Via Interconnections for Half-Inch Sized Package Fabricated by Minimal Fab

A Ball Grid Array (BGA) packaging tool-set and packaging process using a half-inch sized package have been developed. The packaging tool-set is integrated with device manufacturing process line of Minimal Fab that uses half-inch wafers. The packaging line for the half-inch sized package with packaging tools of a die-bonding, a compression molding, a laser ablation, a sputtering and an electroplating of Cu, a redistribution layer (RDL) patterning, a Cu wet-etching, an inkjet, a ball mounting, and a reflow were developed. The packaging process was evaluated by cross-bridge Kelvin resistor (CBKR) test-structures with 3-vias using the BGA package fabricated by the line. Moreover, we have improved electrical contacts between devices and the package by changing Al-Si electrode pads on the device to Cu/Ti pads. As a result, via contact-resistances of the vias with the Cu/Ti electrode pads have reduced by three orders of magnitude than those of the Al-Si electrode pads.