A structure (201) includes a support layer (210) formed of a conductive material, such as a sheet of copper. The support layer has a number of conductive islands (212A...) isolated from other portions of the support layer by isolation gaps (211a...). The support layer (210) is sandwiched between two compound layers (220, 230) each of which is formed of a dielectric layer having a number of via holes (221A..., 231A...) and conductive elements (222A..., 232...A) located in the via holes (221A..., 231A...). The conductive elements (222A..., 232A...) contact the conductive islands (212A...). The structure also includes two conductive layers, (240, 250) formed on the two compound layers (220, 230) such that a trace (241A...) in one of the conductive layers (240, 250) is coupled to a trace (241A) in the other conductive layer (240, 250) through two conductive elements and a conductive island. The support layer can be formed by etching a sheet of conductive materials. The compound layers can be formed by placing a conductive paste in via holes in a dielectric layer. The conductive layers can be formed by lamination followed by etching to form the traces.