Circuit board and semiconductor package substrate comprising same

A circuit board comprising:

• a core insulating layer including an upper surface and a lower surface;
• an upper insulating layer disposed on the upper surface of the core insulating layer;
• a lower insulating layer disposed under the lower surface of the core insulating layer;
• and
• a through electrode penetrating the upper and lower surfaces of the core insulating layer,
• wherein the through electrode includes a first slope disposed adjacent to the upper surface of the core insulating layer and having a width that gradually decreases toward the lower surface of the core insulating layer, and a second slope disposed adjacent to the lower surface of the core insulating layer and having a width that gradually decreases toward the upper surface of the core insulating layer,
• wherein a vertical length of the first slope is different from a vertical length of the second slope, and
• wherein the through electrode includes a first through electrode having a vertical length of the first slope greater than a vertical length of the second slope, and a second through electrode having a vertical length of the first slope smaller than a vertical length of the second slope and spaced apart from the first through electrode in a horizontal direction.