Content last revised on December 11, 2025
SKN 320/16: High-Reliability Stud Diode for Demanding Power Rectification
The **SEMIKRON SKN 320/16** is a stud-mount rectifier diode engineered for exceptional thermal stability and long-term reliability in high-power industrial applications. It combines a robust electrical design of **1600V** | **320A** | **9000A IFSM** with a field-proven mechanical package. Key benefits include superior thermal performance and high surge current immunity. This component is specifically designed to provide durable and predictable rectification in challenging operational environments, directly addressing the need for components that can withstand significant electrical and thermal stress without degradation.
Application Scenarios & Value
Achieving System-Level Ruggedness in Industrial Power Conversion
For high-current rectifiers in applications like welding or battery charging, the SKN 320/16's 9000A surge rating provides unmatched ruggedness. In the input stage of a high-power battery charging station or a DC power supply, this diode is critical for handling the large inrush currents that occur when the system is first energized. Its ability to absorb this significant, non-repetitive surge current (IFSM) prevents catastrophic failure and enhances the overall system's field reliability. The diode's standard recovery characteristics are optimized for line-frequency applications, ensuring efficient performance in uncontrolled rectifiers. The hermetically sealed metal case with a glass insulator provides a robust barrier against environmental contaminants and mechanical stress, a feature essential for equipment deployed in harsh factory settings. While the SKN 320/16 is ideal for uncontrolled rectification, for systems requiring phase control, a thyristor/diode module like the SKKD162/16 offers adjustable output capabilities.
Key Parameter Overview
Decoding the Specs for Thermal and Electrical Reliability
The technical specifications of the SKN 320/16 are tailored for high-power industrial environments where both electrical robustness and thermal management are critical design considerations. The following parameters, sourced from the official datasheet, are pivotal for system-level engineering decisions.
| Parameter Group | Value | Engineering Significance | |
|---|---|---|---|
| Blocking Characteristics | Repetitive Peak Reverse Voltage (VRRM) | 1600 V | Provides substantial safety margin for applications on high-voltage industrial lines, protecting against line transients. |
| Repetitive Peak Reverse Current (IRD) @ Tvj=180°C | ≤ 100 mA | Indicates low leakage current at maximum operating temperature, contributing to lower off-state power loss and better thermal stability. | |
| Forward Characteristics | Average Forward Current (IFAV) @ Tc=125°C | 320 A | Defines the nominal current handling capability under specified cooling conditions, suitable for high-power rectifiers. |
| Forward Voltage (VF) @ 1000A, Tvj=25°C | ≤ 1.35 V | A low forward voltage drop directly translates to lower conduction losses, reducing the heat generated by the device. | |
| Surge Forward Current (IFSM) @ 10ms, Tvj=25°C | 9000 A | Extremely high surge capability ensures survival during fault conditions or high inrush events, critical for system ruggedness. | |
| Thermal and Mechanical | Thermal Resistance, Junction-to-Case (Rth(j-c)) | 0.16 K/W | A low thermal resistance value signifies efficient heat transfer from the semiconductor junction to the case, simplifying heatsink design. |
| Max. Operating Junction Temperature (Tvj max) | 180 °C | A high Tvj max allows for reliable operation in high ambient temperatures or under heavy load conditions. | |
Download the SKN 320/16 datasheet for detailed specifications and performance curves.
Frequently Asked Questions (FAQ)
What is the primary benefit of the hermetic metal case with a glass insulator?
The hermetic sealing provides maximum protection against humidity, dust, and other environmental factors that can cause device failure over time. The glass insulator ensures excellent high-voltage isolation and stable blocking characteristics throughout the component's operational life, making it ideal for applications demanding long-term reliability. What is the key benefit of the hermetic metal and glass case? It ensures long-term stability and reliability in harsh industrial environments.
How does the 0.16 K/W thermal resistance impact my design?
A low Rth(j-c) like 0.16 K/W means the heat generated at the semiconductor junction can be removed more effectively. For a design engineer, this allows for the use of a smaller, more cost-effective heatsink for a given power level, or alternatively, running the device at a higher current while staying within safe temperature limits. This directly impacts system power density and cost. For more insights on thermal design, see this guide on mastering thermal management.
What does the 'anode to stud' configuration mean for mounting?
The 'anode to stud' designation, standard for the **SKN 320/16**, means the anode terminal is electrically connected to the M24 threaded stud used for mounting. In a typical rectifier application, this allows the stud to be mounted directly to a grounded chassis or heatsink that serves as the common anode connection for multiple diodes, simplifying the busbar arrangement and assembly process.
Technical Deep Dive
Inside the Construction: Hermetic Sealing and Thermal Design
The longevity and stable performance of the SEMIKRON SKN 320/16 are not accidental; they are direct results of its fundamental construction. The core of the device is a large-area silicon chip, which is protected by a glass passivation layer. This layer is crucial as it shields the sensitive p-n junction from external contaminants and electrical field variations, ensuring the diode's **1600V** blocking capability remains stable over tens of thousands of operating hours.
Furthermore, the device is housed in a hermetically sealed metal case with a robust glass-to-metal seal for the cathode terminal. This construction creates an impermeable barrier against moisture and corrosive gases, a known failure vector for non-hermetic plastic modules. This makes the SKN 320/16 exceptionally well-suited for applications in challenging environments such as electroplating, chemical processing plants, or marine settings. The efficient thermal pathway, defined by the low Thermal Resistance of 0.16 K/W, can be thought of as a wide-gauge pipe for heat. Just as a wider pipe allows more water to flow with less pressure, the low thermal resistance allows a high volume of thermal energy to flow away from the junction with minimal temperature rise, preventing overheating and extending the component's life.
Application Vignette
Ensuring Uptime in High-Current Welding Power Supplies
Consider the design of a heavy-duty industrial stud welder, which requires massive, short-duration DC pulses. The input stage is an uncontrolled rectifier powered directly from a 480V three-phase line. During the welding process, the transformer draws an immense current, creating significant stress on the rectifier diodes. The SKN 320/16 is an ideal candidate for this stage due to two specific attributes: its high surge current (IFSM) and low thermal resistance (Rth(j-c)).
The **9000A** IFSM rating acts like a robust safety buffer. Think of it as a dam designed to withstand a 100-year flood; it easily handles the predictable, high-current pulses of normal operation while also providing protection against unexpected grid faults or short circuits. This ruggedness prevents nuisance trips and costly downtime. Concurrently, the continuous high current flow generates significant heat. The module's low Rth(j-c) of 0.16 K/W ensures this heat is efficiently transferred to the heatsink. This superior thermal performance keeps the junction temperature well below the **180°C** maximum, enabling the welder to operate at a high duty cycle without the risk of thermal runaway, a common cause of power semiconductor failures. The result is a more reliable, long-lasting piece of industrial equipment.
For technical assistance or to discuss your specific application needs with our engineers, please contact us for a detailed evaluation.
