Compositions and methods for enhancing adhesion between a copper conducting layer and a dielectric material during manufacture of a printed circuit board. Conditioning compositions contain a functional organic compound and preferably a transition metal ion. The functional organic compound, e.g., a purine derivative, is capable of forming a self-assembled monolayer. Adhesion promoting compositions contain an acid, preferably an inorganic acid, and an oxidant. The latter compositions may also contain a corrosion inhibitor and/or a transition metal ion selected from among Zn, Ni, Co, Cu, Ag, Au, Pd or another Pt group metal. The corrosion inhibitor may comprise a nitrogen-containing aromatic heterocyclic compound.