EUPEC (Legacy & Infineon Integration) Profile and High-Power Semiconductor Business Introduction

I. Company Profile
1. General Overview
EUPEC (Europäische Gleichrichter GmbH / European Power Semiconductor Company) was a legendary German manufacturer and a global pioneer in high-power semiconductor devices. Renowned for its rugged "hockey puck" thyristors, diodes, and press-pack IGBTs, EUPEC provided the critical high-voltage, high-current switching components that form the backbone of global energy infrastructure, railway traction, and heavy industrial drives.
Important Industry Note: EUPEC no longer operates as an independent brand. In 2002, the company was acquired by Infineon Technologies, and its product lines, engineering teams, and manufacturing facilities were fully integrated into Infineon’s High Power Semiconductor division. Today, when engineers and procurement specialists search for "EUPEC," they are typically seeking legacy replacements or the modern Infineon equivalents of EUPEC's pioneering press-pack technologies.

2. Development History
EUPEC’s origins trace back to the late 1960s and 1970s in Germany, a period when the global energy grid was rapidly expanding and requiring robust solid-state switches to replace mechanical breakers. EUPEC quickly became the European gold standard for phase-control thyristors and high-power diodes. In the 1990s, they were early pioneers in adapting press-pack technology for IGBTs (Insulated Gate Bipolar Transistors), revolutionizing high-power traction and HVDC (High-Voltage Direct Current) applications. The 2002 acquisition by Infineon combined EUPEC’s unmatched high-power packaging expertise with Infineon’s advanced silicon wafer fabrication, creating a dominant global force in power electronics.

3. Core Advantages (The EUPEC Legacy)
Pioneers of Press-Pack Technology: EUPEC perfected the "pressure contact" or press-pack housing, which eliminated wire bonds and solder joints, drastically increasing thermal cycling capability and lifespan.
Fail-Short Mode Reliability: Their designs ensured that if a semiconductor chip failed under extreme grid stress, it would fail into a short circuit rather than an open circuit, allowing redundant systems to safely bypass the faulty component without catastrophic explosion.
Extreme Ruggedness: Engineered to handle massive surge currents (tens of thousands of amps) and block ultra-high voltages (up to 8.5kV and beyond) in the harshest electrical environments.
Seamless Infineon Integration: The DNA of EUPEC lives on in modern Infineon high-power portfolios, ensuring that legacy system integrators still have access to compatible, next-generation silicon.

II. Main Product Lines (Historical & Modern Equivalents)
EUPEC’s portfolio was strictly focused on megawatt-level power control and switching, categorized into the following core technologies:
Phase Control Thyristors (PCT) & Diodes: The classic "hockey puck" devices used in line-commutated converters for HVDC transmission and industrial smelting.
Press-Pack IGBT Modules: High-power, disc-type IGBTs designed for easy series/parallel stacking in multi-level inverters.
IGCTs (Integrated Gate-Commutated Thyristors) & GTOs: Advanced, highly efficient switches bridging the gap between thyristors and IGBTs for medium-voltage drives.
Power Assemblies & Stacks: Pre-assembled, water-cooled or air-cooled power stacks (valves) ready for direct integration into traction converters and static var compensators (SVCs).
III. High-Power Switching & Grid Control Business (Core Business)
While brands like Kingbright and Kinco focus on visual displays, and Heidenhain focuses on nanometer metrology, EUPEC’s core business was High-Power Switching and Grid-Level Control. This segment provides the massive electronic "valves" that control the flow of gigawatts of electricity across continents and power high-speed trains.

1. Core Technologies and Products
The "Hockey Puck" Press-Pack Design
Unlike standard plastic-molded IGBT modules that use soldered terminals and wire bonds, EUPEC’s press-pack devices feature a ceramic or plastic housing with metal contact plates on both sides. The device is clamped between two heatsinks using a mechanical spring or hydraulic pressure. This ensures perfect double-sided cooling, eliminates the fatigue of wire bonds, and allows for incredibly compact, high-density power stacks.
High-Voltage HVDC Thyristors
EUPEC manufactured some of the world's largest and most reliable thyristors for High-Voltage Direct Current (HVDC) transmission lines. These devices are capable of blocking massive DC voltages and are stacked in series by the hundreds to create the converter valves that link offshore wind farms to the mainland grid or connect asynchronous national power grids.
Traction IGBTs for Railway
For electric locomotives and high-speed trains, EUPEC’s press-pack IGBTs and diodes provided the robust switching required to convert overhead catenary power into precise traction motor control, enduring the constant mechanical vibration and thermal shocks of rail travel.

2. Technical Highlights of the Power Business
Unmatched Thermal Cycling Capability: Because there are no internal solder joints to crack under thermal expansion, EUPEC press-pack devices can endure millions of extreme load cycles, making them ideal for applications like wind turbine pitch control and rolling mill drives.
Explosion-Free and Safe Operation: The rugged clamping mechanism contains the energy of a silicon failure safely within the housing, preventing the catastrophic arc flashes associated with standard modular failures.
Easy Maintenance and Upgradability: In a high-power stack, if a single press-pack diode fails, maintenance crews can simply unclamp the stack, swap out the single "puck," and resume operation, rather than replacing an entire multi-thousand-dollar power module.
Advanced Silicon Integration: Under Infineon, the legacy EUPEC packaging was combined with advanced .EMIT (Emitter Controlled Thyristor) and modern IGBT4/IGBT7 silicon, drastically reducing switching losses while maintaining the rugged mechanical housing.

3. Industry Application Solutions
In the Energy Transmission and HVDC sector, EUPEC thyristors and diodes are the foundational components of Line-Commutated Converters (LCC). They enable the efficient transmission of bulk power over thousands of kilometers with minimal losses, crucial for integrating remote renewable energy sources.
For Railway Traction and Transit, their high-power assemblies are used in the main propulsion inverters of high-speed trains, metro systems, and heavy-haul freight locomotives, providing the torque and speed control necessary for massive electric motors.
In Heavy Industry and Metallurgy, EUPEC components drive the massive DC arc furnaces used in steel recycling, as well as the cycloconverters that control the giant rolling mills shaping hot steel.
For Pulsed Power and Research, specialized EUPEC fast-switching thyristors are utilized in laser power supplies, electromagnetic forming, and particle accelerator magnets, where massive bursts of energy must be released in microseconds.

4. Legacy Support and Modern Migration
For OEMs and maintenance teams dealing with aging infrastructure originally built with EUPEC parts, the modern migration path involves consulting Infineon’s High Power Semiconductor catalog. Infineon provides direct cross-reference guides to map legacy EUPEC part numbers to modern, RoHS-compliant, and higher-efficiency equivalents, ensuring that critical infrastructure can be maintained without redesigning the entire mechanical clamping and cooling systems.

IV. Summary
EUPEC stands as a monumental name in the history of power electronics. By perfecting the press-pack "hockey puck" design, they solved the most severe thermal and mechanical challenges of high-power switching. Although the EUPEC brand name was retired following its acquisition by Infineon Technologies, its engineering philosophy and mechanical designs remain the global standard for HVDC transmission, railway traction, and heavy industrial drives. The legacy of EUPEC continues to silently and reliably switch gigawatts of power, keeping the modern, electrified world moving.