Method of fabricating nozzle assembly having moving roof structure and sealing bridge

1. A method of fabricating an inkjet nozzle assembly having a seal member bridging between a moving portion and a stationary portion, said method comprising the steps of:

(a) providing a partially-fabricated printhead comprising a nozzle chamber sealed with a roof;

(b) etching a via through said roof to define said moving portion on a first side of said via and said stationary portion on a second side of said via;

(c) plugging said via with a plug of sacrificial material;

(d) depositing a layer of flexible material over at least said plug; and

(e) removing said plug to provide said inkjet nozzle assembly having said seal member bridging between said moving portion and said stationary portion,

wherein said seal member is comprised of said flexible material.

2. The method of claim 1 , wherein said flexible material a polymeric material.

3. The method of claim 1 , wherein said flexible material is comprised of polydimethylsiloxane (PDMS).

4. The method of claim 1 , wherein said plug fills said via, such that said seal member is absent from said via.

5. The method of claim 1 , wherein said plug has a head extending out of said via, said head presenting a scaffold surface for deposition of said flexible material.

6. The method of claim 1 , wherein said seal member has a non-planar profile configured for facilitating movement of said moving portion.

7. The method of claim 6 , wherein said seal member comprises a crown portion, said crown portion standing proud of a first end of said seal member connected to said moving portion and a second end of said seal member connected to said stationary portion.

8. The method of claim 1 , wherein said seal member comprises at least one ridge and/or at least one furrow in profile.

9. The method of claim 1 , wherein said seal member is corrugated.

10. The method of claim 1 , further comprising the step of:

etching a nozzle opening through said roof prior to removal of said sacrificial material.

11. The method of claim 10 , wherein said nozzle opening is etched through said moving portion.

12. The method of claim 1 , wherein said moving portion comprises a thermal bend actuator.

13. The method of claim 12 , wherein said thermal bend actuator comprises:

a first active element for connection to drive circuitry; and

a second passive element mechanically cooperating with the first element, such that when a current is passed through the first element, the first element expands relative to the second element, resulting in bending of the actuator.

14. The method of claim 1 , wherein said flexible material is a hydrophobic material, and wherein said deposition of said flexible material is over a substantial portion of said roof such that said roof is relatively hydrophobic.

15. The method of claim 1 , wherein said nozzle chamber comprises sidewalls extending between said roof and a substrate, such that said roof is spaced apart from said substrate.

16. The method of claim 15 , wherein said moving portion is configured to move towards said substrate upon actuation of an actuator.

17. The method of claim 1 , wherein said flexible layer is covered with a sacrificial protective metal layer prior to removal of said plug.

18. The method of claim 17 , wherein said sacrificial protective metal layer is removed after removal of said plug.

19. The method of claim 1 , wherein said plug is removed by exposing said nozzle assembly to an oxidizing plasma.