Method of manufacture of an ink jet printer having a thermal actuator comprising an external coil spring
View Patent ↗A method of manufacturing an ink jet printer having a thermal actuator comprising an external coil spring is disclosed wherein an array of nozzles are formed on a substrate utilising planar monolithic deposition, lithographic and etching processes. Multiple ink jet heads are preferably formed simultaneously on a single planar substrate. The substrate can be a silicon wafer. The print heads are preferably formed utilising standard vlsi/ulsi processing. Integrated drive electronics are preferably formed on the same substrate. The integrated drive electronics can comprise a CMOS process. Ink can be ejected from the substrate substantially normal to the substrate.
1. A method of manufacture of a thermally actuated ink jet printer comprising a series of nozzle chambers from each of which ink is ejected via the utilization of a thermal actuator device, the method comprising the steps of:
(a) initially providing a silicon wafer having a circuitry wafer layer including electrical circuitry necessary for the operation of the thermal actuators on demand;
(b) etching an ink inlet aperture in said circuitry wafer layer;
(c) depositing and etching a first sacrificial layer on top of the silicon and circuitry wafer layer and etching said first sacrificial layer in an area defining a first portion of a nozzle chamber wall, a thermal actuator anchor and a thermal actuator end point;
(d) depositing and etching a first inert material layer defining an actuator path starting at said thermal actuator anchor;
(e) depositing and etching a first conductive material layer adjacent said actuator path and attached to said first inert material layer;
(f) depositing and etching a non-conductive layer over said first conductive material layer, said etching including etching predetermined vias for interconnection of said first conductive material layer with a second conductive material layer;
(g) depositing and etching a second inert material layer on top of said first inert material layer;
(h) depositing and etching said second conductive material layer on top of said non-conductive layer, the second conductive material layer having a conductive interconnect to said first conductive material layer;
(i) depositing and etching a series of inert material layers and sacrificial layers to form a nozzle chamber including an ink ejection hole and a nozzle chamber paddle attached at said thermal actuator end point;
(j) etching an ink supply channel through said wafer to said nozzle chamber; and
(k) etching away said sacrificial layers.
2. A method as claimed in claim 1 wherein said conductive material layers are formed from a material having a Youngs modulus which is higher than that of the inert material layers.
3. A method as claimed in claim 1 wherein said conductive material layers comprise substantially titanium nitride.
4. A method as claimed in claim 1 wherein said first and second inert material layers comprise substantially glass.
5. A method as claimed in claim 1 wherein said actuator path comprises substantially a coil.
6. A method as claimed in claim 1 further comprising the step of etching an ink supply channel through said wafer from a back surface thereof.
7. A method as claimed in claim 1 wherein said wafer comprises a double side polished CMOS wafer.
8. A method as claimed in claim 1 wherein at least step (k) is also utilized to simultaneously separate said wafer into separate printheads.