Polymer capacitor is a chip laminated aluminum electrolytic capacitor with high conductivity polymer material as cathode, which has excellent electrical performance beyond the existing liquid chip aluminum electrolytic capacitor and solid chip tantalum electrolytic capacitor. Polymer capacitors are within the rated voltage range and do not need to be reduced.

The polymer capacitor is made by clamping a separator sheet containing electrolyte between two aluminum foils or tantalum foils. The assembly is then rolled up to obtain a cylindrical shape. Add electrodes, and then package the whole assembly in an aluminum housing. Since solid polymer capacitors are not considered as components that may be replaced in devices, they are usually made of SMT (surface mount technology). This allows them to occupy less space on the PCB (printed circuit board), but it is more difficult to disassemble and solder if they need to be replaced.

Due to its low ESR, polymer capacitors are used in applications that allow large ripple currents. An example of this application is a switched DC-DC converter. A good example is buck, boost and buck boost converters, which keep the voltage of the capacitor relatively constant, but produce high ripple current. In this case, it is preferable to use a capacitor with low ESR to improve power efficiency and improve safety in the case of overload and overheating.

Solid state polymer capacitors can be used to smooth the voltage from the power supply to the sensitive circuit, thereby reducing power noise. In these applications, as long as the operating voltage is low enough, they can easily replace standard electrolytic capacitors.

They can also be used for power bypass and signal decoupling to reduce the signal noise and power noise generated by the equipment, otherwise these noises will be transmitted to the power supply and may affect other equipment connected to the power supply.

Polymer capacitors can usually be found on computer motherboards, especially higher quality capacitor motherboards, such as server motherboards, which largely replace wet electrolytic capacitors.