Circuit substrate

A circuit substrate comprising:

• a first dielectric layer comprising a plurality of first conductive openings, a first surface, and a second surface opposite to the first surface, wherein each of the first conductive openings connects the first surface and the second surface;
• a plurality of conductive structures, the first conductive openings being respectively filled with the conductive structures, each of the conductive structures being integrally formed and comprising a pad part, a connection part, and a protruding part, wherein each of the connection parts connects a corresponding pad part of the pad parts and a corresponding protruding part of the protruding parts, and each of the protruding parts has a curved surface protruding from the second surface, wherein the pad parts, the connection parts, and the protruding parts are made of the same material;
• at least one conductive pattern disposed on the second surface, wherein a thickness of the at least one conductive pattern is greater than a maximum thickness of the protruding parts;
• a second dielectric layer disposed on the first surface of the first dielectric layer, the second dielectric layer comprising a plurality of second conductive openings respectively connecting the pad parts, wherein the pad parts respectively protrude from the first surface and are located in the second dielectric layer;
• and
• a plurality of conductive pillars connecting the pad parts, the second conductive openings being respectively filled with the conductive pillars, each of the conductive pillars comprising a connection pad protruding from a third surface of the second dielectric layer, wherein the third surface is opposite to the first surface.