Patent ID: 6126277
Filing Date: 2000-10-03
Classification: B41J

Abstract:
A very low drop volume thin film ink jet printhead, comprising:a thin film substrate including a plurality of thin film layers;a plurality of tantalum aluminum ink firing heater resistors defined in said plurality of thin film layers, each of said resistors being a square of about 17 micrometers by 17 micrometers;a silicon carbide layer disposed on said plurality of thin film layers over said tantalum aluminum ink firing heater resistors;an ink barrier layer disposed on said silicon carbide layer;respective ink chambers formed in said ink barrier layer over respective tantalum aluminum ink firing resistors and adjacent said silicon carbide layer, each chamber formed by a chamber opening in said barrier layer and a portion of said silicon carbide layer such that a silicon carbide surface fully extends across an area enclosed by said chamber opening, said area being about 22 micrometers by 22 micrometers;said ink chambers being configured to emit ink drops in the range of about 2 to 4 picoliters; andan orifice plate having nozzle orifices disposed over said ink barrier layer, said orifices having an entrance diameter of about 34 micrometers and an exit diameter of about 12 micrometers;whereby detrimental accumulation of ink components on said silicon carbide surface is avoided, variation in drop to drop volume is reduced, and variation in drop velocity is reduced.