Integration of CaCu3Ti4O12 capacitors into LTCC multilayer modules

The sintering behavior and electric properties of multilayer laminates made from tapes of CaCu3Ti4O12 (CCTO) with glass additive were studied. Sintering at 900 °C gives a fine-grained microstructure with a permittivity of ɛ′ = 900. The co-firing behavior of hetero-laminates of CCTO and commercial CT700 glass-ceramic LTCC tapes as well as with polycrystalline zinc titanate (ZT) LTCC tapes was studied. Co-firing of both hetero-laminates is possible, however, cracking due to shrinkage and thermal expansion mismatch was observed in the CCTO/CT700 combination. Co-fired CCTO/ZT multilayer laminates did not show any cracks, delaminations or other defects. CCTO multilayer capacitor elements were integrated into LTCC zinc titanate multilayer laminates and co-fired at 900 °C with AgPd electrodes.