Tantalum and tantalum nitride powder mixtures for electrolytic capacitors substrates

摘要

A process for producing sintered pellets made from blends of refractory metal and refractory metal nitride powders were found to have a higher fraction of intra-agglomerate pores than those made from the refractory metal or refractory metal nitride alone resulting in improved capacitor grade powders, anodes and finished capacitors therefrom. The pellet porosity and total intrusion volume maximizes when the mixture is in the 50-75 W/W % refractory metal nitride range. The total pellet pore surface area was found to be relatively independent of refractory metal nitride concentration above 50%. A substrate consisting of a 50/50 or 25/75 W/W % refractory metal/refractory metal nitride powder mixture should produce solid capacitors with higher capacitance recovery and lower ESR.