SKKH72/22EH4: A 2200V Dual Thyristor Module with Integrated Thermal Management
Content last revised on October 24, 2025.
M1. SEO Title
SKKH72/22EH4 Thyristor Module: 2200V, 75A Dual SCR for Reliable AC Control
M2. Introduction & Key Highlights
Engineered for high-voltage AC control, the Semikron SKKH72/22EH4 integrates a robust 2200V thyristor pair with a factory-fitted heatsink, maximizing thermal performance and simplifying system assembly for enhanced long-term reliability. This module provides critical performance with specifications of 2200V | 75A (ITAV) | Electrically Isolated Baseplate. The key engineering benefits include guaranteed thermal transfer and simplified mechanical assembly. It directly addresses the need for robust power control in demanding industrial environments by providing a pre-validated thermal solution, mitigating risks of improper mounting. For high-voltage AC soft starters and phase controllers demanding proven thermal reliability out of the box, this 2200V module is the optimal choice.
B3. Key Parameter Overview
Decoding the Specs for Thermal Integrity and High-Voltage Operation
The technical specifications of the SKKH72/22EH4 are tailored for robust performance in industrial power control systems. The module's design emphasizes high voltage capability, dependable current handling, and superior thermal characteristics. What is the primary benefit of the integrated EH4 heatsink? It ensures validated thermal performance and significantly simplifies assembly.
| Electrical Characteristics (Tcase = 100°C unless otherwise specified) | |
|---|---|
| Repetitive Peak Off-State and Reverse Voltage (VDRM, VRRM) | 2200V |
| Average On-State Current (ITAV @ Tcase = 85°C) | 75A |
| RMS On-State Current (ITRMS) | 125A |
| Gate Trigger Current (IGT) | typ. 60 mA |
| Thermal and Mechanical Specifications | |
| Thermal Resistance, Junction to Case (Rth(j-c)) | 0.32 K/W (per thyristor) |
| Operating Junction Temperature (Tvj) | -40°C to +125°C |
| Isolation Test Voltage (Visol) | 3000V (RMS, t = 1 min) |
| Housing | SEMIPACK® 1 with Integrated Heatsink (H4) |
This data is a summary of key parameters. For comprehensive details, including characteristic curves and application notes, please refer to the official documentation.
Download the SKKH72/22EH4 datasheet for detailed specifications and performance curves.
B2. Application Scenarios & Value
System-Level Benefits in Industrial AC Power Control
The SKKH72/22EH4 is optimized for AC power control applications where high voltage and reliability are non-negotiable. Its primary function is to act as a solid-state switch for alternating current, making it a cornerstone component in a variety of industrial systems.
A high-fidelity engineering scenario is its use in a Soft Starter for a three-phase induction motor driving a high-inertia load, such as a large industrial ventilation fan. During startup, such motors draw immense inrush currents, and the AC line can experience significant voltage stress. The SKKH72/22EH4's 2200V blocking voltage provides a substantial safety margin on 400V or 690V AC lines, preventing device failure due to transient overvoltages. The integrated heatsink ensures that the thyristor junctions remain within the safe operating temperature range during the repeated, high-stress startup cycles, enhancing the long-term reliability of the entire motor control system.
This module's capabilities are particularly valuable in:
- AC Motor Soft Starters
- Industrial Furnace and Temperature Controls
- Professional Light Dimming Systems (e.g., for theaters)
- AC Motor Speed Control
While the SKKH72/22EH4 provides robust performance, for applications on standard 400V lines that may not require such a high voltage margin but demand higher current handling, the related SKKH92/16E offers a 1600V rating with a higher average current capability.
B1. Technical Deep Dive
A Closer Look at the Integrated Thermal Solution and Electrical Isolation
The "EH4" suffix in the SKKH72/22EH4 part number signifies more than just a component; it represents an integrated engineering solution that directly addresses a common source of field failure: improper heatsink mounting. By integrating the heatsink at the factory, Semikron eliminates variables such as incorrect thermal paste application, uneven mounting pressure, and selection of an inadequate heatsink. This ensures that the specified Thermal Resistance is consistently achieved, providing predictable and reliable thermal performance.
Furthermore, the module is built with an electrically isolated metal baseplate, which utilizes an aluminium oxide (Al2O3) ceramic substrate. This design feature is critical for system-level safety and simplicity. The high dielectric strength of the ceramic substrate isolates the live electrical components from the heatsink and chassis, simplifying the mechanical design of the enclosure and reducing the risk of shock or short circuits. This allows designers to mount the module directly to a grounded chassis without needing additional, often costly and thermally inefficient, insulating layers. This construction is a key enabler for building compact and robust power assemblies compliant with safety standards like UL recognition.
B7. FAQ
Engineering Inquiries on Integration and Reliability
What is the primary engineering advantage of the factory-installed 'EH4' heatsink?
The primary advantage is guaranteed thermal performance. It removes the guesswork and potential for error in heatsink selection and mounting, a critical step where incorrect torque or thermal interface material can lead to premature failure. This pre-validated solution simplifies assembly, reduces labor costs, and increases the end-product's field reliability.
How does the 2200V VDRM rating benefit a system running on a 690V AC line?
A 690V AC line has a peak voltage of approximately 975V. The 2200V rating provides a safety factor of more than 2.2x. This significant margin is crucial for absorbing transient overvoltages caused by line fluctuations, lightning strikes, or switching of other inductive loads. This robustness prevents the thyristor from failing due to overvoltage stress, which is a critical reliability factor in harsh industrial environments.
In what way does the electrically isolated baseplate simplify the overall mechanical and electrical design?
The isolated baseplate allows the module to be mounted directly onto a grounded metal chassis or heatsink without any additional insulating pads or bushings. This simplifies the mechanical layout, reduces the number of parts in the bill of materials, improves heat transfer compared to using external insulators, and enhances the overall dielectric safety of the power assembly.
Take the Next Step in Your Design
For engineers developing high-reliability AC power control systems, the SKKH72/22EH4 offers a streamlined path to a robust and thermally optimized design. To further evaluate its suitability for your specific application or to discuss your system's power requirements, please review the detailed datasheet or contact our technical support team for further information.
