Adhesion improvement of sputtered Cu films on flexible polymer substrates through the design of metal interlayers

Magnetron sputtering is an alternative approach to prepare flexible copper clad laminates because of low cost and thin copper clad laminate thickness. However, Cu film has poor adhesion when directly deposited on polymer substrates, imposing certain limits to the use of magnetron sputtering technique. This work aims to improve the adhesion between the copper film and the polymer substrate. In this work, we succeeded improved the adhesion between the polymer substrates and copper film by introducing different metal interlayers into the polymer/Cu interfaces. It was found that the the copper films with Ni interlayer have the best adhesion with polymer substrates. This study proposes a promising route to overcome the wear adhesion problem between Cu film and polymers in the preparation of magnetron sputtered flexible copper clad laminates.