a modular pagewidth printhead assembly includes a plurality of printhead modules each having : a printhead integrated circuit with a plurality of micro - electromechanical nozzle arrangements , and a fluid distribution assembly of joined liquid crystal polymer micromoldings defining a plurality of discrete fluid paths for supplying discrete fluids to the nozzle arrangements . the modular pagewidth printhead assembly further including a fluid delivery structure configured to receive the printhead modules and to supply said modules with discrete fluids ; and a flexible printed circuit board sandwiched between the supply structure and the printhead modules the flexible printed circuit board is bonded to the supply structure . the circuit board extends around one edge of the supply structure for carrying data and power to the modules . the fluid distribution assembly includes at least one elastomeric pad to take up tolerance when the relevant module is located on the supply structure . each printhead module has a film layer of an inert polymer interposed between the micromoldings , the film layer defining a plurality of holes for fluid flow between said portions .