Texas Instruments DLPTM Products Division
CALCE Electronic Products and Systems Center
University of Maryland
College Park, MD 20742
DMDTM packages, which are used in digital projectors, were subjected to Moir?and Twyman/Green interferometry experiments to measure warpage of the package at different temperatures. From the interferometry fringes, it was found that stress-free temperature of a UV-cured adhesive used in the package was not room temperature as previously assumed, but was actually the glass transition temperature of the adhesive. The experiments showed the importance of accounting for all loads including internal pressure from expansion of air inside the package and also helped to verify the material properties of the components of the package. The article describes the experiments and the modeling steps that led to a calibrated structural finite element model of the package.
Complete article is available to CALCE Consortium Members.