Capacitor technology focuses on high voltage commercial and automotive applications

January 09, 2012 // By Paul Buckley
KEMET has introduced the company's ArcShield capacitor technology for use in high voltage applications susceptible to surface arcing (arc-over discharge).

KEMET ArcShield High Voltage capacitors are primarily suited for applications, such as automotive, that meet or exceed 500 V with exposure to high humidity environments. Conditions such as these promote surface arcing in MLCCs. The ArcShield devices inhibit surface arc-over discharge, thereby preventing damage to the capacitor and surrounding components on a printed circuit board.     

Surface arcing is generally caused by a high voltage gradient between the MLCC's termination surfaces or between one termination surface and the component's internal electrode structure. The phenomenon can either damage surrounding components or lead to a breakdown of the MLCC's dielectric material, ultimately leading to a short-circuit condition (catastrophic failure mode).     

For added reliability, KEMET's Flexible Termination technology is an available option that provides superior flex performance over standard termination systems. The technology was developed to address flex cracks, which are the primary failure mode of MLCCs and typically the result of excessive tensile and shear stresses produced during board flexure and thermal cycling. Flexible Termination technology inhibits the transfer of board stress to the rigid body of the MLCC, therefore mitigating flex cracks which can result in low IR or short circuit failures.

ArcShield High Voltage MLCCs are also available in automotive grade, which undergo stricter testing protocol and inspection criteria. Whether under-hood or in-cabin, these devices are designed for mission and safety-critical automotive circuits or applications requiring proven, reliable performance in harsh environments.     

Typical markets include power supply, LCD fluorescent backlight ballasts, HID lighting, telecom equipment, industrial and medical equipment/control, LAN/WAN interface, analog and digital modems, and automotive. Typical applications include switch mode power supplies (input filters, resonators, tank circuits, snubber circuits, output filters), high voltage coupling and DC blocking, lighting ballasts, voltage multiplier circuits, DC/DC converters and coupling capacitors in Cuk converters.     

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