Title :
Experimental evaluation of solder joint thermal strain in a CSP using digital speckle correlation
Author :
Lu, Hua ; Yeh, Chao-pin ; Wyatt, Karl
Author_Institution :
Motorola Inc., Schaumburg, IL, USA
Abstract :
Thermomechanical strain was directly measured using a computer image processing technique in an area encompassing the solder-copper interface near the corner of an outermost solder ball in a chip scale package (CSP). Due to the ultra-high spatial resolution of the technique, the shear strain concentration was revealed and quantified over the area with linear dimensions in terms of microns. Discussions are given on the significance of the measurement for identifying the root cause for solder joint failure, and on the application prospects for the technique as an experimental tool in emerging areas of research where microscopic strain measurement is needed
Keywords :
assembling; chip scale packaging; failure analysis; image resolution; integrated circuit interconnections; integrated circuit measurement; internal stresses; optical correlation; soldering; speckle; strain measurement; stress analysis; thermal stresses; CSP; Cu; chip scale package; computer image processing technique; digital speckle correlation; microscopic strain measurement; outermost solder ball; shear strain concentration; solder joint failure; solder joint failure root cause; solder joint thermal strain; solder-copper interface; spatial resolution; thermomechanical strain; Area measurement; Capacitive sensors; Chip scale packaging; Computer interfaces; Image processing; Semiconductor device measurement; Soldering; Spatial resolution; Strain measurement; Thermomechanical processes;
Conference_Titel :
Thermal and Thermomechanical Phenomena in Electronic Systems, 1998. ITHERM '98. The Sixth Intersociety Conference on
Conference_Location :
Seattle, WA
Print_ISBN :
0-7803-4475-8
DOI :
10.1109/ITHERM.1998.689552
