Novel interconnect methodologies for ultra-thin chips on foils

Reliable interconnection technology is key to the realization of reliable hybrid microelectronic systems that combine printed electronics and silicon technology. Flexible hybrid electronic systems-in-foil (SiF) that are typically suited for roll-to-roll (R2R) manufacturing place additional requirements and demands on interconnects. In this paper, three novel interconnection methodologies for SiF are compared for a novel face-up integration approach for ultra-thin chip on foil. Laser scribing, inkjet printing and laser-induced forward transfer (LIFT) are the technologies compared with each other, as well as with electroplating, a standard technology widely used in the electronics industry. The comparison is based on experimental investigation into via filling, interconnect deposition, electrical conductivity and interconnect reliability. The selection of an interconnection technology for practical implementation is the key outcome of this paper.