Heatproof improvement of Ag-CNT print-film by boron addition

Carbon nanotubes (CNTs) have been widely studied as electron sources for field emission displays (FEDs). This report concerns heatproofing CNT electron sources formed by screen-printing. Silver-particles are often added to the CNT print paste to secure electro-conductivity in the film and/or to harden the film. However, when the Ag-CNT paste is baked in air, silver promotes the combustion of CNTs. Therefore, to lower the temperature of the heating process or to carry out the heating process in inactive atmospheres (Kim et al., 2001) is necessary in FED-panel-manufacturing, so as not to burn CNTs. The heating process in air is preferred because the heating process in inactive atmospheres raises the FED manufacturing cost. It is known that adding boron to carbon materials improves their heat resistance (McKee, 1991). We made an attempt to improve heatproofing of CNT electron sources by mixing boron into the Ag-CNT paste.