Effects of the sintering atmosphere on the BaZn1/3Ta2/3O3 based Cu multilayer ceramic capacitors

Recent papers report that BaZn1/3Ta2/3O3 (BZT) ceramic can be sintered at a temperature as low as 1050 degrees C owing to the use of flux agents like B2O3 + LiF combined with a slight non-stoichiometry, whereas its usual sintering temperature is 1400 degrees C. This low sintering temperature (below the Cu's melting point = 1083 degrees 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%) in N-2 and H-2 (1%) 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. (c) 2007 Elsevier Ltd. All rights reserved.