||Polymer material tends to absorb moisture of environment to cause volume swelling among various materials of electronic package, such as underfill and substrate. The residual moisture of the package would also be vaporized into vapor phase in the reflow process. These phenomena render expansion mismatch and stress concentration at the interface between each components. If stress induced by moisture, vapor pressure and temperature up to mechanical strength, the product have the risk to damage and affect the operation.|
This paper adopt the finite element software, ANSYS v14.5, to investigate moisture diffusion and structure effects of hygro-thermal-vapor pressure coupling. This study is divided into two parts: First part is about 3D IC package. Second part is about 2.5D IC package. In 3D IC research, whether the mold compound covered and through silicon vias, micro-bumps are discussed under moisture, vapor pressure and temperature effects. In 2.5D IC research, the traditional inorganic passivation layer, Si3N4, is analyzed, in addition, the low-cost organic material is also investigated. Besides, the material properies of organic material will have a sharply change after reflow temperature up to the glass transition temperature (Tg). This paper also focus on this issue and compare the results of these two advanced package under hygro-thermal-vapor pressure coupling.