Insulating ceramic compact, ceramic multilayer substrate, and ceramic electronic device

摘要

An insulating ceramic compact is provided which can be obtained by low-temperature firing, has a low relative dielectric constant and superior high frequency characteristics, and can be co-sintered with a material having a high coefficient of thermal expansion. The insulating ceramic compact is a fired mixture of an MgAl2O4-based ceramic and a borosilicate glass, in which an MgAl2O4 crystal phase and at least one of an Mg3B2O6 crystal phase and an Mg2B2O5 crystal phase are precipitated as primary crystal phases.