Inkjet printhead with CMOS drive circuitry close to ink supply passage

A method of ejecting drops of an ejectable liquid from an inkjet printhead, the printhead comprising a wafer providing a supporting substrate, the wafer having a drop ejection side and a liquid supply side, a plurality of nozzles, each nozzle having a liquid passage leading to it from the liquid supply side of the wafer for providing ejectable liquid to the nozzle, drop ejection actuators and associated drive circuitry corresponding to each nozzle respectively, the nozzles, ejection actuators, associated drive circuitry and liquid passage being formed on and through the wafer using lithographically masked etching techniques;

• wherein,
• the liquid passage is partially etched from the drop ejection side such that the distance between the drive circuitry and the passage is less than 20 microns;
• the method of ejecting drops comprising the steps of:
• providing the ejectable liquid to each of the nozzles using the associated liquid passage;
• and
• actuating the drop ejection actuator to eject drops of the ejectable liquid from the nozzle.

A printer system incorporating an inkjet printhead comprising:

• a wafer providing a supporting substrate, the wafer having a drop ejection side and a liquid supply side;
• a plurality of nozzles, each nozzle having a liquid passage leading to it from the liquid supply side of the wafer for providing ejectable liquid to the nozzle;
• drop ejection actuators and associated drive circuitry corresponding to each nozzle respectively;
• the nozzles, ejection actuators, associated drive circuitry and liquid passage being formed on and through the wafer using lithographically masked etching techniques;
• wherein,
• the liquid passage is partially etched from the drop ejection side such that the distance between the drive circuitry and the passage is less than 20 microns.