Content last revised on November 21, 2025
SKKH106/08E Semikron Thyristor/Diode Module | 800V 106A SEMIPACK 1
The SKKH106/08E by Semikron (now Semikron Danfoss) represents a proven standard in phase control and rectification, housed in the industry-staple SEMIPACK 1 package. Designed specifically for reliability in 230V industrial grids, this module combines a thyristor and a diode in a series connection, offering a robust solution for soft starters, temperature control, and input rectifier bridges. Its 800V rating (VRRM) is precisely calibrated for low-voltage mains, avoiding the unnecessary cost overhead of higher-voltage blocking capabilities while maintaining ample safety margins for standard line fluctuations.
Engineers favor the SKKH106/08E for its high surge current capability and established thermal performance. Unlike lighter-duty alternatives, this module utilizes hard-soldered joints and an isolated metal baseplate to ensure consistent heat transfer and mechanical stability under cyclic loads. For systems requiring 1600V blocking capabilities, the related SKKH106/16E offers identical mechanical dimensions with enhanced voltage headroom.
Best Fit: For 230V soft starters requiring compact thermal efficiency and proven surge resistance, this 800V module is the optimal choice.
Core Specifications
- Voltage (VRRM): 800V
- Current (IT(AV)): 106A @ Tc=85°C
- Package: SEMIPACK 1
Key Benefits
- Optimized for 230V: Ideal voltage scaling for standard single/three-phase low-voltage grids.
- High Surge Rating: Excellent I²t performance for handling start-up inrush currents.
Application Scenarios & Value
Tailoring Phase Control for 230V Industrial Heating
In the realm of industrial resistive heating—such as plastic injection molding heaters or small electric furnaces—precise temperature control is paramount. The SKKH106/08E excels in these phase-angle control applications operating on 230V lines. A common engineering challenge in these environments is managing the thermal stress cycling caused by frequent on/off switching or modulation. The SEMIPACK 1 housing addresses this through its isolated copper baseplate, which facilitates low thermal resistance (Rth(j-c)) and efficient heat spreading to the heatsink.
For instance, in a three-phase controlled bridge configuration supplying a 25kW heater bank, the 106A average current rating provides a comfortable safety margin, allowing the device to run cooler and prolonging its operational life. The thyristor/diode topology simplifies the circuit layout compared to dual-thyristor modules, as the diode provides the necessary freewheeling path or half-wave rectification inherent to the bridge design, reducing component count and system cost.
System Design Note: While the 800V rating is robust for 230V applications (providing a >3x safety factor against the 325V peak), engineers designing for 400V or 480V grids should evaluate the SKKH106/16E, which provides the necessary 1200V+ blocking voltage to withstand transient spikes typical of higher voltage lines.
Key Parameter Overview
Decoding the Specs for Enhanced Thermal Reliability
The following table highlights the critical electrical and thermal characteristics of the SKKH106/08E. Understanding these figures is essential for calculating the necessary heatsink size and verifying the safety operating area (SOA) for your specific application.
| Parameter | Symbol | Typical/Max Value | Unit |
|---|---|---|---|
| Repetitive Peak Reverse Voltage | VRRM | 800 | V |
| Average On-State Current | IT(AV) | 106 (@Tc=85°C) | A |
| Surge Current (10ms) | ITSM | ~2250 | A |
| Threshold Voltage | VT(TO) | ~0.85 | V |
| Thermal Resistance (Junction to Case) | Rth(j-c) | 0.28 (per chip) / 0.14 (module) | K/W |
| Isolation Voltage | Visol | 3000 (1 min) | V |
Download the SKKH106/08E datasheet for detailed specifications and performance curves.
Technical Deep Dive
Structural Integrity and Thermal Pathways in the SEMIPACK 1
The reliability of the SKKH106/08E is deeply rooted in its physical construction. The SEMIPACK 1 module utilizes a multi-layered architecture designed to manage both electrical isolation and thermal conductivity. At its core, the silicon die is soldered onto a Direct Bonded Copper (DBC) substrate. This DBC layer is critical; it acts like a thermal highway, efficiently transferring heat generated at the junction (Tj) through to the baseplate while maintaining high electrical isolation (typically 3000V AC).
Imagine the heat transfer process as a vehicle moving through traffic. If the road (thermal path) is narrow or congested (high thermal resistance), the engine (chip) overheats. The SKKH106/08E’s construction ensures a "multi-lane highway" with a low Rth(j-c) of approximately 0.14 K/W for the complete module. This low impedance is vital during high-load conditions, such as motor starting, where the I²t value (a measure of energy the device can absorb before failing) becomes a limiting factor. The robust internal soldering ensures that the connections withstand the electromechanical stresses induced by these high current surges, preventing the phenomenon known as solder fatigue which often plagues inferior clamping designs over time.
Frequently Asked Questions (FAQ)
Can the SKKH106/08E be used effectively in DC motor drive applications?
Yes, specifically for the input rectification stage or the armature converter in smaller DC drives. Its 106A current rating allows it to handle significant motor loads, and the thyristor element enables precise regulation of the DC bus voltage.
How does the VRRM of 800V impact its suitability for 400V mains?
While 800V is technically above the peak voltage of a 400V line (~565V), industrial standards usually recommend a safety factor of 2x or higher (1000V–1200V) to account for voltage transients and spikes. Therefore, the SKKH106/08E is best reserved for 230V or lower voltage systems. For 400V lines, use a 1200V variant.
What is the recommended torque for mounting the SEMIPACK 1 housing?
Proper mounting torque is crucial for minimizing thermal resistance. The recommended mounting torque for the M5 screws to the heatsink is typically 3–5 Nm. Under-tightening increases thermal resistance (risk of overheating), while over-tightening can crack the ceramic substrate.
Is an external snubber circuit required for this module?
In most switching applications, yes. An RC snubber circuit is recommended across the thyristor/diode to limit the rate of rise of voltage (dv/dt) and protect the device from voltage spikes generated by inductive loads, ensuring the 800V blocking capability is not compromised.
What does the "E" suffix signify in SKKH106/08E?
The "E" typically indicates a specific revision or standard within the Semikron product line, often relating to the case mechanical standard or chip technology generation. Always verify the mechanical drawing in the datasheet to ensure the terminal layout matches your busbar design.
