| 摘要 |
PURPOSE:To make the via viscosity control easy and to simplify the manufacturing process of a ceramic multilayered board as well by a method wherein through holes, whose hole diameters in the upper surface of a dielectric layer are large, whose hole diameters in the lower surface of the layer are small and which have the form of a trapezoidal section, are formed in the dielectric layer. CONSTITUTION:A ceramic dielectric layer 21 is prepared and a through hole 26 having a hole diameter to satisfy the conditions of phi3>=t and phi1<t is provided by punching or the like. In addition to this hole, a through hole 25 of a hole diameter to satisfy the conditions of t<phi2<4t is also provided. A via conductor 27 having a viscosity enough for the hole 25 to be filled with is filled in this layer 21 through the side of the hole diameter phi3 of the hole 26 by printing or the like and a via is formed. |
