Dielectric compositions

A method of bonding a dielectric material to a substrate comprising the steps of:

• I. providing a substrate;
• II. providing a dielectric composition comprising:
• (a) about 30% to about 100% by weight of a glass composition selected from the group consisting of:
• (a-1) a mixture of two glass compositions comprising a first glass composition having a glass transition temperature in the range of about 585.degree. C. to about 620.degree. C. and a second glass composition having a glass transition temperature in the range of about 765.degree. C. to about 815.degree. C.;
• or
• (a-2) a mixture of three glass compositions comprising a first glass composition having a glass transition temperature in the range of about 585.degree. C. to about 620.degree. C., a second glass composition having a glass transition temperature in the range of about 765.degree. C. to about 815.degree. C., and a third glass composition having a glass transition temperature in the range of about 650.degree. C. to about 720.degree. C.;
• (b) up to about 30% by weight of at least one expansion modifier;
• and
• (c) up to about 40% by weight of at least one refractory oxide,
• such first glass composition of (a-1) comprising from about 45% to about 60% by weight SiO.sub.2, from about 2% to about 7% by weight B.sub.2 O.sub.3, from about 14% to about 20% by weight PbO, from about 5% to about 12% by weight Al.sub.2 O.sub.3, up to about 3% by weight MgO, from about 4% to about 12% by weight CaO, up to about 3% by weight K.sub.2 O, and up to about 3% by weight Na.sub.2 O;
• and such second glass composition of (a-1) comprising from about 43% to about 56% by weight SiO.sub.2, from about 20% to about 31% by weight Al.sub.2 O.sub.3, from about 20% to about 27% by weight MgO, and up to about 2% by weight CaO;
• and
• such first glass composition of (a-2) comprising from about 45% to about 60% by weight SiO.sub.2, from about 2% to about 7% by weight B.sub.2 O.sub.3, from about 14% to about 20% by weight PbO, from about 5% to about 12% by weight Al.sub.2 O.sub.3, up to about 3% by weight MgO, from about 4% to about 12% by weight CaO, up to about 3% by weight K.sub.2 O, and up to about 3% by weight Na.sub.2 O;
• such second glass composition of (a-2) comprising from about 43% to about 56% by weight SiO.sub.2, from about 20% to about 31% by weight Al.sub.2 O.sub.3, from about 20% to about 27% by weight MgO, and up to about 2% by weight CaO;
• and such third glass composition of (a-2) comprising from about 30% to about 60% by weight SiO.sub.2, from about 35% to about 65% by weight CaO, and from about 1% to about 15% by weight B.sub.2 O.sub.3 ;
• III. applying to at least one surface of such substrate such dielectric;
• IV. heating such substrate in a nonoxidizing atmosphere to a temperature sufficient to permit such glass composition (a) to fuse;
• and
• V. cooling such substrate to a temperature sufficient to bond such resultant dielectric material to such substrate.