TY - JOUR A1 - Rabe, Torsten A1 - Naghib Zadeh, Hamid A1 - Glitzky, Carsten A1 - Töpfer, J. T1 - Integration of Ni-Cu-Zn ferrite in low temperature Co-fired ceramics (LTCC) modules JF - International Journal of Applied Ceramic Technology N2 - Integration of magnetic functional components in LTCC circuit boards calls for co-firing of dielectric and ferrite tapes. Ni-Cu-Zn ferrites with permeability of µ = 900 were fully densified at the standard LTCC sintering temperature of 900°C. Co-firing of this ferrite with dielectric tapes requires the adaptation of the shrinkage behavior of the materials as well as the thermal contraction during the cooling period – especially in the temperature range below the transformation point of the glass phase of the dielectric tape. To match these preconditions, a new dielectric LTCC material with steep sintering curve and high thermal expansion coefficient was designed. Sintered multilayer laminates composed of Ni-Cu-Zn ferrite and tailored dielectric tapes are free of cracks and possess no open porosity. No significant interdiffusion between the ferrite and dielectric tapes was found using microprobe analysis. Pure ferrite laminates show homogeneous microstructure with large grains up to 50 µm in diameter. However, growth of ferrite grains does not take place near the interface between ferrite and release or dielectric tapes. There is a strong correlation between permeability and volume fraction of large ferrite grains. Compared to pure ferrite laminates the permeability of co-sintered Ni-Cu-Zn ferrite layers is drastically reduced to 400, that is a decrease of more than 50%. PY - 2012 DO - https://doi.org/10.1111/j.1744-7402.2011.00712.x SN - 1546-542X SN - 1744-7402 VL - 9 IS - 1 SP - 18 EP - 28 PB - American Ceramic Soc. CY - Westerville, Ohio AN - OPUS4-25544 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Naghib Zadeh, Hamid A1 - Glitzky, Carsten A1 - Österle, Werner A1 - Rabe, Torsten T1 - Low temperature sintering of barium titanate based ceramics with high dielectric constant for LTCC applications JF - Journal of the European Ceramic Society N2 - The sintering temperature of BaTiO3 powder was reduced to 900 °C due to the ZnO-B2O3-Li2O-Nb2O5-Co2O3 addition. Excellent densification was achieved after sintering at 900 °C for 2 h. The low sintering temperature of newly developed capacitor materials allows a co-firing with pure silver electrodes. The dielectric constant and the temperature stability of the dielectric constant are strongly correlated with the composition of the ZnO-B2O3-Li2O additives. A high dielectric constant up to 3000 and a dielectric loss less than 0.024 were measured on multilayer capacitors sintered at 900 °C with silver inner electrodes. KW - BaTiO3 and titanates KW - Capacitors KW - Dielectric properties KW - LTCC PY - 2011 DO - https://doi.org/10.1016/j.jeurceramsoc.2010.10.003 SN - 0955-2219 SN - 1873-619X VL - 31 IS - 4 SP - 589 EP - 596 PB - Elsevier Ltd. CY - Oxford AN - OPUS4-22886 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Naghib Zadeh, Hamid A1 - Glitzky, Carsten A1 - Rabe, Torsten A1 - Lissner, A. ED - J.G. Herinrich, ED - C. Aneziris, T1 - Development of capacitor materials with sintering temperature below 900 °C T2 - 10th International Conference and Exhibition of the European Ceramic Society (ECerS), June 17-20, 2007, Berlin (Proceedings) T2 - 10th International Conference and Exhibition of the European Ceramic Society (ECerS) CY - Berlin, Germany DA - 2007-06-17 KW - Capacitor KW - LTCC KW - Barium titanate PY - 2007 SN - 3-87264-022-4 SP - 554 EP - 558 PB - Göller CY - Baden-Baden AN - OPUS4-18925 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rabe, Torsten A1 - Glitzky, Carsten A1 - Naghib Zadeh, Hamid A1 - Oder, Gabriele A1 - Eberstein, M. A1 - Töpfer, J. T1 - Silver in LTCC - Interfacial reactions, transport processes and influence on properties of ceramics T2 - CICMT 2009 - 5th International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystems Technologies (Proceedings) T2 - 2009 IMAPS/ACerS - 5th International Conference and Exhibition on Ceramic Interconnect and Ceramic Microsystems Technologies (CICMT) CY - Denver, Colorado, USA DA - 2009-04-21 KW - LTCC KW - Silver conductors KW - Interface KW - Sintering KW - Ferrite KW - Capacitor PY - 2009 SN - 0-930815-87-4 SP - 000085 EP - 000093 AN - OPUS4-19428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Naghib Zadeh, Hamid A1 - Glitzky, Carsten A1 - Rabe, Torsten T1 - Low fired high-K dielectrics buried into LTCC substrates T2 - 5th Ceramic Interconnect and Ceramic Microsystems Technologies Conference N2 - Due to addition of minor amounts of suitable additive combinations to BaTiO3 powder the sintering temperature was reduced to 900 °C. Excellent densification (more than 98% of theoretical density) and good dielectric properties were achieved after sintering at 900 °C for 2 hours. Dielectric properties can be improved by modifying the composition of sintering additives and additon of further dopants. The low sintering temperature of newly developed capacitor material allows a co-sintering with pure silver electrodes. No interfacial reaction between silver electrodes and ceramics was observed by microprobe analysis. The dielectric constants of about 1200 to 3000 and the dielectric losses of about 0.008 to 0.02 were measured (f = 1 kHz, T = 25 °C). The temperature dependency of dielectric constant for new capacitor materials is low, almost X7R characteristics. Furthermore, the densification and the dielectric properties of embedded capacitors in LTCC were investigated. T2 - 5th Ceramic Interconnect and Ceramic Microsystems Technologies Conference CY - Denver, USA DA - 2009-04-20 KW - Capacitor KW - LTCC KW - Barium titanate PY - 2009 SN - 0-930815-87-4 IS - WA 32 SP - 000188 EP - 000192 AN - OPUS4-19377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Naghib Zadeh, Hamid A1 - Glitzky, Carsten A1 - Dörfel, Ilona A1 - Rabe, Torsten T1 - Low temperature sintering of barium titanate ceramics assisted by addition of lithium fluoride-containing sintering additives JF - Journal of the European Ceramic Society N2 - By addition of LiF-containing sintering additives to commercial BaTiO3 powder, more than 98% of the theoretical density was reached at a sintering temperature of 900 °C both on powder compacts and laminates. Dielectric measurements were performed on ceramic samples in the temperature and frequency ranges from -20 °C to 125 °C and from 103 to 106 Hz, respectively. High relative permittivity (εr ~ 3160) and low dielectric loss (tan δ ~ 0.014) were measured for tapes of the favoured material. The breakdown strength for tapes with a thickness of about 80 µm is 30 kV/mm. The microprobe analysis showed, that no interfacial reaction between the dielectric layer and the Ag-electrode had occurred. The newly developed barium titanate ceramics completely densifying at 900 °C turned out to be promising for integration of buried capacitors in LTCC multilayers. KW - LTCC KW - BaTiO3 KW - LiF KW - Capacitors PY - 2010 DO - https://doi.org/10.1016/j.jeurceramsoc.2009.07.005 SN - 0955-2219 SN - 1873-619X VL - 30 IS - 1 SP - 81 EP - 86 PB - Elsevier CY - Oxford AN - OPUS4-20133 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -