A low cost direct writing process for flexible circuit and interconnect fabrication
Abstract
This
thesis
investigates
the
development
of
a
low
cost
fabrication
process
for
flexible
electronics
and
interconnects.
By
using
a
‘direct
writing’
process,
the
use
of
vacuum-‐based
metal
evaporation
and
photoresist
steps
is
not
necessary
and
so
less
complex
equipment
is
needed.
The
process
forms
silver
embedded
on
top
of
a
polyimide
substrate
and
was
first
tested
using
a
UV
laser
to
perform
writing
before
switching
to
a
blue
laser
due
to
excessive
substrate
degradation
observed
from
UV
exposures.
The
blue
light
was
combined
with
a
biologically
friendly
photo
reducing
agent,
which
was
found
to
be
much
more
efficient
at
the
creation
of
silver.
The
methods
of
silver
formation
by
various
means
are
the
main
focus
of
investigation
in
this
thesis
but
process
expansion
and
improvement
were
the
main
goals.
To
this
end,
a
chemical,
rather
than
light-‐based,
process
for
silver
creation
was
found
to
produce
more
consistent
silver
coatings,
however
the
patterning
by
this
method
was
found
to
be
more
challenging.
The
process
was
also
extended
to
a
different
substrate
in
polyetherimide.