Holographic evaluation of electronic circuits using photochrome films

The procedures and the resulting real-time holographic interferograms of three specific studies are presented using both photographic and thin protochromic films: (i) The heat conduction of a spacer used for mounting transistors on a heat sink, (ii) the detection of inner layer short-circuits on a multilayer printed circuit board, and (iii) the detection of a hot spot on a hybrid IC ceramic substrate. Methods of preparing photochromic thin films are described. A 2-minute silent movie of real-time holographic interferometry utilizing photochromic material will be shown.