By Topic

Nondestructive defect detection in multilayer ceramic capacitors using an improved digital speckle correlation method with wavelet packet noise reduction processing

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

3 Author(s)
Chan, Y.C. ; Dept. of Electron. Eng., City Univ. of Hong Kong, Kowloon, Hong Kong ; Hung, K.C. ; Dai, X.

The nondestructive detection of defects in multilayer ceramic capacitors (MLCs) in-surface mount printed circuit board assemblies has been demonstrated by using an improved digital speckle correlation method (DSCM). The internal cracks in MLCs that contribute to the thermal displacements on the MLC surface after dc electrical loading may be uniquely identified using this improved DSCM combined with double lens optical arrangement. However, it is found that Joule heating of the MLC sample takes time, and therefore the thermal displacements on the MLC surface are not obvious at the beginning of the dc electrical loading. In order to shorten the detection time and increase the resolution of the DSCM, a wavelet packet noise reduction process is introduced into the DSCM technique. This new algorithm is used to reduce the background noise in the signal so as to improve the accuracy of detection of defect locations and reduce the detection time. By introducing wavelet packet noise reduction processing, the DSCM is found to be more sensitive to and faster at detecting defects in MLC samples. Furthermore, the DSCM with wavelet packet noise reduction process can cope with the problems of edge effect, rough and warped surface, which are the limitations of the scanning acoustic microscope (SAM)

Published in:

Advanced Packaging, IEEE Transactions on  (Volume:23 ,  Issue: 1 )