The
tantalum capacitor is a
variant of the
electrolytic capacitor.
It has
high capacitance and
small physical size.
It is
available in
values from 0.1
micro Farad to
1000uF. The
dielectric material in these
tantalum capacitors
are
tantalum oxide.
Production of a modern dry electrolyte tantalum capacitor:
The
anode is made from
fused tantalum powder.
This is then given a
layer of oxidized
tantalum.
Then the
capacitor is
dipped in
disolved manganese nitrate,
that
flows in to all the
small holes and cavities in the
tantalum oxide. By heating the
manganese nitrate is
turned in to
manganese oxide(this will act as the
electrolyte in the
finished capacitor). The
cathode is
made from
tin with
a
thin layer of
silver. To
get optimum connection
between the
manganese oxide and the
silver a thin
layer
of
carbon is used. In
old fasion tantalum capacitors
a
liquid electrolyte and a
silver capsule was
used.
The
tantalum capacitor used in all kinds of
mobile devices
due to their
compact size. But as a
result of the
popularity
of these
kinds of
devices,
spesialy the
mobile phones,
the
demand for
tantalum is now very
high. Therefore the
price of this
element has risen by many
times the last
years.