Adhesion characteristics of Cu/Ni–Cr/polyimide flexible copper clad laminates according to Ni:Cr ratio and Cu electroplating layer thickness
The adhesion strength of Cu/Ni–Cr/polyimide flexible copper clad laminate (FCCL) was evaluated according to the composition ratio of the Ni–Cr layer and the thickness of the Cu electroplating layer, by using a 90° peel test. The changes in the morphology, chemical bond and adhesion property were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The peel strength of the FCCL increased with increasing Cr content and increasing Cu electroplating layer thickness. This increasing FCCL peel strength was attributed to a lower C–N bond and higher C–O and carbonyl (C=O) bonds in the polyimide surface compared to the FCCL with a lower adhesion strength. The adhesion property of the FCCLs was significantly affected by the Ni:Cr ratio.
KeywordsPolyimide Adhesion Strength Peel Test Polyimide Film Peel Strength
This work was supported by grant No. RTI04-03-04 from the Regional Technology Innovation Program of the Ministry of Commerce, Industry and Energy (MOCIE).