Y. Zhang et al., Thermal imidization of fluorinated poly(amic acid)s on Si(100) surfaces modified by plasma polymerization and deposition of glycidyl methacrylate, LANGMUIR, 17(7), 2001, pp. 2265-2274
Plasma polymerization of glycidyl methacrylate (GMA) on pristine and plasma
-pretreated Si(100) surfaces was carried out. The epoxide functional groups
of the plasma-polymerized GMA (pp-GMA) could be preserved, to a large exte
nt, by controlling the glow discharge parameters. The pp-GMA. film was used
as an adhesion promotion layer for the thermal imidization of fluorinated
poly(amic acid) (FPAA) precursors on Si substrates. The fluorinated polyimi
de (FPI)/pp-GMA-Si laminates so formed exhibited a 180 degrees -peel adhesi
on strength as high as 10 N/cm. This value was much higher than the negligi
ble adhesion strength for the FPI/Si laminates obtained from thermal imidiz
ation of the FPAAs on either the pristine or the argon-plasma-treated Si su
rfaces. The high adhesion strengths of the FPI/pp-GMA-Si laminates were att
ributed to the synergistic effect of coupling the curing of the epoxide gro
ups in the pp-GMA layer with the imidization process of the FPAAs and the f
act. that the plasma-deposited GMA chains were covalently tethered on the S
i(100) surface. Comparison of the adhesion strengths of the FPI/pp-GMA-Si l
aminates to that. of the polyimide (Pl)pp-GMA-Si laminate, formed by therma
l imidization of the poly(amic acid) precursor of poly(pyromellitic dianhyd
ride-co-4,4 ' -oxydianiline) on pp-GMA-Si, suggests that the presence of fl
uorine-containing groups, such as -CF3, in the PI chains has a negligible e
ffect on the adhesion property of the FPIs on title Si(100) wafer surface m
odified by the present interfacial molecular design and lamination techniqu
e.