MEMS device package with thermally compliant insert

Abstract

A low cost micro-electronic package for MEMS applications includes a package substrate, a MEMS device and a buffer insert which is placed between the MEMS device and the package substrate. The buffer insert has a coefficient of thermal expansion (CTE) which is compatible with the material of the MEMS device and is sufficiently rigid to isolate the MEMS device from thermal, mechanical and other physical stresses applied to the package substrate. In an embodiment, the package is formed as an integrated device which includes both the MEMS device and a signal conditioning integrated circuit, potentially found in the same die. The substrate insert may be made of a material having a CTE value compatible with silicon (Si), such as Kovar, Invar, or an appropriate ceramic material or the like.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more embodiments of the system and method and, together with the detailed description, serve to explain the principles and implementations of the system and method.

In the drawings:

FIG. 1 illustrates a perspective view of a molded package including a MEMS device and a buffer insert according to an embodiment.

FIG. 2 illustrates an exploded view of the molded package according to an embodiment.

FIG. 3A illustrates a partially exploded view of the molded package according to an embodiment.

FIG. 3B illustrates a broken view of the molded package in FIG. 3A according to an embodiment.

FIG. 4 illustrates a cross sectional view of the molded package including the MEMS device shown in FIG. 1 according to an embodiment.

FIG. 5 illustrates a broken view of the molded package in FIG. 1 according to an embodiment.

FIG. 6 illustrates a broken view of an existing molded package.

FIG. 7 illustrates a method of manufacturing in accordance with an embodiment.

Claims

1. A Micro Electronic-Mechanical System (MEMS) package assembly comprising: a package having a plurality of walls configured to form a chamber within the package, the chamber; andan insert coupled to a surface within the chamber and adapted to attach a MEMS device thereon, the insert having a thermal expansion characteristic compatible with at least a portion of the MEMS device, wherein the insert is configured to isolate the MEMS device from a stress force applied in the package.

2. The assembly of claim 1 wherein the package includes a bottom surface within the chamber, wherein at least a portion of the insert is coupled to the bottom surface.

3. The assembly of claim 1 wherein the package includes a bottom surface within the chamber having a recessed area, wherein the insert is coupled to the bottom surface and placed at least partially into the recessed area.

4. The assembly of claim 1 further comprising a MEMS device attached to the insert, wherein a coefficient of thermal expansion (CTE) of the insert is substantially similar to a CTE of the MEMS device.

5. The assembly of claim 1 wherein the package further comprises: a plurality of conductive leads; andan integrated circuit positioned within the chamber and coupled to at least one of the conductive leads.

6. The assembly of claim 1 wherein the chamber is partitioned into a first chamber and a second chamber, wherein a MEMS device is positioned in the first chamber and an integrated circuit is positioned in the second chamber.

7. The assembly of claim 1 wherein the insert is made of at least one of Kovar, Invar and a ceramic material.

8. The assembly of claim 1 wherein the insert includes an aperture therethrough.

9. A Micro Electronic-Mechanical System (MEMS) device assembly comprising: a package having a plurality of walls configured to form a chamber within the package, the chamber having a seating portion;a MEMS device housed within the package and having an interface surface; anda rigid insert made of a material having a coefficient of thermal expansion value (CTE) compatible with a CTE value of the interface surface of the MEMS device, wherein a first surface of the insert is attached to the MEMS device and a second surface of the insert is mounted to the seating portion.

10. The assembly of claim 9 wherein the seating portion includes a recessed area, wherein the insert is placed at least partially into the recessed area.

11. The assembly of claim 9 wherein the package further comprises: a plurality of conductive leads; andan integrated circuit positioned within the chamber and coupled to at least one of the conductive leads.

12. The assembly of claim 9 wherein the chamber is partitioned into a first chamber and a second chamber, wherein the MEMS device is positioned in the first chamber and an integrated circuit is positioned in the second chamber.

13. The assembly of claim 9 wherein the insert is made of at least one of Kovar, Invar and ceramic material.

14. The assembly of claim 9 wherein the insert includes an aperture therethrough.

15. A method for manufacturing a package assembly for a Micro Electronic-Mechanical System (MEMS) device, the method comprising: forming a package having a plurality of walls configured to form a chamber within the package, the chamber having a bottom surface;selecting a MEMS device having a die surface; andcoupling the MEMS device to a rigid insert, wherein the insert is positioned between the bottom surface of the package and the die surface of the MEMS device, the insert having a thermal expansion characteristic compatible with the die surface and configured to isolate the MEMS device from a stress force applied to the package.

16. The method of claim 15 further comprising forming a recessed area into the bottom surface, wherein the insert is able to be placed at least partially into the recessed area.

17. The method of claim 15 further comprising: forming a plurality of conductive leads in the package; andcoupling an integrated circuit to at least one of the conductive leads.

18. The method of claim 15 wherein the insert is made of at least one of Kovar, Invar and ceramic material.

19. The method of claim 15 wherein the MEMS device is coupled to insert after the insert is coupled to the bottom surface of the package.

20. The method of claim 15 wherein the MEMS device is coupled to insert before the insert is coupled to the bottom surface of the package.