Rapid Resistive Interconnection Localization

Resistive interconnections, a type of soft failure, are extremely difficult to find using existing backside methods, and with flip-chip packages, alternative front side approaches are of little or no help. In an effort to address this challenge, a team of engineers developed a new method that uses the effects of resistive heating to directly locate defective vias, contacts, and conductors from either side of the die. In this article, they discuss the basic principles of their new method and demonstrate its use on two ICs in which a variety of resistive interconnection failures were found.