MicroDAC strain measurement for electronics packaging structures

Thermo-mechanical reliability concerns in microelectronics and microsystem technology have led to a significant need in information on stress/strain b ehavior inside microscopic components under load, Because of the decreasing size of structures new measurement tools have to be developed in order to assure future experimental access. Strain measurement from load state micro graphs utilizing correlation techniques seems to be one of the promising ap proaches. Its application to thermally stressed objects in electronics pack aging is the main topic of this paper. Deformation measurements are present ed for solder interconnects of flip chip and chip scale packages. Emphasis is made for the experimental support of finite element simulation by means of experimental validation of mechanical modeling. Furthermore. a wide vari ety of new packaging materials and material compounds are to be characteriz ed. Different material properties for bulk material and microscopic structu res intensify the search for new testing methods. Again correlation algorit hms can be applied to measure strains on microscopic areas and subsequently to obtain material properties, The feasibility to measure coefficients of thermal expansion and Poisson ratios on tiny specimens is demonstrated in t he paper. (C) 2001 Elsevier Science Ltd. All rights reserved.