Wiring substrate and method of manufacturing the same

A method of manufacturing a wiring substrate which includes a substrate main body having a first main face and a second main face opposite the first main face;

• a resistor formed on the first main face;
• two first-main-face-side wiring layers which are each formed on the resistor and which each include a first grounding metal layer formed of a metal having a resistance lower than that of the resistor and a conductor layer formed on the first grounding metal layer, each of the two first-main-face-side wiring layers having an upper surface and side surfaces;
• a second-main-face-side wiring layer formed on the second main face;
• and a via which is formed in the substrate main body and which establishes electrical connectivity between the two first-main-face-side wiring layers and the second-main-face-side wiring layer, the method comprising:
• forming the resistor on the first main face such that the resistor is electrically connected to the via;
• forming the first grounding metal layer on the resistor, the first grounding metal layer having a resistance lower than that of the resistor, and forming a second grounding metal layer on the second main face such that the second grounding metal layer is electrically connected to the via;
• forming first and second mask layers having openings on the first and second grounding metal layers, respectively, and forming in the openings a first conductor layer and a second conductor layer on the first and second grounding metal layers, respectively, to thereby form the two first-main-face-side wiring layers and the second-main-face-side wiring layer;
• removing the first and second mask layers, and forming a third mask layer on the first grounding metal layer between the two first-main-face-side wiring layers;
• forming a conductive covering layer which covers the upper surface and the side surfaces of each of the two first-main-face-side wiring layers by performing electroplating while using the via and the first grounding metal layer as an electricity supply path;
• and
• removing the third mask layer and removing a portion of the first grounding metal layer located between the two first-main-face-side wiring layers.