BW-IFSM/ITSM Inrush Current Tester

                  BW-IFSM/ITSM Surge Current Tester

(Square wave 100μm-10ms/＜1000A, Sine wave 100μm-10ms/＞3000A) Heatable

The surge current test system BW-ITSM (Square wave 100μm-10ms/＜1000A, Sine wave 100μm-10ms/＞3000A) is an important detection equipment for testing SIC-related semiconductor devices.

Test Principle:

• Simulating Surge Current Generation: Specialized circuits or devices are typically used to simulate surge current conditions that may occur in power systems. For example, based on the principle of LC oscillation circuits, rapid capacitor discharge and inductor energy storage/release processes generate surge currents with specific waveforms and amplitudes. Some systems also use power devices such as thyristors to control the discharge process and precisely adjust surge current parameters.

• Response Detection and Analysis: When subjected to surge current, the device under test produces corresponding electrical responses, such as voltage fluctuations, current changes, and alterations in operating status. The test system records these responses using voltage sensors and data acquisition equipment, then processes and analyzes the collected data with software to evaluate the device's surge current tolerance and response characteristics.

Test Significance:

• Assessing Device Reliability: It verifies whether the device may malfunction or be damaged under surge current impact, ensuring stable operation in harsh power environments and providing critical evidence for device quality and reliability. For instance, in power systems, surge current testing ensures the safe operation of transformers, switches, and other equipment during lightning strikes or other surge conditions.

• Features:

1) The system's test control is fully automated, allowing tests to proceed automatically according to the program set by the operator.

2) The system uses a computer to record test results and can convert them into Excel files for processing.

3) The test equipment mainly consists of the following units:

a. Surge Test Unit

b. Blocking Test Unit

c. Automatic Heating and Temperature Control System

d. Computer Control System, where parameter setting, test data recording, and waveform saving are all handled by the computer, enabling one-click testing.

4) Relevant standards referenced: JBT-7624-2013 "Rectifier Diode Test Methods" GB/T 4023-2015/IEC 60747-2:200

I. Technical Conditions

1. Surge Test Unit IFSM

Sine half-wave surge current range: Short-circuit current 50～3000A, resolution 1A, accuracy <2%±1,

Low range: 50～200A, computer-set High range: 100～3000A, computer-set

b. Surge current base width: 0.1ms, 1ms, 8.3ms, 10ms sine half-wave, deviation less than ±3%, single selection.

c. Surge current repeat test interval (adjustable): 2S～300S.

e. Voltage drop test under surge current: Voltage drop test range 0.01-50V, resolution 0.001V, accuracy <2%±0.01

f. Forward surge waveform and conduction voltage drop waveform can be automatically displayed and saved on the computer. Waveform data can also be saved.

g. Square wave surge: Current width 100-5000us, parameters adjustable arbitrarily

h. Square wave current range: Width: Square wave 100-1000us: Corresponding current 50-1000A

Square wave 5-10mS: Corresponding current 50-500A

Square wave 0.1-1mS: Corresponding current 50-1000A

Surge current output mode: Single, Repeat (current unchanged, repeated testing), Increment (test current increases automatically by set step until target or failure)

Heating automatic temperature control system, includes two sets: module for base plate heating control, discrete devices for manual small heating control. Temperature control range: 25-180℃, temperature control error less than 2%, temperature set manually.

2. Blocking Test (used to determine if the device fails after surge current)

a. Forward and reverse voltage test range: 50V～500V adjustable, resolution 1V, accuracy <2%±1.

Set leakage current upper limit protection, then test voltage; if test leakage current exceeds set value, stop applying high voltage. Judged as conduction failure.

b. Reverse voltage output mode: DC, forward and reverse output c. Leakage current: 0.001～10mA, resolution 0.001mA, accuracy ±5% of full scale

e. Test process: Computer-set, one-click automatic testing; automatically determines if surge failure occurs and saves test data

g. Suitable packages: Various diodes, MOS, IGBT, etc., packages such as TO straight plug or modules, two interfaces: straight plug interface below 1000A, and module interface (cabinet side), all interfaces require manual device connection.

3. MOS Device Forward Conduction, Reverse (Body Diode) Test

Forward conduction test: Gate voltage: 5-25V settable, judge blocking voltage apply forward voltage Reverse conduction test: Gate voltage: -10-0V settable, judge blocking voltage apply reverse voltage.

Parameter setting mainly involves several key parameters as shown in Figure 11, including reverse protection voltage, protection current (set leakage current upper limit), pulse interval time (repeat test time), pulse count (repeat count), etc. Note that parameters must not exceed system set range, e.g., pulse count 1-20 times, if input 30, system defaults to 20.

Current width: Select 10uS or 10mS

Current mode: Square wave or sine wave

Current range switching: Low range (50-200A), High range (100-3000A), Square wave 50-1000A

Surge current mode: Single, Repeat, or Increment

Increment test: Set high range current, then set starting current, increment step amount Increment current

E.g.: High range current set 100A, starting current 70A, increment 5A, click run, test stops at 100A

Pulse count is the repeat count

Other diode surge testing:

Can be used for forward surge current (IFSM) testing of various diodes (Diode) and silicon-controlled rectifiers (SCR), including triodes (Triode), MOSFET, IGBT, and other fully controlled devices' built-in diode surge testing. ** **Diode components in practical use, besides long-term rated on-state average current, should also withstand certain multiples of surge overload current without damage to meet various application requirements. If diode surge overload current exceeds allowable range, it may cause performance degradation (such as changes in V-I characteristics, on-state peak voltage) **

Technical Specifications:

Surge current (IFSM/ITSM) adjustment range: 0.30～3.60kA

Resolution 0.01kA, accuracy ±3%±0.01kA

Current waveform: Sine half-wave, base width 10ms

Test frequency: Single

Reverse voltage (VRRM) adjustment range: 0.20～2.00kV, resolution 0.01kV, accuracy ±5％

Reverse voltage test frequency: 50Hz;

Reverse leakage current (IRRM) test range; 1.0～100.0mA, resolution 0.1mA, accuracy ±5％±0.1mA

Operating Mode:

Set surge current magnitude, reverse voltage value, and reverse leakage current protection value via touch LCD screen

The above equipment configuration includes output and test cables, but does not include test "fixtures". The "fixtures" are used to meet the temperature and pressure test conditions required for standard component testing.