Our Measuring Instruments & Test Systems
Innovative measurement technology for power semiconductors since 1960
Device Categories
Laboratory
Characteristic curve measuring devices - when it comes to more than just data sheet value.
Production
Measurement technology - our benchmark is what makes sense for production, not just what is technically feasible. Practical solutions for demanding measurement tasks from nA and µV to kA and kV.
Quality Assurance
Today, product quality is the measure of all things and often the essential sales argument. We supply the tools for testing the service life expectancy of your modules - load cycles and high-temperature blocking bearings, parameterizable and remotely controllable, suitable also for your technology.
Power cycling test station
**70% of all power module failures** trace back to bond wire degradation — a component costing less than a cent. A power cycling test station finds these weak points before they appear in the field. By cyclically applying load current and switching off, periodic temperature swings (ΔTj) occur at the semiconductor junction. The CTE mismatch between silicon (2.6 ppm/K), aluminum bond wire (23 ppm/K) and copper (17 ppm/K) generates shear stress at interfaces with every cycle. Typical failure mechanisms: **bond wire lift-off**, **chip metallization cracking**, **solder fatigue**, and **cascading feedback** — a solder crack increases Rth, junction temperature rises, bond stress grows, until a cascade leads to total failure. The ECPE guideline **AQG 324** defines two power cycling test modes and follows a **test-to-failure principle** — not pass/fail at a fixed cycle count, but generating failure knowledge: - **PCsec** (ton < 5 s): Short heating pulses primarily stress bond wires and chip metallization - **PCmin** (ton > 15 s): Longer heating times test solder layers and package attachment Running only one of the two tests means missing half of the possible failure modes. End-of-life criteria per AQG 324: **+20% Rth** or **+5% VCE(sat)**. **SiC modules** pose special requirements: higher operating temperatures (175-200°C) and steeper temperature gradients create more thermomechanical stress per cycle. Modern interconnect technologies such as silver sintering and copper clips achieve up to **29x longer lifetime** compared to conventional soldering. Schuster Elektronik manufactures power cycling test stations for the full power range: - Load currents from 150 A to 1,000 A - Up to 36 test stations per system - Automatic Rth measurement using VCE(T) method - Qualification per AQG 324 (PCsec and PCmin) - Suitable for Si-IGBT, Si-MOSFET, SiC-MOSFET, diodes and thyristors - Network interface for remote monitoring
HTRB, HTGB, H3TRB
HTRB, HTGB, and H3TRB tests are among the most critical reliability tests in power semiconductor qualification. The three tests are **complementary** — each targets a different device area. Running only one means testing only one-third of potential failure mechanisms. ### HTRB — Junction Integrity Under High Voltage **High Temperature Reverse Bias** stresses devices with reverse voltage (80–100% VRRM) at 150–175 °C for 1,000 hours. The test accelerates thermally activated degradation following the Arrhenius model and reveals: - **Ion migration** — mobile ions (Na⁺, K⁺) drift through the oxide under the electric field, altering surface charge - **Crystal defects and dislocations** — lead to increased leakage current under high-temperature reverse voltage - **Edge termination degradation** — defects in guard rings, JTE and field plates at the chip edge - **Passivation aging** — under combined stress of high temperature and high electric field For SiC devices, leakage current may initially increase before stabilizing — a phenomenon not seen in silicon. AQG 324 therefore recommends **trend analysis** instead of fixed thresholds. ### HTGB — The Most Critical Test for SiC **High Temperature Gate Bias** applies maximum gate voltage at 150–175 °C and tests: - **Gate oxide integrity** — can the oxide withstand sustained field stress? - **Threshold voltage drift (ΔVth)** — does the turn-on threshold shift? - **Charge trapping** — do charges accumulate at the oxide-semiconductor interface? - **Time-dependent dielectric breakdown (TDDB)** — when does the oxide fail? For SiC MOSFETs, HTGB is particularly critical: the SiC/SiO₂ interface has **100 to 1,000x higher defect density** than Si/SiO₂. Carbon atoms from the substrate create electron traps that capture charge carriers and shift threshold voltage. A SiC MOSFET with Vth = 3.5 V at room temperature may turn on at 2.0 V or 5.0 V after 1,000 h HTGB — too low means false turn-on and shoot-through, too high means increased on-resistance. HTGB must be performed in **both polarities**: positive bias drives electron trapping, negative bias drives hole trapping. Testing only one polarity reveals only half the truth. ### H3TRB — When Moisture Becomes a Weapon **High Humidity High Temperature Reverse Bias** combines reverse voltage with 85 °C and 85% R.H. for 1,000 hours. The combination of temperature, humidity and electric field drives electrochemical corrosion inside the device: - **Dendrite growth** — metallic whiskers grow under moisture and electric field between conductors, creating short circuits. Without warning, without parameter drift. - **Electrochemical migration** — metal ions (Ag, Cu) migrate along surfaces - **Passivation integrity** — cracks or pores allow moisture to reach the chip H3TRB is not just a package test: especially for SiC where passivation layers are typically thinner, the combination of moisture and high reverse voltage can also attack the chip surface. Since the **AEC-Q101 revision of 2024**, actual rated voltage applies instead of the old 100 V limit. ### DHTRB — Dynamic Testing for SiC and GaN **Dynamic Reverse Bias** — mandatory for automotive SiC modules since AQG 324 Release 04.1/2025. A SiC MOSFET in a traction inverter switches 100,000 to 500,000 times per second. Throughout the entire static HTRB test, the device never switches once. DHTRB replaces static DC voltage with pulsed voltage profiles up to 500 kHz with adjustable duty cycle (25–75%). Dynamic switching creates four stress types that a static test misses entirely: - **Magnetic field-induced bond forces** — steep di/dt transients exert mechanical forces on bond wires - **Dielectric fatigue** — repeated voltage transitions cause trap formation at the gate oxide - **Accelerated electromigration** — dynamic profiles drive migration at material interfaces - **Localized self-heating** — switching transients create thermomechanical micro-cycles ### Standards - **JEDEC JESD22-A108** — worldwide reference standard for HTRB - **IEC 60749-23** — international standard for high-temperature reverse bias tests - **AQG 324 (ECPE)** — mandatory for automotive power modules: HTRB (QL-05), HTGB (QL-06), H3TRB (QL-07) plus dynamic variants (DHTRB, DGS, dynamic H3TRB) for SiC - **AEC-Q101** — automotive qualification for discrete semiconductors - **MIL-STD-750** — requirements for aerospace and defense ### The HTRB 689 by Schuster Elektronik - Test voltage up to ±2,000 V (Si, SiC, GaN) - 18 single specimens or 9 half-bridge modules per station - Bias current measurement up to 300 mA per channel - Temperature measurement up to 200 °C directly at the DUT baseplate - Modular expansion to more than 10 stations - Three operating modes for voltage generation (different ripple modes) - Automatic limit monitoring with immediate shutdown - Independent gate voltage sources per channel for combined HTRB/HTGB tests - Network interface for remote monitoring and data export
Our Product Catalog
Showing 46 products
Devices by Application
Measuring Systems
Devices by Measured Quantity
BVM 625
BLOCKING VOLTAGE MEASUREMENT UNIT
BVM 729
Characteristic Curve Measuring Device
BVM 738
BLOCKING VOLTAGE¬ TESTER FOR POWER SEMICONDUCTORS
DM 659
FORWARD VOLTAGE MEASURING DEVICE
DM 678
FORWARD VOLTAGE MEASURING SYSTEM WITH MULTIPLEXER
DM 714
FORWARD VOLTAGE MEASURING DEVICE
DM 725
FORWARD VOLTAGE MEASURING DEVICE
DM 736
FORWARD VOLTAGE MEASUREMENT UNIT
DM 821
FORWARD VOLTAGE MEASURING DEVICE FOR POWER SEMICONDUCTORS
DQA 775
FORWARD VOLTAGE, GATE CHARGE, AND AVALANCHE MEASURING DEVICE
DT 616
DIODE TESTER
DTS 761
DYNAMIC TEST SYSTEM FOR POWER SEMICONDUCTORS
DVDT 736
DV/DT TESTER FOR THYRISTORS
FVM 625
FORWARD VOLTAGE MEASUREMENT UNIT
GSG 664
GATE STRESS GENERATOR
HTRB 689
TEST SYSTEM FOR HIGH TEMPERATURE REVERSE BIAS OF POWER SEMICONDUCTORS
HTRB 782
TEST STATION FOR HIGH TEMPERATURE REVERSE BIAS
HTRB 784
PRÜFANLAGE FÜR HOCHTEMPERATURSPERRLAGERUNG
IP 625
ISOLATION TESTER
IP 630
ISOLATION TESTER
JT 777
JEDEC TESTER FOR DIODES
KKM 740
CABLE CAPACITY MEASUREMENT DEVICE
KML 710
BLOCKING VOLTAGE TESTER FOR POWER SEMICONDUCTORS
KTM 604
CAPACITY TOLERANCE MEASURING BRIDGE FOR POWER CAPACITORS
LCM 625
MEASURING DEVICE FOR LEAKAGE CURRENT OF MOS-TRANSISTORS AND IGBTs
LRT 640
LOW RESISTANCE TESTER
LRT 703
LOW RESISTANCE TESTER
MLH 634
MEASURING SYSTEM FOR POWER SEMICONDUCTORS
MU 625
MULTIPLEXER
MU 746
MULTIPLEXER
SML 664
BLOCKING VOLTAGE¬ TESTER FOR POWER SEMICONDUCTORS
SML 726
BLOCKING VOLTAGE-TESTER FOR POWER SEMICONDUCTORS
STS 717
TEST SYSTEM FOR SEMICONDUCTORS
STS 805
MEASUREMENT SYSTEM FOR POWER SEMICONDUCTORS
TLW 739
TEST SYSTEM FOR STABILITY OF SEMICONDUCTOR MODULES UNDER LOAD CHANGE
TLW 763
LOAD CYCLE TESTER FOR POWER SEMICONDUCTORS
TLW 800
TEST SYSTEM FOR STABILITY OF SEMICONDUCTOR MODULES UNDER LOAD CHANGE
TLW 813
LOAD CYCLE TESTER FOR POWER SEMICONDUCTORS
TLW 820
LOAD CYCLE TESTER FOR POWER SEMICONDUCTORS
TPS 625
TEST SYSTEM FOR POWER SEMICONDUCTORS
TPS 746
TEST SYSTEM FOR POWER SEMICONDUCTORS
TSM 664
TEST SYSTEM FOR STATIC ELECTRICAL MEASUREMENTS OF POWER SEMICONDUCTORS
TSM 738
TEST SYSTEM FOR POWER SEMICONDUCTORS
WM 694
THERMAL RESISTANCE TESTER FOR POWER SEMICONDUCTORS
ZEH 634
MEASURING DEVICE FOR GATE- TRIGGER-, LATCHING AND HOLDING CURRENT
ZTH 749
THERMAL RESISTANCE TESTER FOR POWER SEMICONDUCTORS
| Model | Description |
|---|---|
| BVM 625 | BLOCKING VOLTAGE MEASUREMENT UNIT |
| BVM 729 | Characteristic Curve Measuring Device |
| BVM 738 | BLOCKING VOLTAGE¬ TESTER FOR POWER SEMICONDUCTORS |
| DM 659 | FORWARD VOLTAGE MEASURING DEVICE |
| DM 678 | FORWARD VOLTAGE MEASURING SYSTEM WITH MULTIPLEXER |
| DM 714 | FORWARD VOLTAGE MEASURING DEVICE |
| DM 725 | FORWARD VOLTAGE MEASURING DEVICE |
| DM 736 | FORWARD VOLTAGE MEASUREMENT UNIT |
| DM 821 | FORWARD VOLTAGE MEASURING DEVICE FOR POWER SEMICONDUCTORS |
| DQA 775 | FORWARD VOLTAGE, GATE CHARGE, AND AVALANCHE MEASURING DEVICE |
| DT 616 | DIODE TESTER |
| DTS 761 | DYNAMIC TEST SYSTEM FOR POWER SEMICONDUCTORS |
| DVDT 736 | DV/DT TESTER FOR THYRISTORS |
| FVM 625 | FORWARD VOLTAGE MEASUREMENT UNIT |
| GSG 664 | GATE STRESS GENERATOR |
| HTRB 689 | TEST SYSTEM FOR HIGH TEMPERATURE REVERSE BIAS OF POWER SEMICONDUCTORS |
| HTRB 782 | TEST STATION FOR HIGH TEMPERATURE REVERSE BIAS |
| HTRB 784 | PRÜFANLAGE FÜR HOCHTEMPERATURSPERRLAGERUNG |
| IP 625 | ISOLATION TESTER |
| IP 630 | ISOLATION TESTER |
| JT 777 | JEDEC TESTER FOR DIODES |
| KKM 740 | CABLE CAPACITY MEASUREMENT DEVICE |
| KML 710 | BLOCKING VOLTAGE TESTER FOR POWER SEMICONDUCTORS |
| KTM 604 | CAPACITY TOLERANCE MEASURING BRIDGE FOR POWER CAPACITORS |
| LCM 625 | MEASURING DEVICE FOR LEAKAGE CURRENT OF MOS-TRANSISTORS AND IGBTs |
| LRT 640 | LOW RESISTANCE TESTER |
| LRT 703 | LOW RESISTANCE TESTER |
| MLH 634 | MEASURING SYSTEM FOR POWER SEMICONDUCTORS |
| MU 625 | MULTIPLEXER |
| MU 746 | MULTIPLEXER |
| SML 664 | BLOCKING VOLTAGE¬ TESTER FOR POWER SEMICONDUCTORS |
| SML 726 | BLOCKING VOLTAGE-TESTER FOR POWER SEMICONDUCTORS |
| STS 717 | TEST SYSTEM FOR SEMICONDUCTORS |
| STS 805 | MEASUREMENT SYSTEM FOR POWER SEMICONDUCTORS |
| TLW 739 | TEST SYSTEM FOR STABILITY OF SEMICONDUCTOR MODULES UNDER LOAD CHANGE |
| TLW 763 | LOAD CYCLE TESTER FOR POWER SEMICONDUCTORS |
| TLW 800 | TEST SYSTEM FOR STABILITY OF SEMICONDUCTOR MODULES UNDER LOAD CHANGE |
| TLW 813 | LOAD CYCLE TESTER FOR POWER SEMICONDUCTORS |
| TLW 820 | LOAD CYCLE TESTER FOR POWER SEMICONDUCTORS |
| TPS 625 | TEST SYSTEM FOR POWER SEMICONDUCTORS |
| TPS 746 | TEST SYSTEM FOR POWER SEMICONDUCTORS |
| TSM 664 | TEST SYSTEM FOR STATIC ELECTRICAL MEASUREMENTS OF POWER SEMICONDUCTORS |
| TSM 738 | TEST SYSTEM FOR POWER SEMICONDUCTORS |
| WM 694 | THERMAL RESISTANCE TESTER FOR POWER SEMICONDUCTORS |
| ZEH 634 | MEASURING DEVICE FOR GATE- TRIGGER-, LATCHING AND HOLDING CURRENT |
| ZTH 749 | THERMAL RESISTANCE TESTER FOR POWER SEMICONDUCTORS |
Have Questions?
We're happy to advise you on our measuring instruments and test systems.