Heinrich Schlangenotto

Power Semiconductor Devices – Key Components for Efficient Electrical Energy Conversion Systems

In a competitive market, technical systems rely on automation and process control to improve their productivity. Initially, these productivity gains were focused on attaining higher production volumes or less (human) labor-intensive processes to save costs. Today, attention is paid toward energy efficiency because of a global awareness of climate change and, above all, questions related to increasing energy prices, as well as security of energy and increasing urbanization. Consequently, it is expected that the trend toward more electrical systems will continue and accelerate over the next decades. As a result, the need to efficiently process electrical energy will dramatically increase.

Power Device-Induced Oscillations and Electromagnetic Disturbances

Every power electronic switching action results in a deviation from the ideal sinusoidal AC current or the ideal homogeneous DC current. Switching events are usually done periodically in time. Every periodic event can be separated into a row of sinus and cosinus terms by means of Fourier transformation. With this tool, the generated frequencies, the harmonics, and their intensity can be calculated.

Power Electronic Systems

The expression “power electronic system” is used in different contexts with different meanings. A monograph on fundamental power electronic circuittopologies might well be found under the search criterion ‘systems.’ It is therefore appropriate to start with a precise definition of the object of discussion.

Packaging and Reliability of Power Devices

The operation of a power semiconductor device produces dissipation losses. The order of magnitude of these losses shall be estimated in the following example:

Destructive Mechanisms in Power Devices

This chapter will deal with some destructive mechanisms in power devices, and typical failure pictures for them will be shown. Failure analysis requires a lot of experience, especially regarding the conditions in the power circuit at failure, which must be carefully considered. Although some of the failure pictures appear to be similar, it is difficult to draw conclusions only from pictures. However in practice the engineer often has the problem to find the reason for failures, and the following sections might be helpful.

Short Introduction to Power Device Technology

In the following some basic aspects of power device production technology will be described. The selection was done with the aim to describe the process steps which are important for the understanding of the power device operation and limitations.

Quasi-two-dimensional simulations of bipolar silicon power transistors

Abstract The collector current distribution of bipolar power transistors at high current densities has been calculated by quasi-two-dimensional device simulations and compared with infrared recombination radiation measurements. Further, modeling results concerning the influence of transistor doping profile and lateral geometry on the current distribution are reported.