According to one aspect of the disclosure and a particular example application directed to a flip-chip packaged die, a method for detecting a defect in a surface of the die includes directing light through a first beam splitter; directing light of a known wavelength at the beam splitter, wherein the...http://www.google.de/patents/US6992773?utm_source=gb-gplus-sharePatent US6992773 - Dual-differential interferometry for silicon device damage detection
