Patent ID: 6953756

Claim:
A glass ceramic sintered body comprising gahnite and cordierite as crystal phases, having a thermal expansion coefficient at 40 to 400° C. of not larger than 5×10 −6/ ° C. a dielectric constant of not larger than 7 and a Young's modulus of not larger than 150 GPa. obtained by firing a mixed powder of a glass powder having the following composition: SiO 2 : 30 to 55 mass % Al 2 O 3 : 15 to 40 mass % MgO: 3 to 25 mass % ZnO: 2 to 15 mass % B 2 O 3 : 2 to 15 mass % and a filler powder, wherein the glass ceramic sintered body further comprising a CaO-containing glass phase.