Advanced package design for electronic and MEMS applications supported by fe analyses and deformation measurements

Sensor packages have often to be adapted to current customer requirements. Dimensions, interior structures, or materials may change. In general, this influences strongly the thermally induced warpage during the wafer level manufacturing process and of the separated single packages which has to be controlled with respect to reliability issues. Therefore, the package manufacturer needs for a proved methodology: Numerical studies by means of finite element (FE) analyses combined with experimental warpage determination are proposed which enable reliability assessments before real parts are available. Parametric studies by means of FEM are applied to the manufacturing process and its variations, taking into account carefully determined temperature-dependent material data, including cure shrinkage and visco-elastic behaviour of mold compounds. Several modelling strategies (batch module, one single module only, and an intermediate approach) are compared with respect to the computed bending for a typical set of parameters and with the real warpage of a thermally loaded test structure, measured by means of Thermo-Moire.