Effects of the sintering atmosphere on the BaZn_(1/3)Ta_(2/3)O_3 based Cu multilayer ceramic capacitors

摘要

Recent papers report that BaZn_(1/3)Ta_(2/3)O_3 (BZT) ceramic can be sintered at a temperature as low as 1050 deg C owing to the use of flux agents like B_2O_3 + LiF combined with a slight non-stoichiometry, whereas its usual sintering temperature is 1400 deg C. This low sintering temperature (below the Cu's melting point = 1083 deg C) opens the route to fabricate copper based multilayer ceramic capacitors, in condition that a reductive atmosphere is used during the sintering. This paper presents the effect of three various sintering atmospheres (air, H_2 (1 percent ) in N_2 and H_2 (1 percent ) in Ar) on the stability and the dielectric properties of BZT. It is researched a suitable sintering atmosphere to prevent Cu from oxidation and to preserve the dielectric properties of BZT. Using the appropriate atmosphere, copper based multilayer ceramic capacitors, with attractive dielectric properties, have been successfully processed.