Factors that affect hotspot localization in Infrared Lock-in Thermography

Fault localization technique is commonly used in failure analysis process, and is being used to detect the defect location of a faulty semiconductor device. Most of the localization methods are performed directly on top of die surface. However, the Infrared Lock-In Thermograph (IR-LIT) is one of the localization methods that can be performed without the needs to expose the chip surface (before destructive decapsulation process) Therefore, it is very useful in localizing defects that produce a heat-source which is commonly caused by conductive particle short, metallization short and active damage. In order able to perform the hotspot localization at optimum settings, it is important to study the factors that will affect the characteristic for hotspot localization. In this paper, three important factors are studied; namely the thickness of packages, the device biasing power and as well as the lock-in frequency.