Mems Integrated Circuit With Polymerized Siloxane Layer

• US 20100149266A1
• Filed: 02/11/2010
• Published: 06/17/2010
• Est. Priority Date: 03/12/2007
• Status: Active Grant

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, Kerr, Emma Rose, Lawlor, Vincent Patrick, McAvoy, Gregory John, Bagnat, Misty
• Granted Patent: US 8,025,365 B2
• Time in Patent Office: Days
• US Class Current: 347/47
• CPC Class Codes: B41J 2/1404 Geometrical characteristics
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/1601 Production of bubble jet print heads B41J2/1606, B41J2/162 take precedence
• CPC Class Codes: B41J 2/1606 Coating the nozzle area or the ink chamber
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1639 sacrificial molding
• CPC Class Codes: B41J 2/1642 thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1645 thin film formation by spincoating
• CPC Class Codes: B41J 2/1648 Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2002/14475 characterised by nozzle shapes or number of orifices per chamber
• CPC Class Codes: B41J 2202/11 characterised by specific geometrical characteristics
• CPC Class Codes: B41J 2202/15 Moving nozzle or nozzle plate

Abstract

A MEMS integrated circuit comprises: a silicon substrate having a passivated CMOS layer, a MEMS layer disposed on the passivated CMOS layer, and a polymer layer disposed on the MEMS layer. The CMOS layer comprises drive circuitry for actuating actuator devices in the MEMS layer and the polymer layer comprises a polymerized siloxane.

Claims

1. A MEMS integrated circuit comprising:

a silicon substrate having a passivated CMOS layer;

a MEMS layer disposed on said passivated CMOS layer, wherein said CMOS layer comprises drive circuitry for actuating actuator devices in said MEMS layer; and

a polymer layer disposed on said MEMS layer, said polymer layer comprising a polymeric material selected from the group consisting of;

polymerized siloxanes.

2. The MEMS integrated circuit of claim 1, wherein said MEMS layer comprises a plurality of fluidic chambers, each chamber having a roof spaced apart from said substrate and sidewalls extending between said roof and said substrate.

3. The MEMS integrated circuit of claim 2, wherein said polymer layer is disposed on each roof.

4. The MEMS integrated circuit of claim 2, wherein said roof and sidewalls are comprised of a same material by virtue of a co-deposition process.

5. The MEMS integrated circuit of claim 4, wherein said roof and sidewalls are comprised of a material selected from the group consisting of:

silicon nitride, silicon oxide and silicon oxynitride.

6. The MEMS integrated circuit of claim 1, wherein the polymeric material is comprised of polydimethylsiloxane (PDMS).

7. The MEMS integrated circuit of claim 1, wherein one or more of said actuator devices is a thermal bend actuator, each thermal bend actuator comprising:

an active beam connected to said drive circuitry; and

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

8. The MEMS integrated circuit of claim 7, wherein each first active element is connected to said drive circuitry via a connector post, each connector post extending linearly between said active beam and said drive circuitry.

9. The MEMS integrated circuit of claim 7, wherein said thermal bend actuator is configured to bend towards said substrate upon actuation.

10. The MEMS integrated circuit of claim 1, which is a printhead integrated circuit.

11. The MEMS integrated circuit of claim 10, wherein a nozzle plate of said printhead integrated circuit has the polymer layer disposed thereon.

12. The MEMS integrated circuit of claim 10, comprising a plurality of nozzle assemblies defined in said MEMS layer, each nozzle assembly comprising:

a nozzle chamber, a nozzle opening defined in a roof of the nozzle chamber and an actuator for ejecting ink through the nozzle opening,

13. The MEMS integrated circuit of claim 12, wherein said actuator is a heater element configured for heating ink in said chamber so as to form a gas bubble, thereby forcing a droplet of ink through said nozzle opening.

14. The MEMS integrated circuit of claim 13, wherein said heater element is suspended in said nozzle chamber.

15. The printhead of claim 12, wherein said actuator is a thermal bend actuator comprising:

an active beam connected to said drive circuitry; and

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

16. The printhead of claim 15, wherein said thermal bend actuator defines at least part of a roof of each nozzle chamber, whereby actuation of said actuator moves said actuator towards said substrate.

17. The printhead of claim 16, wherein said nozzle opening is defined in either said actuator or in a stationary portion of said roof.

18. The printhead of claim 16, wherein said polymer layer bridges between said actuator and a stationary portion of said roof, thereby defines a mechanical seal for minimizing ink leakage during actuation