Patent ID: 8575052

Claim:
A dielectric ceramic comprising: a main component which contains Mg 2 SiO 4 ; and additives which contain a zinc oxide, a boron oxide, an alkaline earth metal oxide, and a glass component, wherein: in X-ray diffraction, a peak intensity ratio I B /I A is 10% or less where I A is an X-ray diffraction peak intensity of Mg 2 SiO 4 as a main phase for which 2θ is between 36.0° and 37.0° and I B is an X-ray diffraction peak intensity of unreacted zinc oxide for which 2θ is between 31.0° and 32.0° and between 33.0° and 34.0°, the glass component is SiO 2 —BaO—CaO—Li 2 O glass, a content of the zinc oxide, as determined by calculating a mass of the zinc oxide relative to ZnO, is from 8.0 parts by mass to 20 parts by mass relative to 100 parts by mass of the main component, a content of the glass component, as determined by calculating a mass of the glass component relative to SiO 2 —BaO—CaO—Li 2 O glass, is from 2.0 parts by mass to 10.0 parts by mass relative to 100 parts by mass of a dielectric composition having all the same additives but without the glass component, a content of the boron oxide, as determined by calculating a mass of the boron oxide relative to B 2 O 3 , is from 3.0 parts by mass to 10.0 parts by mass relative to 100 parts by mass of the main component, a content of the alkaline earth metal oxide, as determined by calculating a mass of the alkaline earth metal oxide relative to RO, where R represents an alkaline earth metal element, is from 1.0 parts by mass to 4.0 parts by mass relative to 100 parts by mass of the main component, and the dielectric ceramic has a relative density of 96% or greater.