Adhesion promotion of the polyimide–copper interface using silane‐modified polyvinylimidazoles

Abstract

In order to promote the interfacial adhesion strength between polyimide (PI) and copper, the copper surface was treated with polyvinylimidazole (PVI) or silane-modified PVIs. They were prepared by the copolymerization of 1-vinylimidazole (VI) with the following silane coupling agents: 3-(N-styrylmethyl-2-amino-ethylamino)propyltrimethoxysilane (STS), vinyltrimethoxy silane (VTS), allyltrimethoxy silane (ATS), and γ-methacryloxypropyltrimethoxysilane (γ-MPS). The mole ratio of the silane coupling agent to VI was fixed at 1 : 1. The lap shear strengths between PI and copper were measured at the following different bonding temperatures: 290, 320, 350, and 380°C. In each case, the maximum adhesion strength was obtained at 350°C. VTS-modified PVI showed the best performance on adhesion promotion of the PI–copper interface. Fourier transform infrared spectroscopy was applied to investigate the thermo-oxidative degradation of PI and oxidation of copper. In addition, scanning electron microscopic analysis and contact angle measurements were performed for the investigation of the interaction between PI and silane-modified PVIs. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1343–1351, 1998