Provided is a printhead assembly which includes a printhead module having a plurality of modular printhead tiles each having a plurality of micro-electromechanical nozzle assemblies for printing on a printing medium. The assembly also includes a number of printhead controller integrated circuits for controlling the printhead tiles, as well as a casing having an integral heatsink arrangement for the printhead controller integrated circuits. The casing further includes a ducting assembly for ducting ink to the printhead tiles and busbars for interfacing the printhead controller integrated circuits with a controller of a printer.