Peter Hansen |
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Peter Hansen - Interests
Thermal design and virtual qualification of electronic assemblies are some of the main areas of my professional interest. Electronics in operation generates heat, which eventually leads to a rise in temperature within the assembly and in the components. The long term reliability of the product is affected by the ultimate junction temperature, which either result in an overstress failure, decreased lifetime due to thermal aging, or mechanical wearout failures in leads and solder interconnects due to thermal cycling within the allowed temperature limits for the components. The drive for denser packaging and higher power density at compatible cost makes this issue increasingly important. The usual strategy in the thermal design of electronic products is to design for a maximum allowable junction temperature of the components. Proper thermal design therefore requires identification of the tradeoffs between the overall solution cost and the means of proper cooling. With virtual qualification based on Physics of Failure the focus is shifted from designing to a certain temperature, focus on the actual cause of a failure and modeling of the activated failure mechanism. With this process it is possible to design for a predicted lifetime of each component, which allows identification of possible weak spots early in the product development, to avoid over engineering of the product, as well as to identify potential increased performance of the product. Virtual qualification has also superior advantages in tailoring accelerated lifetime tests for assemblies and subassemblies early in the design process. I have been using thermal design and virtual qualification methods in design for power electronic applications designed for medium or high temperature environments. One of the key components in a power electronic application is the power module, which consists of the active power parts. Proper thermal design and identification of the governing failure mechanisms has allowed minimizing cost and maximizing performance and reliability of the power module. For further reading I have included some texts on this site regarding: |
