Wiring substrate

A wiring substrate, comprising:

• a first wiring layer;
• a first insulating layer covering the first wiring layer;
• a second wiring layer stacked on an upper surface of the first insulating layer and electrically connected to the first wiring layer;
• “N” layers of insulating layers including a second insulating layer stacked on the upper surface of the first insulating layer, wherein “N” is a natural number greater than or equal to 1;
• a cavity formed through the “N” layers of insulating layers and exposing an upper surface of the second wiring layer and a side surface of the second wiring layer;
• a surface-processed layer covering the upper surface of the second wiring layer and the side surface of the second wiring layer that are exposed in the cavity;
• an electronic component arranged in the cavity and mounted on the surface-processed layer;
• a filling insulating layer filling the cavity and covering the electronic component;
• and
• a third wiring layer stacked on an upper surface of the filling insulating layer and electrically connected to the electronic component, wherein
• the side surface of the second wiring layer includes a first roughened surface, and
• the upper surface of the second wiring layer includes a second roughened surface having a surface roughness that is greater than the first roughened surface.