An output digitally controlled adjustable drive module and method for power cycle experiment

Abstract

The present application discloses an output digital control adjustable driving module and method for power cycle experiment, which relates to the field of power cycle test. It includes: a primary single chip microcomputer and a host computer connected to it through a serial port, the primary single chip microcomputer is also connected to a plurality of secondary single chip microcomputer groups through an output I / O interface, and the secondary single chip microcomputer groups are connected to the driving module through a voltage regulating module; any of the secondary single chip microcomputer groups includes a positive pressure secondary control unit and a negative pressure secondary control unit, and the voltage regulating module includes a positive pressure regulating unit and a negative pressure regulating unit; the positive pressure secondary control unit is connected to the driving module through the positive pressure regulating unit, and the negative pressure secondary control unit is connected to the driving module through the negative pressure regulating unit. The gate voltage of different power cycle test devices can be adjusted, which makes the adjustment of the gate voltage more convenient and makes the power cycle equipment more integrated.

Description

Technical Field

[0001] The invention relates to the field of power cycle test, and in particular to an output digitally controlled adjustable drive module and method for power cycle experiment. Background Art

[0002] The power cycle test is the most important test for detecting the reliability of semiconductor device packaging. By applying a cyclic current load to the device under test, the device under test will produce cyclic temperature fluctuations. For stacked power semiconductor devices, the mismatch of thermal expansion coefficients of each layer of material will produce cyclic thermal stress, which will be concentrated at the weak points of the device, thus causing aging and failure of the device. Figure 1 This is the most commonly used circuit topology for the power cycle of IGBT (IGBT - Insulated Gate Bipolar Transistor) modules. It is also the most basic topology. As can be seen from the figure, the gate-emitter of the device is directly connected to a voltage source. V ge Keep the module (CE pole) turned on and control the load current through switch S I load Whether it flows through the device under test, use a small current I sense The method of lower saturation pressure drop ( V CE The device junction temperature is measured by the CT method (T). In a switching cycle, when the switch S is closed, the module is heated by the load current, and the junction temperature rises to the specified temperature; after the switch S is opened, the module cools down during this period, and the junction temperature drops to the specified temperature. It can be seen that the device junction temperature fluctuation and maximum junction temperature are mainly determined by the load current and the turn-on time.

[0003] However, in the actual test process, the device junction temperature cannot accurately reach a certain set temperature condition by adjusting the load current and the turn-on time. Considering the influence of the gate voltage on the module IV characteristic curve, such as Figure 2 As shown in the figure, under the same load current, the higher the gate voltage of the device, the lower the on-state voltage drop, the smaller the power loss and the junction temperature. Therefore, in the actual power cycle experiment, it is necessary to adjust the gate voltage of the device under test to achieve the purpose of fine adjustment of the junction temperature of the device. At present, adjustable resistors are widely used in drive circuits to adjust the gate voltage. Therefore, the gate drive circuit needs to be placed in a place in the power cycle device that is easy to operate, which is not conducive to the integrated packaging of the device. Moreover, the adjustment accuracy of the adjustable resistor is not enough, and the voltage cannot be adjusted to a certain set value accurately and quickly. Therefore, it is superior to adjust the voltage by digital control, which can not only make the device more integrated, but also adjust the gate voltage more accurately and quickly.

[0004] For different semiconductor devices, such as MOSFET, due to their different structures, when the junction temperature is measured using the same VCE(T) method, the gate voltage needs to be negative to keep the MOSFET in the off state. Therefore, for the power cycle test of MOSFET devices, the gate voltage needs to be adjustable both positively and negatively. Summary of the invention

[0005] The purpose of the present invention is to achieve the adjustable gate voltage of different power cycle test devices by means of digital control, so as to facilitate the adjustment of the gate voltage and make the power cycle device more integrated.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an output digitally controlled adjustable drive module for power cycle experiments, comprising: a primary single-chip microcomputer and a host computer connected thereto through a serial port, the primary single-chip microcomputer is also connected to a plurality of secondary single-chip microcomputer groups through an output I / O interface, the secondary single-chip microcomputer groups are connected to the drive module through a voltage regulation module; any one of the secondary single-chip microcomputer groups comprises a positive pressure secondary control unit and a negative pressure secondary control unit, the voltage regulation module comprises a positive pressure regulation unit and a negative pressure regulation unit; the positive pressure secondary control unit is connected to the drive module through the positive pressure regulation unit, and the negative pressure secondary control unit is connected to the drive module through the negative pressure regulation unit.

[0007] Furthermore, the first-level single-chip microcomputer and the second-level single-chip microcomputer group both use STM32 series single-chip microcomputers as control chips.

[0008] Furthermore, the driving module is provided with a NI interface for receiving NI signals.

[0009] Furthermore, the secondary single-chip computer groups are set to six groups, and the number of the voltage regulating modules and the driving modules is consistent with the number of the secondary single-chip computer groups.

[0010] Furthermore, any driving signals are isolated from each other.

[0011] The present application also discloses a method for digitally controlling adjustable output for power cycle experiments, using the digitally controlled adjustable output drive module as described above that can be used for power cycle tests of different power semiconductor devices.

[0012] Furthermore, specifically: the first-level single-chip microcomputer communicates with the host computer through the serial port, processes the channel selection information of the host computer, and transmits information such as the positive and negative voltage amplitudes to the second-level single-chip microcomputer. The second-level single-chip microcomputer outputs corresponding pulses to the input end of the voltage regulation module according to the given positive and negative voltage amplitudes, thereby obtaining positive voltage and negative voltage.

[0013] Furthermore, each driving signal needs to be isolated, and the power supply of the secondary microcontroller and the voltage regulation module also needs to be isolated.

[0014] Furthermore, the positive voltage and the negative voltage are simultaneously input to the driving module, and the voltage is output according to the signal given by NI: when NI gives a positive voltage signal, the driving circuit outputs a positive voltage; when NI does not give a signal or gives a negative voltage signal, the driving circuit outputs a negative voltage.

[0015] Beneficial effects of the present invention:

[0016] 1. No need to adjust the adjustable resistor, the gate voltage can be directly set by the host computer to achieve equipment integration.

[0017] 2. The disadvantages of insufficient adjustment precision and delay of the adjustable resistor are avoided. The present invention can accurately and quickly adjust the gate voltage to the set value.

[0018] 3. The integration of driving circuits is realized for different devices under test. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the schematic diagram of the DC power cycle circuit.

[0020] Figure 2 FIG. 4 is the IV characteristic curve of the IGBT device of the present invention.

[0021] Figure 3 This is the control flow chart of the driving circuit. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Embodiment 1:

[0024] A device that adjusts the gate voltage of the device under test by digital control for different power cycle devices.

[0025] A digitally controlled output adjustable driving module that can be used for power cycle tests of different power semiconductor devices comprises: a primary single chip computer 1 and a host computer 5 connected thereto via a serial port, the primary single chip computer is also connected to a plurality of secondary single chip computer groups 2 via an output I / O interface, the secondary single chip computer groups are connected to a driving module 4 via a voltage regulating module 3; any of the secondary single chip computer groups comprises a positive pressure secondary control unit 21 and a negative pressure secondary control unit 22, the voltage regulating modules comprise a positive pressure regulating unit 31 and a negative pressure regulating unit 32; the positive pressure secondary control unit is connected to the driving module via the positive pressure regulating unit, and the negative pressure secondary control unit is connected to the driving module via the negative pressure regulating unit.

[0026] Both the primary MCU and the secondary MCU use STM32 series MCU as control chips. The primary MCU communicates with the host computer through the serial port, processes the channel selection information of the host computer, and transmits information such as positive and negative voltage amplitudes to the secondary MCU. The secondary MCU outputs corresponding pulses to the input end of the voltage regulation module according to the given positive and negative voltage amplitudes, thereby obtaining positive and negative voltages. It should be noted here that since each drive signal needs to be isolated, the power supply of the secondary MCU and the voltage regulation module needs to be isolated. Finally, the positive voltage and negative voltage are input to the drive module at the same time, and the voltage is output according to the signal given by NI: when NI gives a positive voltage signal, the drive circuit outputs a positive voltage; when NI does not give a signal or gives a negative voltage signal, the drive circuit outputs a negative voltage, thereby selecting the IGBT mode and the MOS mode.

[0027] The embodiments described above are only preferred examples of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, any equivalent changes or modifications made according to the structures, features and principles described in the patent application scope of the present invention should fall within the scope of protection of the patent application of the present invention.

Claims

1. An output digitally controlled adjustable drive module for power cycle experiments, characterized in that: include: A primary single-chip computer (1) and a host computer (5) connected thereto via a serial port, wherein the primary single-chip computer is further connected to a plurality of secondary single-chip computer groups (2) via an output I / O interface, and the secondary single-chip computer groups are connected to a drive module (4) via a voltage regulating module (3); any of the secondary single-chip computer groups comprises a positive pressure secondary control unit (21) and a negative pressure secondary control unit (22), and the voltage regulating modules comprise a positive pressure regulating unit (31) and a negative pressure regulating unit (32); the positive pressure secondary control unit is connected to the drive module via the positive pressure regulating unit, and the negative pressure secondary control unit is connected to the drive module via the negative pressure regulating unit; the primary single-chip computer and the secondary single-chip computer group both use STM32 series single-chip computers as control chips; and the drive module is provided with an NI interface for receiving NI signals.

2. The output digitally controlled adjustable drive module for power cycling experiment according to claim 1, characterized in that: The secondary single-chip computer groups are arranged in six groups, and the number of the voltage regulating modules and the driving modules is consistent with the number of the secondary single-chip computer groups.

3. The output digitally controlled adjustable drive module for power cycling experiment according to claim 1, characterized in that: Any driving signals are isolated from each other.

4. A method for digitally controlling the output of a power cycle experiment, characterized in that Use the output digitally controlled adjustable drive module for power cycling experiments as described in any one of claims 1 to 3.

5. The output digital control adjustable method for power cycle experiment according to claim 4, characterized in that Specifically: The first-level single-chip microcomputer communicates with the host computer through the serial port, processes the channel selection information of the host computer, and transmits information such as the positive and negative voltage amplitudes to the second-level single-chip microcomputer. The second-level single-chip microcomputer outputs corresponding pulses to the input end of the voltage regulation module according to the given positive and negative voltage amplitudes, thereby obtaining positive and negative voltages.

6. The output digital control adjustable method for power cycle experiment according to claim 5, characterized in that: Each driving signal needs to be isolated, and the power supply of the secondary microcontroller and the voltage regulation module also needs to be isolated.

7. The output digital control adjustable method for power cycle experiment according to claim 6, characterized in that: The positive voltage and negative voltage are input to the driving module at the same time, and the voltage is output according to the signal given by NI: when NI gives a positive voltage signal, the driving circuit outputs a positive voltage; when NI does not give a signal or gives a negative voltage signal, the driving circuit outputs a negative voltage.

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