Patent ID: 7993510

Claim:
An electroplating solution to be employed for manufacturing a multilayer printed circuit board composed of a substrate bearing a conductor circuit and, as serially layered thereon, a resin insulating layer and a conductor circuit in an alternate fashion and in repetition, characterized by containing 50 to 300 g/L of copper sulfate, 30 to 200 g/L of sulfuric acid, 25 to 90 mg/L of chlorine ion, and 1 to 1000 mg/L of an additive comprising at least a levelling agent and a brightener; the addition ratio of said levelling agent and said brightener being (said levelling agent): (said brightener)=(2:1) to (10:1); and wherein said levelling agent is selected from the group consisting of polyethylene isophthalate, and polyethylene sulfide; wherein the electroplating solution is used in the formation of the conductor circuit and fills an opening part of a via-hole with copper to form a via-hole whose upper face and the upper face of said conductor circuit in the same layer are in approximately the same plane during said process of manufacturing a multilayer printed circuit board.