UPDATE ON THE EVALUATION OF STACKED DIE PACKAGES USING ACOUSTIC MICRO IMAGING
Author: Janet E. Semmens Company: Sonoscan, Inc. Date Published: 1/24/2008
Pan Pacific Symposium
Abstract: An earlier paper concerning evaluation of stacked die packages using Acoustic Micro Imaging (AMI) demonstrated the feasibility of evaluating these devices in two and three die or die/spacer stacks . Since that time additional experience and insight has been gained in working with these types of parts. As expected the die are thinner (= 75 microns), there are usually a greater number of die in the stack, and the methods for attaching the different layers varies. The increasingly thinner dimensions in stacked die packages present increasing challenges for AMI analysis of the devices for internal defects. The material in this paper will present an update on the methods presently available for stacked die evaluation and discuss observations on the behavior of high frequency ultrasound in the packages that may have impact on future techniques for analysis.
Key words: Acoustic Micro Imaging (AMI), stacked die packages