Optimization of Structure Parameters of D2-FBGA Under Thermal Cycle Loading

Visco-elastic parameters of epoxy molding compound(EMC) were tested by using dynamic mechanical analyzer(DMA).Relevant parameters of finite elements were acquired from data simulation.Thicknesses of chip,adhesive agent,partial EMC and substrate of D2-FBGA,considered as optimization parameters,were selected to establish orthogonal table.With MSC and Marc,thermal stress distribution of D2-FBGA was previewed under thermal cycle loading.A regression equation for maximum equivalent stress and the above-mentioned parameters was built through statistical software Stata.Effect of those parameters on maximum equivalent stress was analyzed.A set of optimal structure parameters and the corresponding maximum equivalent stress value were obtained using simplex method.Results showed that the maximum equivalent stress of the device decreased from 90.58 MPa to 66.84 MPa after optimization.