Method of fabricating printhead IC to have displaceable inkjets
View Patent ↗A method of fabricating an inkjet printhead IC is provided which includes etching a circuitry layer to define first regions, depositing thermally expandable material thereover, etching the thermally expandable material and circuitry layer to define second regions having via holes, forming heaters at the second regions electrically contacting the circuitry layer through the via holes, depositing thermally expandable material on the heaters, forming a nozzle at each second region by etching the thermally expandable material to define an arm suspended at one end from the circuitry layer and an inkjet port in the suspended end, and forming channels aligned with the nozzles by etching a substrate carrying the circuitry layer. Each arm is formed to have one of the heaters embedded in the thermally expandable material such that uneven expansion is caused upon heating resulting in displacement of the arm and associated inkjet port relative to the circuitry layer.
1. A method of fabricating an inkjet printhead integrated circuit comprising the steps of:
etching a circuitry layer to define first regions;
depositing first thermally expandable material over the circuitry layer and the first regions;
etching the first thermally expandable material and the circuitry layer to define second regions having via holes;
forming heaters at the second regions electrically contacting the circuitry layer through the via holes;
depositing second thermally expandable material on the heaters;
forming a nozzle at each second region by etching the first and second thermally expandable material to define an arm suspended at one end from the circuitry layer and an inkjet port in the suspended end of the arm, each arm being formed to have one of the heaters embedded in the first and second thermally expandable material such that uneven expansion is caused upon heating resulting in displacement of the arm and associated inkjet port relative to the circuitry layer; and
forming channels aligned with the nozzles by etching a substrate carrying the circuitry layer.
2. A method as claimed in claim 1 , wherein the first and second thermally expandable material is polytetrafluoroethylene.
3. A method as claimed in claim 1 , wherein, in the nozzle forming step, the second thermally expandable material is etched so as to form a rim about each ink ejection port.
4. A method as claimed in claim 1 , wherein the heater and nozzle forming steps are each performed plural times to form a plurality of heaters and nozzles at each second region.
5. A method as claimed in claim 1 , wherein, in the channel forming step, crystallographic etching is performed.
6. A method as claimed in claim 1 , wherein, in the channel forming step, back-etching is performed.
7. A method as claimed in claim 1 , wherein the heater forming step comprises depositing and patterning a conductive material on the first thermally expandable material using a lift-off process.
8. A method as claimed in claim 7 , wherein the conductive material is selected from the group containing gold and copper.