Pålideliglighedsbestemmelse af effekt moduler / Reliability Assessment of Miniaturized Power Modules (Minva)

Power converters are important to today's task of reducing the power consumption of electrical motors. The energy savings will become relative bigger, when power converters drive small permanent magnet (PM) motors. For use of energy efficient motors with converter drives to be common in ordinary consumer products, the need for methods to reduce the cost and miniaturize the converters is great. This should be without sacrificing the reliability of the motor and the application. Power converters are integrated into many different applications. Some of these applications will be of a nature so that the converters have to function in harsh environments. A significant parameter may be the high temperature of the cooling media. This project will attempt to establish a better knowledge of common and cheap materials, in order to use them to the limit, thus saving cost. The focus will be on the substrates used for the power semiconductors and electronics. The approach here will be to characterize the failure mechanisms that may eventually lead to the end of life for the power converter. An analytical evaluation of the materials involved will be attempted, including a study of the material properties in question. After this a detailed study of the wear out failure mechanisms will be done by using accelerated testing, in this case thermal cycling, followed by analysis of the root cause of the failures. The nature and level of acceleration obtained by the tests will be described and related to real applications. When the nature of the failure mechanisms are described, a finite element or empirical computer model of the wear out mechanisms will be made. The model should then be adjusted to relate to the experimental wear out data found. The project is finaliced in 2002 The project is co-sponcered by Danish Energy Agency, Grundfos A/S, Electrolux A/S. (Johannes Juul Mikkelsen, John K. Pedersen; Grundfos A/S; Electrolux A/S)