Local stress measurements in packaging by Raman spectroscopy

This paper discusses the application of micro-Raman spectroscopy to measure mechanical stress in microelectronics packages. Examples are given for loc al stress induced in the silicon chip by solder bumps, stress induced in th e chip by bonding to a Cu substrate, and stress induced during thinning of wafers by polishing. Both 1-dimensional and 2-dimensional results from stre ss measurements are shown. It is demonstrated that micro-Raman spectroscopy is a very useful tool for the study of packaging induced local mechanical stress and offers a means for verification of finite element simulation res ults.