Backside Analysis: Backside Thermal Mapping Using Active Laser Probe

The transition to “flip-chip” packaging forced a renaissance in failure analysis methods, usually referred to as backside failure analysis. This article describes one such technique based on active laser probing. The technique uses the optical properties of the silicon substrate to produce a high-sensitivity, high-resolution thermal map of the device active area. This map can locate shorting defects and be used as a thermal management tool.