Abstract: A multilayer substrate including a multilayer body formed by laminating a plurality of insulating layers including via holes in the insulating layer as an uppermost layer of the multilayer body so as to pass through the insulating layer, and via conductors formed by filling the via holes with a conductive paste. The via holes are formed through lower end positions, upper end positions, and intermediate positions between the lower end positions and the upper end positions such that a diameter enlargement degree toward the upper end positions from the intermediate positions is larger than a diameter enlargement degree toward the intermediate positions from the lower end positions. By forming the via holes as described above, when the via holes are filled with the conductive paste from openings at the small diameter side of the via holes, exudation of the conductive paste from openings at the large diameter side is prevented.

Abstract: A multilayer substrate including a multilayer body formed by laminating a plurality of insulating layers including via holes in the insulating layer as an uppermost layer of the multilayer body so as to pass through the insulating layer, and via conductors formed by filling the via holes with a conductive paste. The via holes are formed through lower end positions, upper end positions, and intermediate positions between the lower end positions and the upper end positions such that a diameter enlargement degree toward the upper end positions from the intermediate positions is larger than a diameter enlargement degree toward the intermediate positions from the lower end positions. By forming the via holes as described above, when the via holes are filled with the conductive paste from openings at the small diameter side of the via holes, exudation of the conductive paste from openings at the large diameter side is prevented.

Abstract: A multilayer circuit board includes a laminate having a plurality of ceramic layers, and a wiring pattern disposed in the laminate, wherein a ceramic layer includes, as the wiring pattern, a fully penetrating via-hole conductor that vertically passes through the ceramic layers, and a serial partially penetrating via-hole conductor that is electrically connected to the fully penetrating via-hole conductor in the ceramic layers and does not pass completely through the ceramic layers.

Abstract: A multilayer circuit board includes a laminate having a plurality of ceramic layers, and a wiring pattern disposed in the laminate, wherein a ceramic layer includes, as the wiring pattern, a fully penetrating via-hole conductor that vertically passes through the ceramic layers, and a serial partially penetrating via-hole conductor that is electrically connected to the fully penetrating via-hole conductor in the ceramic layers and does not pass completely through the ceramic layers.