Aqueous tape casting of Al2O3-BBSZ based LTCC multilayer substrates

Several volatile organic compounds (VOCs) including xylene, methyl ethyl ketone (MEK) etc. are frequently used in organic tape casting slurries. Prolonged exposure to these VOCs can lead to appalling health hazards and hence should be avoided in future for the tape casting process to be environment friendly and sustainable. In the present research, we developed an aqueous tape casting protocol for Al₂O₃-BBSZ LTCC tapes, without using VOCs. The amount of water, binder, and plasticizers were suitably optimized to yield smooth and crack-free tapes. The impressive mechanical, thermal and dielectric properties (ε_r = 7.2 and tan δ = 10⁻² at 5 GHz) reveal that the developed aqueous protocol for tape casting is ideal for generating sustainable hybrid electronic circuits operating at extreme conditions. To the best of our knowledge, this is the first successful attempt of hazard-free aqueous tape casting of alumina-glass ceramic composite for LTCC multilayer circuit applications.