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A. Hajian, M. Stöger-Pollach, M. Schneider, H. Homolka, D. Müftüoglu, U. Schmid:
"Effect of sintering temperature on porosification behavior of fired LTCC substrates";
Talk: 42nd International Conference & Exposition on Advanced Ceramics & Composites, Daytona Beach, Florida, USA; 2018-01-21 - 2018-01-26; in: "Abstract Book", (2018), 144.

Besides its outstanding material properties, low temperature co-fired
ceramic (LTCC) is the technology of choice when targeting the
realization of highly integrated substrates or packaging solutions
for micromachined devices, especially for high-frequency appli-
cations [1]. However, LTCC materials are generally suffering from
high permittivity and we have recently shown that the wet-chemical
porosification under acidic condition allows a permittivity reduction
in the as-fired state [2,3]. In the present study, we have employed
an alternative etching condition for porosification of the LTCC with
a better surface quality which features a suitable bearing plane for
the subsequent realization of metallization lines. In this approach
an aqueous solution of KOH at temperatures lower than 90 °C
was applied as etching solution for porosification of the Ceramtec
GC LTCC samples fired at different sintering peak temperatures of
800, 850, 900, and 950 °C. The surface of the as-fired samples was
porosified in the aforementioned solution and thereby the effect
of sintering peak temperature on the porosification behavior was
studied. Different characterization techniques, including SEM, TEM,
XRD, EELS, and EDX were used for investigation of the morphology
and chemical composition of the fired samples, before and after
porosification which will be presented in the final conference paper.