of tab printhead assembly 42 along line 4 4 in fig3 which shows nozzle plate 44 being secured to substrate 46 as seen traces 38 on tape 28 are bonded to a back surface of nozzle plate 44 traces 30 are bonded to electrodes 54 on substrate 46 for providing energization signals to heater resistors formed on substrate 46 barrier layer 50 and ink channels 52 are also revealed barrier layer 50 may be formed of a photoresist which is defined using conventional photolithographic techniques the same photoresist which forms barrier layer 50 is also formed to provide an insulating portion 58 to insulate traces 30 from the edges of silicon substrate 46 also shown in fig4 are ink droplets 60 being ejected from nozzles 48 fig5 in nozzle plate 44 fig6 is a front view in perspective of a silicon substrate 46 which may be affixed to the back of nozzle plate 44 in fig3 to form tab printhead assembly 42 substrate 46 has formed on it using conventional photolithographic techniques two rows of thin film resistors 64 shown in fig6 exposed through vaporization chambers 66 formed in barrier layer 50 in one embodiment substrate 46 is approximately one half inch long and contains.