Current Research

Brief descriptions of current research projects are given here.

Condition Monitoring of Power Devices

In order to investigate the wire-bond related failures that is commonly observed for power devices, their degradation conditions are detected by IR imaging (watch the video below) that allows an in-situ monitoring method to be experimentally validated.

Solder is the most common method to connect different materials in a power device package. Their health is mostly affecting the device performance and safety. A scanning acoustic microscope is a non-intrusive method used to detect the internal defects or evolving degradations (watch the video below). Inspections are conducted after 800 and 1300 thermal cycles, respectively (Fig. 1).

Design for Reliability of Power Devices

As the reliability test of power semiconductor devices can be time consuming and costly, finite element analysis (FEA) is widely accepted for their performance and failure mechanism studies. A 2-D symmetrical FE model of multi-layered IGBT module is developed (Fig.2) for thermos-mechanical analysis and the distribution of von-Mises stress and plastic strain after thermal cycling are studies (Fig.3).

Transportation Integrated Drive

Electric drive is power dense concerned which largely determines the all-electric range of the electric vehicles. Both functional and physical forms of integration will largely improve the power density and reduce the cost. An integrated charger is proposed for SR motor drives (Fig.4).

Fig.1 SAM images
Fig.2 FE modelling

Fig.3 Thermo-mechanical analysis
Fig.4 Motor drive
Fig.5 Experiment

Share this page: