Glass-ceramic product

Abstract

A glass-ceramic product is disclosed. The glass product is produced by combining 0.1 to 6 wt % of a compound selected from the group consisting of B.sub.2 O.sub.3 and P.sub.2 O.sub.5 with a mixture. The mixture includes 54 to 63 wt % SiO.sub.2, 20 to 28 wt % Al.sub.2 O.sub.3, 10 to 18 wt % MgO and 2 to 6 wt % ZnO. From the combined compound and mixture are formed a glassy material and then glassy material is ground in order to form a frit. The frit is then molded and the molded frit is fired into a crystalline form. The resulting glass-ceramic product has a low permittivity as compared with alumina and low power factor tan .delta.. Further, the product has a coefficient of thermal expansion which is comparable with the value for silicon semiconductor chips. The product also has other desirable characteristics such as its firing and crystallizing temperature, moisture absorption and mechanical strength.

Dependencies are inferred from the claim text.