Stress relief MEMS structure and package
Stress relief structures and methods that can be applied to MEMS sensors requiring a hermetic seal and that can be simply manufactured are disclosed. The system includes a sensor having a first surface and a second surface, the second surface being disposed away from the first surface, the second surface also being disposed away from a package surface and located between the first surface and the package surface, a number of support members, each support member extending from the second surface to the package surface, the support members being disposed on and operatively connected to only a portion of the second surface. The support member are configured to reduce stress produced by package-sensor interaction.
1. A system comprising:
a sensor having a first surface and a second surface, the second surface being disposed away from the first surface; the second surface also being disposed away from a package surface and located between the first surface and the package surface; and
one or more support members, each support member from the one or more support members extending from the second surface to the package surface, the one or more support members being disposed on and operatively connected to only a portion of the second surface, the one or more support members being configured to reduce stress produced by package-sensor interaction; wherein
a first support member from the one or more support members surrounds a central region of the second surface, and a second support member from the one or more support members surrounds the first support member.
2. The system of claim 1 wherein each support member from the one or more support members comprises a closed structure.
3. The system of claim 2 wherein each support member from the one or more support members comprises a hollow cylindrical structure.
4. The system of claim 1 wherein each support member from the one or more support members is comprised of the same material as a section of the sensor proximate to the second surface.
5. The system of claim 1 further comprising a soft material disposed between the second surface, the package surface and the one or more support members.
6. The system of claim 1 wherein each support member from the one or more support members is comprised of the same material as the package surface.
7. The system of claim 1 wherein the one or more support members comprises:
one or more first support members extending away from the second surface; and
one or more second support members extending from the package surface to the second surface;
the one or more second support members configured to receive the one or more first support members.
8. The system of claim 7 wherein each support member from the one or more first support members extends a distance away from the second surface, said distance being smaller than a distance between the second surface and the package surface.
9. The system of claim 7 further comprising a soft material disposed between the second surface, the package surface and the one or more second support members.
10. The system of claim 7 further comprising a soft material disposed between the second surface, the package surface and the one or more first and one or more second support members.
11. The system of claim 1 wherein the one or more support members comprise at least two support members.
12. The system of claim 11 wherein a width of one support member is smaller than a width of other support members.
13. The system of claim 11 wherein a sealing material is applied between the package surface and at least one support member; the sealing material being configured to provide a hermetic seal.
14. The system of claim 11 wherein at least one support member is bonded to the package surface.
15. The system of claim 1 wherein each support member from the one or more support members has a cross-sectional area that varies with distance away from the second surface; the cross-sectional area increasing with distance away from the second surface.
16. The system of claim 1 wherein each support member from the one or more support members comprises two subcomponents: a first subcomponent extending from the second surface to a predetermined location between the second surface and the package surface and a second subcomponent extending from said predetermined location to the package surface; a cross-sectional area of the first subcomponent being smaller than a cross-sectional area of the second subcomponent.
17. The system of claim 3 wherein closed curves in the cylindrical structure are not circles.
18. The system of claim 17 wherein each one of the closed curves comprises a plurality of sections, each section from the plurality of sections being joined to another section from the plurality of sections at one or more points; a slope of said each section not being equal to a slope of said another section at at least one of said one or more points.
19. The system of claim 1 wherein each support member from the one or more support members has a cross-sectional area that varies with distance away from the second surface; the cross-sectional area decreasing with distance away from the second surface.
20. The system of claim 1 wherein each support member from the one or more support members comprises two subcomponents; a first subcomponent extending from the second surface to a predetermined location between the second surface and the package surface and a second subcomponent extending from said predetermined location to the package surface; a cross-sectional area of the first subcomponent being larger than a cross-sectional area of the second subcomponent.