A KGD dynamic parameter test device for silicon carbide MOSFET

Abstract

The utility model provides a KGD dynamic parameter test device for a silicon carbide MOSFET. The coaxial test line is used to connect the detection board and the dynamic test host. The coaxial test line can achieve a distributed inductance of nH level. For example, under the condition of a length of 1 meter, a distributed inductance of less than 30nH can be achieved, so that the device under test can achieve a higher test current, a slighter bus voltage drop, and a higher short-circuit energy during a short-circuit test, and a lower voltage spike can be achieved when the device under test is turned off; the probe protection circuit is arranged close to the test board, and the probe protection circuit is a current balancing and overcurrent protection circuit, which can play a role in uniform current for each group of probes and limit the maximum current of each group of probes. When the device under test is damaged during the short-circuit test, before the bus power supply protection responds (1μs~5μs), the probe protection circuit can first synchronously clamp the maximum current of the probe, thereby protecting the probe from being burned out.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor testing, in particular to a KGD dynamic parameter testing device for a silicon carbide MOSFET. Background Art

[0002] In the field of new energy, the efficiency of energy conversion is particularly important, and the application of wide bandgap devices is one of the important directions for future development. Silicon carbide MOSFET is currently the most widely used wide bandgap power device. With the large-scale commercialization of silicon carbide devices, KGD (Known Good Die) technology plays an important role in improving packaging yield and reducing production costs.

[0003] The KGD dynamic parameter test equipment currently on the market is limited by the application environment space and usually adopts a split layout, that is, the test host needs to be connected to the detection board 50 through a section of signal line. This design increases the distributed parameters of the test loop (mainly inductance), resulting in a decrease in the effect of the KGD dynamic parameter test. The short-circuit test in the KGD dynamic parameter test is particularly important for improving the reliability of silicon carbide MOSFET. Compared with the short-circuit capability of more than 10μs of traditional silicon-based IBGT tubes, silicon carbide MOSFETs generally have a short-circuit capability of less than 5μs, and some are even less than 3μs. The difficulty of the short-circuit test is that on the one hand, the busbar distributed parameters between the device under test DUT and the energy storage capacitor will cause the voltage Vds to drop severely, resulting in serious distortion of the test results; on the other hand, when the device under test DUT is damaged, the probe used for the KGD dynamic parameter test will need to withstand a current pulse of thousands of amperes, causing the probe to be easily burned. Utility Model Content

[0004] The utility model aims to provide a KGD dynamic parameter test device for a silicon carbide MOSFET, which can solve the problems of test result distortion and probe burning during short-circuit testing.

[0005] In order to solve the above problems, the utility model provides a KGD dynamic parameter testing device for silicon carbide MOSFET, comprising a dynamic testing host, a proximal testing device, a detection board, a test board and a device to be tested, wherein the dynamic testing host is connected to the detection board via a coaxial testing line, and is connected to the proximal testing device via a control cable, and can control the proximal testing device, the detection board and the device to be tested, the proximal testing device is connected to the detection board, the device to be tested is connected and arranged on the detection board via the test board, and the detection board comprises a probe protection circuit, the probe tests the electrical characteristics of each end of the device to be tested at the test board and the detection board, the probe protection circuit is arranged close to the test board, and the probe protection circuit is a current sharing and overcurrent protection circuit, which is used to protect the probe in a short circuit test.

[0006] Optionally, the dynamic test host is connected to the detection board via two or more coaxial test lines, and the proximal test device is connected to the detection board via a first connection portion, wherein the first connection portion is a flexible flat cable or a coaxial connection cable.

[0007] Optionally, the proximal test device has a built-in capacitor group, a first relay and a second relay, one end of the dynamic test host is simultaneously connected to one end of the first relay and one end of the second relay, the other end of the dynamic test host is connected to the detection board via more than two coaxial test lines, the other end of the first relay and the other end of the second relay are both connected to the detection board via a signal line, and the first relay and the second relay can perform signal switching for switching time testing and reverse recovery time testing.

[0008] Furthermore, the built-in capacitor group is a non-inductive thin film capacitor group.

[0009] Optionally, the dynamic test host includes a built-in inductor group and a mF-level thin-film high-voltage capacitor group to provide a 3KA, 20μs current pulse in a short-circuit test.

[0010] Optionally, the detection board includes a device under test driver, a probe protection circuit, a short-circuit test relay group, a companion test tube, a piping driver, a coaxial shunt and a coaxial test line input interface electrically connected to a printed circuit board. The probe protection circuit is arranged close to the test board, the coaxial shunt is connected to the device under test through more than two probe protection circuits, and the coaxial shunt is arranged near one side of all the probe protection circuits, and the short-circuit test relay group is placed close to the test board.

[0011] Furthermore, the detection board also includes a capacitor, and the capacitor is connected to the first connection part.

[0012] Among them, the capacitor is a non-inductive thin film high-voltage capacitor, the companion test tube is made of silicon carbide MOS, each of the probe protection circuits has an internal resistance of tens of mΩ and a distributed inductance of less than 10nH, and the maximum current is adjustable from 100A to 500A.

[0013] Furthermore, the piping driver serves as the driver of the accompanying test tube, the device under test driver serves as the driver of the device under test, and both the piping driver and the device under test driver are connected to the printed circuit board via a coaxial socket.

[0014] Furthermore, the coaxial test line input interface is connected to the coaxial test line, and the coaxial test line input interface includes a plurality of ports arranged in parallel, and each port is connected to one of the coaxial test lines.

[0015] Furthermore, the coaxial shunt has a first end and a second end, and the test board is provided with a first probe pin, multiple second probe pins, a third probe pin and a Kelvin pin, all of the first probe pins, the second probe pins and the third probe pins are connected to the detection board through the test board, the first end of the coaxial shunt is connected to the coaxial test line input interface, the first probe pin is connected to the drain of the device under test, multiple second probe pins are grouped, and each group of second probe pins is connected to one end of the probe protection circuit, the other ends of all probe protection circuits are connected to the second end, and all the second probe pins are connected to the source of the device under test, the third probe pin is connected to the positive terminal driven by the device under test, and is connected to the gate of the device under test, and the Kelvin pin is connected to the negative terminal driven by the device under test.

[0016] Compared with the prior art, the utility model has the following beneficial effects:

[0017] The utility model provides a KGD dynamic parameter test device for a silicon carbide MOSFET, comprising a dynamic test host, a proximal test device, a detection board, a test board and a device to be tested, wherein the dynamic test host is connected to the detection board via a coaxial test line, and is connected to the proximal test device via a control cable, and can control the proximal test device, the detection board and the device to be tested, the proximal test device is connected to the detection board, the device to be tested is connected and arranged on the detection board via the test board, and the detection board comprises a probe protection circuit, the probe tests the electrical characteristics of each end of the device to be tested at the test board and the detection board, the probe protection circuit is arranged close to the test board, and the probe protection circuit is a current sharing and overcurrent protection circuit, which is used to protect the probe in a short circuit test. The utility model adopts the coaxial test line to connect the detection board and the dynamic test host. The coaxial test line can achieve nH-level distributed inductance. For example, under the condition of a length of 1 meter, a distributed inductance of less than 30nH can be achieved, so that the device under test can achieve a higher test current, a slighter bus voltage drop, and a higher short-circuit energy during a short-circuit test, and a lower voltage spike can be achieved when the device under test is turned off; the probe protection circuit is arranged close to the test board, and the probe protection circuit is a current balancing and overcurrent protection circuit, which can play a role in uniform current for each group of probes and limit the maximum current of each group of probes. When the device under test is damaged during the short-circuit test, before the bus power supply protection responds (1μs~5μs), the probe protection circuit can first synchronously clamp the maximum current of the probe, thereby protecting the probe from being burned out. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1A schematic diagram of the structure of a KGD dynamic parameter test device for a silicon carbide MOSFET provided in one embodiment of the utility model;

[0019] Figure 2-Figure 3 A schematic diagram of the partial structure of a KGD dynamic parameter testing device provided in one embodiment of the utility model;

[0020] Figure 4 This is a timing diagram of an embodiment of the utility model during a normal short-circuit test;

[0021] Figure 5 This is a timing diagram of an embodiment of the utility model when the device under test DUT breaks down during a short circuit test;

[0022] Figure 6 This is a schematic diagram of an equivalent circuit of a KGD dynamic parameter test device during a switching time test of an embodiment of the utility model;

[0023] Figure 7 Schematic diagram of the equivalent circuit of the KGD dynamic parameter testing device during the reverse recovery time parameter test of an embodiment of the utility model.

[0024] Explanation of the reference numerals: 10 - dynamic test host; 20 - coaxial test line; 30 - proximal test device; 40 - first connection part; 41 - signal line; 50 - detection board; 51 - device under test driver; 52 - probe protection circuit; 53 - piping driver; 54 - coaxial shunt; 55 - coaxial test line input interface; 60 - test board; 61 - first probe pin; 62 - second probe pin; 63 - third probe pin; 631 - Kelvin pin; 70 - oscilloscope. DETAILED DESCRIPTION

[0025] The following is a further detailed description of a KGD dynamic parameter test device for a silicon carbide MOSFET of the utility model. The utility model will be described in more detail below with reference to the accompanying drawings, in which preferred embodiments of the utility model are shown. It should be understood that those skilled in the art can modify the utility model described herein and still achieve the beneficial effects of the utility model. Therefore, the following description should be understood as being widely known to those skilled in the art, and not as a limitation to the utility model.

[0026] For the sake of clarity, not all features of the actual embodiments are described. In the following description, well-known functions and structures are not described in detail because they would make the utility model confusing with unnecessary details. It should be recognized that in the development of any actual embodiment, a large number of implementation details must be made to achieve the developer's specific goals, such as changing from one embodiment to another according to the limitations of the relevant system or the relevant business. In addition, it should be recognized that such development work may be complex and time-consuming, but it is just routine work for those skilled in the art.

[0027] In order to make the purpose and features of the utility model more obvious and easy to understand, the specific implementation of the utility model is further described below in conjunction with the accompanying drawings. It should be noted that the accompanying drawings are all in a very simplified form and use inaccurate ratios, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model.

[0028] like Figure 1 As shown, this embodiment provides a KGD dynamic parameter test device for silicon carbide MOSFET, including a dynamic test host 10, a proximal test device 30, a detection board 50, a test board 60 and a device under test DUT. The dynamic test host 10 is connected to the detection board 50 through a coaxial test line 20, and is connected to the proximal test device 30 through a control cable, and can control the proximal test device 30, the detection board 50 and the device under test DUT. The proximal test device 30 is connected to the detection board 50 and is used for signal switching of switching time test and reverse recovery time test. The device under test DUT is connected to the detection board 50 through the test board 60, and the detection board 50 includes a probe protection circuit 52. The probe tests the electrical characteristics of each end of the device under test DUT at the test board 60 and the detection board. The probe protection circuit 52 is arranged close to the test board 60, and the probe protection circuit 52 is a current sharing and overcurrent protection circuit, which is used to protect the probe in a short circuit test. Wherein, the device under test DUT is a silicon carbide MOSFET.

[0029] In this embodiment, the coaxial test line 20 is used to connect the detection board 50 and the dynamic test host 10. The coaxial test line 20 can achieve a distributed inductance of nH level. For example, under the condition of a length of 1 meter, a distributed inductance of less than 30nH can be achieved, so that the device under test DUT can achieve a higher test current, a slighter bus voltage drop, and a higher short-circuit energy during a short-circuit test, and the device under test DUT can achieve a lower voltage spike when it is turned off; the probe protection circuit 52 is arranged close to the test board 60, and the probe protection circuit 52 is a current balancing and overcurrent protection circuit, which can play a role in uniform current for each group of probes and limit the maximum current of each group of probes. When the device under test DUT is damaged during the short-circuit test, before the bus power supply protection response (1μs~5μs), the probe protection circuit 52 can first synchronously clamp the maximum current of the probe, thereby protecting the probe from being burned out.

[0030] like Figure 2 As shown, in detail, the dynamic test host 10 is used to control the entire KGD dynamic parameter test device, and the dynamic test host 10 includes a built-in inductor group and a mF-level thin film high-voltage capacitor group, so as to provide a 3KA, 20μs high current pulse in the short circuit test. The mF-level thin film high-voltage capacitor group has the characteristics of small self-inductance, small equivalent series resistance, small loss, good frequency characteristics, and can withstand high voltage and large current shocks, and can play an important role in the short circuit test. The dynamic test host 10 is connected to the detection board 50 through more than two coaxial test lines 20, and as many coaxial test lines 20 as possible can be used within the scope allowed by space, for example, more than 10 lines. Among them, the coaxial test line 20 is a high-current coaxial test line 20, and the coaxial test line 20 includes a core and a shielding layer, the shielding layer insulation sleeve is arranged on the outside of the core, and the core is used to connect the voltage VDD, and the shielding layer is used to ground PGND. In this embodiment, the coaxial test line 20 can achieve a distributed inductance of less than 30nH under the condition of a length of 1m, so that the device under test DUT can achieve a higher test current, a slighter bus voltage drop, a higher short-circuit energy and a lower voltage spike when the device under test DUT is turned off in a short-circuit test. This design plays an important role in short-circuit testing.

[0031] The near-end test device 30 is also connected to the detection board 50 through a signal line, and the signal line is also connected to the built-in inductance group. The near-end test device 30 is connected to the dynamic test host 10 through a control cable, and is also connected to the detection board 50 through a first connecting portion 40. The near-end test device 30 has a built-in capacitor group (not shown in the figure), a first relay K1 and a second relay K2, one end of the dynamic test host 10 is simultaneously connected to one end of the first relay K1 and one end of the second relay K2, and the other end of the dynamic test host 10 is connected to the detection board 50 through more than two coaxial test lines 20, and the other end of the first relay K1 and the other end of the second relay K2 are both connected to the detection board 50. The first relay K1 and the second relay K2 are both connected to the detection board 50 through the signal line, and are responsible for the signal switching of the switching time test and the reverse recovery time test. The first relay K1 and the second relay K2 are both AC test relays, and the built-in capacitor group is a non-inductive film capacitor group. Among them, the first relay K1 and the second relay K2. The capacitance of the built-in capacitor group is between 1uF and 10uF, and they are all capacitor extensions of the detection board 50 .

[0032] The first connecting portion 40 can be a flexible flat cable FPC or a coaxial connecting cable, which can effectively reduce the busbar distributed inductance of the device under test DUT during the switching process when the built-in capacitor group is connected to the detection board 50. The structure of the coaxial connecting cable is the same as that of the coaxial test line 20, that is, it includes a core and a shielding layer, the shielding layer is insulated and sleeved on the outside of the core, and the core is used to connect the voltage VDD, and the shielding layer is used to connect the ground PGND. The flexible flat cable FPC can be a double-sided software combined board (FPC+PCB), and the front and back sides thereof are the PGND connecting line and the VDD connecting line respectively.

[0033] The detection board 50 includes a printed circuit board PCB, a device under test driver 51, a probe protection circuit 52, a short-circuit test relay group, a test tube HDUT, a pipe drive 53, a coaxial shunt 54, a coaxial test line input interface 55 and a capacitor C. The near-end test device 30, the test board 60, the coaxial test line input interface 55, the short-circuit test relay group, the test tube HDUT, the coaxial shunt 54, the pipe drive 53, the device under test driver 51, the capacitor C and the probe protection circuit 52 are all arranged on the printed circuit board PCB. The printed circuit board PCB has electrical connection lines inside and on the surface to connect the near-end test device 30, the test board 60, the coaxial test line input interface 55, the short-circuit test relay group, the test tube HDUT, the coaxial shunt 54, the pipe drive 53, the device under test driver 51, the capacitor C and the probe protection circuit 52. The coaxial shunt 54 has a first end and a second end, and the second end is connected to a plurality of current protection points arranged in parallel on the printed circuit board PCB.

[0034] The coaxial test line input interface 55 is connected to the coaxial test line 20 so that the detection board 50 is electrically connected to the dynamic test host 10. The coaxial test line input interface 55 includes multiple ports arranged in parallel, each port being connected to one of the coaxial test lines 20 to reduce stray inductance.

[0035] One end of the capacitor C is simultaneously connected to the drain of the test tube HDUT, one end of the coaxial test line input interface 55, the voltage VDD, the other end of the first relay K1, and one end of the short-circuit test relay group, and the other end of the capacitor C is simultaneously connected to the first end of the coaxial shunt 54, the ground GND, the other end of the coaxial test line input interface 55, and the other end of the second relay K2. The gate of the test tube HDUT is connected to the positive end of the pipe driver 53, and the source of the test tube HDUT is simultaneously connected to the other end of the short-circuit test relay group, the negative end of the pipe driver 53, the other end of the dynamic test host 10, and the test board 60. When the first connection part is a coaxial connection line, one end of the capacitor C is connected to the voltage VDD through the core of the coaxial connection line, and the other end of the capacitor C is connected to the ground PGND through the shielding layer of the coaxial connection line. When the first connection portion is a flexible flat cable FPC, one end of the capacitor C is connected to a voltage VDD through a VDD connection line connected to the flexible flat cable FPC, and the other end of the capacitor C is connected to a ground PGND through a VDD connection line connected to the flexible flat cable FPC.

[0036] The second end of the coaxial shunt 54 is connected to one end of the probe protection circuit 52 through each current protection point, and the other end of each probe protection circuit 52 is connected to the test board 60. The positive terminal and the negative terminal of the device under test driver 51 are both connected to the device under test DUT through the test board 60, that is, the positive terminal of the device under test driver 51 is connected to the gate of the device under test DUT through the test board 60.

[0037] Among them, the dynamic test host 10 passes through the proximal test device 30 and is connected to the source of the accompanying test tube HDUT on the detection board 50, the other end of the short-circuit test relay group and the negative end of the pipe drive 53 through the signal line; the other end of the first relay K1 and the other end of the second relay K2 are both connected to the detection board 50 through the signal line.

[0038] Wherein, the capacitor C can be a non-inductive thin film high voltage capacitor to effectively reduce the bus stray inductance of the device under test DUT during the switching process. The companion test tube HDUT can use silicon carbide MOS as the test tube and be set as close to the test board 60 as possible to reduce the bus stray inductance. The probe protection circuit 52 is, for example, a current equalization and current limiting circuit, which is set close to the test board 60. Wherein, each of the probe protection circuits 52 has an internal resistance of tens of mΩ and a distributed inductance of less than 10nH, and the maximum current is adjustable from 100A to 500A.

[0039] The coaxial shunt 54 is connected to the device under test through more than two probe protection circuits, and the coaxial shunt is arranged near one side of all the probe protection circuits 52 to reduce stray inductance. The pipe driver 53 is used as the driver of the accompanying test tube HDUT, and the device under test driver 51 is used as the driver of the device under test DUT. The pipe driver 53 and the device under test driver 51 are both connected to the printed circuit board PCB through a coaxial socket to have low stray inductance and support the function of automatically adjusting the gate resistance RG of the device under test DUT.

[0040] The short-circuit test relay group includes more than two relays connected in parallel, and the short-circuit test relay group is placed as close to the test board 60 as possible to reduce stray inductance. In this embodiment, the short-circuit test relay group includes a first short-circuit test relay K3 and a second short-circuit test relay K4.

[0041] The test board 60 is provided with a first probe pin 61, multiple second probe pins 62, a third probe pin 63 and a Kelvin pin 631. All of the first probe pins 61, the second probe pins 62, the third probe pin 63 and the Kelvin pin 631 are connected to the detection board 50 through the test board 60. The source of the accompanying test tube HDUT is connected to the drain of the device under test DUT through the first probe pin 61. Multiple second probe pins 62 are grouped, and the second probe pins 62 of each group are connected to the other end of the probe protection circuit 52. All of the second probe pins 62 are connected to the source of the device under test DUT. The third probe pin 63 is connected to the positive terminal of the device under test driver 51 and the gate of the device under test DUT. The Kelvin pin 631 is connected to the negative terminal of the device under test driver 51 to obtain the waveforms of the voltage Vds, voltage Vgs and current Ids of the device under test DUT.

[0042] In this embodiment, the second probe pins 62 are divided into more than two groups of second probe pins, and the number of groups of second probe pins is as large as possible. Each group of second probe pins has at least one second probe pin 62, and each group of second probe pins 62 is independently connected to a probe protection circuit 52.

[0043] The KGD dynamic parameter test device of the silicon carbide MOSFET also includes an oscilloscope 70. During the test, the oscilloscope 70 contacts the coaxial shunt 54, the first probe pin 61, the second probe pin 62, the third probe pin 63 and the Kelvin pin 631 through probes to complete the electrical characteristics test. Since each of the probe protection circuits 52 has an internal resistance of tens of mR and a distributed inductance of less than 10nH, the maximum current is adjustable from 100A to 500A. When some probes are in poor contact, the internal resistance of the probe protection circuit 52 can play a role in uniform current for each group of probes and limit the maximum current of each group of probes. When the device under test DUT is damaged during the short-circuit test, before the bus power supply protection responds (1μs to 5μs), the probe protection circuit 52 can first synchronously clamp the maximum current of the probe, thereby protecting the probe from being burned out.

[0044] like Figure 4As shown, during a normal short-circuit test, in the first time period I, the first relay K1 and the second relay K2 of the proximal test device 30 are disconnected, and the first short-circuit test relay K3 and the second short-circuit test relay K4 are both turned on. At this time, a high voltage VDS is applied between the source and drain of the device under test DUT; in the second time period II, the output voltage Vgs outputs a positive voltage, the device under test DUT is turned on, and the current IDS begins to rise, and the current of the probe protection circuit 52 is IDS / n, where n is the number of the probe protection circuits 52; in the third time period III, after the short-circuit current IDS reaches the maximum, the device under test DUT enters the protection stage, and the current IDS begins to decrease; in the fourth time period IV, the short-circuit test is completed, the output voltage Vgs outputs a negative voltage, and the device under test DUT is turned off.

[0045] When the DUT breaks down during the short circuit test and the source and drain of the DUT are turned on, the probe protection circuit 52 turns on the protection. Figure 5 As shown, in the first time period I, the first relay K1 and the second relay K2 of the proximal test device 30 are disconnected, and the first short-circuit test relay K3 and the second short-circuit test relay K4 are both turned on. At this time, a high voltage Vds is applied between the source and drain of the device under test DUT; in the second time period II, the output voltage Vgs outputs a positive voltage, the device under test DUT is turned on, and the current IDS begins to rise, and the current of the probe protection circuit 52 is IDS / n, where n is the number of the probe protection circuits 52; in the third time period III, after the current IDS reaches the maximum, the device under test DUT enters the protection stage, and the current begins to decrease; in the fourth time period IV, the device under test DUT accumulates too much energy and is broken down, and the source and drain of the device under test DUT are turned on, and the clamping current of the probe protection circuit 52 maintains the maximum current until the power is turned off, where the maximum current is I_Limit*n. Wherein, n is the number of the probe protection circuits 52.

[0046] The KGD dynamic parameter test device can perform short circuit test, and can also perform switching time test and reverse recovery time parameter test by respectively changing the states of the first relay K1 and the second relay K2. Figure 6 As shown, during the switch time test, the first relay K1 is turned on, and the second relay K2, the first short-circuit test relay K3 and the second short-circuit test relay K4 are all turned off. Figure 7 As shown, during the reverse recovery time parameter test, the second relay K2 is turned on, and the first relay K1, the first short-circuit test relay K3 and the second short-circuit test relay K4 are all turned off.

[0047] In summary, the utility model provides a KGD dynamic parameter test device for silicon carbide MOSFET, which adopts a split layout, multi-line use, and partial circuit forward to the detection board design. It has flexible layout, low distributed inductance of busbar and gate drive circuit, supports probe overcurrent protection, supports multiple dynamic parameter tests, short-circuit test current is above 3KA, and has high test data accuracy. The device can improve KGD dynamic test technology, reduce the packaging and testing cost of silicon carbide MOSFET, and promote the large-scale commercialization of silicon carbide MOSFET.

[0048] In addition, it should be noted that, unless otherwise specified or indicated, the terms "first" and "second" in the specification are only used to distinguish the various components, elements, steps, etc. in the specification, and are not used to indicate the logical relationship or sequential relationship between the various components, elements, steps, etc.

[0049] It is understandable that, although the utility model has been disclosed as a preferred embodiment, the above embodiment is not intended to limit the utility model. For any technician familiar with the art, without departing from the scope of the technical solution of the utility model, the above disclosed technical content can be used to make many possible changes and modifications to the technical solution of the utility model, or modified into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the utility model without departing from the content of the technical solution of the utility model still falls within the scope of protection of the technical solution of the utility model.

Claims

1. A KGD dynamic parameter test device for silicon carbide MOSFET, characterized in that: The invention comprises a dynamic test host, a proximal test device, a detection board, a test board and a device to be tested. The dynamic test host is connected to the detection board via a coaxial test line and is connected to the proximal test device via a control cable, and is capable of controlling the proximal test device, the detection board and the device to be tested. The proximal test device is connected to the detection board, and the device to be tested is arranged on the detection board via the test board, and the detection board comprises a probe protection circuit. The probe tests the electrical characteristics of each end of the device to be tested at the test board and the detection board. The probe protection circuit is arranged close to the test board, and the probe protection circuit is a current sharing and overcurrent protection circuit, which is used to protect the probe in a short circuit test.

2. The KGD dynamic parameter test device of silicon carbide MOSFET according to claim 1, characterized in that: The dynamic test host is connected to the detection board via two or more coaxial test lines, and the proximal test device is connected to the detection board via a first connection portion, wherein the first connection portion is a flexible flat cable or a coaxial connection cable.

3. The KGD dynamic parameter test device of silicon carbide MOSFET according to claim 1, characterized in that: The proximal test device has a built-in capacitor group, a first relay and a second relay. One end of the dynamic test host is connected to one end of the first relay and one end of the second relay at the same time. The other end of the dynamic test host is connected to the detection board through more than two coaxial test lines. The other end of the first relay and the other end of the second relay are both connected to the detection board through a signal line. The first relay and the second relay can perform signal switching for switching time testing and reverse recovery time testing.

4. The KGD dynamic parameter test device of silicon carbide MOSFET according to claim 3, characterized in that: The built-in capacitor group is a non-inductive film capacitor group.

5. The KGD dynamic parameter test device of silicon carbide MOSFET according to claim 1, characterized in that: The dynamic test host includes a built-in inductor group and a mF-level thin-film high-voltage capacitor group to provide a 3KA, 20μs current pulse in a short-circuit test.

6. The KGD dynamic parameter test device of silicon carbide MOSFET according to claim 2, characterized in that: The detection board includes a device under test driver, a probe protection circuit, a short-circuit test relay group, a companion test tube, a piping driver, a coaxial shunt and a coaxial test line input interface electrically connected to a printed circuit board. The probe protection circuit is arranged close to the test board, the coaxial shunt is connected to the device under test through more than two probe protection circuits, and the coaxial shunt is arranged near one side of all the probe protection circuits. The short-circuit test relay group is placed close to the test board.

7. The KGD dynamic parameter test device of silicon carbide MOSFET according to claim 6, characterized in that: The detection board further includes a capacitor, and the capacitor is connected to the first connection portion. Among them, the capacitor is a non-inductive thin film high-voltage capacitor, the companion test tube is made of silicon carbide MOS, each of the probe protection circuits has an internal resistance of tens of mΩ and a distributed inductance of less than 10nH, and the maximum current is adjustable from 100A to 500A.

8. The KGD dynamic parameter test device of silicon carbide MOSFET according to claim 6, characterized in that: The piping driver serves as the driver of the accompanying test tube, and the device under test driver serves as the driver of the device under test. Both the piping driver and the device under test driver are connected to the printed circuit board via a coaxial socket.

9. The KGD dynamic parameter test device of silicon carbide MOSFET according to claim 6, characterized in that: The coaxial test line input interface is connected to the coaxial test line, and the coaxial test line input interface includes a plurality of ports arranged in parallel, and each port is connected to one of the coaxial test lines.

10. The KGD dynamic parameter test device of silicon carbide MOSFET according to claim 6, characterized in that: The coaxial shunt has a first end and a second end, and the test board is provided with a first probe pin, multiple second probe pins, a third probe pin and a Kelvin pin, all of the first probe pins, the second probe pins, the third probe pin and the Kelvin pin are connected to the detection board through the test board, the first end of the coaxial shunt is connected to the coaxial test line input interface, the first probe pin is connected to the drain of the device under test, multiple second probe pins are grouped, and each group of second probe pins is connected to one end of the probe protection circuit, the other ends of all probe protection circuits are connected to the second end, and all the second probe pins are connected to the source of the device under test, the third probe pin is connected to the positive terminal driven by the device under test, and is connected to the gate of the device under test, and the Kelvin pin is connected to the negative terminal driven by the device under test.

Images