each comprise a printhead chip 8 bonded to a tab tape automated bond film 6 accommodated and supported by a micro moulding 5 which is in turn adapted to mate with the cover moulding 4 the printhead chip 8 is typically a micro electro mechanical system s mems device the present invention will now be described with particular reference to the applicant 39 s memjet u2122 technology various aspects of which are described in detail in the cross referenced documents it will be appreciated that memjet u2122 is only one embodiment of the invention and used here for the purposes of illustration only it is not to be construed as restrictive or limiting in any way on the extent of the broad inventive concept a memjet u2122 printhead is composed of a number of identical printhead modules 2 described in greater detail below a memjet u2122 printhead is a drop on demand 1600 dpi inkjet printer that produces bi level dots in up to 6 colors to produce a printed page of a particular width since the printhead prints dots at 1600 dpi dots per inch each dot is approximately 22 5 u03bcm in diameter and the dots are spaced 15 875 u03bcm apart because the printing is bi level the input image is typically dithered or error diffused for best results the modules 2 are designed such that the printhead chips 8 of adjacent modules can exactly abut one another so that there are no gaps or overlap in the printing produced to achieve this the modules 2 must be precisely aligned with each other after being mounted on the metal chassis 1 aligning.