Effect of Cr Thickness on Adhesion Strength of Cu/Cr/Polyimide Flexible Copper Clad Laminate Fabricated by Roll-to-Roll Process

The adhesion strength Of a Cu/Cr/polyimide (PI) flexible copper clad laminate (FCCL), which was manufactured by the roll-to-roll Process, Was evaluated according to the thickness of the Cr seed layer Using the 90 degrees peel test. The changes in the morphology, chemical bonding and adhesion properties were characterized by scanning electron microscopy. atomic force microscopy and X-ray photoelectron spectroscopy. The peel strength of the FCCL. decreased with increasing Cr layer thickness. The higher FCCL peel strength was attributed to the lower proportion of C-N bonds and higher proportion of C-O or carbonyl (C=O) bonds, On the PI surface compared to the FCCL with the lower adhesion strength. The FCCL with the higher peel strength had a fractured PI surface with it higher surface roughness. The adhesion strength between the metal and PI wits mostly attributed to the chemical interaction between the metal layer and the functional groups of the PI. [doi:10.2320/matertrans.M2009276]