New assembling technique for BGA packages without thermal processes

A new assembling technique for flip-chip mounting without heating processes was developed. The proposed construction is an FR4 substrate with ring shaped connectors. It is a typical flip-chip technology. The chip is placed, with its active part face-down, directly on to the connecting areas of the substrate. The electrical connection is obtained through a mechanical contact between the ring-shaped clips and the chip bumps. The main advantage of the ring-clip-bump attachment technique is the possibility for multi-chip modules repairing without thermal processes. It is a lead-free assembling technology involving only “conventional” processes.