Methods for Predicting the Remaining Life of Electronic Assemblies With Carbon Nanotubes and an Optical Transduction Technique

Life consumption monitoring is a method of quantifying the degradation of a system by monitoring the life cycle environment. With current research demonstrating the value of nanotubes as sensors, they may prove to be an inexpensive, compact, and reliable means to monitor not only system environments, but also physical signs of degradation. Life consumption monitoring of electronic assemblies can be cost-effectively done using optical strain measurement techniques. In this study, current output from an optical sensor can be used to interpret combined temperature and vibration histories. This may be accomplished by passing monofrequency light through optical fibers in a peripheral arrangement on a dummy chip. Any deviation from the null condition results in misalignment of the fibers, and hence reduction in intensity and current output. With appropriate failure data at different stress levels, it is possible to determine damage and estimate the remaining life. The key challenges are to determine whether such an optical health monitoring scheme can be sufficiently accurate and robust, and whether the results can be applied to a variety of packages at any location on a circuit assembly.