Integrated test chips improve IC assembly

The use of test dies integrated with a semiconductor wafer to gauge environmental stresses effectively during the packaging and processing phases is discussed. These special-purpose assembly test chips (ATCs) are designed primarily for studying failures of the package-centered and composite types. These chips usually provide a way to stress the die, and they include transducers for monitoring the die´s response to the stress. A variety of structures has been used to measure parameters associated with package-related failures. Corrosion detectors, moisture detectors, mechanical stress sensors, mobile ion sensors, thermal resistance measurement circuits, and multifunction test chips are examined.<>