Viscoelastic properties effect on solder ball failure analyses

The effects of material properties modeling on the solder failure analyses by numerical simulations are studied. The packaging structure of plastic ball grid array on printed circuit board was modeled. Two different types of molding compounds and two different types of substrates were employed and combined for the plastic ball grid array package modeling. The material properties were assumed as temperature dependent elastic and viscoelastic, and the strain energy densities of solder balls were calculate and analyzed. The results showed that the mechanism of the energy density developments were very different depending on the material properties modeling and their combinations. This study demonstrated that appropriate modeling of the material properties is critical for interpretation and understanding the microelectronics reliability mechanisms.