The effects of Cr oxidation and polyimide degradation on interface adhesion strength in Cu/Cr/polyimide flexible films

Interface adhesion strength of Cu/Cr/polyimide was measured and the effects of annealing atmosphere were investigated. Adhesion strength decreased after annealing in vacuum by 25% and in air by 41%, which was attributed, respectively, to broken carbonyl bonds and to the formation of Cr oxide. Failure mode changed accordingly from cohesive to interfacial at a Cr/polyimide interface.