Characterization and modeling of non-linear inelastic behavior of organic packages at component and system levels

Organic substrates in electronic packaging are made of laminated dielectric and plated copper layers surrounding a fiber-reinforced glass core. Their constituent materials have typically been assumed to be linear elastic for simplicity in the microelectronic packaging analysis. However, the viscoelasticity of dielectric materials and the viscoplasticity of copper in the substrates impact the substrate behavior and in some cases must be considered. This paper presents a series of investigations on the non-linear time-dependent behavior of organic packages through experimentation and finite element analysis (FEA), including characterization and model validation of substrate core, modeling simplification and case study of packages during the package assembly process, and package substrate behavior in the system stack.