Enamelled Steel Substrates for Printed Circuits

Abstract

The preparation of steel substrates coated with intermediate ground and final ceramic coatings is described. The basic material for the preparation of both coatings is the same kind of special glass. The coatings were thermally treated up to 960℃. The resulting substrates were tested for the usage in thick film technology by applying ruthenium resistor compositions designed for use on ceramic substrates. The resistors were fired up to 900℃ and their resistance and TCR were measured. They showed almost the same dependence on firing temperature as the resistors printed on alumina substrates. The TCR was only shifted towards more positive values.

Ceramic on metal substrates produced by plasma spraying for thick film technology

“…the firing temperature of the substrate is limited to 700C. Only Kuzel 6 has shown the possibility of heating the substrates up to 860C. Also the heat conductivity of typical enamels is several times lower than that of alumina (Lebailly 7 had reported the value of 5.15 W/(m K)).…”