Testing device and testing method for semiconductor three-terminal device SOA curve

Abstract

The application provides a testing device and a testing method for a semiconductor three-terminal device SOA curve, and the testing device comprises an adjustable power supply, an adjustable signal supply and a control and human-computer interaction module, the adjustable power supply is connected with a power terminal and a grounding terminal of a device under test, and is controlled by the control and human-computer interaction module, so as to provide a power voltage with adjustable voltage value for the device under test; the adjustable signal supply is connected with a signal terminal of the device under test, and is controlled by the control and human-computer interaction module, so as to provide a driving signal with adjustable amplitude and adjustable pulse width time for the device under test; the control and human-computer interaction module is connected with the power terminal and the grounding terminal of the device under test, and is used for detecting the voltage of the power terminal of the device under test and the current flowing through the device under test at different time points, and drawing an SOA curve based on the detected voltage and current. Through the testing device and the testing method provided by the application, the problems that the existing device cannot fix one parameter to adjust another parameter, the testing efficiency is low, and there is no energy control circuit and the like are solved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor device testing, and in particular to a testing apparatus and method for testing the SOA curve of a semiconductor three-terminal device. Background Technology

[0002] The safe operating area (SOA) reference curve for traditional devices is provided by each device manufacturer. It is a theoretical curve calculated using parameters such as the device's on-resistance (Rdson) and transient thermal resistance. This curve deviates from the actual curve, which can lead to the risk of device burn-out during actual use. In particular, when the device is used in the critical region of the SOA curve, the risk of burn-out will increase significantly.

[0003] like Figure 1 As shown, the existing SOA curve testing device includes: a control unit, a power source, and a monitoring unit. The gate of the device under test (DUT) is connected to the control unit, the drain of the DUT is connected to the power source, and the source of the DUT is grounded through a sixth resistor. The input terminal of the monitoring unit is connected to the drain voltage and the voltage drop of the sixth resistor, respectively. The control unit includes: a microcontroller U1, a switch B1, a first operational amplifier U2, a second operational amplifier U3, and a sixth resistor R6. The serial input port of the microcontroller U1 is connected to the switch B1, which is grounded at one end. The serial output port is connected to the inverting input terminal of the first operational amplifier U2 through the second resistor R2. The output terminal of the first operational amplifier U2 is connected to one fixed terminal of a variable resistor RV1, and the other fixed terminal is grounded. The adjustment terminal is connected to the inverting input terminal of the second operational amplifier U3 through the fourth resistor R4. The output terminal of the second operational amplifier U3 is connected to the gate of the DUT through the seventh resistor R7.

[0004] The specific testing process is as follows:

[0005] First, when the device under test (DUT) is not installed in the test device, calculate the number of machine cycles required for the microcontroller cycle based on the pulse time, and adjust the pulse time using the microcontroller's built-in function to complete the pulse time setting; or, adjust the pulse time by modifying the values ​​in the microcontroller program, and then re-burn the modified program into the microcontroller to complete the pulse time setting.

[0006] Next, adjust the power source to voltage output mode and set its output voltage to the drain voltage to complete the drain voltage setting; adjust the amplitude of the voltage at the inverting input terminal of the second operational amplifier U3 to be equal to the voltage drop of the sixth resistor R6 through the variable resistor RV1 to complete the drain current setting.

[0007] Finally, the device under test DUT is loaded into the test device, the monitoring unit is connected to the drain voltage and voltage drop respectively, the monitoring unit is set to automatic capture mode, the single-chip microcomputer power supply, power supply and reset switch are turned on in turn, the monitoring unit directly displays the waveforms of the drain voltage and drain current, and the pulse time is automatically read through the time function test function of the monitoring unit;

[0008] When the pulse time is equal to the set value and lasts, the waveforms of the drain voltage and the drain current are normal without clipping, oscillation or spike, the test is passed, and the device under test DUT can normally work under the parameter point condition;

[0009] When the pulse time lasts to a certain moment, the drain voltage rapidly decreases, the drain current rapidly increases, the protection of the power supply is started, when the drain current continues to rise to a certain value, the power supply output is cut off, the drain voltage and the drain current return to zero, the test fails, and the device under test DUT cannot normally work under the parameter point condition.

[0010] The existing SOA curve test device has the following disadvantages:

[0011] 1. When the drain current is adjusted through the variable resistor RV1, the voltage across the device under test DUT changes due to the presence of the sixth resistor R6, so that the voltage and current of the device under test DUT change, so that one parameter (voltage or current) cannot be fixed during the test to adjust the other parameter (current or voltage);

[0012] 2. The device under test DUT is directly connected to the power supply during the test, which requires higher reliability and response time of the power supply, and is extremely unfavorable to the safety of the test personnel and the safety of the equipment;

[0013] 3. The current flowing through the sixth resistor R6 is adjusted by changing the voltage across the variable resistor RV1, and the current is step-adjustable from 0 to 10A, if a higher current range needs to be tested, the resistance and other parameters in the circuit need to be changed to realize, and the universality is poor.

[0014] 4. The whole test process is not automatic and integrated, and the intelligence is too low. SUMMARY

[0015] In view of the above-mentioned disadvantages of the prior art, the purpose of the present application is to provide a test device and a test method for SOA curve of a semiconductor three-terminal device, which is used to solve the above-mentioned many problems existing in the prior art test device.

[0016] To achieve the above-mentioned purpose and other related purposes, the present application provides a test device for SOA curve of a semiconductor three-terminal device, which comprises: an adjustable power supply, an adjustable signal power supply and a control and man-machine interaction module, wherein,

[0017] The adjustable power supply is connected to the power terminal and the ground terminal of the device under test, and is controlled by the control and human-computer interaction module to provide a power voltage with adjustable voltage value for the device under test.

[0018] The adjustable signal supply is connected to the signal terminal of the device under test, and is controlled by the control and human-computer interaction module to provide a driving signal with adjustable amplitude and adjustable pulse width time for the device under test.

[0019] The control and human-computer interaction module is connected to the power terminal and the ground terminal of the device under test, and is used to detect the voltage of the power terminal of the device under test and the current flowing through the device under test at different time points, and draw an SOA curve based on the detected voltage and current.

[0020] Optionally, the test device uses the output characteristics of the device under test to adjust the amplitude of the driving signal output by the adjustable signal supply to step the current flowing through the device under test by fixing the power voltage output by the adjustable power supply, to realize the maximum withstand current test of the device under test under a fixed power terminal voltage.

[0021] Optionally, the test device further comprises an energy control module connected between the adjustable power supply and the device under test, and controlled by the control and human-computer interaction module, used to adjust the number of parallel capacitors according to the size of the current power voltage, charge the parallel capacitors, end the charging when the charging voltage reaches the current power voltage, and discharge the parallel capacitors to provide energy to the power terminal of the device under test.

[0022] Optionally, the test device further comprises a sampling module connected between the energy control module and the control and human-computer interaction module, used to sample the charging voltage; at this time, the control and human-computer interaction module is further used to compare the sampling voltage and the current power voltage, and control the parallel capacitors in the energy control module to end the charging when the sampling voltage reaches the current power voltage.

[0023] Optionally, the energy control module comprises a first-level control switch and N capacitor branches, the first end of the first-level control switch is connected to the output end of the adjustable power supply, the second end of the first-level control switch is connected to the power terminal of the device under test, and N capacitor branches are connected in parallel between the second end of the first-level control switch and the ground; the capacitor branch comprises a capacitor control switch and a capacitor connected in series; wherein, the first-level control switch and the capacitor control switch are controlled by the control and human-computer interaction module, and N is a positive integer greater than or equal to 1.

[0024] Optionally, the energy control module further comprises a second control switch connected between the second end of the first control switch and the power terminal of the device under test, wherein the second control switch is controlled by the control and human-computer interaction module.

[0025] Optionally, the testing device further comprises an isolation module connected between the control and human-computer interaction module and the adjustable power supply, and between the control and human-computer interaction module and the adjustable signal supply; when the testing device further comprises an energy control module, the isolation module is further connected between the control and human-computer interaction module and the energy control module.

[0026] The application further provides a testing method implemented by the semiconductor three-terminal device SOA curve testing device according to any one of the above, the testing method comprising:

[0027] S1: setting detection time points under different pulse width times by the control and human-computer interaction module, setting a voltage range and a first setting step value of a power voltage output by the adjustable power supply, setting an amplitude range and a second setting step value of a driving signal output by the adjustable signal supply, setting a pulse width time range and a third setting step value, and controlling the power voltage of the adjustable power supply, the amplitude of the driving signal of the adjustable signal supply and the pulse width time to start outputting from the minimum value;

[0028] S2: outputting a driving signal to the signal terminal of the device under test and outputting a power voltage to the power terminal of the device under test to drive the device under test; in the current pulse width time, the control and human-computer interaction module detects the voltage of the power terminal of the device under test and the current flowing through the device under test at different detection time points and saves the data;

[0029] If the device under test is not damaged in the current pulse width time, the control and human-computer interaction module steps the amplitude of the driving signal based on the second setting step value, and repeatedly executes the steps of S2 until the amplitude of the driving signal is stepped to the maximum value, at which time the control and human-computer interaction module issues an indication to remind the tester that the device under test has reached the maximum saturation current;

[0030] If the device under test is damaged in the current pulse width time, the control and human-computer interaction module issues an alarm to remind the tester to replace the device under test;

[0031] S3: the control and human-computer interaction module steps the power voltage based on the first setting step value, and controls the amplitude and pulse width time of the driving signal of the adjustable signal supply to start outputting from the minimum value again; the steps of S2-S3 are repeatedly executed until the power voltage is stepped to the maximum value;

[0032] S4: the control and human-computer interaction module steps the pulse width time of the driving signal based on the third setting step value, controls the power voltage of the adjustable power supply and the amplitude of the driving signal of the adjustable signal supply to start outputting from the minimum value again, and repeats the steps of S2-S4 until the pulse width time of the driving signal is stepped to the maximum value.

[0033] S5: the control and human-computer interaction module draws an SOA curve according to the saved voltage and current data and displays the SOA curve.

[0034] Optionally, when the test device further comprises an energy control module and a sampling module, before the driving signal and the power voltage are output to the device under test, S2 further comprises: the control and human-computer interaction module controls the number of parallel capacitors in the energy control module according to the current power voltage, and charges the parallel capacitors based on the current power voltage; the sampling module samples the charging voltage, the control and human-computer interaction module compares the charging voltage and the current power voltage, and controls the energy control module to end charging when the charging voltage reaches the current power voltage.

[0035] Optionally, the method for judging whether the device under test is damaged comprises: the control and human-computer interaction module judges whether the current flowing through the device under test is mutated, and if mutated, judges that the device under test is damaged, otherwise, judges that the device under test is not damaged.

[0036] Optionally, the method for drawing an SOA curve comprises: for an undamaged device, the control and human-computer interaction module draws an SOA point according to the average voltage and the maximum saturation current under the current pulse width time and the current driving signal amplitude; for a damaged device, the control and human-computer interaction module draws an SOA point according to the average voltage and the average current under the current pulse width time and the previous driving signal amplitude.

[0037] As described above, the test device and the test method for the SOA curve of a semiconductor three-terminal device of the present application, through the design of the adjustable power supply, the adjustable signal supply and the control and human-computer interaction module, the current is adjusted by the output characteristics of the device under test, the resistance value does not need to be frequently adjusted, one parameter can be fixed to adjust another parameter, rather than both the voltage and the current changing, the test is time-saving and labor-saving, and the reliability is high; moreover, the device of the present application is an automatic device, the intelligence degree is high, the human-computer interaction is friendly, and the test preparation time and the test time are greatly saved. Through the design of the energy control module, the present application avoids the problem of the adjustable power supply being damaged due to the failure of the device under test and the problem of the device being severely damaged due to the further release of the energy of the capacitor, provides two-level protection for the entire device, and increases the safety. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 shows the circuit diagram of the prior test device.

[0039] Figure 2 shows the circuit diagram of the test device according to the present application.

[0040] Figure 3 shows the curve diagram of the output characteristic of the semiconductor three-terminal device according to the present application.

[0041] Figure 4 shows the flow chart of the test method according to the present application.

[0042] Figure 5 shows the comparison diagram of the measured SOA curve and the theoretical SOA curve.

[0043] Element Number Description

[0044] 100 adjustable power supply

[0045] 200 adjustable signal supply

[0046] 300 control and human-computer interaction module

[0047] 400 energy control module

[0048] 401 capacitor branch

[0049] 500 sampling module DETAILED DESCRIPTION

[0050] The present application is described in detail below with specific reference to particular embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification. The present application can also be implemented or applied in other different embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the present application.

[0051] Reference is made to Figures 2 to 5 . It should be noted that the diagrams provided in the embodiments only schematically illustrate the basic concept of the present application, and although the diagrams only show the components related to the present application, they are not drawn according to the number, shape and size of the components in actual implementation, and the shape, number and proportion of the components in actual implementation can be arbitrarily changed, and the layout form of the components can also be more complex.

[0052] As shown in Figure 2 , the present embodiment provides a test device for the SOA curve of a semiconductor three-terminal device, which comprises an adjustable power supply 100, an adjustable signal supply 200 and a control and human-computer interaction module 300, wherein,

[0053] The adjustable power supply 100 is connected to the power terminal and the ground terminal of the DUT and is controlled by the control and human-computer interaction module 300 to provide the DUT with a power voltage with adjustable voltage value.

[0054] The adjustable signal supply 200 is connected to the signal terminal of the DUT and is controlled by the control and human-computer interaction module 300 to provide the DUT with a driving signal with adjustable amplitude and adjustable pulse width.

[0055] The control and human-computer interaction module 300 is connected to the power terminal and the ground terminal of the DUT to detect the voltage of the power terminal of the DUT and the current flowing through the DUT at different time points and draw an SOA curve based on the detected voltage and current.

[0056] In this embodiment, the test device uses the output characteristics of the DUT to adjust the amplitude of the driving signal output by the adjustable signal supply 200 to step the current flowing through the DUT by fixing the power voltage output by the adjustable power supply 100, i.e., when the power terminal voltage is fixed, the signal terminal voltage is increased from low to high, and the current flowing through the DUT will continuously increase (as shown in the figure), to realize the maximum withstand current test of the DUT under the fixed power terminal voltage, thereby realizing the SOA curve test of the DUT. Figure 3 In actual application, the "signal terminal" in this embodiment generally refers to the control terminal of a semiconductor three-terminal device, such as the gate of a MOSFET, the base of a BJT, and the gate of an IGBT. The "power terminal" generally refers to a connection terminal of a semiconductor three-terminal device for voltage input, such as the drain of an NMOS, the source of a PMOS, the emitter of an NPN, the collector of a PNP, and the collector of an IGBT. The "ground terminal" generally refers to a connection terminal of a semiconductor three-terminal device for grounding, such as the source of an NMOS, the drain of a PMOS, the collector of an NPN, the emitter of a PNP, and the emitter of an IGBT.

[0057] Specifically, the power voltage output by the adjustable power supply 100 is adjusted based on a first set step value within a set voltage range, where the set voltage range and the first set step value can be set by the control and human-computer interaction module 300 according to actual needs, but generally, the set voltage range of the adjustable power supply 100 is wide, such as 0-1500V. In actual application, the adjustable power supply 100 can be implemented by using a linear power supply scheme.

[0058] Specifically, the driving signal output by the adjustable signal power supply 200 is adjusted in amplitude based on a second set step value within a set amplitude range and adjusted in pulse width time based on a third set step value within a set pulse width time range, wherein the set amplitude range, the second set step value, the set pulse width time range and the third set step value can be set according to actual needs through the control and human-computer interaction module 300, but generally, the amplitude of the driving signal output by the adjustable signal power supply 200 is small, such as 0-30V. In actual application, the adjustable signal power supply 200 can be implemented by using a scheme of a flyback topology power supply structure plus a chopping switch tube, wherein the chopping switch tube is connected to the flyback output end of the flyback topology power supply structure; the control and human-computer interaction module 300 controls the on-time of the switch in the flyback topology power supply structure to achieve the purpose of adjusting the amplitude of the driving signal by the second set step value, and controls the on-time of the chopping switch tube to achieve the purpose of adjusting the pulse width time of the driving signal by the third set step value.

[0059] Specifically, the control and human-computer interaction module 300 serves as the general control unit of the test device, for sending instructions to each module, controlling the working time sequence of each module, receiving data sent by each module and performing data processing, etc. In actual application, the control and human-computer interaction module 300 can be implemented by using a scheme of a FPGA / DSP series digital controller plus a human-computer interaction interface, which realizes the control and display in one and also realizes the automation of the test. Alternatively, the embodiment uses a FPGA model EP4CE15E22C8 chip as the digital controller, which has rich internal resources, including 15408 logic units (LE), 504 embedded memories (kbit), 56 embedded multipliers (18"18), 4 general analog phase-locked loops (PLL), 20 global clock networks and 343 user I / O ports.

[0060] Specifically, as shown in FIG. 2, the test device comprises a control and human-computer interaction module 300, a signal source module 100, a signal processing module 200, a signal output module 400 and a signal receiving module 500. Figure 2As shown, the test device further comprises an energy control module 400 connected between the adjustable power supply 100 and the DUT and controlled by the control and man-machine interaction module 300, for adjusting the number of parallel capacitors according to the size of the current power voltage, charging the parallel capacitors, ending the charging when the charging voltage reaches the current power voltage, and providing energy to the power end of the DUT through the discharge of the parallel capacitors. Correspondingly, the test device further comprises a sampling module 500 connected between the energy control module 400 and the control and man-machine interaction module 300, for sampling the charging voltage; at this time, the control and man-machine interaction module 300 is further used for comparing the sampling voltage and the current power voltage, and controlling the parallel capacitors in the energy control module 400 to end the charging when the sampling voltage reaches the current power voltage. In this embodiment, by additionally arranging the energy control module 400 between the adjustable power supply 100 and the DUT, the DUT and the adjustable power supply 100 can be isolated during the test of the DUT, avoiding the problem that the adjustable power supply 100 is damaged due to the failure of the DUT, greatly improving the safety of the adjustable power supply 100, and further reducing the equipment maintenance and purchase cost.

[0061] More specifically, as Figure 2As shown, the energy control module 400 comprises: a first-stage control switch T1 and N capacitor branches 401, a first end of the first-stage control switch T1 is connected to an output end of the adjustable power supply 100, a second end of the first-stage control switch T1 is connected to a power end of the device under test DUT, and the N capacitor branches 401 are connected in parallel between the second end of the first-stage control switch T1 and the ground; the capacitor branch 401 comprises: a capacitor control switch S1-Sn and a capacitor C1-Cn, which are connected in series; wherein, the first-stage control switch T1 and the capacitor control switch S1-Sn are controlled by the control and human-computer interaction module 300, and N is a positive integer greater than or equal to 1. Further, the energy control module 400 further comprises: a second-stage control switch T2, which is connected between the second end of the first-stage control switch T1 and the power end of the device under test DUT, wherein the second-stage control switch T2 is controlled by the control and human-computer interaction module 300. In this embodiment, the first-stage control switch T1 serves as a total switch for capacitor charging, and plays a role of isolating the device under test DUT and the adjustable power supply 100 during the testing process of the device under test DUT; the second-stage control switch T2 is used to disconnect the connection between the device under test DUT and the N parallel capacitor branches 401 when the device under test DUT fails, so as to prevent the problem of serious device damage caused by further release of capacitor energy. Alternatively, the first-stage control switch T1, the second-stage control switch T2 and the capacitor control switch S1-Sn can be selected from any one of MOSFET, BJT, IGBT and relay, of course, other devices capable of playing a switching role are also applicable to this embodiment.

[0062] In order to make the parallel capacitor provide an approximately fixed voltage to the power end of the device under test DUT during discharging, the number of parallel capacitors needs to be set according to the power voltage output by the adjustable power supply 100, satisfying the formula: n=(20.5W) / (C1V1 2 ), wherein n is the number of parallel capacitors, W is the damage energy (theoretical value) of the device under test DUT, C1 is the capacitance value (the same for each capacitor), and V1 is the charging voltage, that is, the current power voltage; the specific derivation process is as follows: during the testing process of the device under test DUT, the voltage across the parallel capacitor slightly decreases due to discharging for the device under test DUT, assuming that the voltage across the parallel capacitor before discharging is V1, and the voltage across the parallel capacitor after discharging is V2, and the acceptable voltage drop amplitude is 5% of V1, then there is the formula V1-V2=5%V1; when the damage energy of the device under test DUT is W, and the current total capacitance is C, during the capacitor discharging process, it satisfies the formula (1 / 2)*CV1 2 -(1 / 2)*CV22 =W; When the capacitance of each capacitor is C1, the number of capacitors required to be connected in parallel satisfies the formula n = C / C1; Combining the above three formulas, we can get the formula n = (20.5W) / (C1V1) 2 It should be noted that the "acceptable voltage drop" can be set according to actual needs and does not necessarily have to be set to 5% of V1. The formula for the number of parallel capacitors n varies slightly depending on the set value of the "acceptable voltage drop", but this has no substantial impact on this embodiment.

[0063] Specifically, the testing device further includes an isolation module (not shown in the figure), connected between the control and human-machine interaction module 300 and the adjustable power supply 100, and between the control and human-machine interaction module 300 and the adjustable signal power supply 200; when the testing device also includes an energy control module 400, the isolation module is also connected between the control and human-machine interaction module 300 and the energy control module 400. In this embodiment, by adding the isolation module between the control and human-machine interaction module 300 and the adjustable power supply 100, the adjustable signal power supply 200, and the energy control module 400, isolation protection is achieved, preventing the small signal generated by the control and human-machine interaction module 300 from being affected by the large signal generated by other modules; in practical applications, the isolation module can be implemented using an optocoupler isolation scheme.

[0064] like Figure 4 As shown, this embodiment also provides a test method implemented using the semiconductor three-terminal device SOA curve testing device described above, the test method including:

[0065] S1: The control and human-machine interaction module sets the detection time point under different pulse width times, the set voltage range and first set step value of the power voltage output by the adjustable power supply, the set amplitude range and second set step value of the drive signal output by the adjustable signal power supply, the set pulse width time range and third set step value, and controls the power voltage of the adjustable power supply, the amplitude of the drive signal of the adjustable signal power supply and the pulse width time to be output from the minimum value.

[0066] S2: Output a drive signal to the signal terminal of the device under test and output a power voltage to the power terminal of the device under test to drive the device under test; within the current pulse width time, the control and human-machine interaction module detects the power terminal voltage of the device under test and the current flowing through the device under test at different detection time points and saves the data.

[0067] If the device under test is not damaged within the current pulse width time, the control and human-machine interaction module steps the amplitude of the drive signal based on the second set step value, and repeats step S2 until the amplitude of the drive signal is stepped to the maximum value. At this time, the control and human-machine interaction module issues an instruction to remind the tester that the device under test has reached the maximum saturation current.

[0068] If the device under test is damaged within the current pulse width time, the control and human-machine interaction module will issue an alarm to remind the tester to replace the device under test.

[0069] S3: The control and human-machine interaction module steps the power voltage based on the first set step value, and controls the amplitude and pulse width of the adjustable signal power supply drive signal to start outputting from the minimum value again; repeat steps S2-S3 until the power voltage is stepped to the maximum value, and obtain the data of an SOA curve under the pulse width time.

[0070] S4: The control and human-machine interaction module steps the pulse width time of the drive signal based on the third set step value, and controls the power voltage of the adjustable power supply and the amplitude of the drive signal of the adjustable signal power supply to start outputting from the minimum value again; repeat steps S2-S4 until the pulse width time of the drive signal is stepped to the maximum value, and obtain data of multiple SOA curves under different pulse width times.

[0071] S5: The control and human-machine interaction module plots and displays the SOA curve based on the saved voltage and current data.

[0072] For S1, the detection time point is positively correlated with the pulse width time, that is, the larger the pulse width time, the more detection time points should be set, and vice versa. In practical applications, the control and human-machine interaction module sets the detection time point based on its own sampling rate. At this time, the higher the sampling accuracy of the control and human-machine interaction module, that is, the more detection time points, the more accurate the SOA curve it plots.

[0073] For S2, the method for determining whether the device under test (DUT) is damaged includes: the control and human-machine interface module determines whether the current flowing through the DUT undergoes a sudden change; if a sudden change occurs, the DUT is determined to be damaged; otherwise, the DUT is determined to be undamaged. The control and human-machine interface module can distinguish between the data of undamaged devices and the data of damaged devices, such as by specially identifying the data of undamaged devices (e.g., using color, marking, etc.) and not specially identifying the data of damaged devices, to facilitate subsequent SOA curve plotting.

[0074] When the test device further includes an energy control module and a sampling module, before outputting a driving signal and a power voltage to the device under test, S2 further includes: the control and human-computer interaction module controls the number of parallel capacitors in the energy control module according to the current power voltage, and charges the parallel capacitors based on the current power voltage; the sampling module samples the charging voltage, and the control and human-computer interaction module compares the charging voltage with the current power voltage, and when the charging voltage reaches the current power voltage, controls the energy control module to end the charging. In practical applications, the control and human-computer interaction module can control the number of capacitor control switches S1-Sn in the energy control module according to the current power voltage, so as to control the number of parallel capacitors; then controls the first-stage control switch T1 to turn on, charges the parallel capacitors, and when the charging voltage reaches the current power voltage, controls the first-stage control switch T1 to turn off to end the charging. When the adjustable signal power supply outputs a driving signal to the signal terminal of the device under test, the control and human-computer interaction module controls the second-stage control switch T2 to turn on and discharges to the power terminal of the device under test; after the current pulse width time ends, the adjustable signal power supply is turned off, and the control and human-computer interaction module controls the second-stage control switch T2 and the relevant capacitor control switches to turn off. When the device under test is damaged, the control and human-computer interaction module immediately controls the second-stage control switch T2 to turn off, preventing serious device damage caused by further release of capacitor energy.

[0075] For S5, the method for drawing the SOA curve includes: for an undamaged device, the control and human-computer interaction module draws an SOA point according to the average voltage and the maximum saturation current at the current pulse width time and the current driving signal amplitude; for a damaged device, the control and human-computer interaction module draws an SOA point according to the average voltage and the average current at the current pulse width time and the previous driving signal amplitude. In practical applications, in addition to observing the displayed SOA curve at the control and human-computer interaction module end, testers can also view historical data.

[0076] Figure 5 A SOA curve of the MOSFET obtained by the test device and test method of this embodiment, where the pulse width time is 1 ms; from Figure 5 It can be seen that there is a relatively obvious gap between the measured curve and the theoretical curve, and the measured curve is closer to the actual situation.

[0077] In summary, the testing apparatus and method for SOA curves of semiconductor three-terminal devices of the present invention, through the design of an adjustable power supply, an adjustable signal power supply, and a control and human-machine interface module, utilizes the output characteristics of the device under test (DUT) to adjust the current, eliminating the need for frequent resistance adjustments. Furthermore, it allows for the fixing of one parameter while adjusting another, rather than both voltage and current changing, resulting in time-saving, labor-saving, and highly reliable testing. Moreover, the device of the present invention is automated, highly intelligent, and features a user-friendly human-machine interface, significantly reducing test preparation and testing time. The present invention also avoids the problem of damage to the adjustable power supply due to DUT failure and severe device damage caused by further release of capacitor energy through the design of the energy control module, providing two levels of protection for the entire device and increasing safety. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0078] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A testing apparatus for SOA curves of semiconductor three-terminal devices, characterized in that, The testing device includes: an adjustable power supply, an adjustable signal power supply, and a control and human-machine interaction module, wherein... The adjustable power supply is connected to the power terminal and ground terminal of the device under test (DUT) and is controlled by the control and human-machine interface module to provide the DUT with an adjustable power voltage. The adjustable signal power supply is connected to the signal terminal of the device under test and is controlled by the control and human-machine interaction module to provide the device under test with an adjustable amplitude and an adjustable pulse width and time drive signal. The control and human-machine interaction module is connected to the power terminal and ground terminal of the device under test (DUT) and is used to detect the power terminal voltage and current flowing through the DUT at different time points, and to plot the SOA curve based on the detected voltage and current. The testing device utilizes the output characteristics of the device under test (DUT) by fixing the power voltage output by the adjustable power supply and adjusting the amplitude of the drive signal output by the adjustable signal power supply from low to high, thereby increasing the current flowing through the DUT step by step and achieving the maximum withstand current test of the DUT under a fixed power terminal voltage.

2. The testing apparatus for SOA curves of semiconductor three-terminal devices according to claim 1, characterized in that, The testing device further includes an energy control module, connected between the adjustable power supply and the device under test, and controlled by the control and human-machine interaction module, for adjusting the number of parallel capacitors according to the current power voltage and charging the parallel capacitors, ending charging when the charging voltage reaches the current power voltage, and providing energy to the power terminal of the device under test through the discharge of the parallel capacitors.

3. The testing apparatus for SOA curves of semiconductor three-terminal devices according to claim 2, characterized in that, The testing device further includes a sampling module connected between the energy control module and the control and human-machine interaction module, used to sample the charging voltage; at this time, the control and human-machine interaction module is also used to compare the sampled voltage with the current power voltage, and when the sampled voltage reaches the current power voltage, control the parallel capacitor in the energy control module to end charging.

4. The testing apparatus for SOA curves of semiconductor three-terminal devices according to claim 2, characterized in that, The energy control module includes: a first-level control switch and N capacitor branches. The first end of the first-level control switch is connected to the output end of the adjustable power supply, and the second end of the first-level control switch is connected to the power end of the device under test. The N capacitor branches are connected in parallel between the second end of the first-level control switch and ground. Each capacitor branch includes a capacitor control switch and a capacitor connected in series. Both the first-level control switch and the capacitor control switch are controlled by the control and human-machine interaction module, and N is a positive integer greater than or equal to 1.

5. The testing apparatus for SOA curves of semiconductor three-terminal devices according to claim 4, characterized in that, The energy control module further includes a second-level control switch, which is connected between the second terminal of the first-level control switch and the power terminal of the device under test, wherein the second-level control switch is controlled by the control and human-machine interaction module.

6. The testing apparatus for SOA curves of semiconductor three-terminal devices according to any one of claims 1-5, characterized in that, The testing device further includes: an isolation module connected between the control and human-machine interaction module and the adjustable power supply, and between the control and human-machine interaction module and the adjustable signal power supply; when the testing device further includes an energy control module, the isolation module is also connected between the control and human-machine interaction module and the energy control module.

7. A testing method using the semiconductor three-terminal device SOA curve testing apparatus as described in any one of claims 1-6, characterized in that, The testing method includes: S1: The control and human-machine interaction module sets the detection time point under different pulse width times, the set voltage range and first set step value of the power voltage output by the adjustable power supply, the set amplitude range and second set step value of the drive signal output by the adjustable signal power supply, the set pulse width time range and third set step value, and controls the power voltage of the adjustable power supply, the amplitude of the drive signal of the adjustable signal power supply and the pulse width time to be output from the minimum value. S2: Output a drive signal to the signal terminal of the device under test and output a power voltage to the power terminal of the device under test to drive the device under test; within the current pulse width time, the control and human-machine interaction module detects the power terminal voltage of the device under test and the current flowing through the device under test at different detection time points and saves the data. If the device under test is not damaged within the current pulse width time, the control and human-machine interaction module steps the amplitude of the drive signal based on the second set step value, and repeats step S2 until the amplitude of the drive signal is stepped to the maximum value. At this time, the control and human-machine interaction module issues an instruction to remind the tester that the device under test has reached the maximum saturation current. If the device under test is damaged within the current pulse width time, the control and human-machine interaction module will issue an alarm to remind the tester to replace the device under test. S3: The control and human-machine interaction module steps the power voltage based on the first set step value, and controls the amplitude and pulse width of the adjustable signal power drive signal to start outputting from the minimum value again; repeat steps S2-S3 until the power voltage is stepped to the maximum value; S4: The control and human-machine interaction module steps the pulse width time of the drive signal based on the third set step value, and controls the power voltage of the adjustable power supply and the amplitude of the drive signal of the adjustable signal power supply to start outputting from the minimum value again; repeat steps S2-S4 until the pulse width time of the drive signal is stepped to the maximum value. S5: The control and human-machine interaction module plots and displays the SOA curve based on the saved voltage and current data.

8. The test method according to claim 7, characterized in that, When the testing device further includes an energy control module and a sampling module, before outputting a drive signal and power voltage to the device under test, S2 further includes: the control and human-machine interaction module controlling the number of parallel capacitors in the energy control module according to the current power voltage, and charging the parallel capacitors based on the current power voltage; the sampling module sampling the charging voltage; the control and human-machine interaction module comparing the charging voltage and the current power voltage; and controlling the energy control module to end charging when the charging voltage reaches the current power voltage.

9. The test method according to claim 7, characterized in that, The method for determining whether the device under test is damaged includes: the control and human-machine interaction module determines whether the current flowing through the device under test changes abruptly; if abrupt change occurs, the device under test is determined to be damaged; otherwise, the device under test is determined to be undamaged.

10. The test method according to claim 7, characterized in that, The method for plotting SOA curves includes: for undamaged devices, the control and human-machine interaction module plots SOA points based on the average voltage and maximum saturation current under the current pulse width time and the current drive signal amplitude; for damaged devices, the control and human-machine interaction module plots SOA points based on the average voltage and average current under the current pulse width time and the previous drive signal amplitude.

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