Simulation and measurement of the flip chip solder bumps with a Cu-plated plastic core

Multi-scale in-situ micro-mechanical characterization of Polymer Core Solder Ball (PCSB) coatings for BGA interconnections

“…Three materials are defined in the model: copper, nickel-phosphorus and SAC305. In this study, two different copper and nickel-phosphorus materials are compared: the first simulation considers the properties found in literature [29][30][31][32] and the second one the properties characterized by the micromechanical tests presented in section 3. The material properties of SAC305 were found in [31].…”

“…The problem need to be studied more globally with numerical approaches. Multiple investigations dealt with the development of numerical models to predict solder ball behaviour under different mechanical [27,[29][30][31][32][33][34] and thermomechanical [4,20,22,33] conditions. All of them considered the mechanical properties of bulk materials to describe thin coatings.…”

“…All of them considered the mechanical properties of bulk materials to describe thin coatings. For instance, Young modulus (E) of bulk Nickel-Phosphorus was between 60-200 GPa [29][30][31][32] depending on the phosphorus content. For copper, Young modulus (E) was usually chosen between 110-130 GPa [31,32,34,35] depending on crystal orientation.…”

Reliability of Wafer Level Chip Scale Packages

“…To better understand the physical mechanisms behind these EM failure modes and related mechanisms, Finite Element Modeling (FEM) was used, results of which are presented elsewhere [16]. Two graphs are shown in Fig.…”