New Industry Products

Tantalum Capacitors for Non-Critical Medical Devices

March 23, 2018 by Paul Shepard

AVX Corporation has released the new T4Z Medical Series HRC4000 medical-grade tantalum capacitors. Designed to replace commercial capacitors in the filtering, hold-up, and charging circuits of non-critical medical devices that require high-reliability and strict change control.

To ensure consistent, high-reliability performance, the series is manufactured at AVX’s high-reliability, ISO-13485-certified plant in Biddeford, Maine, using strict manufacturing control, statistical screening, and testing procedures compliant with FDA regulations for medical devices.

Implantable are expected to include non-life-sustaining devices, such as heart monitors, neurostimulators, insulin pumps, and temporary cardiac monitors; external, life-sustaining devices, such as automated external defibrillators and external heart pump controllers.

Other applications include external non-life-sustaining devices, such as patient monitoring and diagnostic equipment. The new T4Z Medical Series solid tantalum capacitors are based on a MIL-PRF-55365 product line with more than 25 years of proven high-reliability performance in the medical industry.

T4Z Medical Series capacitors offer the lowest dc leakage values in the market: 0.01CV standard, with custom potential down to 0.005CV — or half that of typical industry limits — enabling longer lifetime performance and improved reliability compared to commercial tantalum capacitors.

They are currently available in eight compact, lightweight case sizes ranging from 2.54mm x 1.27 mm x 1.27mm (L x W x H) ±0.38mm and 0.016g to 7.24mm x 3.81mm x 2.79mm ±0.38mm and 0.335g with solder-plated, solder-fused, gold-plated, or 100% tin terminations. They offer capacitance values extending from 0.1μF to 330μF, eight standard voltage ratings spanning 4–50V, and rated operating temperatures extending from -55°C to +125°C. Custom DCL and ESR values are available upon request.

The T4Z Medical Series utilizes the industry-leading design for molded tantalum capacitors intended for use in high-reliability medical devices, which is conservative, robust, and strictly change-controlled to ensure continuity.

They are manufactured using Weibull reliability grading, which subjects each batch to accelerated burn-in to provide a calculated failure rate; military-style screening and conformance testing, which ensures consistent, high-reliability part performance; and process control, which ensures a stable, normalized leakage distribution.

In addition, each lot is subjected to sample function testing, which simulates the manufacturing environment to further ensure exceptional part performance. As a result, T4Z Medical Series capacitors deliver basic reliability better than 0.1% per 1,000 hours with a 90% confidence level.

“Subjecting our T4Z Medical Series HRC4000 medical-grade tantalum capacitors to such rigorous design and manufacturing process controls, statistical screening, and testing procedures allows us to consistently achieve higher-reliability components with significantly lower dc leakage levels than commercial solid tantalum capacitors, and to better satisfy the exacting demands of even non-critical medical applications,” said Lizzie Geismar, product marketing manager for AVX’s high-reliability tantalum division.

T4Z Medical Series capacitors can be shipped in bulk, 7” tape and reel, or waffle packaging, and — by virtue of being manufactured in a facility with five-plus years of guaranteed tantalum powder — are not subject to the long lead-times common to the commodity tantalum market, instead offering short, consistently stable lead-times that extend to a maximum of eight weeks.