An interconnect (124) suitable for attachment of integrated circuit assemblies to each other comprises a polymer member (130), possibly dielectric, coated with a conductive material (144) which provides one or more conductive lines. In some embodiments, the conductive material covers a part, but not all, of the polymer member. In some embodiments, multiple conductive lines are formed on the polymer member. In some embodiments, the polymer member is conductive. Such interconnects replace metal bond wires in some embodiments. Other features are also provided.