Wolfgang Staiger

Optimized cooling systems for high-power semiconductor devices

Straightforward air cooling of semiconductor devices has gradually been replaced by methods using liquid coolants, especially water cooling. In this paper, more advanced cooling devices for hockey-puck-type and module-type semiconductors are suggested. An established heat sink made of aluminum nitride for the water cooling of hockey-puck-type semiconductors has been used as a basis for the development of high-performance heat sinks for increased heat flux densities. By means of thermal and fluid dynamics simulation tools the internal geometry has been optimized with regard to improved heat transfer and reduced pressure drop. The simulation results have been confirmed by a number of experiments using various measuring techniques. As an alternative cooling method for semiconductor modules, a modified baseplate comprising a number of fins for direct water cooling has been suggested. For an intelligent temperature management control algorithms have been developed, resulting in a prototype application-specific integrated circuit which has been implemented for test purposes.

An integrated design approach for the hardware optimization of electrical power modules for automotive electrotraction

In this paper, a systematic approach is presented for the design and optimization of forced liquid cooled electronic modules with high power dissipation. The steps of the design cycle include hydrodynamical evaluation of the heat sink, thermal management, thermomechanical optimization and especially lifetime prediction of soldered joints. Utilized engineering tools comprise computational fluid dynamics, finite differences and finite element programs. These are coupled via software interfaces in order to enable data exchange as well as efficient cooperation of the designers. Applying these means, performance, reliability and costs of a certain module have been optimized. By use of a design-for-reliability procedure substantial savings with regard to development time, prototyping effort and consequently costs can been achieved.

Ein prädiktives, sich an Fahrzeugumfelddaten anpassendes Gangwechselsystem für Kfz (A Predictive Gear Shift System for Motor Vehicles using Environmental Data)

Abstract Der Beitrag beschäftigt sich mit Strategien und Algorithmen für die optimale Gangwahl bei Kraftfahrzeugen mit automatisiertem Getriebe. Zum Zweck der Simulation wurde ein vorausschauendes Fahrermodell entwickelt. Darüber hinaus entstand eine Funktion zur Prädiktion der Fahrzeug-Geschwindigkeit, welche sowohl in der Simulation als auch im endgültigen prädiktiven Schaltalgorithmus verwendet wird. Der Aufbau wird beschrieben und die Funktion sowohl in der Simulation als auch auf der Straße getestet.