TY - JOUR A1 - Eberstein, Markus A1 - Glitzky, Carsten A1 - Gemeinert, Marion A1 - Rabe, Torsten A1 - Schiller, Wolfgang Arno A1 - Modes, C. T1 - Design of LTCC with high thermal expansion JF - International Journal of Applied Ceramic Technology N2 - New applications of low-temperature co-fired ceramics (LTCC), such as pressure sensors or integrated functional layers, require materials that possess higher coefficients of thermal expansion (CTE). To fabricate LTCC with elevated CTE, two methods of material design are examined: firstly, glass ceramic composites (GCC), which consist of >50 vol% glass in the starting powder, and, secondly, glass-bonded ceramics (GBC), where glass is added as a sintering aid only. The CTE of GBC is mainly determined by the crystalline component. For GCC, the CTE can be well predicted, if CTE and elastic data of each phase in the microstructure are known. A nonlinear characteristic of the CTE versus phase composition was found with increasing Ecrystals/Eglass ratio and absolute CTE difference between the components. The glass composition and glass amount can be used to compensate the fixed properties of a crystalline material in a desired way. However, because the CTE and permittivity of a glass cannot be chosen independently, an optimum glass composition has to be found. For a given LTCC, it is possible to control the devitrification by shifting the glass composition. In this way, the resulting CTE values can be predicted more exactly and tailoring becomes possible. Different LTCC materials, based on the crystalline compounds Ba(La,Nd)2Ti4O12, ZrO2 (Y-TZP), SiO2 (quartz), and specially developed glasses, possessing an elevated CTE of around 10 × 10-6 K-1 while showing permittivity εr between 6 and 63, are introduced. KW - LTCC KW - Glass ceramic composites KW - Coefficient of thermal expansion CTE KW - Design PY - 2009 DO - https://doi.org/10.1111/j.1744-7402.2008.02316.x SN - 1546-542X SN - 1744-7402 VL - 6 IS - 1 SP - 1 EP - 8 PB - American Ceramic Soc. CY - Westerville, Ohio AN - OPUS4-18675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -