Electromagnetic Micro-Generator and Method for Manufacturing the Same

Abstract

A micro-generator includes an integrated circuit (IC) wafer. A micro-electro mechanical system (MEMS) wafer, with a movable micromechanical element, is bonded to the IC wafer. A plurality of first metal coils associated with a plurality of trenches is arranged in one of the IC wafer and the MEMS wafer. A plurality of micro-magnets is provided in the other of the IC wafer and the MEMS wafer. Each micro-magnet is associated with a respective trench and is formed from a magnet layer deposited, plated or bonded to the MEMS wafer or IC wafer. Movement of the micro-mechanical element generates a voltage in the first metal coils.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The electromagnetic micro-generator and method for manufacturing the same are explained in more detail below with reference to the accompanying drawings, where:

FIG. 1 illustrates a micro-generator according to an exemplary embodiment of the invention;

FIGS. 2A to 2C illustrate examples of different coil and magnet arrangements possible in the micro-generator shown in FIG. 1; and

FIGS. 3A and 3B show transformers according to exemplary embodiments of the invention.

Claims

1. A micro-generator, comprising: an integrated circuit (IC) wafer;a microelectromechanical system (MEMS) wafer bonded to the IC wafer, the MEMS wafer comprising a movable micromechanical element;a plurality of first metal coils;a plurality of trenches associated with the first metal coils; anda plurality of micro-magnets, each micro-magnet being associated with a respective trench, wherein the micro-magnets are formed from a magnet layer disposed on at least one of: the MEMS wafer and the IC wafer;wherein the IC wafer comprises at least one of: the plurality of first metal coils, the plurality of trenches, and the plurality of micro-magnets,wherein the MEMS wafer comprises at least one of: the plurality of first metal coils, the plurality of trenches and the plurality of micro-magnets, andwherein upon movement of the micromechanical element, the micro-magnets are arranged to move within the trenches relative to the first metal coils such that a voltage is induced in the first metal coils.

2. The micro-generator according to claim 1, wherein the trenches and the first metal coils are disposed in one of the IC wafer and the MEMS wafer, and the micro-magnets are disposed on the other of the IC wafer and the MEMS wafer.

3. The micro-generator according to claim 1, further comprising isolation trenches for isolating adjacent micro-magnets.

4. The micro-generator according to claim 1, further comprising metal shields for reducing losses, the metal shields being disposed between adjacent coils.

5. The micro-generator according to claim 1, further comprising loss reducing trenches arranged opposing respective coils.

6. A micro-transformer for a micro-generator, the transformer comprising: an integrated circuit (IC) wafer;a microelectromechanical system (MEMS) wafer bonded to the IC wafer, the MEMS wafer comprising a movable micromechanical element;a plurality of first metal coils for carrying a first voltage inducible by the micro-generator;a plurality of second metal coils associated with the first metal coils; andmagnetic material;wherein the IC wafer comprises at least one of: the first metal coils, the second metal coils, and the magnetic material,wherein the MEMS wafer comprises at least one of: the first metal coils, the second metal coils, and the magnetic material, andwherein the first and second metal coils and the magnetic material are arranged such that the first voltage induces a second voltage in the second metal coils, the second voltage being larger than the first voltage.

7. The micro-transformer according to claim 6, wherein the first and second metal coils are disposed in one of the IC wafer and the MEMS wafer, and the magnetic material is disposed on the other of the IC wafer and the MEMS wafer.

8. A micro-generation system, comprising: the micro-transformer for a micro-generator according to claim 6; andthe micro-generator.

9. A method of manufacturing a micro-generator, the method comprising: forming an integrated circuit (IC) wafer comprising at least one of: a plurality of first metal coils, a plurality of trenches associated with the first coils, and a layer of magnetic material;forming a MEMS wafer, the MEMS wafer comprising a movable micromechanical element and at least one of: a plurality of first metal coils, a plurality of trenches associated with the first coils, and a layer of magnetic material;forming a plurality of micro-magnets from the magnetic layer, a micro-magnet being associated with each trench;bonding the MEMS wafer to the IC wafer to define a micro-generator wafer such that, in response to the micromechanical element moving, the micro-magnets move within the trenches relative to the first metal coils thereby inducing a voltage in the first metal coils; anddicing the micro-generator wafer to form individual micro-generators.

10. The method of manufacturing a micro-generator according to claim 9, wherein the trenches and the first coils are disposed in one of the IC wafer and the MEMS wafer, and the layer of magnetic material is disposed on the other of the IC wafer and the MEMS wafer.

11. The method of manufacturing a micro-generator according to claim 9, wherein the plurality of first metal coils are formed by performing a multilayer IC process.

12. The method of manufacturing a micro-generator according to claim 9, wherein the trenches are formed by performing a deep reactive ion etching.

13. The method of manufacturing a micro-generator according to claim 9, wherein the layer of magnetic material is formed by deposition, plating, or bonding.

14. The method of manufacturing a micro-generator according to claim 9, wherein the micro-magnets are formed by etching or abbreviating the magnetic layer.