Dielectric composition containing cordierite and glass

A castable glass-ceramic composition for forming a glass-ceramic dielectric body having a dielectric constant of less than about 4.5, a thermal expansion coefficient of less than about 4.0 ppm/.degree.C., said composition consisting essentially of:

• (a) 70-85 wt. % of a mixture consisting essentially of finely divided particles of 40-50 volume percent borosilicate glass containing 20-35 wt. % boron oxide and 60-75 wt. % silicon oxide and 50-60 volume percent cordierite;
• (b) 15-30 wt. % of an organic medium comprised of a polymeric binder dissolved in an organic solvent.

A glass-ceramic composition for forming a glass-ceramic dielectric body having a dielectric constant of less than about 4.5 and a sintered density greater than 95% of theoretical density, said composition consisting essentially of a mixture of finely divided particles of less than about 70 .mu.m:

• (a) 35-35 volume percent borosilicate glass containing 20-35 wt. % boron oxide and 60-75 wt. % silicon oxide;
• and
• (b) 55-65 volume percent cordierite, the particle size ratio of (b) to (a) being greater than about eleven.

A glass-ceramic composition for forming a glass-ceramic dielectric body having a dielectric constant of less than about 4.5 and a sintered density greater than 95% of theoretical density, said composition consisting essentially of a mixture of finely divided particles of less than about 70 .mu.m:

• (a) 45-55 volume percent borosilicate glass containing 20-35 wt. % boron oxide and 60-75 wt. % silicon oxide;
• and
• (b) 45-55 volume percent cordierite, the particle size ratio of (b) to (a) being greater than about four.

A glass-ceramic composition for forming a glass-ceramic dielectric body having a dielectric constant of less than about 4.5, a firing temperature of less than about 950.degree. C. and a sintered density of greater than 95% theoretical density, said composition formed from a mixture consisting essentially of:

• (a) 40-50 volume percent borosilicate glass containing 20-35 wt. % boron oxide, 60-75 wt. % silicon oxide and less than about 3 wt. % alkali oxides;
• and
• (b) 50-60 volume percent cordierite.

A glass-ceramic composition for forming a glass-ceramic dielectric body having a dielectric constant of less than about 4.5, a dielectric loss of less than 0.3, a firing temperature of less than about 950.degree. C. and a sintered density of greater than 95% theoretical density, said composition formed from a mixture consisting essentially of:

• (a) 40-50 volume percent borosilicate glass containing 20-35 wt. % boron oxide and 60-75 wt. % silicon oxide and less than about 3 wt. % alkali oxides;
• and
• (b) 50-60 volume percent cordierite.