In an integrated circuit, signal propagation loss is
proportional
to the frequency, dissipation factor (
D
f
), and square root of dielectric constant (
D
k
). The loss becomes obvious as we move to high-frequency communication.
Therefore, a polymer having low
D
k
and
D
f
is critical for copper-clad laminates at higher
frequencies. For this purpose, a 4-vinylbenzyl ether phenoxy-2,3,5,6-tetrafluorophenylene-terminated
OPE (VT-OPE) resin was synthesized and its properties were compared
with the thermoset of commercial OPE-2St resin. The thermoset of VT-OPE
shows a higher
T
g
(242
vs
229 °C), a relatively high cross-linking density (1.59
vs
1.41 mmole cm
–3
), a lower coefficient
of thermal expansion (55
vs
76 ppm/°C), better
dielectric characteristic at 10 GHz (
D
k
values of 2.58
vs
2.75,
D
f
values of 0.005
vs
0.006), lower water absorption
(0.135
vs
0.312 wt %), and better flame retardancy
(UL-94 VTM-0
vs
VTM-1 with dropping seriously) than
the thermoset of OPE-2St. To verify the practicability of VT-OPE for
copper-clad laminate, a laboratory process was also performed to prepare
a copper-clad laminate, which shows a high peeling strength with copper
foil (5.5 lb/in), high thermal reliability with a solder dipping test
at 288 °C (>600 s), and the time for delamination of the laminate
in thermal mechanical analysis (TMA) at 288 °C is over 60 min.