Summary and Outlook

Abstract

In this book, the technique of lock-in thermography is being reviewed with special emphasis on its application to the characterization and functional testing of electronic components. The investigation of shunting phenomena in solar cells, which our lock-in thermography originally was developed for, among a lot of other applications is presented to demonstrate and discuss all the different possibilities of this rather new technique. We hope to have shown that the use of lock-in thermography instead of conventional (steady-state) thermography is a qualitatively new thermographic approach to electronic device testing and failure analysis. It not only improves the sensitivity tremendously by up to 3 orders of magnitude, but it also considerably improves the effective spatial resolution of the investigations by suppressing lateral heat conduction. Besides, it opens new ways of correcting the IR emissivity of the investigated surface. Since the objects investigated usually are in a quasi-adiabatic state, the results of lock-in thermography are not influenced by heat conduction to the surrounding and therefore can more easily be evaluated quantitatively. With these properties and with the further development of reasonably priced thermocameras, lock-in thermography is most promising to become a widely used technique in electronic device testing in future. This book was intended to contribute to this development and to generally encourage a wider application of lock-in thermography, which, at the moment of writing this book, still has to be considered a rather exotic measurement technique reserved for a few specialists.