*Department of Physics, Kumaraguru College of Technology, Coimbatore, Tamilnadu, India
**Department of Electronics and Instrumentation, Bharathiar University, Coimbatore, India
Online published on 2 August, 2016.
In this paper, a non contact, non-destructive Laser speckle phase correlation and cross correlation techniques are used to measure small deformation of solder joint in the printed circuit board. Laser speckle images are recorded before and after deformation. Phase correlation technique is used for acquire the fringe pattern by subtracting these speckle images. This fringe pattern gives information on the subject of the deformation. Laser Speckle displacement can be assessed in terms of cross-correlation of speckle intensity peak deviation from the origin. Its height is lower than that of the autocorrelation and hence deformation is measured.
Laser speckle, fringe pattern, cross-correlation, image processing, deformation
