Etching agent and method for producing circuit board

Abstract

The present invention includes an etching agent that selectively etches a copper layer of a processing target in which a noble metal layer containing a metal nobler than copper and the copper layer coexist, the etching agent including: a copper ion; one or more nitrogen-containing compounds selected from the group consisting of a heterocyclic compound having two or more nitrogen atoms in a ring and an amino group-containing compound having 8 or less carbon atoms; a polyalkylene glycol; and a halogen ion, in which the polyalkylene glycol is contained in an amount of 0.0005% by weight or more and 7% by weight or less, and the halogen ion is contained in an amount of 1 ppm or more and 250 ppm or less.

Dependencies are inferred from the claim text.