An inkjet printhead includes a compact substrate of increased stability and structural integrity to provide a high resolution 600 dot-per-inch nozzle array having a one-half inch swath. A plurality of ink vaporization chambers are respectively aligned with the nozzles in two longitudinal columns, one column extending longitudinally along one edge of the substrate and a second column extending longitudinally along an opposite edge of the substrate, with ink feed channels communicating through an ink passage from an underside of the substrate around both edges of the substrate to the vaporization chambers. The ink feed channels have thereby been eliminated from the central portion of the substrate, and replaced by the ink feed channels at the edges of the substrate.