FEATURE DISTRIBUTION
CLOSING THE PIPE: Perfect tantalum mine to line
James Lewis, Technical Marketing Director at Kemet Electronics Corp. explores how corporate social policies and manufacturing processes have evolved to maintain a sustainable supply of assured conflict-free, competitively priced, high-quality Mn
O2 and organic polymer tantalum capacitors S
olid tantalum capacitors can be either Mn
O2 or organic polymer types,
depending on the cathode technology used. In either case, they are chosen by designers for applications requiring a combination of high volumetric efficiency and high reliability. Polymer tantalum capacitors deliver additional benefits such as very high energy per unit volume, minimal voltage derating, and a benign failure mode, whereas Mn
O2
capacitors can ignite or produce smoke upon failure.
Defence and aerospace equipment must operate faultlessly in harsh environments, and often are required to survive for a long period in the field without degradation. Typical examples include high-power airborne radar, which can impose high pulse loads capable of exposing latent faults that can lead to failure of Mn
O2
capacitors resulting in ignition. The instances and the consequences of tantalum capacitor failure can be all minimised by taking great care to ensure that the raw tantalum used is of high purity and to eliminate imperfections that can enter during capacitor manufacturing processes. Great care is also required in the sourcing of tantalum, to ensure compliance with legislation on conflict minerals; in particular, the Dodd-
10 SEPTEMBER 2014 | ELECTRONICS
Frank Wall Street Reform and Consumer Protection Act section 1502. The best way to ensure compliance with this legislation is to work directly with communities and mining groups producing tantalum, particularly in areas such as the Democratic Republic of Congo (DRC). Producing high-quality, conflict-free capacitors demands a means of ensuring the tantalum used is perfect, from the mine to the end of production line.
“CLOSED-PIPE” INFRASTRUCTURE To ensure high material quality and maintain a competitively priced source of conflict-free tantalum, Kemet put its “closed-pipe” tantalum supply chain strategy into action in 2011. So far, it is the only producer of tantalum capacitors to own such an infrastructure. This infrastructure comprises multiple elements including a tantalum powder manufacturer in Nevada, named Kemet Blue Powder Corporation, as well as a tantalum ore processing facility in Matamoros, Mexico.
To ensure a source of conflict-free tantalum ore to supply these facilities, the company approached Mining Mineral Resources (MMR), a company with a successful history of working in DRC.
KEMET Blue Powder has the expertise to design new powders and optimise manufacturing processes. This
infrastructure is able to produce chemically pure capacitor-grade tantalum powder, keeping concentrations of metallic and most non- metallic impurities down to very low levels
MMR has concessions from the DRC government to mine tantalum in the conflict-free Katanga Province. Kemet is also combining its own efforts with the work of traceability schemes such as those developed by the International Tin Research Institute (ITRI) and the implementation of other “in-region” sourcing initiatives. All the facilities have been audited and validated as being compliant with the Electronic Industry Citizenship Coalition (EICC)/Global e- Sustainability Initiative (GeSI) Conflict- Free Smelter Program (CFSP). Working to support long-term sustainability and security for all involved, the company also started the initiative Partnership for Social and Economic Sustainability, and committed $1.5 million over its first two years for social sustainability projects at the mine and village. The Partnership teamed with the Kisengo Foundation, a non-profit organisation dedicated to raising the standard of living in and around the village of Kisengo in Katanga Province by investing in hospitals, schools, and infrastructure projects to ensure safe and reliable water supply, electricity, and roads. This infrastructure is able to produce chemically pure capacitor-grade tantalum powder, keeping concentrations of metallic and most non-metallic impurities down to very low levels in the ppm range. However, this alone does not guarantee capacitors capable of satisfying the most demanding industrial and defence applications. Impurities can be introduced during capacitor manufacturing, which can cause imperfections in the dielectric, resulting in potential tantalum capacitor failures. In order to address these issues, Kemet has developed two breakthrough process and screening technologies to deliver high reliability tantalum capacitors. The company’s F-Tech tantalum manufacturing capability features techniques for optimising chemical purity to eliminate hidden dielectric defects that could continue to grow in the field, leading to capacitor failure. The company’s T patented Simulated
Breakdown Screening (SBDS) is a non- destructive testing technique that simulates capacitor breakdown voltage without damaging the capacitor. In comparison, traditional DC leakage (DCL) tests cannot detect small defects in the dielectric, and performing breakdown- voltage tests under accelerated conditions can actually induce more defects.
Kemet
www.kemet.com/conflictfree 01279 460 122
Enter 201 / ELECTRONICS
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44