A cost effective method of fabricating a large array or pagewidth silicon device having high resolution is disclosed. The pagewidth device is assembled by abutting silicon device sub-units such as image sensors or thermal ink jet printheads. For printheads, the sub-units are fully operational small printheads comprising an ink flow directing channel plate and a heating element plate which are bonded together. A plurality of individual printhead sub-units are obtained by dicing aligned and bonded channel wafers and heating element wafers. The abutting edges of the printhead sub-units are diced in such a manner that the resulting kerfs have vertical to inwardly directed sides which enable high tolerance linear abutment of adjacent sub-units. Alternatively, the wafer surface containing the heating elements is first anisotropically etched to form small V-grooves, one wall of which protects against microcracking during the dicing operation. The other wall of the V-groove is obliterated by the slanted dicing blade.