A flexible polymeric dielectric layer (12) having first and second major surfaces, the first major surface having a conductive layer (20) thereon, the dielectric layer having at least one conduit (10) extending from the second major surface to the first major surface, the conduit having at least one lateral dimension of at least about one centimeter and being at least partially filled with conductive material (18), the conductive layer including at least one conductive feature (21) substantially aligned with the conduit (10), the conductive feature (21) supporting a plurality of light emitting semiconductor devices (22).