Wiring substrate and manufacturing method thereof

A wiring substrate, comprising:

• a substrate comprising a metal core, insulation layers on a front side and a rear side of the metal core, and a front layer and a rear layer configured as a mounting surface for components and provided on the insulation layers, the front layer and the rear layer being formed of material different from a material forming the insulation layers;
• a concave section formed in a side edge part of the substrate and exposed to both the front layer and the rear layer of the substrate;
• and
• a connection terminal disposed in the same layer as a layer of the metal core, extended from a side surface portion of the concave section and bent in a direction perpendicular to a surface of the substrate, the side surface portion being substantially perpendicular to the front and rear layers of the substrate,
• wherein a portion of the connection terminal is disposed to penetrate inside the side surface portion to thereby fix the connection terminal to the substrate,
• wherein a section of the connection terminal only contacts the substrate at the side surface portion,
• wherein a plurality of the connection terminals are installed in the side surface portion of the concave section in a longitudinal direction, and two adjacent connection terminals of the plurality of the connection terminals are configured such that respective portions of the two adjacent connection terminals which penetrate inside the side surface portion are unitary in the substrate to thereby electrically connect the two adjacent connection terminals, and
• wherein the wiring substrate further comprises:
• another concave section formed in another side edge part of the substrate, the other concave section being opposite the concave section such that sides of the concave section and sides of the other concave section are aligned;
• and
• another connection terminal extended from a side surface portion of the other concave section.