MEMS actuator device
A method for making an actuator device includes providing a wafer comprising a layer of an electrically conductive material and forming a plurality of rotationally symmetrical dies in the electrically conductive material, each die including a plurality of radial tabs and complementarily sized radial recesses arranged in alternating fashion and at equal angular increments around the circumfery of the die. To maximize the use of available wafer space, the dies are arranged in a pattern on the wafer in which each die is rotated relative to adjacent dies through an angle of 360 degrees divided by twice the number of tabs or recesses on the die and, except for dies located at an outer periphery of the wafer, each die is disposed in edge-to-edge near abutment with an adjacent die and each tab of each die is nested within a complementary recess of an adjacent die.
1. A method for making an actuator device, the method comprising:
providing a wafer comprising a layer of an electrically conductive material; and
forming a plurality of rotationally symmetrical dies in the electrically conductive material, each die having a plurality of edges, each die including a plurality of radial tabs and complementarily sized radial recesses arranged in alternating fashion and at equal angular increments around the circumfery of the die with either a tab or a recess but not both formed on each edge,
wherein, except for dies located at an outer periphery of the wafer, each die is disposed in edge-to-edge near abutment with an adjacent die and each tab of each die is nested within a complementary recess of an adjacent die.
2. The method of claim 1 , wherein each die comprises three tabs and three complementary recesses arranged at 60 degree increments around the circumfery of the die.
3. The method of claim 1 , wherein the electrically conductive material comprises a semiconductor.
4. The method of claim 3 , wherein the semiconductor comprises one or more of polycrystalline silicon or monocrystalline silicon.
5. The method of claim 1 , wherein the forming comprises photolithography.
6. The method of claim 5 wherein the photolithography comprises one or more of etching or micromachining.
7. The method of claim 6 , wherein the etching comprises deep reactive ion etching (DRIE).
8. The method of claim 6 , wherein the micromachining comprises one or more of ion milling, laser ablation, chemical mechanical polishing (CMP), micro-electrical discharge forming, or micro-forging.
9. The method of claim 1 , further comprising singulating the dies from the wafer.
10. The method of claim 1 , wherein the electrically conductive material is a first electrically conductive material, and further comprising plating a surface of at least one of the tabs with a second electrically conductive material.
11. The method of claim 10 , wherein the second electrically conductive material comprises gold, monocrystalline silicon or polycrystalline silicon.
12. An actuator device, comprising a rotationally symmetrical die made of an electrically conductive material and including a plurality of radial tabs and complementarily sized radial recesses arranged in alternating fashion and at equal angular increments around the circumfery of the die with either a tab or a recess but not both formed on each edge.
13. The actuator device of claim 12 , wherein each die comprises three tabs and three complementary recesses arranged at 60 degree increments around the circumfery of the die.
14. The actuator device of claim 12 , wherein
the die comprises one of a plurality of dies singulated from a wafer comprising a layer of the electrically conductive material within which the dies are formed and arranged in a pattern in which each die is rotated relative to adjacent dies through an angle of 360 degrees divided by twice the number of tabs or recesses on the die and,
except for dies located at an outer periphery of the wafer, each die is disposed in edge-to-edge near abutment with an adjacent die and each tab of each die is nested within a complementary recess of an adjacent die.
15. The actuator device of claim 12 , wherein the electrically conductive material comprises a semiconductor.
16. The actuator device of claim 15 , wherein the semiconductor comprises one or more of polycrystalline silicon or monocrystalline silicon.
17. The actuator device of claim 12 , wherein the die is formed by photolithography.
18. The actuator device of claim 17 wherein the photolithography comprises one or more of etching or micromachining.
19. The actuator device of claim 18 , wherein the etching comprises deep reactive ion etching (DRIE).
20. The actuator device of claim 18 , wherein the micromachining comprises one or more of ion milling, laser ablation, chemical mechanical polishing (CMP), micro-electrical discharge forming, or micro-forging.
21. The actuator device of claim 12 , wherein at least one of the tabs is plated with an electrically conductive material.
22. The actuator device of claim 21 , wherein the electrically conductive material comprises gold, monocrystalline silicon or polycrystalline silicon.
23. A miniature camera incorporating the actuator device of claim 12 .
24. An electronic device incorporating the miniature camera of claim 23 .
25. The electronic device of claim 24 , wherein the device comprises a cellular telephone, a laptop computer, a personal digital assistant or a surveillance device.