Hara, Yasuhiro, et al. Current Applied Physics, 2012, 12, S38-S41.
This work combines atmospheric pressure plasma modification and polymer film grafting to modify the surface of PFA to enhance the adhesion of chemically plated Cu layer on the PFA sheet surface.
Surface modification and metallization process of PFA sheet
· PFA sheets with a thickness of 0.1 mm were utilized as substrates for electroless copper plating after inducing the formation of peroxide radicals on the PFA surface using atmospheric-pressure helium (He) plasma irradiation.
· Poly (4-vinylpyridine) (P4VP, MW: 60K) was dissolved in a 1-butanol solution, and the plasma-treated samples were immersed in the P4VP solution (4 wt.%). The hydrophilic nature of the sample surface post-plasma irradiation facilitated the uniform formation of a thin layer of P4VP butanol solution on the sample surface.
· The grafted samples were activated by immobilizing the Pd catalyst needed for the electroless copper deposition. They were dipped in a SnCl2/PdCl2 colloidal solution for 4 minutes and then rinsed thoroughly with ultrapure water for 5 minutes.
· The Pd/Sn-catalyzed samples were further activated by immersion in a NaOH solution for 4 minutes to remove the Sn catalyst from the sample surface, followed by thorough rinsing with ultrapure water for 5 minutes.
· The surface-activated samples were then placed in an electroless copper plating bath for 40 seconds. Finally, the copper-deposited samples were rinsed thoroughly with ultrapure water.
