Electroless copper plating solution and high-frequency electronic component

摘要

An electroless copper plating solution which can ensure superior adhesion of a copper plating film to a flat ceramic surface having low roughness and which can form a high-frequency electronic component having superior high-frequency conductivity and a high Q value is provided. Also provided is a high frequency electronic component formed by using this electroless copper plating solution. The electroless copper plating solution of contains copper ions, nickel ions, formaldehyde or a derivative thereof, and tartaric acid or a salt thereof. The ratio of the content of the nickel ions to that of the copper ions on a molar basis is in the range of about 0.0001 to 0.015.