Abstract: An electrostatic discharge (ESD) protector includes a ceramic body having a cavity provided therein, and two discharge electrodes facing each other across the cavity. The discharge electrodes are made of metal containing more than 80 wt. % of tungsten. The discharge electrodes contain not more than 2.0 atomic % of tungsten bonded to oxygen to a total amount of tungsten contained in the discharge electrodes. This ESD protector does not cause a short-circuiting even upon having high-voltage static electricity applied to the discharge electrodes repetitively, thus having high reliability.

Abstract: A dielectric porcelain composition of the present invention includes a first component and second component. If the first component is represented by the general formula of xBaO-yNd2O3-zTiO2-wBi2O3 (provided that x+y+z+w=100), x, y, z, and w satisfy 12?x?16, 12?y?16, 65?z?69, and 2?w?5, respectively. The second component includes 30 to 37 wt % of BaO, 33 to 46 wt % of SiO2, 8 to 12 wt % of La2O3, 3 to 7 wt % of Al2O3, 0 to 1 wt % of SrO, 0 to 10 wt % of Li2O, 0 to 20 wt % of ZnO, and 7 wt % or less of B203. The compounding ratio of the second component is between 10 wt % and 30 wt % when the sum of the first and second components is 100. In addition, 0.1 to 1 parts by weight of Li2O and 3 to 10 parts by weight of ZnO, relative to 100 parts by weight of the sum of the first and second components, is also contained as a third component. An average particle diameter of the dielectric mixed powder forming dielectric porcelain composition before firing is 0.9 ?m or less.

Abstract: An un-sintered multi-layered body includes a first ceramic layer having a surface, a conductor provided on the surface of the first ceramic layer, an insulator provided on the surface of the first ceramic layer and covering an end of the conductor, and a second ceramic layer provided on the conductor and the insulator. The un-sintered multi-layered body is baked at a temperature at which the first ceramic layer can be sintered but the second ceramic layer cannot be sintered. After the un-sintered multi-layered body is baked, the second ceramic layer is removed, thereby providing a multi-layered ceramic substrate. The insulator has a thickness not smaller than 10 ?m and not larger than 40 ?m. This method makes the insulator dense and allows the conductor to be formed easily.

Abstract: A dielectric porcelain composition of the present invention includes a first component and second component. If the first component is represented by the general formula of xBaO—yNd2O3-zTiO2-wBi2O3 (provided that x+y+z+w=100), x, y, z, and w satisfy 12?x?16, 12?y?16, 65?z?69, and 2?w?5, respectively. The second component includes 30 to 37 wt % of BaO, 33 to 46 wt % of SiO2, 8 to 12 wt % of La2O3, 3 to 7 wt % of Al2O3, 0 to 1 wt % of SrO, 0 to 10 wt % of Li2O, 0 to 20 wt % of ZnO, and 7 wt % or less of B203. The compounding ratio of the second component is between 10 wt % and 30 wt % when the sum of the first and second components is 100. In addition, 0.1 to 1 parts by weight of Li2O and 3 to 10 parts by weight of ZnO, relative to 100 parts by weight of the sum of the first and second components, is also contained as a third component. An average particle diameter of the dielectric mixed powder forming dielectric porcelain composition before firing is 0.9 ?m or less.