Laser Voltage Probe (LVP): A Novel Optical Probing Technology for Flip-Chip Packaged Microprocessors

摘要

A novel optical probing technique to measure voltage waveforms from flip-chip packaged complementary metal-oxide-semiconductor (CMOS) integrated circuits (IC) is described. This infrared (IR) laser based technique allows signal waveform acquisition and high frequency timing measurement directly from active P-N junctions through the silicon backside substrate on IC's mounted in flip-chip stand-alone or multi-chip module packages as well as wire-bond packages on which the chip backside is accessible. The technique significantly improves silicon debug & failure analysis (FA) through-put time (TPT) as compared to backside electron-beam (E-beam) probing because of the elimination of backside trenching and probe hole generation operations.