The effect of seed metal on the surface morphology of copper foil and adhesion property

Polyimide films are extensively used as base films in FPCB and TAB. Moreover, the low adhesion strength of this interface lead to peeling. Many studies have investigated ways to increase the adhesion strength at the interfaces. This study aimed to investigate the effects of the seed layer with an electrodeposited copper foil on the surface morphology and mechanical characteristics of copper foil, and then we show adhesion strength of between seed layer and polyimide. Platinum, palladium, Pt-Pd alloy were used as seed metals. Electrochemical experiments, in conjunction with SEM, XRD, AFM and four-point probe, were performed to characterize the morphology and mechanical characteristics of the copper foil. Large particles were observed on the surface of the copper deposition layer when a copper foil was electroplated on the Pd seed layer. However, a homogeneous surface, low resistivity and a high level of adhesion strengths were obtained when the Pt seed layer was used. The maximum value of peel strength was 1.19 N/cm.