to be published 2004 Proceedings - 24th Capacitor and Resistor Technology Symposium, San Antonio, Texas, March 29 - April 1, 2004.

Identification of Missing or Insufficient Electrolyte Constituents in Failed Aluminum Electrolytic Capacitors

C. Hillman and N. Helmold
University of Maryland
College Park, MD 20742


Beginning in late 2001, a number of online newsgroups and industry publications started reporting the early lifetime failures of low effective series resistance (ESR) aluminum electrolytic capacitors manufactured in Taiwan The most obvious characteristic of these failures was the bulging of the capacitor enclosure prior to loss of electrical function (see Figure 1). These capacitors had been produced in the millions under contract to multiple capacitor suppliers, and they had widespread use in the mass-produced electronic products of several companies, potentially causing the early failure of hundreds of thousands of end units.

While several phenomenological articles describing the bulging and early failure of these capacitors were published in late 2002 and early 2003, the root cause of the failures was only speculated to be a missing component of their electrolyte. Responding to the request of one of the capacitor suppliers, the CALCE Electronic Products and Systems Center (EPSC) undertook an extensive study of 1000 microfarad, 10 volt, aluminum electrolytic capacitors susceptible to bulging and early failure.

Complete article is available to CALCE Consortium Members.


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