Figure 1 shows that original Polymer Tantalum capacitors had low working voltages and high DC leakage making them usable only in commercial electronics, while the current polymer tantalum capacitors have high working voltages and low DC leakage and are broadly used in high reliability applications .
Tantalum electrolytic capacitors have been on the market for more than half a century, in a range of applications. However, the most common design uses MnO 2 as the electrolyte, which can be thermodynamically unstable and, upon failure, can damage the circuit.
This kind of capacitor had a high capacitance density, good low-temperature performance, and long service life, and was widely used in various electronic devices. However, solid tantalum electrolytic capacitors with MnO 2 still have several drawbacks. Firstly, the use of MnO 2 with high resistance makes it have a high ESR.
The inherently conductive poly (3,4-ethylenedioxytheophene) (PEDOT) is the most commonly used cathode in polymer tantalum capacitors . The conductivity of the PEDOT cathode is higher than the conductivity of the liquid electrolyte cathode in Wet Tantalum capacitors and the MnO 2 cathode in Solid Electrolytic Tantalum capacitors.
In 1956, H.E. Haring and R.L. Taylor from Bell Labs designed the first generation of solid tantalum electrolytic capacitors, which utilized tantalum pentoxide (Ta 2 O 5) as the dielectric layer, manganese dioxide (MnO 2) as the cathode material, and graphite silver paste as the auxiliary cathode layer .
Tantalum electrolytic capacitors have been on the market for more than half a century, in a range of applications. However, the most common design uses MnO2 as the electrolyte, which can be thermodynamically unstable and, upon failure, can damage the circuit.