Glazed ceramic substrate

Abstract

A glazed ceramic substrate for use in electric or electronic devices, obtained by forming a glass coating layer directly on a major surface of a ceramic substrate such as an alumina substrate. The glass as the material of the coating layer contains 50-60 Wt % of SiO.sub.2, 10-30 Wt % of Al.sub.2 O.sub.3, 15-30 Wt % of CaO and MgO, and 2-6 Wt % of ZrO.sub.2 as essential components, optionally with the addition of small amount(s) of at least one of TiO.sub.2, BaO, ZnO, PbO, P.sub.2 O.sub.5, B.sub.2 O.sub.3, Na.sub.2 O and K.sub.2 O. The coating layer formed of this glass is excellent in its high-temperature stability, so that the glazed ceramic substrate is particularly suitable for use in thermal heads of thermal printing devices.

Dependencies are inferred from the claim text.