Abstract: A wiring substrate includes an insulating layer, a connection pad buried in the insulating layer in a state that an upper surface of the connection pad is exposed from an upper surface of the insulating layer and a lower surface and at least a part of a side surface of the connection pad contact the insulating layer, and a concave level difference portion formed in the insulating layer around an outer periphery part of the connection pad, wherein an upper surface of the connection pad and an upper surface of the insulating layer are arranged at a same height.

Abstract: A wiring substrate includes a core substrate. The core substrate includes a first surface, a second surface, and an opening extending through the core substrate between the first and second surfaces. A first conductive film is formed on the first surface and covers the opening. A second conductive film is formed on the second surface. The second conductive film covers the opening. An electronic component is arranged in the opening and connected to the first conductive film. An insulator fills the opening. A first wiring portion includes alternately stacked insulative layers and wiring layers and covers the first surface of the core substrate and the first conductive film. A second wiring portion includes alternately stacked insulative layers and wiring layers, and covers the second surface of the core substrate and the second conductive film.

Abstract: A wiring substrate includes an insulating layer, a connection pad buried in the insulating layer in a state that an upper surface of the connection pad is exposed from an upper surface of the insulating layer and a lower surface and at least a part of a side surface of the connection pad contact the insulating layer, and a concave level difference portion formed in the insulating layer around an outer periphery part of the connection pad, wherein an upper surface of the connection pad and an upper surface of the insulating layer are arranged at a same height.

Abstract: A wiring substrate includes an insulating layer, a pad, and a solder resist layer. The insulating layer has a first surface formed with a first recess portion. The pad is embedded in the first recess portion. The pad includes a second surface and a third surface. The third surface that is located at a lower position than the first surface so as to expose an inner wall surface of the first recess portion. The pad is formed with a second recess portion in a center portion of the third surface. The solder resist layer is provided on the first surface. An adjacent portion of the first surface to a peripheral portion of the first recess portion is smaller in roughness than a region of the first surface peripheral to the adjacent portion of the first surface.

Abstract: A wiring substrate includes an insulating layer, a connection pad buried in the insulating layer in a state that an upper surface of the connection pad is exposed from an upper surface of the insulating layer and a lower surface and at least a part of a side surface of the connection pad contact the insulating layer, and a concave level difference portion formed in the insulating layer around an outer periphery part of the connection pad, wherein an upper surface of the connection pad and an upper surface of the insulating layer are arranged at a same height.

Abstract: A wiring substrate includes an insulating layer, a pad, and a solder resist layer. The insulating layer has a first surface formed with a first recess portion. The pad is embedded in the first recess portion. The pad includes a second surface and a third surface. The third surface that is located at a lower position than the first surface so as to expose an inner wall surface of the first recess portion. The pad is formed with a second recess portion in a center portion of the third surface. The solder resist layer is provided on the first surface. An adjacent portion of the first surface to a peripheral portion of the first recess portion is smaller in roughness than a region of the first surface peripheral to the adjacent portion of the first surface.

Abstract: A wiring substrate includes a core substrate. The core substrate includes a first surface, a second surface, and an opening extending through the core substrate between the first and second surfaces. A first conductive film is formed on the first surface and covers the opening. A second conductive film is formed on the second surface. The second conductive film covers the opening. An electronic component is arranged in the opening and connected to the first conductive film. An insulator fills the opening. A first wiring portion includes alternately stacked insulative layers and wiring layers and covers the first surface of the core substrate and the first conductive film. A second wiring portion includes alternately stacked insulative layers and wiring layers, and covers the second surface of the core substrate and the second conductive film.

Abstract: A wiring substrate includes an insulating layer, a connection pad buried in the insulating layer in a state that an upper surface of the connection pad is exposed from an upper surface of the insulating layer and a lower surface and at least a part of a side surface of the connection pad contact the insulating layer, and a concave level difference portion formed in the insulating layer around an outer periphery part of the connection pad, wherein an upper surface of the connection pad and an upper surface of the insulating layer are arranged at a same height.