Magnetic based current imaging has become a mainstream tool for package level fault isolation of shorts and high resistance defects (resistive opens). This technology is rapidly gaining acceptance for die level fault isolation as well due to recent improvements in resolution. Participants will be introduced to the basics of magnetic current imaging including the two sensors used today, SQUIDs (superconducting quantum interference devices) and magnetoresistive sensors. Applications, using both of these sensors, will be shown at both die and package levels.