Title :
Measurement of thermally induced warpage of BGA packages/substrates using phase-stepping shadow moire
Author :
Wang, Yinyan ; Hassell, Patrick
Author_Institution :
Electron. Packaging Services Ltd. Co., Atlanta, GA, USA
Abstract :
A phase-stepping technique is applied to the analysis of fringe pattern images of BGAs (ball grid arrays) obtained by shadow moire interferometry. The sensitivity of the fringe pattern analysis is shown to be significantly increased. Thermally induced warpage of BGAs is successfully measured in real-time as the sample is driven through a simulated reflow process. The paper discusses the technique of phase stepping and its application to the shadow moire method. Applications of the technology are presented
Keywords :
assembling; ball grid arrays; bending; integrated circuit packaging; light interferometry; moire fringes; reflow soldering; sensitivity; thermal stresses; BGA packages; BGA substrates; BGAs; ball grid arrays; fringe pattern analysis sensitivity; fringe pattern images; phase-stepping shadow moire interferometry; phase-stepping technique; shadow moire interferometry; shadow moire method; simulated reflow process; thermally induced warpage; Electronic packaging thermal management; Electronics packaging; Etching; Glass; Gratings; Optical interferometry; Optical surface waves; Pattern analysis; Phase measurement; Surface topography;
Conference_Titel :
Electronic Packaging Technology Conference, 1997. Proceedings of the 1997 1st
Print_ISBN :
0-7803-4157-0
DOI :
10.1109/EPTC.1997.723923
