METHOD AND SYSTEM FOR FLIP CHIP PACKAGING OF MICRO-MIRROR DEVICES

• US 20080211043A1
• Filed: 02/28/2008
• Published: 09/04/2008
• Est. Priority Date: 03/02/2007
• Status: Active Grant

• Current Assignee: Miradia Inc. (Walsin Lihwa Corporation)
• Original Assignee: Miradia Inc. (Walsin Lihwa Corporation)
• Inventors: Chen, Dongmin
• Granted Patent: US 7,723,144 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: B81B 7/0067 for controlling the passage of optical signals through the package
• CPC Class Codes: B81C 2203/0118 Bonding a wafer on the substrate, i.e. where the cap consists of another wafer
• CPC Class Codes: H01L 2224/8121 using a reflow oven
• CPC Class Codes: H01L 2224/81815 Reflow soldering
• CPC Class Codes: H01L 24/81 using a bump connector
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/14634 Assemblies, i.e. Hybrid structures
• CPC Class Codes: H01L 27/14687 Wafer level processing
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/1461 MEMS
• CPC Class Codes: H01L 31/0203 Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80

Abstract

A package for a micro-electromechanical device includes a substrate adapted to support the micro-electromechanical device. The micro-electromechanical device is electrically coupled to a plurality of electrodes. The package also includes a thermally conductive structure coupled to the substrate, an electrical contact layer having a plurality of traces in electrical communication with the plurality of electrodes, and an interposer structure coupled to the substrate. The interposer structure includes a continuous annular region defining a recessed region bounded by a bond surface. The package further includes a transparent cover coupled to the interposer structure and sealing the micro-electromechanical device in the recessed region to isolate the micro-electromechanical device in a controlled environment.

Claims

1. A package for a micro-electromechanical device, the package comprising:

a substrate adapted to support the micro-electromechanical device, the micro-electromechanical device being electrically coupled to a plurality of electrodes;

a thermally conductive structure coupled to the substrate;

an electrical contact layer having a plurality of traces in electrical communication with the plurality of electrodes;

an interposer structure coupled to the substrate, wherein the interposer structure includes a continuous annular region defining a recessed region bounded by a bond surface; and

a transparent cover coupled to the interposer structure and sealing the micro-electromechanical device in the recessed region to isolate the micro-electromechanical device in a controlled environment.

2. The package of claim 1 wherein the micro-electromechanical device comprises an array of micro-mirror devices.

3. The package of claim 2 wherein the array of micro-mirror devices are fabricated on the substrate.

4. The package of claim 1 wherein the thermally conductive structure comprises a thermally conductive epoxy layer and a thermally conductive dielectric layer.

5. The package of claim 1 wherein the electrical contact layer comprises two or more layers of wire traces.

6. The package of claim 1 wherein the interposer structure comprises at least one of glass or silicon.

7. The package of claim 1 wherein the transparent cover comprises a glass layer.

8. The package of claim 1 wherein the bond surface comprises a glass frit material.

9. The package of claim 1 wherein the bond surface comprises a metal material.

10. The package of claim 7 further comprising at least one of an aperture or an antireflective coating coupled to the glass layer.

11. The package of claim 1 further comprising one or more channels providing for fluid communication between an atmosphere associated with the micro-electromechanical device and an external atmosphere.

12. The package of claim 1 wherein the controlled environment comprises a hermetically sealed environment.

13. A method of fabricating a package for an array of micro-mirror devices, the method comprising:

bonding an interposer structure to a first side of a substrate including the array of micro-mirror devices, wherein a plurality of micro-mirrors in the array of micro-mirror devices are in electrical communication with a plurality of electrodes;

bonding a transparent cover to the interposer structure to form a controlled environment for the array of micro-mirror devices;

forming a thermally conductive structure coupled to a second side of the substrate; and

forming an electrical contact structure in electrical communication with the plurality of electrodes.

14. The method of claim 13 wherein the thermally conductive structure comprises a thermally conductive epoxy layer and a thermally conductive dielectric layer.

15. The method of claim 14 wherein the electrical contact layer comprises two or more layers of wire traces.

16. The method of claim 13 wherein forming an electrical contact structure comprises providing a plurality of wire traces leading from the plurality of electrodes located at a peripheral portion of the array of micro-mirror devices to a ball grid array coupled to the thermally conductive structure.

17. The method of claim 13 wherein the interposer structure comprises at least one of a glass substrate or a silicon substrate.

18. The method of claim 13 wherein the transparent cover comprises a glass substrate.

19. The method of claim 18 wherein the interposer structure is fabricated from a portion of the glass substrate.

20. The method of claim 18 further comprising forming at least one of an aperture or an antireflective coating coupled to the glass layer.

21. The method of claim 13 further comprising forming one or more channels providing for fluid communication between an atmosphere associated with the micro-electromechanical device and an external atmosphere.

22. The method of claim 13 wherein the method forms at least one of a hermetically sealed package or a quasi-hermetically sealed package.