Content last revised on June 21, 2026
VUO28-12NO7 | 1200V 40A Three-Phase Rectifier Bridge Module
Engineered for superior thermal performance and long-term reliability, the VUO28-12NO7 is a three-phase rectifier bridge featuring a low forward voltage and robust Direct Copper Bonded (DCB) substrate construction. This module integrates six diodes in a three-phase bridge configuration, delivering key specifications of 1200V VRRM | 40A IdAVM | VF = 1.07V. Its primary engineering benefits include high operational efficiency and enhanced thermal cycling durability. The module's DCB substrate provides a low thermal resistance path and withstands mechanical stress from temperature changes, significantly enhancing its reliability in demanding industrial applications. For designers of AC motor drives and power supplies needing a robust front-end rectifier for 400/480V systems, the VUO28-12NO7's low thermal resistance makes it a thermally efficient choice.
Key Parameter Overview
Decoding the Specs for Enhanced Thermal Reliability
The technical specifications of the VUO28-12NO7 are optimized for efficiency and robust operation in industrial power conversion systems. The parameters are grouped below to facilitate engineering evaluation.
| Parameter | Symbol | Conditions | Value |
|---|---|---|---|
| Maximum Ratings | |||
| Repetitive Peak Reverse Voltage | VRRM | 1200 V | |
| Average Forward Current | IdAVM | TC = 100°C; resistive load | 40 A |
| Surge Forward Current | IFSM | TVJ = 45°C, t = 10 ms (50 Hz), sine | 350 A |
| I²t Value | I²t | TVJ = 45°C, t = 10 ms (50 Hz), sine | 610 A²s |
| Electrical Characteristics | |||
| Forward Voltage per Diode | VF | IF = 25 A; TVJ = 25°C | 1.07 V |
| Threshold Voltage | VF0 | For power loss calculation only | 0.85 V |
| Slope Resistance | rF | For power loss calculation only | 9.5 mΩ |
| Reverse Current per Diode | IR | TVJ = 25°C; VR = VRRM | 0.05 mA |
| Thermal and Mechanical Specifications | |||
| Operating Junction Temperature | TVJ | -40 to +150 °C | |
| Storage Temperature | Tstg | -40 to +125 °C | |
| Thermal Resistance, Junction to Case | RthJC | Per diode; DC current | 1.40 K/W |
| Thermal Resistance, Case to Heatsink | RthCH | Module base; flat, greased surface | 0.10 K/W |
| Isolation Test Voltage | VISOL | 50/60 Hz, RMS, t = 1 min | 3000 V~ |
| Weight | Typical | 30 g | |
Download the VUO28-12NO7 datasheet for detailed specifications and performance curves.
Application Scenarios & Value
System-Level Benefits in Industrial Power Conversion
The VUO28-12NO7 is an optimal choice for the front-end rectification stage in a variety of power conversion applications. What is the benefit of low forward voltage? Lower power loss and higher efficiency. Its robust design provides tangible benefits in applications where reliability and thermal efficiency are critical design criteria.
Consider an engineer designing the input rectifier stage for a compact Variable Frequency Drive (VFD) intended for operation within an enclosed cabinet with restricted airflow. The primary challenges are minimizing internal heat generation to prevent thermal derating and ensuring the rectifier can withstand the frequent power cycles associated with motor start/stop operations. The VUO28-12NO7 directly addresses this scenario. Its low forward voltage (VF) of 1.07V at nominal current minimizes conduction losses, which directly reduces the waste heat dissipated into the enclosure. Furthermore, its DCB substrate construction provides superior thermal cycling capability compared to conventional modules, ensuring mechanical integrity and a long service life despite the temperature fluctuations. For applications requiring higher current handling, the related VUB72-16NO1 offers a similar voltage rating with increased output capability.
- AC Motor Drives
- Switched Mode Power Supplies (SMPS)
- DC Power Supplies
- Battery Charging Systems
- Power Tools
Frequently Asked Questions
Engineering Inquiries and Design Considerations
What is the engineering advantage of the 3000V isolation voltage?
The 3000V RMS isolation voltage provides a high degree of electrical separation between the live power circuit and the module's baseplate, which is typically mounted to a grounded heatsink. This simplifies system design by ensuring compliance with safety standards, enhances personnel safety, and prevents potential ground loop issues in complex industrial control systems.
How does the Direct Copper Bonded (DCB) substrate in the VUO28-12NO7 contribute to a longer operational life?
Why is DCB construction important? It improves thermal transfer and long-term reliability. The DCB substrate eliminates traditional solder layers between the ceramic insulator and the copper base. This design is less susceptible to fatigue and cracking caused by the mechanical stress of repeated temperature changes (thermal cycling), a common failure mode in power modules. This inherent robustness results in a significantly longer and more reliable operational life, especially in applications with frequent load variations.
Technical Deep Dive
A Closer Look at the DCB Substrate and its Impact on Thermal Management
At the core of the VUO28-12NO7's reliability is its use of a Direct Copper Bonded (DCB) substrate with an Aluminium Oxide (Al2O3) ceramic insulator. This advanced construction is a critical differentiator from older technologies that rely on soldered baseplates, and it provides two fundamental engineering advantages: superior thermal performance and enhanced mechanical durability.
First, the DCB structure creates a highly efficient, low-resistance path for heat to travel from the semiconductor die to the heatsink. By eliminating solder layers, which act as insulators, the thermal resistance from junction to case (RthJC) is minimized. This is analogous to replacing a narrow, congested side street with a wide, open highway for heat transfer. The practical result is a lower operating junction temperature for a given amount of dissipated power, which directly increases the module's lifespan and allows for more compact thermal management solutions. Second, the close match between the thermal expansion coefficients of copper and Al2O3 ceramic significantly reduces mechanical stress during temperature fluctuations. This resilience prevents the delamination and micro-cracking that plague soldered modules over time, making the VUO28-12NO7 exceptionally well-suited for applications involving frequent power cycling, such as motor drives and welding power supplies.
Get in Touch for Technical and Sourcing Inquiries
To evaluate the VUO28-12NO7 for your application, please contact our technical sales team for further information, datasheets, and sourcing details. We provide engineering-level support to help you integrate this high-reliability rectifier module into your power system designs effectively.
