title: Detecting nonuniformity in small welds and solder seams using optical correlation and electronic processing.
abstract: Using holographic matched filtering and electronic processing, small variations in surface displacement along the seam of a hermetic microcircuit package can be detected when the seam is stressed. Destructive analysis of a solder-sealed package reveals a strong correlation between optical signal variations and nonuniformity of solder adhesion and wetting along the seam. The technique promises potential application as a means of nondestructively inspecting for flaws in small welded or soldered seams.
authors.forename: J W
authors.initials: JW
authors.lastname: Wagner