Study on 3D stack package with anodic alumina substrate

The need for 3D stack package is driven by rapidly developed integrated circuit and semiconductor industry. A 3D stack package with anodic alumina substrate was created for integration of multifunctional microsystems. The penetrating anodization of aluminum substrate was investigated. The stack and encapsulation model for COB (Chip on Board) was established with ANSYS. The encapsulating technology of the stacked module and laser ablation of interconnection between external leads in anodic alumina substrate and vertical bus plating on the faces of module were studied. The results show that 4 inches anodic alumina substrate with 0.1 mm thickness is achieved by 30 °C oxalic acid and 60 V voltages. The simulation results show that the maximal deformation of four layers COB structure with interlayer dam is 0.081 mm at 125 °C. The encapsulated solid state memory is 55% smaller and 40% lighter compared with similar 3D-plus memory.