fig3 next to the first carrier sub assembly onto shim 25 and within the slot 21 the second carrier sub assembly is then positioned lengthwise so that there is correct lengthwise relative positioning of its printhead segment 4 and the segment 4 of the previously placed segment 4 as determined using suitable fiducial marks not shown on the exposed front surface 44 of each of the printhead segments 4 that is lengthwise alignment is carried out between successive printhead segments 4 even though it is the printhead segment carrier 8 that is actually manipulated this relative alignment is carried out to such sub micron accuracy as is required to match the printing resolution capability of the printhead segments 4 finally the bonding of the second carrier sub assembly to shim 25 is completed the above process is then repeated with further carrier sub assemblies being successively positioned aligned and bonded into place until all carrier subassemblies are in position within the slot 21 and bonded in their correct positions the shield plate 5 has a thin film of silicon sealant applied to its underside and is mated to the printhead segment carriers 8 and tab films 9 along the entire length of the printhead assembly 1 by suitable choice of adhesive properties of the silicon sealant the shield plate 5 can be made removable to enable access to the printhead segment carriers 8 printhead segments 4 and tab films 9 for servicing and or exchange a sub assembly of pcb 11 and printhead control and ancillary components 73 to 76 is secured to profile 10 using four screws 23 the tab films 9 are wrapped around the exterior walls 16 17 of profile 10 and are bumped and bonded i e physically and electrically connected to the.