Research Areas
Our research areas cover the entire spectrum of modern power electronics—from the development and optimization of substrates, through packaging and bonding, to analysis and thermal management. In state-of-the-art laboratories and through practical projects, students and researchers investigate materials, manufacturing processes, and electrical and thermal properties to design efficient, reliable, and durable power modules.
Assembly and interconnection technology deals with the creation of electronic systems through the electrical, thermal, and mechanical interconnection of individual components into functional assemblies. It serves as the interface between semiconductor technology and the final application and encompasses processes such as soldering, sintering, bonding, and potting.
Key functions include ensuring secure electrical connections, efficient heat dissipation, and mechanical protection of sensitive components. The reliability, performance, and service life of electronic systems are largely determined by the appropriate selection of materials and processes.
Power modules are used to efficiently control, convert, or switch electrical power. They integrate multiple semiconductor devices—such as IGBTs, MOSFETs, diodes, or thyristors—into a single package, thereby providing a compact, reliable solution for high currents and voltages.
Typical applications:
- Motor drive control (in industrial plants, trains, electric vehicles, and elevators. They enable inverter functions for three-phase motors.)
- Energy generation and conversion (used in photovoltaic inverters, wind turbines, and fuel cells for the efficient conversion of direct current to alternating current.)
- Power supply systems (In UPS systems (uninterruptible power supply) or grid-feeding systems, power modules ensure a stable power supply
- High-power applications in industry and transportation (e.g., welding equipment, railway technology, traction drives, where high currents and voltages must be reliably switched.)
Power modules today are significantly more compact and powerful than they were around 1990: The feature size has shrunk from 220 µm to 90 µm, and the power density has risen from 30 kW/cm² to over 250 kW/cm². Modern modules contain up to six IGBTs and are increasingly using silicon carbide (SiC) instead of pure silicon.
The increasing power density and miniaturization of modern power modules place high demands on thermal management, reliability, and manufacturing technology. Higher currents and temperatures up to 200 °C—compared to the previous limit of 125 °C—place greater stress on materials and connections, while the use of silicon carbide (SiC) requires new production and joining methods. At the same time, costs are rising, making it necessary to carefully balance performance, efficiency, and cost-effectiveness.
From the wafer to the module—areas that require constant optimization:
- Mechanical interfaces, assembly
- External electrical interfaces
- Internal connections and sensors (condition monitoring)
- Thermal management and interfaces to the cooler
- Synchronization of parallel circuits
- Internal inductance (resistance to rapid current changes = less interference energy)
At the Assembly and Interconnection Technology Laboratory at HAW Kiel, we focus on the development, analysis, and optimization of modern interconnection technologies for power electronic components. Our primary areas of focus include:
New assembly and connection conceptse for power modules (e.g., using wire bonding, soldering, potting, pressure sintering, or vacuum brazing)—with the aim of improving electrical, thermal, and mechanical performance.
Practical implementation and prototype productiong: Concepts are not merely conceptualized but are brought to life until they are fully functional—this allows materials, processes, and structures to be tested and evaluated under realistic conditions.
Thermal and Electrical Management of components and assemblies — to ensure reliability and service life under real-world operating conditions.
Sustainable and efficient manufacturing processes: Development and investigation of energy-efficient, robust joining technologies with a focus on industrial applications and scalability.