Papers by Keyword: Shadow Moiré

Abstract:
The reconstruction of instantaneous contour is a common method to analyze the kinetic characteristic of a continual deformation object. In this paper a continuous wavelet transform method (CWT) is applied to analyze the instantaneous contour of a continual deformation object based on shadow moiré technique. The modulated moiré fringe patterns are captured by use of a high-speed CCD camera and the temporal intensity variation of each pixel related to the object deformations is recorded. The intensity variation of each pixel is analyzed along the time axis by CWT. From the extraction of the ridges and from the value of the CWT along the ridges, the information of modulated phase relative to the contour of object can be obtained. In this application, a cantilever beam with a motion in the Z direction is tested by use of the method and the high-quality instantaneous contour of the continual deformation object can be retrieved. Experimental results prove that the CWT can successfully be applied to the instantaneous contour analysis of continual deformation object and these results demonstrate the advantages of the CWT with respect to the applicable simplicity and the resistance of noise pollution.

Abstract: In this study, epoxy molded multi chip package was investigated and a highly reliable structure against failure of copper trace on PCB substrate was proposed. Function failure caused by the pattern crack during component level thermal cycle test was considered. In-plane and out-of-plane movements of package during thermal loading were measured by moiré interferometry and shadow moiré. Measured data were compared with numerical analysis results. Two dimensional and three dimensional numerical analysis were performed considering visco-elastic material properties. Tensile stress in the core layer was analyzed quantitatively and qualitatively. Analysis showed that the reliability of pattern crack could be improved by decreasing the chip thickness and increasing the core thickness, and that the material property of die adhesive was important.