TY - JOUR A1 - Mieller, Björn A1 - Naghib Zadeh, Hamid A1 - Rabe, Torsten T1 - Improved co-firing of ferrite and dielectric tape based on master sintering curve predictions and shrinkage mismatch calculations JF - Journal of the American ceramic society N2 - Co-firing of low temperature co-fired ceramics (LTCC) and functional ceramics like ferrites is a promising approach to increase the level of integration in future microsystems, and to create new applications for LTCC technology. Besides the development of compatible material combinations, the configuration of the sintering process is an important issue for successful co-firing. A method is presented to derive the linear shrinkage mismatch of a material combination based on density data calculated from the master sintering curves (MSCs) of the individual materials. The influence of the firing profile on the constraint in the combined multilayer can be anticipated using this method. To investigate and improve the co-firing of ferrite and dielectric tape, the shrinkage mismatch with respect to heating rate was studied. A significant reduction of shrinkage mismatch was found for increased heating rates. The calculated results are verified by lateral shrinkage measurements on combined laminates. PY - 2013 DO - https://doi.org/10.1111/jace.12179 SN - 0002-7820 SN - 1551-2916 N1 - Geburtsname von Mieller, Björn: Brandt, B. - Birth name of Mieller, Björn: Brandt, B. VL - 96 IS - 3 SP - 726 EP - 730 PB - Blackwell Publishing CY - Malden AN - OPUS4-27955 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rabe, Torsten A1 - Naghib Zadeh, Hamid A1 - Glitzky, C. A1 - Töpfer, J. T1 - Integration of Ni-Cu-Zn ferrite in LTCC-modules T2 - CICMT 2011 - 7th International conference and exhibition on ceramic interconnect and ceramic microsystems technologies (Proceedings) 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 p=900 were developed which can be fully densified at the Standard LTCC sintering temperature of 900 °C. Successful co-firing of this ferrite with dielectric tapes requires the adaptation of the shrinkage behavior of the materials as well as the thermal expansion during the cooling period - especially in the temperature range below the transformation point of the glassy 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 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 by EDX measurements. Compared to pure ferrite laminates the permeability of co-sintered Ni-Cu-Zn ferrite layers is drastically reduced to 400, i.e. a decrease of more than 50 %. To investigate the origin of this permeability reduction, Ni-Cu-Zn ferrite laminates were sintered separately, and in combination with alumina release tapes or dielectric tapes, respectively. SEM and EDX analysis of co-fired laminates reveal differences in the ferrite grain growth behavior. Ferrite laminates with homogeneous microstructure and grain size up to 50 pm exhibit large permeability. 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 high permeability and volume fraction of large ferrite grains. Regions of fine and coarse grains inside the ferrite layers show different bismuth concentration; the Bi-content is larger in regions of fine ferrite grains. T2 - CICMT 2011 - 7th International conference and exhibition on ceramic interconnect and ceramic microsystems technologies CY - San Diego, CA, USA DA - 05.04.2011 KW - LTCC KW - Co-firing KW - Ferrite KW - Shrinkage behavior KW - Constrained sintering KW - Keramische Multilayer KW - Grenzflächenreaktion PY - 2011 SN - 0-930815-92-0 SP - 000266 EP - 000275 PB - IMAPS, International Microelectronics and Packaging Society AN - OPUS4-25072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Naghib Zadeh, Hamid A1 - Rabe, Torsten A1 - Toepfer, J. A1 - Karmazin, R. T1 - Co-firing of LTCC modules with embedded ferrite layers T2 - EMPC-2011 - 18th European microelectronics & packaging conference (Proceedings) N2 - Further miniaturization of electronic packaging calls for integration of magnetic functional components into LTCC modules. For integration of magnetic function into LTCC, low fired MnZn- and NiCuZn-ferrites which can be fully densified at the standard LTCC sintering temperature of 900°C were developed. To co-fire these ferrite tapes with dielectric tapes the sintering shrinkage and the coefficient of thermal expansion of ferrite and dielectric tapes must be matched. For each ferrite material a new LTCC dielectric material was designed. The embedded ferrite tapes into new LTCC dielectric tapes can be sufficiently densified during co-firing at 900°C without any cracking. Compared to separately sintered ferrites the permeability of embedded ferrite tapes is reduced. For embedded NiCuZn ferrites permeabilities between 230 and 570 (at 2 MHz) according to the thickness of the embedded ferrite layer were measured. For embedded MnZn ferrites a permeability of 300 was measured. T2 - EMPC-2011 - 18th European microelectronics & packaging conference CY - Brighton, UK DA - 12.09.2011 KW - LTCC KW - Co-firing KW - Ferrite PY - 2011 SN - 978-0-9568086-0-8 IS - TuA2 SP - 1 EP - 6 AN - OPUS4-25021 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 - CONF A1 - Naghib Zadeh, Hamid A1 - Rabe, Torsten T1 - Pressure-assisted sintering of multilayer transformer using LTCC-compatible NiCuZn-ferrite and silver conductor T2 - CICMT 2012 - 8th International conference on ceramic interconnect & ceramic microsystems technologies (Proceedings) T2 - CICMT 2012 - 8th International conference on ceramic interconnect & ceramic microsystems technologies CY - Erfurt, Germany DA - 2012-04-16 KW - LTCC KW - Ferrite KW - Silver conductor PY - 2012 SP - 000476 EP - 000483 (Session WP 1 / WP 15) AN - OPUS4-27775 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Naghib Zadeh, Hamid A1 - Rabe, Torsten A1 - Karmazin, R. T1 - Integration of MnZn-ferrite tapes in LTCC multilayer JF - Journal of electroceramics N2 - For co-firing of MnZn-ferrite tapes and LTCC dielectric tapes, the sintering shrinkage curves and the coefficient of thermal expansion of ferrite and dielectric tapes were matched. Highly densified embedded ferrite without any cracks could be manufactured by co-firing at 900 °C in nitrogen atmosphere. However, the permeability of MnZn-ferrite co-fired between dielectric tapes is significantly reduced (µ´=100) compared to that of the separately sintered ferrite (µ´=500). Changes in the phase stability and microstructure of MnZn-ferrite were investigated to explain the permeability reduction in the embedded ferrite. It is supposed that early densification of the dielectric tapes on the top and bottom of the ferrite layer prevent the gas exchange during sintering which is necessary for (Mn,Zn)Fe2O4 spinel formation. As a result, high amount of Fe2O3 secondary phase and a Mn-rich spinel phase with low permeability remain in the embedded ferrite layer. KW - LTCC KW - MnZn-ferrite KW - Co-firing PY - 2013 DO - https://doi.org/10.1007/s10832-013-9800-5 SN - 1385-3449 SN - 1573-8663 VL - 31 IS - 1-2 SP - 88 EP - 95 PB - Kluwer Acad. Publ. CY - Boston, Mass. [u.a.], USA AN - OPUS4-29385 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Töpfer, J. A1 - Hesse, J. A1 - Bierlich, S. A1 - Barth, S. A1 - Capraro, B. A1 - Rabe, Torsten A1 - Naghib Zadeh, Hamid A1 - Bartsch, H. T1 - Integration of Ni-Cu-Zn and hexagonal ferrites into LTCC modules: Cofiring strategies and magnetic properties JF - Journal of the Japan society of powder and powder metallurgy = Funtai-oyobi-funmatsu-yakin N2 - We have studied the integration of Ni-Cu-Zn ferrite spinels as well as substituted hexagonal Co2Y-and M-type ferrites into LTCC (Low Temperature Ceramic Co-firing) modules. The cofiring behavior and the magnetic properties of these materials were investigated and evaluated for multilayer applications. Ni-Cu-Zn ferrites exhibit permeabilities of µ=300–500 for operating frequencies in the MHz range. Cu-substituted Y-type ferrites Ba2Co2-x-yZnxCuyFe12O22 in combination with sintering additives display sufficient shrinkage and densification at 900°C. A permeability of µ=10 is observed; however, substituted Co2Y-type ferrites do not exhibit long-term stability at 900°C. Co/Ti-substituted M-type ferrites BaFe12-2yCoyTiyO19 (y=1.2) with planar magneto-crystalline anisotropy exhibit excellent soft magnetic behavior. Using sintering additives, complete densification is reached at 900°C and a permeability of µ=15 and a resonance frequency of larger than 1?GHz are observed. Integration of ferrite multilayer inductor components into LTCC modules using free and constrained cofiring technologies is demonstrated. KW - Ferrites KW - Cofiring KW - LTCC modules KW - Permeability PY - 2014 UR - https://www.jstage.jst.go.jp/article/jjspm/61/S1/61_S214/_pdf DO - https://doi.org/10.2497/jjspm.61.S214 SN - 0532-8799 SN - 1880-9014 VL - 61 SP - Suppl. S1, S214 EP - S217 PB - Ky¯okai CY - Ky¯oto AN - OPUS4-31045 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 -