Structuration of the low temperature co-fired ceramics (LTCC) using novel sacrificial graphite paste with PVA–propylene glycol–glycerol–water vehicle

Fabrication of membranes and microchannels in low-temperature co-fired ceramic (LTCC) substrate using novel water-based sacrificial carbon pastes

“…This is a considerable improvement over the previous PVA-PG-G-H 2 O vehicle [19,20], which was more difficult to prepare and whose stability is too dependent on the H 2 O concentration (whose behavior in turn strongly depends on ambient humidity). On the other hand, while PG and BG both have low toxicity and similar (low) volatility, BG was found to be somewhat more aggressive, which was an issue on the thinnest (50 !m) LTCC tapes.…”

“…The diameters of the membranes were equal to 5, 7.5 and 10 mm. In order to minimize the swelling of the membranes [20,21] the additional escaping channels were added. Layer (c) covers deposited patterns and contains orifices for the escaping channels.…”

“…Commercially available thick-film pastes are usually formulated using terpineol or dibutyl carbitol as solvents for the organic vehicle [18], which are aggressive to the LTCC binder of most commercial compositions [19]. In order to eliminate this problem, we have proposed a graphite sacrificial paste with a polyvinyl alcohol (PVA) dissolved in a propylene glycol (PG)-glycerol (G)-water vehicle [19,20]. However, we have noticed that the viscosity of the PVA-PG-G-water-based SVM paste tends to increase over time.…”

Overview on low temperature co-fired ceramic sensors

“…Although such a vehicle is well-suited to printing small amounts of ink on thick LTCC tapes, the aggressivity of its solvent and co-solvent to tape binders [59] will result in severe tape degradation when printing thick ink layers, such as sacrificial inks [62,63] and especially onto thin tapes. This issue may be addressed using a binder / solvent chemistry with solubility parameters [59] more different from that of the LTCC tape binder, as demonstrated using hydrophilic binders such as polyvinyl alcohol (PVA) [62] and polyvinyl pyrrolidone (PVP) [63], the latter, as EC, also requiring a plasticiser (see Fig.…”

“…This issue may be addressed using a binder / solvent chemistry with solubility parameters [59] more different from that of the LTCC tape binder, as demonstrated using hydrophilic binders such as polyvinyl alcohol (PVA) [62] and polyvinyl pyrrolidone (PVP) [63], the latter, as EC, also requiring a plasticiser (see Fig. 3.…”