report on the sources of any tin, tantalum, tungsten, or gold
contained in their products.
This, of course, has direct relevance to companies producing tantalum capacitors. A significant percentage of the
world’s tantalum ore is located in the Democratic Republic
of Congo (DRC), which, sadly, has also been an epicenter of
the conflict minerals trade.
Whereas some companies have sought to ensure compliance simply by refusing to buy any minerals from the
DRC, others found this to be detrimental for the country’s
economy and people.
KEMET’s initiative in the DRC is just the first stage of
what has become the industry’s only closed-pipe, vertically
integrated tantalum supply chain. By bringing all activities under control, from the mine through production of
high-quality powder, to final assembly and screening of
tantalum capacitors, this approach provides the highest
possible assurances of ethical sourcing and product quality.
Positively conflict free
Rather than taking a negative approach by withdrawing
from the DRC, the company researched mining companies
in the region to identify a suitable partner. The organization that was selected, Mining Mineral Resources (MMR),
has a successful history of working in the DRC, and has
received concessions from the country’s government to
mine tantalum in the conflict-free Katanga Province. It was
decided that developing the mine with MMR would not
only ensure a secure source of conflict-free tantalum, but
could positively impact the lives of the people of the village of Kisengo for the longer term.
The Kisengo facilities have been audited and are compliant with the Electronic Industry Citizenship Coalition
(EICC)/Global e-Sustainability Initiative (GeSI) Conflict-Free
Smelter Program (CFSP). The Kisengo mine is managed locally by the Coopérative des Artisanaux Miniers du Congo
(CDMC), and all miners share in the proceeds on a daily
basis. The involvement of the CDMC enables lean practices
to maximise output while ensuring fairness for all workers.
Traveling the closed pipe
The tantalum ore mined at Kisengo is washed, weighed,
and logged, and subsequently exported to a facility in
Matamoros, Mexico dedicated to processing the ore into
K-Salt, which is a necessary intermediate product for pro-
ducing tantalum capacitors. From Matamoros, the K-Salt is
shipped to the Carson City, Nevada, where it is converted
to tantalum capacitor powder. This tantalum powder is
then ready to be used by component manufacturing sites
located worldwide, to produce tantalum capacitors.
This network represents a closed-pipe, vertically integrated supply chain capable of guaranteeing the supply of
conflict-free tantalum for use in capacitors. The closed-pipe
aspect to this supply chain is critical, preventing tantalum
ore or processed products from unknown and possibly
non-conflict-free sources from entering the supply chain
Ensuring chemical purity
The capacitor-grade tantalum powder is chemically pure,
with concentrations of metallic and non-metallic impurities
down to very low levels in the ppm range. However, impurities can be introduced during capacitor manufacturing,
which can create imperfections in the dielectric that may
cause the capacitor to fail.
The tantalum manufacturing capability features techniques for optimizing chemical purity to eliminate hidden
dielectric defects that could continue to grow in the field,
leading to capacitor failure.
Any defects present in the dielectric can introduce weak-nesses in the capacitor, which may be manifested as a lower
than usual breakdown voltage. Unfortunately, conventional
end-of-line breakdown tests performed under accelerated
conditions can induce stress-related faults in good capacitors. As an alternative, DC-keakage (DCL) testing can safely
identify weak capacitors but often is unable to detect devices that have only small defects in the dielectric. The F-Tech
process and SBDS can be applied together or individually,
thereby giving customers the flexibility to select either as
an option or to specify both for ultimate peace of mind.
By bringing control of all production processes, from mining the tantalum ore to producing high-quality tantalum
powder and capacitor parts, and non-destructively screening devices at the end of line, this unique closed-pipe supply delivers perfect tantalum capacitors that can be trusted
at every level from ethics to in-system performance. ■