opened on the cooling box 1. The opening position of the clamping groove 11 is close to one side of the cooling box 1, and the clamping groove 11 is a through - groove. A locking groove 12 is opened on the surface of the cooling box 1 around the outer periphery of the clamping groove 11, and the locking groove 12 is a keyway. A sealing plate 13 is provided at the position of the cooling box 1 corresponding to the locking groove 12. The sealing plate 13 is the same size as the locking groove 12. The sealing plate 13 can cover the clamping groove 11, thereby closing the inside of the cooling box 1. A measured module 14 is fixedly connected to the sealing plate 13 corresponding to the cold - zone box. A driving plate and a main - power connection plate are provided on the sealing plate 13. A bus bar 15 is provided at the position of the sealing plate 13 corresponding to the main - power connection plate. The bus bar 15 and the main - power connection plate are connected by a copper column 16. The stray inductance of the copper column 16 is 4 nh. The material of the sealing plate 13 is a PCB board, and the thickness of the sealing plate 13 is 3 mm.

[0034] During use, the positive and negative poles of the main - power connection plate are connected to the main - circuit board and the external bus - bar 15 capacitor through the copper column 16, which can reduce the stray inductance of the overall circuit, minimize the stray inductance of the signal loop, and obtain the best driving waveform. The sealing plate 13 uses a multi - layer stacked PCB structure to further reduce the stray inductance. The driving plate is arranged opposite to the measured module 14, so that the signal of the measured module 14 can be conducted to the driving plate in the first time.

[0035] Referring to Figure 3 and Figure 4 , a spring frame 2 is fixedly connected to the cooling box 1 at the position corresponding to the locking groove 12. A vertically arranged elastic member 21 is fixedly connected to the spring frame 2. The axis of the elastic member 21 is vertically arranged. The other end of the elastic member 21 is fixedly connected to a locking block 22. A coaxial guide rod 23 is fixedly connected inside the elastic member 21. A guide groove 24 is opened on the locking block 22 corresponding to the guide rod 23. The guide groove 24 is opened in the vertical direction. The guide rod 23 can be slidably connected in the guide groove 24 in the vertical direction. A guide inclined surface 25 is opened at the end of the locking block 22 away from the elastic member 21. The guide inclined surface 25 starts from the lower end of the locking block 22 and slopes upward toward the side close to the sealing plate 13. The guide inclined surface 25 can be in contact with the sealing plate 13.

[0036] During use, the sealing plate 13 closes the cooling box 1. The sealing plate 13 is placed in the locking groove 12 and abuts against the guiding inclined surface 25 on the locking block 22, which can push the locking block 22 to slide vertically. The elastic member 21 has a tendency to push the locking block 22 vertically downward. The sliding direction of the locking block 22 is limited by the guiding rod 23 and the guiding groove 24. When the cooling box 1 operates on the module 14 to be measured, thermal expansion and contraction of the sealing plate 13 are likely to occur. The elastic member 21 drives the locking block 22 to slide downward, enabling the sealing plate 13 to close the cooling box 1.

[0037] Refer to Figure 2 and Figure 6 As shown in and, a plurality of reset components 3 are vertically formed in the locking groove 12. Each reset component 3 includes two reset grooves 31 formed in the locking groove 12. The two reset grooves 31 are parallel to each other. A reset spring 32 with a vertical axis is fixedly connected in the reset groove 31. The lower end of the reset spring 32 is fixedly connected to the reset groove 31, and the upper end of the reset spring 32 is fixedly connected to a reset block 33. A rotating rod 34 is rotatably connected to the side of the reset block 33 close to each other. A rotating wheel 35 is fixedly connected to the middle of the rotating rod 34. The rotating direction of the rotating wheel 35 is the same as the pushing direction of the sealing plate 13. A pressing plate 36 is fixedly connected to the cooling box 1 corresponding to the position of the clamping groove 11. The gap between the pressing plate 36 and the clamping groove 11 is the same as the thickness of the sealing plate 13.

[0038] During use, when the sealing plate 13 slides to close the cooling box 1, the sealing plate 13 abuts against the rotating wheel 35, and the upper surface of the sealing plate 13 abuts against the pressing plate 36, enabling the sealing plate 13 to abut against the locking groove 12. When the sealing plate 13 slides, the pressing plate 36 limits the sliding direction of the sealing plate 13. When the sealing plate 13 slides, the sealing plate 13 abuts against the outer peripheral surface of the rotating wheel 35, thereby driving the rotating rod 34 and the rotating wheel 35 to rotate synchronously. When the sealing plate 13 abuts against the pressing plate 36, the sealing plate 13 pushes the rotating wheel 35 and the reset block 33 to slide along the direction of the reset groove 31. The reset spring 32 is compressed, and the reset spring 32 has a force to push the rotating wheel 35 to reset.

[0039] Refer to Figure 1 and Figure 2 As shown in and, fixing bolts 4 are threadedly connected to the cooling box 1 corresponding to the four sides of the sealing plate 13. Positioning holes 42 are formed in the sealing plate 13 corresponding to the positions of the fixing bolts 4. The fixing bolts 4 can pass through the positioning holes 42. A plastic housing 41 is fixedly connected to the cooling box 1 corresponding to the positions of the fixing bolts 4. The plastic housing 41 can be threadedly engaged with the end of the fixing bolt 4 extending into the cooling box 1.

[0040] During use, insert the fixing bolt 4 into the positioning hole 42. The end of the fixing bolt 4 can be threadedly engaged with the plastic housing 41, and the plastic housing 41 reduces the conduction of external heat from the fixing bolt 4 to the inside of the cooling box 1, preventing the temperature inside the cooling box 1 from being unstable.

[0041] Refer to Figure 1 and Figure 7 , above the sealing plate 13 of the cooling box 1, a hot air duct 5 with a horizontal axis is provided. One end of the hot air duct 5 is fixedly connected to a hot air blower 51, and the other end of the hot air duct 5 communicates with the outside; a refrigerator 52 is arranged inside the cooling box 1. The cold air outlet of the refrigerator 52 communicates with the inside of the cooling box 1. A heat conduction pipe 53 is arranged at the exchange port of the refrigerator 52. The heat conduction pipe 53 is interconnected with the exchange port of the refrigerator 52. The heat conduction pipe 53 is interconnected with the hot air duct 5. A gas check valve 54 is arranged on the heat conduction pipe 53, and the gas check valve 54 enables the gas in the heat conduction pipe 53 to flow only from the refrigerator 52 to the hot air duct 5. A water bag 55 is arranged between the hot air duct 5 and the sealing plate 13, and a thermometer 56 is arranged on the water bag 55.

[0042] During use, the heat generated by the refrigerator 52 is sent to the hot air duct 5 to increase the utilization rate of gas heat energy. Subsequently, the gas check valve 54 is used to prevent the gas in the hot air duct 5 from flowing back. The water bag 55 is observed through the thermometer 56, and the temperature is conducted through the water bag 55. Since the specific heat capacity of water is greater than that of air, the probability of sudden temperature change of the sealing plate 13 is reduced through the water bag 55, preventing damage to the sealing plate 13 caused by sudden temperature change.

[0043] The above are all the preferred embodiments of this application. The protection scope of this application is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A low-inductance device for double-pulse low-temperature testing of silicon carbide, characterized in that: It includes a cooling box (1). Inside the cooling box (1), a module under test (14) is arranged. Corresponding to the position of the module under test (14) outside the cooling box (1), a sealing plate (13) is arranged. The sealing plate (13) can seal the cooling box (1), and the sealing plate (13) integrates a drive board and a main power connection board; the drive board on the sealing plate (13) is arranged corresponding to the module under test (14); above the sealing plate (13) corresponding to the cooling box (1), a hot air duct (5) is arranged horizontally along the axis. One end of the hot air duct (5) is fixedly connected with a hot air blower (51), the other end of the hot air duct (5) communicates with the outside, and a water bag (55) is arranged between the hot air duct (5) and the sealing plate (13), and the hot air duct (5) is in mutual abutment with the upper surface of the sealing plate (13) through the water bag (55).

2. The low-inductance device for double-pulse low-temperature testing of silicon carbide according to claim 1, characterized in that: The sealing plate (13) adopts a multi-layer stacked PCB structure; the sealing plate (13) is connected with a bus bar (15) through a copper column (16), and the stray inductance of the copper column (16) is 4 nh; the sealing plate (13) is a PCB board with a thickness of 3 mm.

3. The low-inductance device for double-pulse low-temperature testing of silicon carbide according to claim 1, characterized in that: A locking groove (12) is opened at the position of the cooling box (1) corresponding to the sealing plate (13). The locking groove (12) is a key groove. At the position of the cooling box (1) corresponding to the locking groove (12), a locking block (22) is arranged. The locking block (22) abuts against the sealing plate (13). A guiding inclined surface (25) is opened at one end of the locking block (22) close to the sealing plate (13). The guiding inclined surface (25) starts from the lower end of the locking block (22) and is inclined upward towards the side close to the sealing plate (13). An elastic member (21) for pushing the locking block (22) to abut against the sealing plate (13) is arranged above the locking block (22). A vertically arranged guiding rod (23) is arranged inside the locking block (22). A guiding groove (24) is opened at the position of the locking block (22) corresponding to the guiding rod (23), and the guiding rod (23) can be slidably connected in the guiding groove (24).

4. The low-inductance device for double-pulse low-temperature testing of silicon carbide according to claim 1, characterized in that: A fixing bolt (4) is arranged at the position of the cooling box (1) corresponding to the sealing plate (13). A plastic shell (41) is arranged inside the cooling box (1) corresponding to the position of the fixing bolt (4). The plastic shell (41) can be threadedly connected with the fixing bolt (4). A positioning hole (42) is arranged at the position of the sealing plate (13) corresponding to the plastic shell (41), and the fixing bolt (4) can be inserted into the positioning hole (42).

5. The low-inductance device for double-pulse low-temperature testing of silicon carbide according to claim 1, characterized in that: A thermometer (56) is arranged on the water bag (55). The thermometer (56) can detect the temperature of the water bag (55), and the water bag (55) is in mutual abutment with the outside air.

6. The low-inductance device for double-pulse low-temperature testing of silicon carbide according to claim 5, characterized in that: A refrigerator (52) is arranged inside the cooling box (1). A heat conduction pipe (53) is arranged between the exchange port of the refrigerator (52) and the hot air duct (5), and a gas one-way valve (54) is arranged inside the heat conduction pipe (53).

7. The low-inductance device for double-pulse low-temperature testing of silicon carbide according to claim 3, characterized in that: A plurality of reset grooves (31) are formed in the locking groove (12). The adjacent reset grooves (31) are parallel to each other. A reset spring (32) is arranged in the reset groove (31). A reset block (33) is slidably connected in the reset groove (31). The reset spring (32) can push the reset block (33) to slide in a direction away from the cooling box (1). A rotating rod (34) that moves synchronously is arranged on the reset block (33). A rotating wheel (35) that moves synchronously and rotates synchronously is arranged on the rotating rod (34). The rotating direction of the rotating wheel (35) is the same as the pushing direction of the sealing plate (13). A pressing plate (36) is fixedly connected to the cooling box (1) at a position corresponding to the clamping groove (11). The gap between the pressing plate (36) and the clamping groove (11) is the same as the thickness of the sealing plate (13).

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