MEMS package structure and method for fabricating the same

• US 9,359,190 B2
• Filed: 06/30/2014
• Issued: 06/07/2016
• Est. Priority Date: 06/30/2014
• Status: Active Grant

• Current Assignee: Himax Display Incorporated (Himax Technologies Incorporated)
• Original Assignee: Himax Display Incorporated (Himax Technologies Incorporated)
• Inventors: Su, Chun-Hao
• Primary Examiner(s): Zhang, Yuanda
• Assistant Examiner(s): CARTER, MICHAEL W
• Application Number:
  US14/320,562
• Publication Number:
  US 20150375993A1
• Time in Patent Office: 708 Days
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 7/0038 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters

Abstract

A MEMS package structure is disclosed. The MEMS package structure includes a first glass substrate on a micro-electromechanical systems (MEMS) structure, a sealant adhered between the first glass substrate and the MEMS structure; and a first moisture barrier on the sidewalls of the first glass substrate, the sealant, and the MEMS structure.

Claims

1. A method for fabricating MEMS package structure, comprising:

providing a micro-electromechanical systems (MEMS) structure

mounting a first glass substrate onto the MEMS structure via a sealant;

coating a moisture barrier on the sidewalls of the first glass substrate, the sealant, and the MEMS structure, wherein the moisture barrier comprises a self-assembly monolayer (SAM); and

forming a molding glue on the moisture barrier such that the moisture barrier is between the molding glue and the sealant.

2. The method of claim 1, further comprising:

adhering a metal frame onto a substrate;

disposing the first glass substrate and MEMS structure onto the metal frame and the substrate; and

disposing a second glass substrate on the metal frame.

3. The method of claim 2, wherein the sealant comprises epoxy and the substrate comprises a ceramic substrate.

4. The method of claim 1, wherein the step of coating the moisture barrier comprises:

(a) forming a moisture resistant layer on the sidewalls of the first glass substrate, the sealant, and the MEMS structure;

(b) forming a protective layer on the moisture resistant layer; and

(c) forming a water resistant layer on the protective layer.

5. The method of claim 4, wherein the moisture resistant layer comprises AlO_x.

6. The method of claim 4, wherein the protective layer comprises SiO_x.

7. The method of claim 4, wherein the water resistant layer comprises the self-assembly monolayer (SAM).

8. The method of claim 4, further comprising repeating steps (a) and (b) before performing step (c).

9. The method of claim 4, further comprising performing an atomic layer deposition (ALD) process for forming the moisture resistant layer and the protective layer.

10. The method of claim 4, further comprising performing a chemical vapor deposition (CVD) process for forming the water resistant layer.

11. The method of claim 1, further comprising performing a surface treatment on the surface of the first glass substrate and the MEMS structure for generating OH bond before coating the moisture barrier.

12. The method of claim 11, wherein the surface treatment comprises an O₂ plasma treatment or a ultraviolet ozone treatment.

13. A MEMS package structure, comprising:

a first glass substrate on a micro-electromechanical systems (MEMS) structure;

a sealant adhered between the first glass substrate and the MEMS structure;

a first moisture barrier on the sidewalls of the first glass substrate, the sealant, and the MEMS structure, wherein the first moisture barrier comprises a self-assembly monolayer (SAM); and

a molding glue on the first moisture barrier such that the first moisture barrier is between the molding glue and the sealant.

14. The MEMS package structure of claim 13, further comprising:

a metal frame adhered onto a substrate;

the first glass substrate and the MEMS structure on the substrate; and

a second glass substrate on the metal frame.

15. The MEMS package structure of claim 13, further comprising:

a substrate having a base and a step-shaped portion on the base;

the first glass substrate and the MEMS structure on the base of the substrate and enclosed by the step-shaped portion; and

a second glass substrate on the step-shaped portion of the substrate.

16. The MEMS package structure of claim 15, further comprising a second moisture barrier between the second glass substrate and the step-shaped portion of the substrate.

17. The MEMS package structure of claim 13, wherein the first moisture barrier comprises:

a moisture resistant layer on the sidewalls of the first glass substrate, the sealant, and the MEMS structure;

a protective layer on the moisture resistant layer; and

a water resistant layer on the protective layer.

18. The MEMS package structure of claim 17, wherein the moisture resistant layer comprises AlO_x.

19. The MEMS package structure of claim 17, wherein the protective layer comprises SiO_x.

20. The MEMS package structure of claim 17, wherein the water resistant layer comprises the self-assembly monolayer (SAM).