a modular pagewidth printhead assembly includes a plurality of printhead modules , a fluid delivery structure and a flexible printed circuit board . each printhead module includes a printhead integrated circuit with a plurality of micro - electromechanical nozzle arrangements , and a fluid distribution assembly of liquid crystal polymer micromoldings defining a plurality of discrete fluid paths when joined for supplying discrete fluids to the nozzle arrangements . the fluid delivery structure is configured to receive the printhead modules and to supply said modules with discrete fluids . the flexible printed circuit board is sandwiched between the supply structure and the printhead modules , and is bonded to the supply structure to keep it in place . the circuit board extends around one edge of the supply structure for carrying data and power to said 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 .