Design, simulation and integration of heat spreaders

Heat spreaders are widely used in microelectronics to distribute heat loss as well as possible so that thermal resistance is minimized. A material is a heat spreader if it spreads the heat (distributes it over a larger area), so this task is usually performed by a material with good thermal conductivity, e.g. copper, aluminum, silicon or (artificial) diamond. However, the coefficient of thermal expansion (CTE) should always be considered, and it should be adapted as well as possible to the component (chip, semiconductor). A compromise is a heat spreader made of composite materials such as Cu/W with a matched CTE but less good thermal conductivity. Basically, however, a heatspreader is nothing more than a substrate under a semiconductor, e.g. laser, LED, transistor.

At Fraunhofer IZM, heat spreaders are used in the form of:

  • Cu/W or Cu/Mo for optoelectronics (laser) and RF technology. IZM's expertise lies in the interconnection technology of semiconductor components to the heat spreaders
  • Si in wafer level / 3D packaging. work of WLSI
  • As Cu layers in panel level packaging (e.g. low-inductance packages)
  • In power electronics
  • LED packaging
  • Lead-frame based packages
  • Design of electronic packages

Working Group

Metallic Interconnection Technologies

Our portfolio includes the development and application of metal bonding technologies for LEDs, optical, and RF components and power electronics.


Working Group

Assembly and encapsulation

We research integration technologies for system-in-package products, focusing in particular on device assembly for highly integrated packages and joining/encapsulation processes based on polymeric materials.


Packaging for power electronics

Besides die attach soldering and Al heavy wire bonding, new packaging concepts are pursued to built power electronics systems which shall provide improved thermal performance and higher reliability.


Low-inductance packages for fast-switching semiconductors

The Secret for Miniature Converters with High Power Density.


Reliability evaluation with FEM

To identify weak points in the early stages of development, or to obtain the optimum geometry under consideration of external loads, finite element simulation (FE) are applied. By means of so-called multiphysics simulations, e.g. thermo-mechanical, electro-thermal, and electro-mechanical couplings can be considered.