Compliant electrostatic transfer head with defined cavity

• US 9,828,244 B2
• Filed: 09/30/2014
• Issued: 11/28/2017
• Est. Priority Date: 09/30/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Golda, Dariusz, Bathurst, Stephen P., Higginson, John A., Bibl, Andreas, Birkmeyer, Jeffrey
• Primary Examiner(s): Monbleau, Davienne
• Assistant Examiner(s): Cruz, Leslie Pilar
• Application Number:
  US14/502,994
• Publication Number:
  US 20160094160A1
• Time in Patent Office: 1,155 Days
• CPC Class Codes: B81C 99/002 Apparatus for assembling MEMS, e.g. micromanipulators micromanipulators per se B25J7/00
• CPC Class Codes: H01H 59/0009 making use of micromechanics
• CPC Class Codes: H10N 30/30 with mechanical input and electrical output, e.g. functioning as generators or sensors

Abstract

A compliant electrostatic transfer head and method of forming a compliant electrostatic transfer head are described. In an embodiment, a compliant electrostatic transfer head includes a base substrate, a cavity template layer on the base substrate, a first confinement layer between the base substrate and the cavity template layer, and a patterned device layer on the cavity template layer. The patterned device layer includes an electrode that is deflectable toward a cavity in the cavity template layer. In an embodiment, a second confinement layer is between the cavity template layer and the patterned device layer.

Claims

1. A compliant electrostatic transfer head comprising:

a base substrate;

a cavity template layer on the base substrate;

a first confinement layer between the base substrate and the cavity template layer;

a patterned device layer on the cavity template layer, the patterned device layer comprising an electrode that is deflectable toward a cavity in the cavity template layer; and

a second confinement layer between the cavity template layer and the patterned device layer, wherein the second confinement layer spans along a top surface of the cavity template layer and directly above the cavity; and

wherein the cavity includes a bottom surface defined by the first confinement layer and cavity sidewalls defined by the second confinement layer.

2. The compliant electrostatic transfer head of claim 1, wherein the cavity comprises substantially vertical sidewalls.

3. The compliant electrostatic transfer head of claim 1, wherein the second confinement layer is formed directly on the cavity template layer.

4. The compliant electrostatic transfer head of claim 1, further comprising a spring support layer between the cavity template layer and the patterned device layer.

5. The compliant electrostatic transfer head of claim 4, further comprising an insulating layer between the spring support layer and the patterned device layer, wherein the insulating layer electrically insulates the patterned device layer from the spring support layer.

6. The compliant electrostatic transfer head of claim 1, wherein the patterned device layer comprises a pair of electrodes that is deflectable toward the cavity in the cavity template layer, and the electrode is one of the pair of electrodes.

7. The compliant electrostatic transfer head of claim 6, wherein the pair of electrodes includes a first electrode lead integrally formed with a first mesa structure protruding above the first electrode lead, and a second electrode lead integrally formed with a second mesa structure protruding above the second electrode lead.

8. The compliant electrostatic transfer head of claim 7, wherein the patterned device layer further comprises a first trace interconnect integrally formed with a first electrode, and a second trace interconnect integrally formed with a second electrode.

9. The compliant electrostatic transfer head of claim 8, wherein the first and second electrodes form an electrode beam profile extending between the first and second trace interconnects.

10. The compliant electrostatic transfer head claim 9, wherein the each of the first and second electrodes comprises a double bend.

11. The compliant electrostatic transfer head of claim 10, wherein the electrode beam profile comprises an S-shape configuration.

12. The compliant electrostatic transfer head claim 7, wherein the first and second mesa structures are separated by trench characterized by a width of 1.0 um or less, and the trench is filled with a dielectric material.

13. The compliant electrostatic transfer head of claim 1, wherein the first confinement layer and the second confinement layer comprise a same material.

14. The compliant electrostatic transfer head of claim 1, wherein the first confinement layer and the second confinement layer comprise SiO₂.

15. The compliant electrostatic transfer head of claim 14, wherein the patterned device layer comprises silicon.

16. The compliant electrostatic transfer head of claim 15, wherein the cavity template layer comprises silicon.

17. The compliant electrostatic transfer head of claim 16, wherein the base substrate comprises silicon.

18. A compliant electrostatic transfer head comprising:

a base substrate;

a cavity template layer on the base substrate;

a first confinement layer between the base substrate and the cavity template layer;

a patterned device layer on the cavity template layer, the patterned device layer comprising an electrode that is deflectable toward a cavity in the cavity template layer; and

a second confinement layer between the cavity template layer and the patterned device layer, wherein the second confinement layer spans along a top surface of the cavity template layer and directly above the cavity;

a spring support layer between the cavity template layer and the patterned device layer; and

an insulating layer between the spring support layer and the patterned device layer, wherein the insulating layer electrically insulates the patterned device layer from the spring support layer.

19. The compliant electrostatic transfer head of claim 18, wherein the patterned device layer comprises a pair of electrodes that is deflectable toward the cavity in the cavity template layer, and the electrode is one of the pair of electrodes.

20. The compliant electrostatic transfer head of claim 19, wherein the pair of electrodes includes a first electrode lead integrally formed with a first mesa structure protruding above the first electrode lead, and a second electrode lead integrally formed with a second mesa structure protruding above the second electrode lead.