Inkjet printhead employing piezoelectric actuator and method of manufacturing the inkjet printhead
A piezoelectric inkjet printhead includes a fluid path forming substrate having a pressure chamber, a piezoelectric actuator formed on the fluid path forming substrate to provide a drive force to the pressure chamber to eject ink, and a damping layer formed on the piezoelectric actuator to dampen a residual vibration of the piezoelectric actuator.
1. A piezoelectric inkjet printhead, comprising:
a fluid path forming substrate having a pressure chamber;
a nozzle substrate attached to a first surface of the fluid path forming substrate and having a nozzle formed therein for ejecting ink from the pressure chamber;
a piezoelectric actuator having upper and lower electrodes and a piezoelectric layer disposed between the upper and lower electrodes, and formed on a second surface of the fluid path forming substrate to provide a drive force to the pressure chamber to eject ink, the second surface facing the first surface interposing the pressure chamber therebetween; and
a damping layer formed to cover at least the upper portion of the piezoelectric actuator and an area of the fluid path forming substrate corresponding to a location of the pressure chamber to dampen a residual vibration of the piezoelectric actuator.
2. The piezoelectric inkjet printhead of claim 1 , further comprising:
a printed circuit to apply a drive voltage to drive the piezoelectric actuator,
wherein the damping layer is formed on a conjunction portion between the printed circuit and the piezoelectric actuator.
3. The piezoelectric inkjet printhead of claim 2 , wherein a Young's modulus of the damping layer is smaller than a Young's modulus of the piezoelectric actuator and a mechanical loss rate of the fluid path forming substrate.
4. The piezoelectric inkjet printhead of claim 3 , wherein the Young's modulus of the damping layer is not more than about 5,000 MPa.
5. The piezoelectric inkjet printhead of claim 4 , wherein the damping layer is formed of a compound selected from the group consisting of silicone rubber, an epoxy, polyurethane, a photoresist substance, and combinations thereof.
6. The piezoelectric inkjet printhead of claim 3 , wherein the damping layer is formed of a compound selected from the group consisting of silicone rubber, an epoxy, polyurethane, a photoresist substance, and combinations thereof.