3-D Graphic Image of Vibration Pattern of Printed Circuit Board by Using Holography

The authors have developed a holographic patten measuring system (HPMS) for quantitative measurement of microscopic displacement and mechanical vibration with high precision. In this study, by using the holographic interferometry technique, the microscopic displacement of PCB surface was measured with fringe pattern in case of vibration and shock that were imposed by the operation of mounted electromagnetic relay, and some different vibration patterns were observed corresponding to fixing condition of the Printed Circuit Board. In addition, a graphic image processing technique was applied and the displacement level could be quantitatively measured with an accuracy of about 0.1 mum, and could be evaluated by the 3-D graphic image pattern.