CN109765470B - Characteristic test method of power semiconductor device with precise and controllable temperature and current - Google Patents

Abstract

The present invention provides a power semiconductor device characteristic testing method with precise and controllable temperature and current, including a switching characteristic testing method, a recovery characteristic testing method and a conduction characteristic testing method of the power semiconductor device under a set current and temperature. The test method includes: applying a set of test pulse sequences including three pulses to the switch tube under test, and testing the turn-off characteristics of the switch tube at the falling edge of the first pulse; the second pulse compensates the loss of load current; Test the conduction characteristics of the switch tube or diode between the end of one pulse and the start of three pulses; test the turn-on characteristics of the switch tube and the recovery characteristics of the diode at the rising edge of the third pulse; so as to achieve a power semiconductor with precisely controllable temperature and current Device characteristic test effect.

Description

Characteristic test method of power semiconductor device with precise and controllable temperature and current

technical field

The invention relates to the technical field of semiconductors, in particular, to a characteristic testing method of a power semiconductor device with an accurately controllable temperature and current.

Background technique

With the increase in the rated capacity of power electronic devices and the complexity of the working environment, the requirements for the reliability of power semiconductor devices in applications are also increasing. Power semiconductor devices are relatively expensive components and main heat sources in power electronic systems. Accurate modeling and evaluation of their loss and thermal characteristics is an important means to improve the economy and safety of power electronic equipment.

Analysis of the loss and thermal characteristics of power semiconductor devices requires the establishment of thermal impedance and loss models. Therefore, it is necessary to reproduce and test the switching and conduction characteristics of power semiconductor devices under various voltage, current, and temperature conditions. However, in order to obtain accurate power semiconductor device characteristic parameters, there are higher requirements for test conditions and test methods: the voltage, load current, and device temperature of the power semiconductor device need to be adjusted during testing; The current and temperature of the device are consistent with the set values; due to the differences of the same type of power semiconductor devices, it is necessary to measure multiple devices and repeat the test.

In the prior art, the double-pulse test method is usually used to extract the switching characteristics of the power semiconductor device, and the I/V curve measuring instrument is used to extract the conduction characteristics of the power semiconductor device. However, these methods are inconvenient to adjust the load current and device temperature; the parasitic parameters are large, and the test conditions are far from the actual application; the current and temperature are inaccurate when testing the switching characteristics and conduction characteristics; Switching characteristics or conduction characteristics of a device; inability to test the recovery characteristics of anti-parallel diodes in the power semiconductor device under test.

SUMMARY OF THE INVENTION

In view of the defects in the prior art, the purpose of the present invention is to provide a characteristic testing method of a power semiconductor device whose temperature and current are precisely controllable.

The invention provides a characteristic testing method of a power semiconductor device whose temperature and current are precisely controllable, which is used to test the power semiconductor device including a switch tube and a diode, and to test the switching characteristic and recovery characteristic of the power semiconductor device under set conditions. and turn-on characteristics; the method includes:

Each test stage applies a set of test pulse sequences including N pulses to the tested switch tube in the tested module, where N is an integer greater than 2;

Test the turn-off characteristics of the switch tube under test at the falling edge of the first pulse signal;

Between the end of the first pulse signal and the start of the Nth pulse signal, test the conduction characteristics of the switch tube and/or diode under test; the pulse signal between the first pulse signal and the Nth pulse signal is used for To compensate for the loss of test current;

On the rising edge of the Nth pulse, the conduction characteristic of the switch tube under test and/or the recovery characteristic of the diode are tested.

Optionally, it includes: the module under test includes at least one unit under test, the unit under test is used to simulate the working state of the power semiconductor device; the unit under test includes a switch tube and a diode The full-bridge structure of any topology formed by the power semiconductor devices and the corresponding load module;

Wherein, the power semiconductor device includes any one or any of the following features:

Power semiconductor devices including module-based, press-fit, and discrete packaging technologies;

Including semiconductor chips based on silicon, silicon carbide, and gallium nitride;

The load module includes any of the following features:

pure inductive circuit;

A hybrid electrical impedance network composed of inductors, capacitors, resistors, and transformers.

Optionally, the set conditions include: voltage conditions, current conditions, and temperature conditions; wherein:

The temperature conditions include: the temperature of the tested module regulated by the temperature control module;

The current conditions include: the first pulse stops when the test current reaches the set value; the Nth pulse starts when the test current reaches the set value.

Optionally, the pulse signal between the first pulse signal and the Nth pulse signal is used as a compensation pulse signal to compensate for the current drop between the first pulse signal and the Nth pulse signal due to circuit parasitic parameters; When the temperature of the tested module recovers and remains at the set value, it starts to apply the compensation pulse signal, and when the load current is within the preset range, it stops applying the compensation pulse. Optionally, also include:

In the freewheeling state of the load current, test the conduction voltage drop characteristics of the diode in the freewheeling circuit;

When the load current changes from the freewheeling state to the charging and discharging state, test the recovery characteristics of the diodes in the freewheeling circuit;

Wherein, the charging and discharging state refers to: the load current flows through a closed loop formed by at least one switch tube, a load module, and a DC voltage source;

The freewheeling state means that the load current flows through a closed loop formed by a diode and a load module, or a closed loop formed by a switch tube, a diode and a load module.

Optionally, when the unit under test includes a full-bridge structure, test the conduction voltage drop characteristic of the switch;

The on-voltage drop characteristics of the test switch tube include:

A continuous turn-on signal is applied to at least one power semiconductor device in the unit under test, so that the unit under test is in a load current freewheeling state, and in this load current freewheeling state, the conduction of the power semiconductor device in the freewheeling loop is detected. Through-voltage drop characteristics.

Optionally, also include:

According to the detected voltage and current values of the power semiconductor device, the loss characteristic of the power semiconductor device is calculated.

Optionally, calculating the loss characteristics of the power semiconductor device according to the detected voltage and current values of the power semiconductor device, including:

During the detected switching process of the power semiconductor device, the product of the voltage across the power semiconductor device and the current flowing through the power semiconductor device is time-integrated to obtain the switching loss energy of the power semiconductor device;

During the detected conduction process of the power semiconductor device, the product of the voltage across the power semiconductor device and the flowing current is used to obtain the conduction loss of the power semiconductor device;

During the detected recovery process of the diode, the product of the voltage across the power semiconductor device and the flowing current is integrated with time to obtain the recovery loss energy of the diode.

Compared with the prior art, the present invention has the following beneficial effects:

1. In the method for testing the characteristics of power semiconductor devices with accurate and controllable temperature and current provided by the present invention, the test circuit structure is similar to the circuit topology commonly used in power semiconductor devices, so that the loss test of the power semiconductor devices can be better performed, and the obtained The data is closer to the characteristics of the device under test under actual operating conditions.

2. The method for testing the characteristics of a power semiconductor device with an accurate and controllable temperature and current provided by the present invention can realize the switching loss and on-state characteristic testing of multiple tested devices under the conditions of set voltage, current and temperature.

3. The method for testing the characteristics of a power semiconductor device with an accurately controllable temperature and current provided by the present invention can effectively reduce the influence of the parasitic capacitance in the load on the switching process of the device under test, thereby obtaining more accurate switching loss test results.

Description of drawings

Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

1 is a flowchart of a method for testing the characteristics of a power semiconductor device with an accurately controllable temperature and current provided by the present invention;

2 is a schematic structural diagram of Embodiment 1 of a unit under test provided by the present invention;

3 is a schematic structural diagram of Embodiment 2 of the unit under test provided by the present invention;

4 is an electrical state, a temperature state and a load current waveform diagram of a switch tube and its anti-parallel diode in one test cycle according to an embodiment of the power semiconductor device characteristic testing method provided by the present invention;

FIG. 5 is a flowchart of an embodiment of a method for testing characteristics of a power semiconductor device provided by the present invention in a switching tube testing stage;

6 is a waveform diagram of drive signals and load currents of all switch tubes in a tested module in one test cycle according to an embodiment of a method for testing characteristics of a power semiconductor device provided by the present invention;

FIG. 7 is a flowchart of testing the characteristics of all power semiconductor devices in one test cycle according to an embodiment of the method for testing the characteristics of a power semiconductor device provided by the present invention.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the inventive concept. These all belong to the protection scope of the present invention.

FIG. 1 is a flowchart of a method for testing the characteristics of a power semiconductor device with precisely controllable temperature and current provided by the present invention. When the unit under test is a half-bridge structure, the switch tube without parallel load is used as the switch tube under test, and N tests are sent to the switch tube under test in turn under the condition that the DC voltage and the temperature of all power semiconductor devices are stable at the set value. Pulse, the turn-off characteristics of the switch tube under test, the conduction characteristics and recovery characteristics of the diode connected in series with the switch tube under test, and the turn-on characteristics of the switch tube under test can be measured in sequence according to the sequence in the flow chart, that is, a cycle is completed. When the unit under test is a full-bridge structure, all four switches can be used as the switches under test, and can be used as the switches under test in turn to test the switching characteristics and conduction characteristics of all switches in the full-bridge structure and the conduction of all diodes. Characteristics and recovery characteristics, Figure 4-7 specifically describes the implementation process of this method by taking a unit under test with a full-bridge structure and N=3 as an example.

FIG. 2 is a schematic structural diagram of the first embodiment of the unit under test provided by the present invention, and FIG. 3 is a schematic structural diagram of the second embodiment of the unit under test provided by the present invention. Figure 2 is a half-bridge structure, the switching characteristics of the switch tube in DUT_L and the conduction characteristics and recovery characteristics of the diode in DUT_H in the figure can be tested by the test method provided by the present invention. and the DC voltage source to form a charging and discharging circuit; Figure 3 is a full-bridge circuit, the switching characteristics and conduction characteristics of all switch tubes and the conduction characteristics and recovery characteristics of all diodes in the figure can be tested by the test method provided by the present invention, Diode_1H in the figure , The load and the DC voltage source form a freewheeling circuit, and there are four similar freewheeling circuits. IGBT_1H, load, IGBT_2L and the DC voltage source form a charging and discharging circuit, and there are two similar charging and discharging circuits.

4 is an electrical state, temperature state and load current waveform diagram of a switch tube and its anti-parallel diode in one test cycle according to an embodiment of a method for testing the characteristics of a power semiconductor device provided by the present invention, and FIG. 5 is a power semiconductor device provided by the present invention. The flow chart of the embodiment of the characteristic testing method in a switching tube testing stage. Referring to Figure 4 and Figure 5, take a switch IGBT_1H as an example, where Diode_1H represents its anti-parallel diode, and the waveform diagram and flow chart show the principle of realizing accurate temperature and current testing.

As shown in Figure 5, a test cycle is divided into four stages corresponding to the test stages of the four IGBTs of the full-bridge circuit, respectively. In the first test stage, IGBT_1H is the device under test, and three test pulses are applied to it. The first pulse corresponds to the 0-t1 stage. After charging the load current to the set value, it is turned off. The turn-off characteristics of IGBT_1H can be tested to ensure the accuracy of the current at this time. During the charging process, the temperature control module is used. The cooling function keeps the case temperature of IGBT_1H near the set value, which ensures the accuracy of the temperature when testing the turn-off characteristics; the conduction characteristics of Diode_1L are tested in the t1-t2 stage to stabilize the case temperature of each power semiconductor device and ensure the test conduction. The accuracy of the temperature when the characteristic is on; the second pulse corresponds to the t2-t3 stage, which is used to compensate the load current loss caused by parasitic parameters, and the load current is compensated to be equal to or slightly larger than the set value, and the loss caused by the parasitic parameters is small. , the turn-on process time of the second pulse is short, and the temperature variation range of each power semiconductor device is not large; in the t3-t4 stage, the conduction characteristics of IGBT_2L are tested and the case temperature of each power semiconductor device is stabilized. Freewheeling state, so the current loss and temperature change are small, which ensures the accuracy of temperature and current when testing the conduction characteristics; the third pulse corresponds to t4-t5, and a pulse is sent when the load current drops to the set value to ensure In order to ensure the accuracy of the current during the test, the turn-on characteristics of IGBT_1H and the recovery characteristics of Diode_1L are tested at the rising edge of the pulse. After the temperature stabilization process of t3-t4, the accuracy of the temperature during the test is guaranteed.

FIG. 6 is a waveform diagram of the driving signals and load currents of all switch tubes in the tested module in one test cycle according to an embodiment of the method for testing the characteristics of a power semiconductor device provided by the present invention; FIG. 7 is a method for testing the characteristics of a power semiconductor device provided by the present invention. Example Flow chart for testing all power semiconductor device characteristics in one test cycle.

Referring to Figure 6 and Figure 7, 0-T1 stage: the switch under test is IGBT_1H, IGBT_2L is turned on, IGBT_1L and IGBT_2H are turned off, IGBT_1H receives three test pulses, and the process shown in Figure 2 tests the turn-off characteristics of IGBT_1H, The turn-on characteristics of IGBT_2L, the turn-on characteristics of IGBT_1H and the recovery characteristics of Diode_1L. Stage T1-T2: The switch tube under test is IGBT_2H, IGBT_1L is turned on, IGBT_1H and IGBT_2L are turned off, and IGBT_2H receives three test pulses. The turn-on characteristics of , and the recovery characteristics of Diode_2L. Stage T2-T3: The switch tube under test is IGBT_2L, IGBT_1H is turned on, IGBT_1L and IGBT_2H are turned off, and IGBT_2L receives three test pulses. The turn-on characteristics of , and the recovery characteristics of Diode_2H. Stage T3-T4: The switch under test is IGBT_1L, IGBT_2H is turned on, IGBT_1H and IGBT_2L are turned off, and IGBT_1L receives three test pulses. The turn-on characteristics of , and the recovery characteristics of Diode_1H.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above-mentioned specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essential content of the present invention. The embodiments of the present application and features in the embodiments may be combined with each other arbitrarily, provided that there is no conflict.

Claims (7)

1. A method for testing the characteristics of a power semiconductor device with accurately controllable temperature and current is characterized by being used for testing the power semiconductor device comprising a switching tube and a diode and testing the switching characteristics, recovery characteristics and conduction characteristics of the power semiconductor device under set conditions; the method comprises the following steps:

each test stage is used for applying a group of test pulse sequences comprising N pulses to a tested switch tube in a tested module, wherein N is an integer greater than 2;

testing the turn-off characteristic of the switch tube to be tested at the falling edge of the first pulse signal;

testing the conduction characteristic of the switch tube and/or the diode to be tested between the end of the first pulse signal and the start of the Nth pulse signal; the pulse signal between the first pulse signal and the Nth pulse signal is used for compensating the loss of the test current;

testing the conduction characteristic of the switch tube to be tested and/or the recovery characteristic of the diode at the rising edge of the Nth pulse;

wherein:

the pulse signal between the first pulse signal and the Nth pulse signal is used as a compensation pulse signal and is used for compensating current drop between the first pulse signal and the Nth pulse signal caused by circuit parasitic parameters; and when the temperature of the module to be measured is recovered and maintained at the set value, starting to apply the compensation pulse signal, and when the load current is within the preset range, stopping applying the compensation pulse.

2. The method for testing the characteristics of the power semiconductor device with the accurately controllable temperature and the accurately controllable current as claimed in claim 1, comprises the following steps: the module to be tested comprises at least one unit to be tested, and the unit to be tested is used for simulating the working state of the power semiconductor device; the unit to be tested comprises a full-bridge structure in any topological form and corresponding load modules, wherein the full-bridge structure is composed of power semiconductor devices including a switching tube and a diode;

wherein the power semiconductor device comprises any one of the following features:

power semiconductor devices including module-based, compression-bonded, or discrete packaging technologies;

semiconductor chips including silicon, silicon carbide or gallium nitride based;

the load module comprises any of the following features:

a pure inductive circuit;

and the mixed electrical impedance network consists of an inductor, a capacitor, a resistor and a transformer.

3. The method for testing the characteristics of the power semiconductor device with the accurately controllable temperature and current according to claim 1, wherein the setting conditions comprise: voltage conditions, current conditions, and temperature conditions; wherein:

the temperature conditions include: the temperature of the tested module is regulated by a temperature control module;

the current conditions include: the first pulse is stopped when the test current reaches a set value; the nth pulse starts when the test current reaches the set value.

4. The method for testing the characteristics of the power semiconductor device with the accurately controllable temperature and the accurately controllable current as claimed in claim 1, further comprising:

testing the conduction voltage drop characteristic of a diode in a follow current loop under the load current follow current state;

testing the recovery characteristic of a diode in a freewheeling loop when the load current is converted from a freewheeling state to a charging and discharging state;

wherein, the charge and discharge state refers to that: the load current flows through a closed loop formed by at least one switching tube, a load module and a direct-current voltage source;

the follow current state is as follows: the load current flows through a closed loop formed by a diode and the load module, or a closed loop formed by a switch tube, a diode and the load module.

5. The method for testing the characteristics of the power semiconductor device with the accurately controllable temperature and current as claimed in claim 2, wherein when the unit to be tested comprises a full-bridge structure, the conduction voltage drop characteristic of the switch tube is tested;

the conduction voltage drop characteristic of the test switch tube comprises:

and applying a continuous opening signal to at least one power semiconductor device in the unit to be tested so as to enable the unit to be tested to be in a load current follow current state, and detecting the conduction voltage drop characteristic of the power semiconductor device in the follow current loop in the load current follow current state.

6. The method for testing the characteristics of the power semiconductor device with the accurately controllable temperature and the accurately controllable current as claimed in claim 1, further comprising:

and calculating the loss characteristic of the power semiconductor device according to the detected voltage current value of the power semiconductor device.

7. The method for testing the characteristics of the power semiconductor device with the accurately controllable temperature and the accurately controllable current as claimed in claim 6, wherein: calculating loss characteristics of the power semiconductor device according to the detected voltage current value of the power semiconductor device, wherein the loss characteristics comprise the following steps:

integrating the product of the voltage at two ends of the power semiconductor device and the current flowing through the power semiconductor device with respect to time during the detected switching process of the power semiconductor device to obtain the switching loss energy of the power semiconductor device;

in the detected conducting process of the power semiconductor device, obtaining the conducting loss of the power semiconductor device by the product of the voltage at two ends of the power semiconductor device and the current flowing through the power semiconductor device;

and in the recovery process of the detected diode, integrating the product of the voltage at two ends of the power semiconductor device and the flowing current with time to obtain the recovery loss energy of the diode.

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