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Publications in Scientific Journals:

F. Steinhäußer, K. Hradil, S. Schwarz, W. Artner, M. Stöger-Pollach, A. Steiger-Thirsfeld, A. Bittner, U. Schmid:
"Wet chemical porosification of LTCC in phosphoric acid: Celsian forming tapes";
Journal of the European Ceramic Society, 35 (2015), 4465 - 4473.



English abstract:
The wet chemical porosification oflow temperature co-fired ceramics (LTCC) applying orthophosphoric acid enables the implementation ofareas with low permittivity directly into the as-fired substrate surface. Currently, the corresponding chemical reaction is only investigated for the widely used anorthite forming tape DuPont 951. In this paper the research is extended to cover celsian forming tapes with different ceramic particles. As the investigations show, the residual glass after porosification together with the grains should provide stable phases or components and ensure a bearing surface for further metallization. In the LTCC investigated here, the necessary selective etching to the containing celsian phase is given. However, the locality ofthe pores suffers from the presence ofwillemite, which is a second predominantly dissolved phase. The high amount of modifier oxides and the agglomeration of the dispersed corundum grains further weaken the stability of the LTCC substantially with respect to this treatment.

Keywords:
LTCC, porosification, wet chemical etchning, high frequency application, Celsian


"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)
http://dx.doi.org/10.1016/j.jeurceramsoc.2015.08.007


Created from the Publication Database of the Vienna University of Technology.