TY - JOUR A1 - Glitzky, Carsten A1 - Rabe, Torsten A1 - Eberstein, Markus A1 - Schiller, Wolfgang Arno A1 - Töpfer, J. A1 - Barth, S. A1 - Kipka, A. T1 - LTCC-Modules with integrated ferrite layers - Strategies for material development and co-sintering JF - Journal of microelectronics and electronic packaging N2 - The integration of passive components (resistors, capacitors, inductors) into LTCC modules is a challenging task in multilayer ceramics technology. We report on multilayer assemblies consisting of combined layers of ferrite and dielectric LTCC tapes. Ni-Cu-Zn ferrites with maximum shrinkage at 900°C were processed to green tapes and laminated with dielectric LTCC tapes. Cosintering at 900°C led to multilayers with different defects such as incomplete densification of the ferrite layers, cracks, and warpage. Since ferrite tapes do not really allow compositional changes without deterioration of magnetic properties, the dielectric tape was modified with the following objectives: (i) matching of the shrinkage curves of dielectric and ferrite materials, (ii) adjusting the coefficients of thermal expansion to avoid cracking during cooling, and (iii) controlling of interface reactions. Using this concept we fabricated dense and defect-free multilayers consisting of dielectric and ferrite layers. However, compositional changes of the individual ferrite tapes require the development of a specific dielectric tape material with tailored properties. KW - Coefficient of thermal expansion (CTE) KW - Cofiring KW - Ferrite KW - LTCC KW - Shrinkage PY - 2009 SN - 1551-4897 VL - 6 IS - 1 SP - 49 EP - 53 CY - Washington, DC AN - OPUS4-19708 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 -