Real Time Warpage Measurement of a Plastic BGA by Projected Grating Method

摘要

Optical techniques provide non-contact, full field measurement for the shape and deformation induced thermally mechanically. In this paper, a new portable projected grating moire system, recently designed and built for component level warpage measurement, is presented and demonstrated. The system is coupled with an environmental chamber for real time measurement during thermal loading. Within a 50 mm square range, a few microns shape and out of plane deformation can be resolved with a standard CCD camera. An imaging analysis software is developed for automatic deformation measurement. Results on a plastic BGA (ball grid array) are reported. This new technique allows precision measurement of warpage, providing valuable information on packaging reliability, manufacturing process, and modeling validation.