We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Industry

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What Is a Polymer Capacitor?

By Jerry Morrison
Updated: May 17, 2024
Views: 5,573
Share

A polymer capacitor is a type of electrolytic capacitor with a solid ionic conductor rather than a liquid electrolyte. Capacitors are electric storage devices usually composed of two metallic conductors. Electrolytic capacitors replace one or both conductors with an electrolyte solution. In a polymer capacitor, the electrolyte is paper impregnated with organic semiconductor crystals instead of a liquid. The solid electrolyte enables a faster discharge rate and better response to current fluctuations.

The use of an electrolyte as a conductor allows electrolytic capacitors to hold a greater charge in a device of smaller volume. This makes them particularly suited for use in power supply filters, storing the charge needed to mitigate fluctuations in output. Using a solid electrolyte in the polymer capacitor enables a further reduction in size while increasing performance and durability.

In theory, a perfect capacitor would have an equivalent series resistance (ESR) rating of zero. There would be no electrical resistance from any of its components and none of the associated heat build up. A polymer capacitor typically has a lower ESR rating that remains stable over a greater temperature range than other electrolytic designs. Lower ESR ratings enable a faster response to greater transitions in current

Power supplies that have an alternating current (AC) input often experience a periodic fluctuation in direct current (DC) output called ripple. Some power supply systems, such as those used for computer motherboards, subject capacitors to a great deal of stress from ripple current. Polymer capacitors are far more resistant to this stress and have a longer operational life.

The metal conductor of a polymer capacitor is usually made from thin aluminum foil. An aluminum oxide dielectric is layered onto the foil by an electrochemical process called anodization. The foil with the dielectric layer forms the anode, or path of entry, for an electrical current. An electrolyte impregnated separator sheet and an uninsulated length of foil make up the cathode, or path exit, for an electrical current.

The effective surface area of the foil elements in an aluminum polymer capacitor is increased by etching before the aluminum oxide dielectric is generated. Paper impregnated with an organic semiconductor or a conductive polymer separates the anode and cathode foils. The layered elements are rolled into a coil, equipped with pin connectors and sealed in an aluminum sleeve.

Polymer capacitors are much more expensive than wet electrolytics. They are generally produced in small, low-voltage versions for use in devices such as cell phones, graphics cards and high-end server motherboards. Their specialized use makes finding polymer capacitors more difficult as relatively few consumer-oriented distributors carry them in stock.

Share
WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.

Editors' Picks

Discussion Comments
Share
https://www.wisegeek.net/what-is-a-polymer-capacitor.htm
Copy this link
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.