Patent ID: 8199455

Claim:
A glass ceramic composition comprising: a first ceramic powder containing forsterite as a primary component; a second ceramic powder containing at least one of strontium titanate and titanium oxide as a primary component; 2 to 20 percent by weight of a third ceramic powder containing BaZrO 3 as a primary component; more than 2 up to 20 percent by weight of a fourth ceramic powder containing SrZrO 3 as a primary component; and 3 to 20 percent by weight of a borosilicate glass containing 3 to 15 percent by weight of lithium calculated in the form of Li 2 O, 20 to 50 percent by weight of magnesium calculated in the form of MgO, 15 to 30 percent by weight of boron calculated in the form of B 2 O 3 , 10 to 35 percent by weight of silicon calculated in the form of SiO 2 , 6 to 20 percent by weight of zinc calculated in the form of ZnO, and at least 5 percent by weight at least one additive component selected from the group consisting of calcium oxide, barium oxide, and strontium oxide calculated in the form of CaO, BaO, and SrO, respectively, wherein the content of the additive component contained in the borosilicate glass powder is up to 15 percent by weight when in the form of CaO, and up to 25 percent by weight when in the form of BaO or SrO, and when the second ceramic powder includes the ceramic powder containing strontium titanate as a primary component, the content of strontium titanate is in the range of 3 to 13 percent by weight in the form of SrTiO 3 , and when the second ceramic powder includes the ceramic powder containing titanium oxide as a primary component, the content of titanium oxide is in the range of 0.3 to 10 percent by weight in the form of TiO 2 .