Method of fabricating inkjet nozzle chambers having filter structures
View Patent ↗A method of fabricating a plurality of inkjet nozzles on a substrate. The method comprises the steps of: (a) providing a substrate having a plurality of trenches corresponding to ink inlets; (b) depositing sacrificial material so as fill the trenches and form a scaffold on the substrate; (c) defining openings in the sacrificial material; (d) depositing roof material over the sacrificial material to form nozzle chambers and filter structures simultaneously; (e) etching nozzle apertures through the roof material; and (f) removing the sacrificial material.
1. A method of fabricating a plurality of inkjet nozzles on a substrate, each nozzle comprising a nozzle chamber having a roof spaced apart from said substrate and sidewalls extending from said roof to said substrate, one of said sidewalls having a chamber entrance for receiving ink from at least one ink inlet defined in said substrate, said chamber entrance including at least one filter structure, said method comprising the steps of:
(a) providing a substrate having a plurality of trenches corresponding to said ink inlets;
(b) depositing sacrificial material on said substrate so as fill said trenches and form a scaffold on said substrate;
(c) defining openings in said sacrificial material, said openings being positioned to form said chamber sidewalls and said at least one filter structure when filled with roof material;
(d) depositing roof material over said sacrificial material to form simultaneously said nozzle chambers and said at least one filter structure;
(e) etching nozzle apertures through said roof material, each nozzle chamber having at least one nozzle aperture; and
(f) removing said sacrificial material.
2. The method of claim 1 , wherein said filter structure comprises a column of roof material extending from said substrate to said roof.
3. The method of claim 1 , wherein each chamber entrance includes a plurality of filter structures arranged across said entrance.
4. The method of claim 1 , wherein each chamber entrance includes a plurality of rows of filter structures arranged across said entrance.
5. The method of claim 4 , wherein said rows of filter structures are staggered.
6. The method of claim 1 , wherein each nozzle chamber contains an actuator for ejecting ink through said nozzle aperture.
7. The method of claim 1 , wherein said actuator is formed prior to fabrication of said nozzle chamber.
8. The method of claim 1 , wherein said substrate is a silicon wafer.
9. The method of claim 8 , wherein said silicon wafer comprises at least one surface oxide layer.
10. The method of claim 1 , wherein said sacrificial material is photoresist.
11. The method of claim 10 , wherein said openings are defined by exposing said photoresist through a mask followed by development.
12. The method of claim 1 , wherein said photoresist is UV cured prior to deposition of said roof material, thereby preventing reflow of said photoresist during deposition.
13. The method of claim 10 , wherein said photoresist is removed by plasma ashing.
14. The method of claim 1 , further comprising the step of etching ink supply channels from an opposite backside of said substrate, said ink supply channels being in fluid communication with said ink inlets.
15. The method of claim 1 , wherein said chamber entrance receives ink from an ink conduit extending along a row of nozzles, whereby step (c) further comprises defining further openings in said sacrificial material, said further openings being positioned to form said ink conduit when filled with roof material.
16. The method of claim 15 , wherein said ink conduit receives ink from said at least one ink inlet.