Wet chemical porosification of LTCC in phosphoric acid: Celsian forming tapes

Wet chemical porosification of LTCC in phosphoric acid: Anorthite forming tapes

“…This reaction was also observed during the porosification of celsian forming LTCC [14]. The broad peak at 2Â = 22 • in the background of the X-ray diffraction diagram (see Fig.…”

“…GC features an even higher atomic amount of B relative to Si of 42.2%. Both values are much higher than compared to the celsian forming tapes with 5-8% investigated in [14]. Most probably, PbO and B 2 O 3 together work as flux additives [31], which is due to the role of Al 3+ in the network of borosilicate glasses.…”

“…Although the porosification was also evaluated at multiphase glass ceramics (GC) like Ferro A6 [13], the most promising results could be achieved with glass ceramic composites (GCC) using ortho-phosophoric acid as solvent [12,14]. The GCC powders consist of about 50-80 vol% of glass and a crystalline powder as a dispersive component [15].…”

“…The GCC powders consist of about 50-80 vol% of glass and a crystalline powder as a dispersive component [15]. In the investigated tapes, predominantly the feldspars anorthite (Ca[Al 2 Si 2 O 8 ]) [12] or celsian (Ba[Al 2 Si 2 O 8 ]) [14] could be leached selectively to the glass and the dispersed alumina embedded as filler. Especially above a temperature of approx.…”

“…One reason is attributed to the presence of a second predominantly dissolved phase of willemite (Zn 2 [SiO 4 ]) which was detected in the celsian forming samples. Additionally, the overall lower etch resistance of the glass must be taken into account [14].…”