Stress relief mems structure and package

Patent metadata

Field	Value
Publication number	US-2016229688-A1
Application number	US-201514616017-A
Country	US
Kind code	A1
Filing date	Feb 6, 2015
Priority date	Feb 6, 2015
Publication date	Aug 11, 2016
Grant date	—

Abstract

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.

First claim

What is claimed is:

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; 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.

2 . The system of claim 1 wherein a first support member from the one or more support members surrounds a central region of the second surface; and wherein a second support member from the one or more support members surrounds the first support member.

3 . The system of claim 1 wherein each support member from the one or more support members comprises a closed structure.

4 . The system of claim 3 wherein each support member from the one or more support members comprises a hollow cylindrical structure.

5 . 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.

6 . 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.

7 . 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.

8 . 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.

9 . The system of claim 8 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.

10 . The system of claim 8 further comprising a soft material disposed between the second surface, the package surface and the one or more second support members.

11 . The system of claim 8 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.

12 . The system of claim 1 wherein the one or more support members comprise at least two support members.

13 . The system of claim 12 wherein a width of one support member is smaller than a width of other support members.

14 . The system of claim 12 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.

15 . The system of claim 12 wherein at least one support member is bonded to the package surface.

16 . 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.

17 . 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.

18 . The system of claim 4 wherein closed curves in the cylindrical structure are not circles.

19 . The system of claim 18 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.

20 . A method for fabricating a sensor system with reduced stress due to package-sensor interaction, the method comprising:
etching into a surface of a component of a sensor structure, the sensor structure having a first surface, in order to form a second surface of the sensor structure and one or more support structures disposed on the 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; the one or more support structures being configured to reduce stress produced by package-sensor interaction.

21 . The method of claim 20 wherein the one or more support structures is configured such that, in the sensor system, each support structure from the one or more support structures extends from the second surface to the package surface.

22 . The method of claim 20 wherein the component is a silicon component.

23 . The method of claim 20 wherein a first support member from the one or more support structures surrounds a central region of the second surface; and wherein each subsequent support structure surrounds prior support structures.

24 . The method of claim 23 wherein each support structure from the one or more support structures comprises a closed structure.

25 . The method of claim 23 wherein each support structure from the one or more support structures comprises a hollow cylindrical structure.

26 . The method of claim 25 wherein closed curves in the cylindrical structure are not circles.

27 . The method of claim 26 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.

28 . The method of claim 20 wherein each support member from the one or more support structures extends a distance away from the second surface, said distance being smaller than a distance between the second surface and the package surface.

29 . The method of claim 20 further comprising:
trimming each support structure such that said each support structure from the one or more support structures 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.

30 . The method of claim 20 further comprising:
trimming each support structure such that said each support structure from the one or more support structures 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.

31 . The method of claim 20 further comprising:
trimming each support structure such that said each support structure from the one or more support structures

Assignees

• Mks Instr Inc

Inventors

• Gu Lei
• Bart Stephen F

Classifications

• B81B7/0048 Primary

  between the MEMS die and the substrate · CPC title

• B81C1/00547

  Etching processes not provided for in groups B81C1/00531 - B81C1/00539 · CPC title

• B81C1/00

  Manufacture or treatment of devices or systems in or on a substrate (B81C3/00 takes precedence) · CPC title

• B81B2201/0264

  Pressure sensors · CPC title

• B81C1/00325

  for reducing stress inside of the package structure · CPC title