System and methods for hermetic sealing of post media-filled MEMS package

• US 6,946,728 B2
• Filed: 02/19/2004
• Issued: 09/20/2005
• Est. Priority Date: 02/19/2004
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Chen, Chien-Hua, Haluzak, Charles C., Michael, Donald
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): Nguyen, Dao H.
• Application Number:
  US10/783,849
• Publication Number:
  US 20050184382A1
• Time in Patent Office: 579 Days
• Field of Search: 298/40, 298/41, 257/678, 257/698, 257/777, 257/778
• US Class Current: 257/698
• CPC Class Codes: B81C 1/00285 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: B81C 1/00293 maintaining a controlled atmosphere with processes not provided for in B81C1/00285
• CPC Class Codes: B81C 2203/0145 Hermetically sealing an opening in the lid

Abstract

This invention provides a system and method for hermetically sealing a post media-filled package with a metal cap. The method can include the operation of filling a MEMS package through a fill port with at least one medium. A further operation can be plugging the fill port in the MEMS package with a sealant. Another operation can include depositing a metal cap over the sealant to hermetically seal the fill port.

Claims

1. A micro-electro-mechanical system (MEMS) package for hermetically sealing a MEMS device, comprising:

the MEMS package having a fill port, wherein the fill port is a through hole capable of having at least one medium inserted through the fill port;

at least one low temperature curing sealant placed within the fill port wherein the at least one low temperature curing sealant substantially fills the fill port; and

a metal cap placed over the at least one low temperature curing sealant in a specific pattern wherein the metal cap substantially hermetically seals the fill port.

2. A MEMS package as in claim 1, further comprising a MEMS device placed within the MEMS package.

3. A MEMS package as in claim 2, further comprising a bond ring surrounding the MEMS device.

4. A MEMS package as in claim 3, wherein the fill port is located in a break in the bond ring.

5. A MEMS package as in claim 1, further comprising a lid disposed above the bond ring.

6. A MEMS package as in claim 5, wherein the fill port is a through-hole located in the lid.

7. A MEMS package as in claim 5, wherein the lid is selected from the group of materials consisting of glass and silicon.

8. A MEMS package as in claim 1, wherein the least one low temperature curing sealants placed within the fill port is an organic sealant selected from the group consisting of thermal-set epoxy, UV curable epoxy, two-part epoxy, silicone, and spin-on polyamides.

9. A MEMS package as in claim 1, wherein the at least one low temperature curing sealant is an inorganic sealant.

10. A MEMS package as in claim 1, wherein the at least one medium is a gas selected from the group of media consisting of air, nitrogen, oxygen, and argon.

11. A MEMS package as in claim 1, wherein the at least one medium is a liquid selected from the group of liquid media consisting of a low vapor pressure oil, a lubricant, and a hydrophobic fluid.

12. A MEMS package as in claim 11, wherein the liquid refractive index is similar to a lid refractive index.

13. A MEMS package as in claim 11, wherein the liquid has a coefficient of thermal expansion similar to that of the MEMS device.

14. A MEMS package as in claim 1, wherein the at least one medium is a solid selected from the group of solid media consisting of sol gel.

15. A MEMS package as in claim 1, wherein the at least one low temperature curing sealant is cured using a low temperature curing process, wherein the low temperature curing process occurs at a temperature less than 100 degrees Celsius.

16. A MEMS package as in claim 1, wherein the metal cap is formed over the at least one low temperature curing sealant using a low temperature process selected from the group consisting of electron beam deposition and physical vapor deposition.

17. A MEMS package as in claim 1, comprising a metal cap made from one or more types of metal, said one or more types of metal selected from the group consisting of gold, titanium, silver, aluminum, chromium, and tantalum.

18. A micro-electro-mechanical system (MEMS) package for hermetically sealing a MEMS device, comprising:

a means for filling a MEMS package through a fill port with at least one medium;

a means for plugging the fill port in the MEMS package with at least one low temperature curing sealant; and

a means for hermetically sealing a metal cap in a specific pattern over the at least one low temperature curing sealant.