• Faddoul, Rita

Abstract

The aim of this work is to study the printability of silver inks on LTCC (Low Temperature Co-fired Ceramics) flexible tapes by rotogravure printing. Commercial and newly developed LTCC tapes with different surface energies and pore sizes were investigated. Silver inks were prepared and formulated by adding 35 to 55% silver particles (D50 ~ 2-3 μm) to a mixture of water/ethylene glycol/glycerol. Ink surface tension and viscosity were determined in order to establish their effects on the ink transfer from the cylinder to the substrate. Substrates were printed by rotogravure printing process with the formulated inks. The printing cylinder was engraved in intaglio, with a 45 μm cell depth to allow deposition of high ink thickness. Printed line properties such as thickness, width and roughness, were determined in order to establish the relationship between substrates characteristics, ink properties and printability. High silver contents (50-55%) and viscosities allowed deposition of thick lines (5.6 μm). Thus, 55% silver ink was printed on different substrates. An optimum 45% silver weight allowed printing of narrower (160 μm) and smoother (1.4 μm) lines.

Topics

• Deposition
• impedance spectroscopy
• pore
• surface
• silver
• viscosity
• ceramic