IEEE Transactions on Components and Packaging Technologies vol:28 issue:3 pages:484-492
9th Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems Las Vegas, NV, JUN 01-04, 2004
The mechanical stress induced in Si chips by the packaging process (effect of die attach, flip chip bumping, etc.) is measured by micro-Raman spectroscopy. The measurements are performed on the (110) cross-section surface of the polished samples. This study shows that the current Raman formula for top-surface measurements cannot be used for cross-section measurements due to the anisotropic property of Si. The new formula for cross-section measurements is introduced in this paper. The experimental results are compared to finite element simulations. The Raman results correlate very well with the FE calculations. It shows that micro-Raman spectroscopy is a very interesting technique to study packaging induced stress in Si chips and to validate finite element calculations.