Comprehensive Analysis of the Impact of Various Surface Modification Techniques on Difficult-to-Adhesion Resins

This study explores the impact of various surface modification techniques—vacuum ultraviolet (VUV) irradiation, oxygen plasma treatment, and atmospheric pressure plasma treatment—on cycloolefin polymer (COP) films to improve resin-to-metal adhesion for semiconductor packaging. The chemical properties, including the density of hydrophilic functional groups, were analyzed using water contact angle measurements and X-ray photoelectron spectroscopy. Meanwhile, the physical properties, such as surface roughness and strength, were assessed using atomic force microscopy and a micro slurry-jet erosion test. Oxygen plasma treatment resulted in the highest functional group density at the topmost surface (~1 nm), while VUV irradiation achieved the highest density in the extreme surface layer (~10 nm). Both oxygen plasma and atmospheric pressure plasma treatments enhanced surface roughness, while VUV irradiation resulted in a smoother surface. Surface strength, as measured by erosion resistance, was weakest with VUV irradiation, followed by oxygen plasma treatment, with atmospheric pressure plasma treatment showing the highest strength. These findings highlight the importance of understanding resin surface properties after surface modification to optimize resin-metal adhesion. While the study focuses on COP, the analytical methods used are broadly applicable to various resins, providing valuable insights for advancing resin-based technologies in semiconductor packaging.