A method for fabricating packaged semiconductor devices; attaching a batch-sized metallic grid with openings onto an adhesive tape having an insulating clear core covered by a layer of UV-releasable adhesive, the openings sized larger than a semiconductor chip; attaching a semiconductor chip onto the tape of each window, the chip terminals facing the adhesive surface; laminating insulating material of low coefficient of thermal expansion to fill gaps between each chip and respective grid; turning over assembly to place a carrier under backside of chips and lamination and to remove the tape; plasma-cleaning the assembly front side and sputtering uniform at least one metal layer across the assembly; optionally plating metal layers; and patterning the metal layers to form rerouting traces and extended contact pads for assembly.