Adhesion Properties of Electroplating Process Between Polyimide and Metal Layer for Polymer/Metal Hybrid Bonding

This article investigates the adhesion properties between the polyimide layers and the Ti/Cu layer after the electroplating process. The adhesion strength was evaluated by the four-point bending system, and the influence factors were confirmed by using different electroplating times and currents. The fracture interface after the four-point bending measurement was characterized, and the interface spectrum between the polyimide and the Ti/Cu layer was analyzed. The results showed that the modified polyimide-like material has better adhesion performance than the conventional polyimide. Moreover, the mechanism of degradation was proposed. As a result, the modified polyimide-like material can be applied in electroplating, a redistribution layer (RDL) formation, and packaging at the back-end-of-line processes.