Polymer Capacitors

Polymer capacitors (also known as polymer electrolytic capacitors or polymer e caps) are a type of electrolytic capacitor. A capacitor is a two-terminal electrical components that can store energy, somewhat like a battery. Polymer capacitors have conductive polymer as their electrolyte material within a layered aluminium design. These capacitors combine unique properties from the polymer material in terms of high conductivity, extended temperature range and no risk of drying out, to make a capacitor that offers large capacitance and very low ESR (equivalent series resistance) with high ripple current capability and offer a longer operating life.

Polymer capacitors offer a lot of package options between 2.2 to 470 microfarad and special features include a conductive polymer instead of a liquid electrolyte.

Dependent on the nature of the electrolyte, capacitors may also be referred to as wet meaning they have a liquid electrolyte or solid. Solid Electrolytes may be hybridized with aluminium but normally refers to polymer or tantalum based capacitors.

Aluminium polymer capacitors have very good behaviour against bias effects of voltage and temperature as well as good ageing characteristics. In comparison to ceramic capacitors, polymer electrolytic capacitors offer significant advantages, especially their DC bias performance. In addition, the use of polymer capacitors becomes interesting when increasing the capacitance while maintaining cost. The special design process can also be used to significantly reduce the parasitic effects (especially the ESL). This means for applications the potential to handle high ripple current, have low parasitic inductances, high reliability and very good temperature properties.

Typical Applications

Aluminum polymer capacitors, because of their construction, have significant advantages for electronic applications. Due to their low ESR, low ESL values and high expected lifetime make this technology extremely interesting for many applications which allow for a large ripple current Polymer capacitors are found in many applications such as:

• Power Supplies
• Computer motherboards
• Domestic appliances
• Coupling or blocking
• Smoothing
• Decoupling or bypassing
• Noise filtering

These types of capacitors can easily replace standard electrolytic capacitors, provided that the operating voltage is sufficiently low.