Test system of power device

Abstract

The utility model discloses a test system of a power device, which comprises a first circuit module and a second circuit module, and is characterized in that the first circuit module is configured to generate a driving signal based on an input signal; the second circuit module is detachably mounted on the first circuit module, and a to-be-tested power device is mounted on the second circuit module; the second circuit module is configured to be electrically connected with the first circuit module when being mounted on the first circuit module, and generate a test signal based on the driving signal so as to test the performance of the to-be-tested power device; according to the technical scheme, the second circuit module can be directly replaced to perform the performance test of the next to-be-tested power device, so that the test replacement time is effectively shortened, the test process is simplified, and the test efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of integrated circuit technologies, and particularly to a test system for power devices. Background Art

[0002] During the application process of integrated circuits, for the testing of various devices, specific test systems are usually used for testing.

[0003] During the actual operation process, the R & D personnel of this application found that for the testing of power devices, the power device to be tested is usually directly welded on the test main board, and the welded power device to be tested is directly tested through the test main board. If the next power device needs to be tested, the previously welded power device needs to be disassembled and then the next power device to be tested needs to be re-welded. The time for changing the test is relatively long, which affects the test efficiency. Summary of the Utility Model

[0004] The main technical problem to be solved by this application is to provide a test system for power devices. The test system is set as a detachable first circuit module and second circuit module, and the second circuit module can be replaced. The power device to be tested is installed on the second circuit module. When the next power device to be tested needs to be tested, the second circuit module can be detached from the first circuit module, and the next second circuit module can be replaced, thereby replacing the corresponding power device to be tested. That is, the second circuit module can be directly replaced to perform the performance test of the next power device to be tested, effectively reducing the test change time, simplifying the test process, and improving the test efficiency.

[0005] To solve the above technical problem, a technical solution adopted by this application is: to provide a test system for power devices, including: a first circuit module and a second circuit module. The first circuit module is configured to generate a driving signal based on an input signal; the second circuit module is detachably installed on the first circuit module, and a power device to be tested is installed on the second circuit module; the second circuit module is configured to: when installed on the first circuit module, be electrically connected to the first circuit module, and generate a test signal based on the driving signal to perform a performance test on the power device to be tested.

[0006] Different from the current technology, the test system for power devices provided by this application includes a first circuit module and a second circuit module. The first circuit module is configured to generate a driving signal based on an input signal; the second circuit module is detachably mounted on the first circuit module; the second circuit module is configured to: when mounted on the first circuit module, be electrically connected to the first circuit module, and the power device under test on the second circuit module is also electrically connected to the first circuit module, and then generate a test signal based on the driving signal to perform a performance test on the power device under test; that is, the technical solution of this application can directly replace the second circuit module to perform the performance test on the next power device under test, effectively reducing the test replacement time, simplifying the test process, and improving the test efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0008] Among them:

[0009] Figure 1 is a schematic structural diagram of the first embodiment of the test system for power devices in this application;

[0010] Figure 2 is a schematic structural diagram of the second embodiment of the test system for power devices in this application;

[0011] Figure 3 is a structural block diagram of an embodiment of the first circuit board in this application;

[0012] Figure 4 is a structural block diagram of an embodiment of the first circuit module in this application;

[0013] Figure 5 is a schematic structural diagram of an embodiment of the control unit in this application;

[0014] Figure 6 is a schematic structural diagram of the winding of the transformer unit in an embodiment of this application;

[0015] Figure 7 is a circuit diagram of an embodiment of the first circuit module in this application;

[0016] Figure 8 is a structural block diagram of an embodiment of the second circuit board in this application;

[0017] Figure 9 is a structural block diagram of an embodiment of the second circuit module in this application;

[0018] Figure 10 It is the circuit diagram of an embodiment of the second circuit module in this application;

[0019] Figure 11 It is the circuit diagram of an embodiment of the absorption circuit in this application;

[0020] Figure 12 It is the circuit diagram of an embodiment of the drive circuit in this application;

[0021] Figure 13 It is the circuit diagram of an embodiment of the test system in this application.

[0022] In the drawings, test system 10, first circuit module 100, first circuit board 110, first side b1, second side b2, third side b3, fourth side b4, opening 111, first input end 112 corresponding to the input circuit, second input end 113 corresponding to the input circuit, output end 114 corresponding to the output circuit, first circuit unit 120, input circuit 121, transformer unit 122, primary winding 1221, secondary winding 1222, auxiliary winding 1223, control unit 123, drive unit 124, first energy storage unit 125 (C1), first output circuit 126, second output circuit 127, connection area R, first connection end 130, first connection end 131 of Vd, first connection end 132 of DRV, first connection end 133 of Vbus, first connection end 134 of GND, second circuit module 200, second circuit board 210, fifth side b5, sixth side b6, seventh side b7, eighth side b8, installation position 211, second circuit unit 220, absorption circuit 221, drive circuit 222, filtering unit Cbus, power device under test 223, second connection end 230, second connection end 231 of Vd, second connection end 232 of DRV, second connection end 233 of Vbus, second connection end 234 of GND, first output capacitor C0, first output resistor Rload, first energy storage unit C1, secondary diode D1, input power supply Vin, input capacitor Cin, second resistor R2, switching diode Z1, PN junction diode Z2, second capacitor C2, absorption resistor Rc, absorption capacitor Cc, absorption zener diode Zc, absorption diode Dc, test resistor Rs, absorption resistor Rc, first absorption diode Dc1, second absorption diode Dc2, first drive resistor Rgon, second drive resistor Rgoff, third drive resistor Rez, drive capacitor Cez, first drive diode Zez1, second drive diode Zez2. Detailed implementation manners

[0023] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. It can be understood that the specific embodiments described herein are only used to explain the present application, rather than limiting the present application. Additionally, it should be noted that for the sake of description, only the parts related to the present application rather than all the structures are shown in the accompanying drawings. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0024] Reference to "embodiment" in the application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0025] The steps in the embodiments of the present application are not necessarily processed in the order described. The steps can be rearranged as needed, or steps in the embodiment can be deleted, or steps can be added to the embodiment. The step descriptions in the embodiments of the present application are only optional order combinations and do not represent all order combinations of the steps in the embodiments of the present application. The step order in the embodiment cannot be considered a limitation of the present application.

[0026] The term "and / or" in the embodiments of the present application refers to any and all possible combinations including one or more of the associated listed items. It should also be noted that when used in this specification, "including / comprising" specifies the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or components and / or their groups.

[0027] The terms "first", "second", etc. in the present application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0028] In the current technology, due to the limitations of the test device, during the test of the device under test, it is usually necessary to remove the previously welded power device under test and then re-weld the next power device under test. Frequent welding and removal will cause the solder pads to fall off due to repeated desoldering and soldering, prolonging the test change time, reducing the service life of the test system, and thus resulting in a long test time, affecting the test efficiency, and greatly limiting the improvement of production capacity.

[0029] Therefore, a test system for power devices is proposed, in which the first circuit module and the second circuit module are detachably installed, and the second circuit module can be directly replaced to perform the performance test of the next power device under test, effectively reducing the test change time, simplifying the test process, and improving the test efficiency.

[0030] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of the first embodiment of the test system for power devices in this application.

[0031] As Figure 1 shown. The test system 10 in this application includes: a first circuit module 100 and a second circuit module 200. Among them, the first circuit module 100 is configured to generate a drive signal based on an input signal; the second circuit module 200 is detachably connected to the first circuit module 100, that is, the second circuit module 200 is detachably installed on the first circuit module 100, and a power device under test is installed on the second circuit module. The second circuit module 200 is configured to: when installed on the first circuit module 100, the second circuit module 200 is electrically connected to the first circuit module 100, and the power device under test is electrically connected to the first circuit module 100 through the second circuit module 200, and then perform a performance test on the power device under test based on the test signal generated by the drive signal.

[0032] Among them, the second circuit module electrically connected to the first circuit module is the current second circuit module or the replaced second circuit module. That is, after testing the power device under test on the current second circuit module, the current second circuit module 200 is replaced, and the replaced second circuit module is electrically connected to the first circuit module, so that the first circuit module 100 performs a performance test on the power device under test on the replaced second circuit module 200.

[0033] Among them, the power device under test can be various types of power devices to be tested, such as diodes, field effect transistors, insulated gate bipolar transistors, etc. Specifically, for example, silicon carbide (SiC) power devices.

[0034] In a traditional high-voltage flyback power supply test system, to meet the high withstand voltage requirements of the system, at least two Si MOSFETs need to be connected in series, that is, two power devices under test are connected in series. However, limited by the limitations of the Si material itself, the auxiliary power supply scheme based on Si MOSFETs has application disadvantages such as large volume, low efficiency, and complex topology. In the existing technology, a single-board setting is usually adopted, and the test is directly carried out through a single board. During the test, the previously welded power device needs to be disassembled, and then the next power device under test needs to be re-welded, which takes a lot of time for changing the test, and the pads will also fall off due to repeated disassembly and welding.

[0035] Therefore, in this application, the test system is modularly set up as a first circuit module 100 and a second circuit module 200, and the first circuit module 100 and the second circuit module are detachably set. The power device under test is installed on the second circuit module 200. Then, during the test, the second circuit module can be directly replaced to perform the performance test of the next power device under test, which can effectively shorten the time for changing the test, improve the test efficiency, and at the same time avoid the pads falling off due to repeated disassembly and welding, extending the service life of the test system.

[0036] In some embodiments, the number of the second circuit modules 200 can include multiple, and each second circuit module 200 is correspondingly installed with a power device under test; when performing the performance test of the next power device under test, the second circuit module 200 currently connected to the first circuit module 100 needs to be disassembled, and then the replaced next second circuit module 200 is installed on the first circuit module 100, so that the first circuit module is electrically connected to the power device under test installed on the replaced second circuit module 200, and then the corresponding performance test is carried out.

[0037] Refer to Figure 2 , Figure 2 which is a schematic structural diagram of the second embodiment of the test system for power devices in this application.

[0038] As Figure 2 shown, the first circuit module 100 includes a first circuit board 110, a first circuit unit 120 provided on the first circuit board 110, and a first connection end 130 provided on the first circuit board 110; the first connection end 130 is electrically connected to the first circuit unit 120; the second circuit module 200 includes a second circuit board 210, a second circuit unit 220 provided on the second circuit board 210, and a second connection end 230 provided on the second circuit board 210; the second connection end 230 is electrically connected to the second circuit unit 220.

[0039] Among them, the second connection end 230 is detachably connected to the first connection end 130, and the second connection end 230 is configured to be electrically connected to the first connection end 130 when connected to the first connection end 130, so that the first circuit module and the second circuit module can be quickly and detachably connected, effectively shortening the replacement and measurement time and improving the test efficiency.

[0040] In some embodiments, a plurality of first connection ends 130 are provided on the first circuit board 110, and a corresponding plurality of second connection ends 230 are provided on the second circuit board 210. Each second connection end has a corresponding first connection end, and each second connection end is detachably connected to the corresponding first connection end, so that the second circuit module 200 can be detached from the first circuit module 100, and the next second circuit module 200 can be replaced and installed on the first circuit module 100 to test the next power device to be measured.

[0041] Among them, in order to more clearly show the first circuit board and the second circuit board, please refer to the following figure.

[0042] Please refer to Figure 3 , Figure 3 which is a structural block diagram of an embodiment of the first circuit board in the present application.

[0043] As Figure 3 shown, the first circuit board 110 has a first side b1, a second side b2, a third side b3, and a fourth side b4. The first side b1 and the third side b3 are opposite and spaced apart, the second side b2 and the fourth side b4 are opposite and spaced apart, the second side b2 connects the first side b1 and the third side b3, and the fourth side b4 connects the first side b1 and the third side b3.

[0044] Among them, an opening 111 is provided on the first circuit board, and the opening is configured to provide an avoidance space for the power device to be measured when the second connection end is connected to the first connection end; the opening 111 corresponds to the power device to be measured on the second circuit module, that is, the power device to be measured on the second circuit module can extend out from the opening 111 on the first circuit board, thereby reducing the parasitic inductance corresponding to the gate drive circuit of the power device to be measured, improving the heat dissipation performance of the device, and at the same time improving the power density of the test system.

[0045] In some embodiments, a plurality of first connection ends 130 are provided on the first circuit board 110, and a connection area R is provided on the first circuit board 110. The opening 111 is provided in the connection area R, and the plurality of first connection ends 130 are also provided in the connection area R, and the opening is located between the plurality of first connection ends 130.

[0046] Specifically, the number of the first connection ends 130 can be 2, 4, 6, etc. Each first connection end is detachably connected to the corresponding second connection end on the second circuit board. Taking 4 first connection ends 130 as an example, the 4 first connection ends 130 are respectively located at different positions in the connection area R, that is, they do not repeat. For example, they can respectively correspond to Vd (diode part), DRV (daily reference value, driving part), Vbus (power supply part), and GND (Ground, grounding end); that is, the first connection end 131 of Vd (diode part) is correspondingly connected to the power device to be measured, the first connection end 132 of DRV (daily reference value, driving part) is correspondingly connected to the driving unit in the first circuit module, the first connection end 133 of Vbus (power supply part) is correspondingly connected to the input circuit in the first circuit module, and the first connection end 134 of GND (Ground, grounding end) is correspondingly connected to the grounding end.

[0047] Among them, the first connection end can be a female header. For example, a double-row three-column surface-mount female header with a plastic height of 2 mm and a hole pitch of 1.27 mm is respectively connected to the second circuit board through the above 4 first connection ends.

[0048] In some embodiments, the first circuit board 110 is further provided with a first input end 112 corresponding to the power supply part of the input circuit, a second input end 113 corresponding to the grounding end of the input circuit, and an output end 114 corresponding to the output circuit.

[0049] In order to further represent the positional relationship of each component in the first circuit unit on the first circuit board, the following uses drawings to represent the first circuit module.

[0050] Please refer to Figure 4 , Figure 4 which is a structural block diagram of an embodiment of the first circuit module in the present application.

[0051] As Figure 4 shown, the first circuit module includes a first circuit board 110, a first circuit unit 120 on the first circuit board, and a first connection end; among them, the first circuit unit 120 includes an input circuit 121, a transformer unit 122, a control unit 123, a driving unit 124, a first energy storage unit 125, a first output circuit 126, and a second output circuit 127.

[0052] Specifically, the input circuit 121 is disposed close to the first side b1 of the first circuit board 110; the control unit 123, the driving unit 124, the first energy storage unit 125, and the second output circuit 127 are disposed close to the second side b2 of the first circuit board 110, and both the control unit 123 and the driving unit 124 are located between the input circuit 121 and the second output circuit 127; the first output circuit 126 is disposed close to the third side b3 of the first circuit board 110; the transformer unit 122 is disposed close to the fourth side b4 of the first circuit board 110, and the transformer unit 122 is located between the input circuit 121 and the first output circuit 126.

[0053] Further, a connection area R is also provided on the first circuit board 110, and the first connection end and the opening are provided in the connection area R. Refer to Figure 3 , and the connection area R is located between the input circuit 121, the control unit 123, the driving unit 124, the first energy storage unit 125 (C1), the first output circuit 126, the second output circuit 127, and the transformer unit 122.

[0054] Further, the first output end of the input circuit 121 is electrically connected to the first output circuit 126 through the transformer unit 122, and the second output end of the input circuit 121 is electrically connected to the control unit 123. The first end of the control unit is electrically connected to the driving unit 124, and the second end of the control unit is electrically connected to the second output circuit 127 through the first energy storage unit 125. The first energy storage unit 125 and the driving unit 124 are respectively grounded;

[0055] The control unit is configured to: when the second circuit module is installed on the first circuit module, sense the input voltage corresponding to the input circuit, and when the input voltage reaches the voltage threshold, output a control signal to the driving unit so that the driving unit generates a driving signal based on the control signal.

[0056] Wherein, the input circuit 121 is connected to the control unit 123 so that the control unit 123 can sense the input voltage of the input circuit 121.

[0057] Wherein, the input circuit 121 can be a high-voltage input circuit for inputting a DC high-voltage input voltage; the control unit 123 can be a control chip for sensing the input voltage of the input circuit, and when the input voltage reaches the voltage threshold, the control unit 123 generates and outputs a corresponding control signal to the input end of the driving unit according to the input voltage; the driving unit 124 can be a driving chip, and the driving unit generates and outputs a corresponding driving signal based on the control signal after receiving the control signal, that is, outputs a driving signal with a large current.

[0058] In some embodiments, the control chip corresponding to the control unit may be an NCP1342 quasi-resonant flyback controller, which has a VCC overvoltage protection function. When the VCC exceeds 28V, the system automatically powers off. The chip also has a high-voltage soft start function. The system has a 4ms high-voltage soft start time to reduce the electrical stress impact on the system at the moment of high-voltage power-on. And it enables the maximum frequency limit to be adjustable, flexibly adjusting the maximum switching frequency of the system. Moreover, it enables the current limiting and power limiting protection points to be adjustable, adjusting the overcurrent and over-power protection points of the power loop through the corresponding system parameters. It can also enable the system to achieve over-temperature protection. When the control chip detects that the temperature exceeds the critical value, the system will perform a power-off operation and wait for the temperature to drop to a reasonable value before restarting.

[0059] Continuing to refer to Figure 4 , the transformer unit 122 on the first circuit board 110 is electrically connected to the input circuit 121; the first output circuit 126 is configured to filter the electrical energy released by the transformer unit 122 and output it to the load for power supply. That is, when the power device to be measured is turned on, the transformer unit 122 does not output externally, and the current on the primary side of the transformer unit increases linearly, thereby increasing the inductive energy storage of the transformer unit, that is, storing electrical energy in the transformer unit. When the power device to be measured is turned off, the current on the primary side of the transformer unit is cut off, and the magnetic field energy in the transformer unit is transferred to the output terminal through the secondary side and undergoes the filtering operation of the first output circuit 126, and then is output to the load for power supply.

[0060] Continuing to refer to Figure 4 , a first energy storage unit C1(125) (not marked in the figure but marked in the circuit diagram) and a second output circuit 127 are further provided on the first circuit board 110; the first energy storage unit C1 is electrically connected to the control unit 123 and the drive unit 124; the second output circuit 127 is respectively connected to the control unit 123, the drive unit 124, and the first energy storage unit C1. The second output circuit 127 is configured such that when the power device to be measured is turned on, the second output circuit 127 is in the off state, and the auxiliary winding in the second output circuit does not transfer energy externally. When the power device to be measured is turned off, the auxiliary winding filters and stores energy in the first energy storage unit C1, so that the first energy storage unit C1 can provide energy to the control unit 123 and the drive unit 124 for power supply to enable them to work normally.

[0061] In some embodiments, Figure 5 is a schematic structural diagram of an embodiment of the control unit in the present application.

[0062] As Figure 5As shown, the control unit 123 can be an NCP1342 quasi-resonant flyback controller, including Fault pin, FMAX pin, FB pin, ZCD / OPP pin, CS pin, HV pin, VCC pin, DRV pin and GND pin; among them, the maximum operating frequency can be limited by adjusting the parameters of the FMAX pin; by setting the CS parameters through the CS pin, the corresponding over-current and over-power protection can be achieved; by reasonably using the control pins of the control chip, the corresponding functions such as VCC over-voltage protection and chip over-temperature protection can be achieved.

[0063] In some embodiments, the transformer unit 122 includes a primary winding 1221, a secondary winding 1222 and an auxiliary winding 1223; the primary winding 1221 corresponds to the primary side, and the secondary winding 1222 corresponds to the secondary side; the primary winding 1221 is electrically connected to the input circuit 121 and the power device to be measured in the second circuit unit respectively, the secondary winding 1222 is electrically connected to the first output circuit 126, and the auxiliary winding 1223 is electrically connected to the driving unit 124 and the control unit 123. For the specific electrical connection method, please refer to the circuit schematic diagram of the first circuit module. Figure 7 。

[0064] Further, in order to more clearly show the winding method of the transformer unit, please refer to Figure 6 , Figure 6 is a schematic structural diagram of an embodiment of the winding of the transformer unit in this application.

[0065] As Figure 6 shown, in the sandwich winding method, the secondary winding 1222 is sandwiched between two layers of primary windings 1221, and the auxiliary winding 1223 and another primary winding 1221 together form a composite winding, and the composite winding is sandwiched between two layers of primary windings 1221, which increases the effective coupling area between the secondary side and the secondary side, greatly reduces the leakage inductance of the transformer unit, and also reduces the interlayer distributed capacitance of the secondary side.

[0066] Among them, the primary winding uses three-layer insulated wire with a diameter of 0.4mm - 0.6mm, such as 0.5mm three-layer insulated wire, the secondary winding uses litz wire with a diameter of 0.05mm - 0.2mm, such as 0.1mm × 130 litz wire, and the auxiliary winding uses enameled wire with a diameter of 0.3mm - 0.5mm, such as 0.43mm enameled wire, which can well meet the system power output of 65W when the output voltage is 24V. Using PC44 ferrite core with RM12 skeleton, the primary inductance is 1810μH, the secondary inductance is 18.2μH, and the auxiliary winding inductance is 18.8μH.

[0067] To more clearly show the first circuit module, it is shown in a circuit diagram.

[0068] Please refer to Figure 7, Figure 7 It is a circuit diagram of an embodiment of the first circuit module in this application.

[0069] As Figure 7 shown, the first circuit module 100 includes an input circuit 121, a driving unit 124, a control unit 123, a transformer unit 122, a first output circuit 126, and a second output circuit 127. Among them, the input circuit 121 includes an input power supply Vin and an input capacitor Cin. The connection fulcrum of the input power supply Vin and the input capacitor Cin is connected to the first end of the transformer unit, that is, the first input end of the primary side of the transformer unit. The second input end of the primary side of the transformer unit 122 is connected to the test socket of the second circuit module 200, and the absorption circuit of the second circuit module is connected to the first input end and the second input end of the primary side of the transformer unit. The secondary side of the transformer unit 122 is connected to the first output circuit 126. Among them, the first output circuit 126 includes a secondary diode D1, and a first output capacitor C0 and a first output resistor Rload connected in parallel. The first end of the parallel connection is connected to the first output end of the secondary side of the transformer unit 122, the second end of the parallel connection is connected to the load, and the secondary diode D1 is connected to the second output end of the secondary side of the transformer unit.

[0070] The control unit 123 connects the driving unit 124 to the driving circuit of the second circuit module, and the driving unit 124 is connected to the second output circuit 127 through a second resistor R2. The control unit 123 is grounded through a first energy storage unit C1, and the first energy storage unit C1 is also connected to the connection fulcrum between the second output circuit 127 and the second resistor R2. A switching diode Z1 is also connected to the ground at the connection fulcrum between the second output circuit 127 and the second resistor R2. A PN junction diode Z2 is also connected to the ground at the connection fulcrum between the driving unit 124 and the second resistor R2, and a second capacitor C2 is also connected to the ground.

[0071] When the input voltage of the input circuit reaches the voltage threshold, the control unit 123 can sense that the input voltage reaches the voltage threshold. The control unit 123 outputs a corresponding control signal and transmits it to the input end of the drive unit 124, and the drive unit then outputs a high-current drive signal. The drive signal forms corresponding positive and negative drive voltages through the drive circuit of the second circuit module, and finally controls the switching of the gate of the power device under test, so that the flyback power supply enters the working state; by controlling the duty cycle of the conduction time of the power device, the magnitudes of the output voltage and current can be adjusted. When the power device under test is conducting, the secondary diode D1 is in the off state, and the energy on the secondary side of the transformer unit 122 is not output externally, while the winding current corresponding to the primary side of the transformer unit linearly increases, increasing the inductive energy storage of the transformer unit. When the power device under test is turned off, the current on the primary side of the transformer is cut off, and the magnetic field energy in the transformer unit is transferred to the output end through the corresponding winding on the secondary side, and after filtering by the first output circuit, it is finally output to the load for power supply. Losses will occur during both the high-speed switching action and the conduction period of the power device under test on the second circuit module, and the losses form heat that diffuses to the second circuit board and is dissipated. The absorption circuit in the second circuit module is used to absorb the voltage spike of Vds during the turn-off period of the power device under test, and the energy generated by absorbing the Vds spike is dissipated in the form of heat through the second circuit board.

[0072] For a representation of the second circuit board, please refer to the following figures.

[0073] Please refer to Figure 8 , Figure 8 which is the structural block diagram of an embodiment of the second circuit board in this application.

[0074] As Figure 8 shown, the second circuit board has a fifth side b5, a sixth side b6, a seventh side b7, and an eighth side b8; the fifth side is opposite to and spaced from the seventh side, the sixth side is opposite to and spaced from the eighth side, the sixth side connects the fifth side and the seventh side, and the eighth side connects the fifth side and the seventh side.

[0075] A plurality of corresponding second connection terminals 230 are provided on the second circuit board 210, such as 2, 4, 6, etc. Taking 4 second connection terminals 230 as an example for illustration, among them, the 4 second connection terminals 230 are in different positions, that is, they do not repeat. For example, they can respectively correspond to Vd (diode part), DRV (daily reference value, drive part), Vbus (power supply part) and GND (Ground, ground terminal); that is, the second connection terminal 231 of Vd (diode part) is correspondingly connected to the power device to be measured, the second connection terminal 232 of DRV (daily reference value, drive part) is correspondingly connected to the drive circuit in the second circuit module, the second connection terminal 233 of Vbus (power supply part) is correspondingly connected to the input end in the second circuit module, and the second connection terminal 234 of GND (Ground, ground terminal) is correspondingly connected to the ground terminal.

[0076] Among them, the second connection terminal 230 can be a pin header, such as a double-row three-column surface-mount pin header, with a plastic height of 1 mm and a pin pitch of 1.27 mm, and is respectively connected to the first circuit board through the above-mentioned 4 second connection terminals.

[0077] Among them, an installation position 211 corresponding to the power device to be measured is provided on the second circuit board 210, and the power device to be measured is installed on the installation position 211 of the second circuit board 210, and the installation position 211 on the second circuit board 210 corresponds to the opening on the first circuit board 110, so that the power device to be measured installed at the installation position 211 corresponds to the opening on the first circuit board 110, thereby reducing the parasitic inductance corresponding to the gate drive circuit of the power device to be measured, improving the heat dissipation performance of the device, and at the same time improving the power density of the test system.

[0078] In addition, a plurality of second connection ends are arranged in one-to-one correspondence with a plurality of first connection ends; each second connection end is detachably connected to the correspondingly arranged first connection end, and each second connection end is configured to be electrically connected to the correspondingly arranged first connection end when connected to the correspondingly arranged first connection end; specifically, the second connection end 231 of Vd (diode part) on the second circuit board 210 is correspondingly connected to the first connection end 131 of Vd (diode part) on the first circuit board 110; the second connection end 232 of DRV (daily reference value, drive part) on the second circuit board 210 is correspondingly connected to the first connection end 132 of DRV (daily reference value, drive part) on the first circuit board 110; the second connection end 233 of Vbus (power supply part) on the second circuit board 210 is correspondingly connected to the first connection end 133 of Vbus (power supply part) on the first circuit board 110; the second connection end 234 of GND (Ground, grounding end) on the second circuit board 210 is correspondingly connected to the first connection end 134 of GND (Ground, grounding end) on the first circuit board 110, enabling the detachable connection between the first circuit module and the second circuit module, effectively reducing the measurement change time, simplifying the test process, and improving the test efficiency.

[0079] In some embodiments, on the second circuit board of the second circuit module, a second circuit unit is provided, and the second circuit unit 220 includes a drive circuit 222, an absorption circuit 221, a filter unit Cbus, and a power device under test.

[0080] Please refer to Figure 9 , Figure 9 which is a structural block diagram of an embodiment of the second circuit module in the present application.

[0081] As Figure 9 shown, the second circuit board in the second circuit module has a fifth side b5, a sixth side b6, a seventh side b7, and an eighth side b8; the fifth side is opposite to and spaced from the seventh side, the sixth side is opposite to and spaced from the eighth side, the sixth side connects the fifth side and the seventh side, and the eighth side connects the fifth side and the seventh side.

[0082] Then, the absorption circuit and the filter unit are arranged close to the fifth side of the second circuit board; the drive circuit is arranged close to the sixth side of the second circuit board; the power device under test is arranged close to the eighth side, which is beneficial to improving the power density of the system.

[0083] Further, on the second circuit board 210 of the second circuit module 200, the input end of the absorption circuit 221 is electrically connected to the input circuit of the first circuit module, the first output end of the absorption circuit 221 is electrically connected to the power device under test, and the second output end of the absorption circuit is electrically connected to the transformer unit in the first circuit unit. The absorption circuit 221 is configured to absorb the spike voltage generated between the input circuit and the power device under test; the input end of the drive circuit 222 is configured to be electrically connected to the drive unit in the first circuit unit when the second circuit module is installed on the first circuit module, and the output end of the drive circuit is electrically connected to the power device under test. The drive circuit 222 is configured to form a positive and negative voltage drive waveform based on the drive signal generated by the drive unit, thereby controlling the switching of the power device under test and forming a corresponding test signal to perform a performance test on the power device under test.

[0084] Among them, the drive circuit range corresponding to the positive and negative voltage drive waveform of the drive circuit 222 is -5V - 20V.

[0085] Continue to refer to Figure 9 , a filtering unit Cbus is further provided on the second circuit board 210 of the second circuit module.

[0086] Continue to refer to Figure 9 , the filtering unit Cbus is electrically connected to the absorption circuit 221 and the input circuit of the first circuit module respectively, that is, when the second circuit module is installed on the first circuit module, the input end of the absorption circuit is electrically connected to the input circuit in the first circuit unit through the filtering unit; the filtering unit Cbus is configured to filter the input voltage of the input circuit.

[0087] To more clearly represent the second circuit module, a circuit diagram is shown.

[0088] Please refer to Figure 10 , Figure 10 which is a circuit diagram of an embodiment of the second circuit module in the present application.

[0089] As Figure 10As shown, the input circuit of the first circuit module connects the absorption circuit 221 and the power device under test 223 to ground. The filtering unit Cbus is connected to the fulcrum between the input circuit and the absorption circuit 221, and the filtering unit Cbus is grounded. The driving unit of the first circuit module connects the driving circuit 222 and the power device under test 223 to ground. Among them, the absorption circuit 221 includes an absorption resistor Rc, an absorption capacitor Cc, an absorption zener diode Zc, and an absorption diode Dc. The absorption resistor Rc, the absorption capacitor Cc, and the absorption zener diode Zc are connected in parallel. One end of the parallel connection is connected to the input circuit of the first circuit module and is connected to the filtering unit Cbus to ground. The other end of the parallel connection is connected to the absorption diode Dc and is connected to the D terminal of the power device under test, that is, the drain of the corresponding power device under test. The driving circuit 222 is connected to the G terminal of the power device under test, that is, the gate of the corresponding power device under test. The S terminal of the power device under test is connected to the test resistor Rs to ground, that is, the source of the corresponding power device under test.

[0090] To more clearly show the absorption circuit and the driving circuit, the following is shown in the drawings.

[0091] Please refer to Figure 11 and Figure 12 , Figure 11 is the circuit diagram of an embodiment of the absorption circuit in this application; Figure 12 is the circuit diagram of an embodiment of the driving circuit in this application.

[0092] As Figure 11 shown, the absorption circuit 221 includes: an absorption resistor Rc, an absorption capacitor Cc, an absorption zener diode Zc, a first absorption diode Dc1, and a second absorption diode Dc2. Specifically, the absorption resistor Rc, the absorption capacitor Cc, and the absorption zener diode Zc are connected in parallel. The first end of the parallel connection is connected to the input circuit of the first circuit module and is connected to the filtering unit Cbus to ground. The second end of the parallel connection is connected to the first absorption diode Dc1 and the second absorption diode Dc to the D terminal of the test socket. And, the first end of the parallel connection is connected to one end of the secondary side of the transformer unit, and the second end of the parallel connection is connected to the other end of the secondary side of the transformer unit through the second absorption diode Dc2.

[0093] Among them, the absorption voltage stabilizing diode Zc is an avalanche diode, and the absorption capacitor Cc is taken as 2.2 nF 1 kV, which is used to absorb the spike voltage brought by the leakage inductance of the transformer when the power device under test is turned off; the absorption resistor Rc is taken as 200 kΩ, which is used to consume the energy stored in the Cc capacitor in each cycle; the first absorption diode Dc1 and the second absorption diode Dc2 are both 1 kV 1 A; when the input voltage Vin of the input circuit is applied with 1000 V and the power device under test is turned on, the first absorption diode Dc1 and the second absorption diode Dc2 can be used to prevent the current from directly passing from the input end of the absorption circuit through the absorption circuit to the ground end; in addition, an absorption avalanche diode Zc of 540 V is selected, which can be used to clamp the corresponding spike voltage Vds, so as to protect the power device under test from being broken down due to overvoltage of the spike voltage Vds at the moment of turning off.

[0094] As Figure 12 shown, the drive circuit 222 is an EZDrive circuit, including a drive chip 2221, a first drive resistor Rgon, a second drive resistor Rgoff, a third drive resistor Rez, a drive capacitor Cez, a first drive diode Zez1, and a second drive diode Zez2; among them, the first end of the drive chip 2221 is connected to the drive unit of the first circuit module; the second end of the drive chip 2221 is connected to the first drive resistor Rgon and the third drive resistor Rez to the G end of the test socket; the third end of the drive chip 2221 is connected to the second drive resistor Rgoff and the drive capacitor Cez to the S end of the test socket, and the connection fulcrum of the third drive resistor Rez and the drive capacitor Cez is connected to the first drive diode Zez1 and the second drive diode Zez2 to the S end of the test socket; and the connection fulcrum of the first drive resistor Rgon and the third drive resistor Rez is connected to the connection fulcrum of the second drive resistor Rgoff and the drive capacitor Cez; the fourth end of the drive chip 2221 is connected to the S end of the test socket, and the connection fulcrum between the fourth end of the drive chip 2221 and the second drive diode Zez2 is grounded.

[0095] Among them, the driving chip 2221 is a single-channel driving chip, with a peak driving pull current of 1 A and a peak driving sink current of up to 1.2 A; it has a wide-voltage input power supply, and the highest power supply voltage Vcc can reach 30 V; the input voltage Vin of the input circuit of the first circuit module can withstand up to 30 V; the static power consumption is only 2 mA. The output structure has independent pull current OUTD terminal and sink current OUTS terminal pins, which can be used to independently control the turn-on and turn-off speeds of the power device under test. The first driving resistor Rgon and the second driving resistor Rgoff are taken as 10 Ω and 2 Ω, and the turn-on and turn-off speeds of the power device under test can be controlled by selecting the values of the first driving resistor Rgon and the second driving resistor Rgoff; the third driving resistor Rez is taken as 4.7 kΩ to provide a gate driving power supply path after the power device under test is turned on; the driving capacitor Cez is taken as 10 nF to maintain the required negative voltage energy when the power device under test is turned off; the first driving diode Zez1 is a gate positive voltage clamp, and the second driving diode Zez2 is a gate negative voltage clamp. Different values of the first driving diode Zez1 and the second driving diode Zez2 correspond to different positive and negative driving voltages. By reasonably selecting the values of the driving circuit topology parameters, the corresponding positive and negative driving voltage outputs can be realized.

[0096] Furthermore, the second circuit board 210 can adopt an aluminum substrate structure. The aluminum substrate structure at least includes a metal layer, an insulating layer, and a circuit layer stacked in sequence. That is, the metal layer can be an aluminum substrate, such as an aluminum base layer, and the circuit layer can be a conductive coating layer, such as a copper-clad layer; then, the second circuit board 210 includes an aluminum base layer, an insulating layer, and a copper-clad layer stacked in sequence. In some embodiments, a solder mask layer is further provided on the copper-clad layer. That is, the insulating layer is provided on the aluminum base layer, the copper-clad layer is provided on the insulating layer, and the solder mask layer is provided on the copper-clad layer; among them, the thickness of the copper-clad layer is 0.5 oz - 2 oz, for example, 1 oz, and 1 oz (ounce) is equal to about 35 microns (um) or 0.035 millimeters (mm) of copper foil thickness; the thickness of the insulating layer is 0.05 mm - 0.2 mm, for example, 0.15 mm, and the withstand voltage level of the insulating medium in the insulating layer is 3000 V, and the thermal conductivity is 1 W / (m·K). The overall thickness of the first circuit board is between 1 mm - 3 mm, for example, 1.6 mm, 2 mm, etc.; that is, the second circuit board has a good heat dissipation effect. The power device under test, the driving circuit, and the absorption circuit are soldered on the second circuit board 210, and the second circuit board 210 does not need to be assisted by a heat sink and a cooling fan for heat dissipation; even when the system is under the condition of the highest DC input voltage and the output is full load of 65 W, the temperature of the power device under test on the second circuit board 210 will not be too high.

[0097] In some embodiments, the area of the second circuit board 210 is smaller than that of the first circuit board 110; for example, if the area of the second circuit board 210 is 40 mm × 40 mm, then the area of the first circuit board 110 can be 80 mm × 80 mm. Correspondingly, the area of the connection region R in the first circuit board 110 can correspond to the area of the second circuit board 210, that is, the area of the connection region R in the first circuit board 110 can be 40 mm × 40 mm.

[0098] To show the complete circuit diagram of the test system, please refer to Figure 13 , Figure 13 which is the circuit diagram of an embodiment of the test system in this application.

[0099] Figure 13 It is connected on the basis of Figure 8 and Figure 10 . For the detailed connection relationship, please refer to the descriptions of Figure 8 and Figure 10 , which will not be elaborated here.

[0100] In this embodiment, the first circuit module and the second circuit module of the test system are detachably arranged, making the overall layout of the test system compact and improving the power density of the test system; and the test system is modularly arranged, integrating the power device under test, the drive circuit and the absorption circuit onto the detachable second circuit module. Thus, in the horizontal evaluation of multiple power devices, different power devices under test can be installed on different second circuit modules. After testing one power device, the next power device under test can be replaced by directly replacing the second circuit module for testing. Compared with the traditional scheme that requires removing the previously soldered power device and then re-soldering the next power device under test, this scheme can effectively and significantly shorten the replacement testing time, and at the same time, it can also avoid the detachment caused by repeated disassembly of the pads, thereby prolonging the overall service life of the test system.

[0101] Moreover, in this scheme, the power device, the drive circuit and the absorption circuit that generate more heat are integrated into the second circuit module, and the second circuit board of the second circuit module adopts a power loop design with an aluminum substrate structure, which has excellent heat dissipation ability. Even when fully loaded with 65 W, no additional radiator is required, that is, no additional heat dissipation components are needed compared with the prior art.

[0102] Furthermore, in this scheme, a 1700V 1Ω SiC MOSFET is used as the main power loop MOS tube, that is, the power device under test. Due to the high breakdown voltage characteristic of Vds, the input voltage range of the DC bus can reach 300 V to 1000 V, which can cover most application scenarios of high-voltage auxiliary power supplies.

[0103] Further, in this solution, an EZDrive circuit is added, that is, a drive circuit is added, so that the drive voltage is adjustable, covering the gate drive switches of SiC MOSFETs in the full voltage range from -5V to +20V.

[0104] Further, in this solution, the NCP1342 quasi-resonant flyback controller is used as the control chip of this system. This chip has a VCC overvoltage protection function. When the VCC exceeds 28V, the system automatically powers off. This chip also has a high-voltage soft start function. The system has a 4ms high-voltage soft start time to reduce the electrical stress impact on the system at the moment of high-voltage power-on. Using this chip makes the maximum frequency limit adjustable, flexibly adjusting the maximum switching frequency of the system. Using this chip makes the current limit and power limit protection points adjustable, and the overcurrent and over-power protection points of the power circuit are adjusted through the corresponding parameters of the system. Using this chip enables the system to achieve over-temperature protection. When the control chip detects that the temperature exceeds the critical value, the system will perform a power-off operation and wait for the temperature to drop to a reasonable value before restarting.

[0105] In several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, indirect couplings or communication connections of devices or units, which can be electrical, mechanical, or other forms.

[0106] In addition, each functional unit in each embodiment of this application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0107] The above is only the implementation manner of this application, and does not limit the patent scope of this application. Any equivalent structure or equivalent process transformation made using the content of this application's specification and drawings, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of this application.

Claims

1. A test system for a power device, characterized in that, Comprising: A first circuit module configured to generate a drive signal based on an input signal; A second circuit module removably mounted on the first circuit module, and a power device under test is mounted on the second circuit module; the second circuit module is configured to: when mounted on the first circuit module, be electrically connected to the first circuit module, and generate a test signal based on the drive signal to perform a performance test on the power device under test.

2. The test system according to claim 1, wherein The number of the second circuit modules is plural, and each of the second circuit modules is correspondingly mounted with a power device under test; Wherein, the first circuit module is configured to: be electrically connected to the second circuit module mounted on the first circuit module to perform a performance test on the power device under test on the electrically connected second circuit module; the second circuit module mounted on the first circuit module is one of the plural second circuit modules.

3. The test system according to claim 1, wherein The first circuit module includes a first circuit board, a first circuit unit provided on the first circuit board, and a first connection end provided on the first circuit board; the first connection end is electrically connected to the first circuit unit; The second circuit module includes a second circuit board, a second circuit unit provided on the second circuit board, and a second connection end provided on the second circuit board; the second circuit unit includes the power device under test, and the second connection end is electrically connected to the second circuit unit; Wherein, the second connection end is detachably connected to the first connection end, and the second connection end is configured to: when connected to the first connection end, be electrically connected to the first connection end.

4. The test system according to claim 3, wherein The second circuit board at least includes a metal layer, an insulating layer, a circuit layer, and a solder mask layer stacked in sequence; the area of the second circuit board is smaller than the area of the first circuit board; And / or An opening is provided on the first circuit board, and the opening is configured to: when the second connection end is connected to the first connection end, provide an avoidance space for the power device under test.

5. The test system according to claim 3, wherein The first circuit unit includes an input circuit, a transformer unit, a first output circuit, a second output circuit, a control unit, a drive unit, and a first energy storage unit; Wherein, a first output end of the input circuit is electrically connected to the first output circuit through the transformer unit, and a second output end of the input circuit is electrically connected to the control unit, a first end of the control unit is electrically connected to the drive unit, a second end of the control unit is electrically connected to the second output circuit through the first energy storage unit, and the first energy storage unit and the drive unit are respectively grounded; The control unit is configured to: when the second circuit module is mounted on the first circuit module, sense the input voltage corresponding to the input circuit, and when the input voltage reaches a voltage threshold, output a control signal to the driving unit so that the driving unit generates the driving signal based on the control signal.

6. The test system according to claim 5, wherein the transformer unit includes a primary winding, a secondary winding, and an auxiliary winding; the primary winding is electrically connected to the input circuit and the power device under test in the second circuit unit respectively, the secondary winding is electrically connected to the first output circuit, and the auxiliary winding is electrically connected to the driving unit and the control unit respectively; wherein, the secondary winding is sandwiched between two layers of the primary winding, and the auxiliary winding and the other primary winding together form a composite winding, and the composite winding is sandwiched between two layers of the primary winding.

7. The test system according to claim 5, wherein the second circuit unit includes: a driving circuit, an absorption circuit, a filtering unit, and a power device under test; wherein, the input end of the driving circuit is configured to: when the second circuit module is mounted on the first circuit module, be electrically connected to the driving unit in the first circuit unit, and the output end of the driving circuit is electrically connected to the power device under test; the input end of the absorption circuit is configured to: when the second circuit module is mounted on the first circuit module, be electrically connected to the input circuit in the first circuit unit through the filtering unit, the first output end of the absorption circuit is electrically connected to the power device under test, and the second output end of the absorption circuit is electrically connected to the transformer unit in the first circuit unit; the driving circuit is configured to: generate a test signal based on the driving signal generated by the first circuit unit to perform a performance test on the power device under test.

8. The test system according to claim 7, characterized in that, The driving circuit is an EZDrive circuit.

9. The test system according to claim 7, wherein the first circuit board has a first side, a second side, a third side, and a fourth side, the first side and the third side are opposite and spaced apart, the second side and the fourth side are opposite and spaced apart, the second side connects the first side and the third side, and the fourth side connects the first side and the third side; Among them, the input circuit is arranged near the first side of the first circuit board; the control unit, the drive unit, the first energy storage unit and the second output circuit are arranged near the second side of the first circuit board, and both the control unit and the drive unit are located between the input circuit and the second output circuit; the first output circuit is arranged near the third side of the first circuit board; the transformer unit is arranged near the fourth side of the first circuit board, and the transformer unit is located between the input circuit and the first output circuit; the first connection end is arranged in the connection area of the first circuit board, and the connection area is located between the input circuit, the control unit, the drive unit, the first energy storage unit, the first output circuit, the second output circuit and the transformer unit; The second circuit board has a fifth side, a sixth side, a seventh side and an eighth side. The fifth side and the seventh side are opposite and spaced apart. The sixth side and the eighth side are opposite and spaced apart. The sixth side connects the fifth side and the seventh side. The eighth side connects the fifth side and the seventh side; Among them, the absorption circuit and the filtering unit are arranged near the fifth side of the second circuit board; the drive circuit is arranged near the sixth side of the second circuit board; the power device under test is arranged near the eighth side.

10. The test system according to claim 9, wherein The number of the first connection ends is multiple, and the number of the second connection ends is multiple. The multiple second connection ends are arranged in one-to-one correspondence with the multiple first connection ends; each of the second connection ends is detachably connected to the corresponding first connection end, and each of the second connection ends is configured to be electrically connected to the corresponding first connection end when connected to the corresponding first connection end; An opening is provided on the first circuit board. The opening is provided in the connection area of the first circuit board, and the opening is located between the multiple first connection ends in the connection area; The power device under test mounted on the second circuit board is located between the multiple second connection ends.

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