HERMETIC SEALING OF MICRO DEVICES

• US 20090289349A1
• Filed: 05/21/2008
• Published: 11/26/2009
• Est. Priority Date: 05/21/2008
• Status: Abandoned Application

• Current Assignee: Spatial Photonics Incorporated (Himax Technologies Incorporated)
• Original Assignee: Spatial Photonics Incorporated (Himax Technologies Incorporated)
• Inventors: Novotny, Vlad, Matus, Gabriel
• Application Number:
  US12/124,962
• Publication Number:
  US 20090289349A1
• Time in Patent Office: Days
• US Class Current: 257/698
• CPC Class Codes: B81B 7/0041 maintaining a controlled atmosphere with techniques not provided for in B81B7/0038
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate
• CPC Class Codes: B81C 2203/019 characterised by the material or arrangement of seals between parts
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 23/057 the leads being parallel to the base
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 24/48 of an individual wire connector
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/12044 OLED
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/1461 MEMS
• CPC Class Codes: H01L 2924/16195 Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 2924/16235 Connecting to a semiconductor or solid-state bodies, i.e. cap-to-chip
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding

Abstract

An encapsulated device includes a micro device on a substrate, a micro chamber that encapsulates the micro device on the substrate; and a layer of hermetic-sealing material that provides at least some degree of hermeticity on one or more outer surfaces of the micro chamber to at least partially hermetically seal the micro device in the micro chamber.

Claims

1. An encapsulated device, comprising:

a micro device on a substrate;

a micro chamber that encapsulates the micro device on the substrate, wherein the micro chamber is defined in part by one or more walls extending away from a surface of the substrate, one surface of a wall of the one or more walls being adjacent to the micro device and an opposite surface of the wall defining an outer surface of the micro chamber; and

a layer of inorganic sealing material that provides at least some degree of hermeticity fully covering the one or more outer surfaces of the micro chamber to seal the micro device in the micro chamber.

2. The encapsulated device of claim 1, wherein the layer of inorganic-sealing material is isotropically deposited using a technique selected from the group consisting of atomic layer deposition (ALD), chemical vapor deposition (CVD), plasma enhanced CVD (PECVD), physical vapor deposition (PVD) and electroplating.

3. The encapsulated device of claim 1, wherein the layer of inorganic-sealing material conforms to the one or more outer surfaces of the micro chamber.

4. The encapsulated device of claim 1, wherein the layer of inorganic-sealing material has a thickness smaller than 5 microns.

5. The encapsulated device of claim 4, wherein the layer of inorganic-sealing material has a thickness in a range between about .5micron and about 5 microns.

6. The encapsulated device of claim 4, wherein the layer of inorganic-sealing material has a thickness in a range between about 1 and about 100 nanometers.

7. The encapsulated device of claim 1, wherein the inorganic-sealing material comprises a material selected from the group consisting of Al₂O₃, SiO₂, TiO₂, Si₃N₄, SiO₂, C, Ni, Au, Cu, Pt, Sn, Sb, and Ag.

8. The encapsulated device of claim 1, wherein the micro chamber comprises:

an interposer plate bonded to an upper surface of the substrate, wherein the interposer plate includes an opening in which the micro device is positioned after the interposer plate is bonded to the upper surface of the substrate; and

an encapsulation cover bonded to the interposer plate, wherein the interposer plate and the encapsulation cover form the micro chamber to encapsulate the micro device.

9. The encapsulated device of claim 8, wherein the encapsulation cover is made of a transparent material.

10. The encapsulated device of claim 9, wherein the interposer plate is bonded to the substrate and the encapsulation cover is bonded to the interposer plate by an organic adhesive.

11. The encapsulated device of claim 10, wherein the substrate includes an electrical terminal on its upper surface in the vicinity of the micro device, and wherein the electrical terminal is configured to receive an electrical signal to control to the micro device.

12. The encapsulated device of claim 11, wherein the interposer plate includes a recess in which the electrical terminal is positioned after the interposer plate is bonded to the upper surface of the substrate.

13. A method for hermetically sealing a plurality of micro devices on a substrate to form the encapsulated device of claim 1, comprising:

constructing a plurality of non-hermetic micro chambers on the substrate to respectively encapsulate the plurality of micro devices; and

depositing a layer of inorganic-sealing material on the outer surfaces of the micro chambers to fully cover the outer surfaces and hermetically seal the micro devices within the micro chamber.

14. The method of claim 13, wherein the layer of inorganic-sealing material is deposited isotropically.

15. The method of claim 13, wherein the layer of inorganic-sealing material is deposited using a deposition technique selected from the group consisting of atomic layer deposition (ALD), chemical vapor deposition (CVD), plasma enhanced CVD (PECVD), physical vapor deposition (PVD) and electroplating.

16. The method of claim 13, wherein the step of constructing a plurality of non-hermetic micro chambers comprises:

bonding encapsulation covers respectively to a plurality of interposer plates to form micro chambers;

bonding the plurality of combined encapsulation covers and interposer plates to an upper surface of the substrate, wherein the interposer plate includes a device recess in which the micro device is positioned.

17. The method of claim 16, wherein the steps of bonding the interposer plates and the encapsulation covers comprise the application of a sealing material.

18. The method of claim 13, wherein the substrate includes an electrical terminal on an upper surface of the substrate in the vicinity of the micro device, wherein the electrical terminal is configured to receive an electrical signal to control to the micro device.

19. The method of claim 18, wherein the interposer plate includes a terminal recess in which the electrical terminal is positioned when the interposer plate is bonded to the upper surface of the substrate.

20. The method of claim 18, further comprising disposing a sealing material to cover the electrical terminal and at least a portion of the layer of inorganic-sealing material on the micro chamber.

21. The method of claim 13, wherein the layer of inorganic-sealing material conforms to the one or more outer surfaces of the micro chamber.

22. The method of claim 13 including the additional step of testing the micro devices on the substrate before depositing the layer of inorganic sealing material.

23. The method of claim 17 including the additional step of testing the micro devices on the substrate after application of the sealing material by sending a signal to the electrical terminal to control the micro device.

24. The method of claim 16 including the additional step of dispensing anti-stiction material on the micro devices before bonding the combined encapsulation covers and interposer plates to the upper surface of the substrate.