MEMS DEVICE PACKAGING METHODS

• US 20070117275A1
• Filed: 11/22/2005
• Published: 05/24/2007
• Est. Priority Date: 11/22/2005
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: DCamp, Jon, Curtis, Harlan
• Granted Patent: US 7,491,567 B2
• Time in Patent Office: Days
• US Class Current: 438/127
• CPC Class Codes: B81B 2201/0235 Accelerometers
• 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 2203/019 characterised by the material or arrangement of seals between parts
• CPC Class Codes: H01L 2924/15192 Resurf arrangement of the internal vias

Abstract

A method of packaging a MEMS device that includes, for example, the steps of providing a MEMS die that has a MEMS device, a seal ring and bond pads disposed thereon, providing a MEMS package that has a recess, a seal ring and bond pads disposed thereon, positioning the MEMS die over the MEMS package to align the seal rings and bond pads, inserting the MEMS die and MEMS package into a vacuum chamber and evacuating gasses therefrom to form a controlled vacuum pressure therein, sealing the MEMS package and the MEMS die together at the seal rings to form a package having a hermitically sealed interior chamber and simultaneously forming electrical connections between the corresponding bond pads.

Claims

1. A method of packaging a MEMS device, comprising the steps of:

providing a MEMS die having a MEMS device and bond pads disposed thereon;

providing a MEMS package having a recess and bond pads disposed adjacent to the recess;

positioning the MEMS die over the MEMS package

aligning the MEMS device of the MEMS die with the recess of the MEMS package, and aligning at least some of the bond pads of the MEMS die with at least some of the bond pads of the MEMS package;

inserting the MEMS die and MEMS package into a chamber and producing a controlled environment therein; and

sealing the MEMS die and MEMS package together along a ring to form a package having a hermitically sealed interior chamber that includes the MEMS device, as well as forming electrical connections between selected bond pads of the MEMS die with selected bond pads of the MEMS package.

2. The method of claim 1 wherein the step of sealing further comprises the step of forming the hermitically sealed interior chamber at a controlled vacuum pressure.

3. The method of claim 1 further comprising the steps of:

providing a solder pre-form; and

placing the solder pre-form between the MEMS die and the MEMS package along the ring.

4. The method of claim 3, wherein the solder pre-form has a melting temperature and further comprising the step of raising the temperature of the solder pre-form to the melting temperature.

5. The method of claim 1 wherein the MEMS device is a MEMS gyroscope.

6. The method of claim 1 wherein the MEMS device is a MEMS accelerometer.

7. The method of claim 1, further comprising the step of verifying the operability of the MEMS device prior to the step of sealing the MEMS package and the MEMS die together.

8. The method of claim 1, further comprising the step of verifying the operability of the MEMS device electronically subsequent to the step of sealing the MEMS package and the MEMS die together.

9. The method of claim 3, wherein the MEMS die includes a seal ring, and the MEMS package includes a corresponding seal ring, wherein the seal ring of the MEMS die and the seal ring of the MEMS package are aligned with the solder pre-form.

10. The method of claim 9, wherein the MEMS die seal ring comprises a material selected from the group of gold, aluminum, silver, tin, lead, and combinations thereof.

11. The method of claim 1, wherein the MEMS die and MEMS package are sealed together along the ring by a glass frit bond.

12. The method of claim 1, further comprising the step of providing a getter in the hermetically sealed interior chamber.

13. The method of claim 12, wherein the getter is a thin film getter.

14. The method of claim 1, wherein the step of sealing the MEMS die and the MEMS package together further comprises sealing the MEMS die and MEMS package using thermo-compression bonding.

15. The method of claim 1, wherein the step of sealing the MEMS die and the MEMS package together further comprises sealing the MEMS die and MEMS package using resistance welding.

16. The method of claim 1, wherein the step of sealing the MEMS die and the MEMS package together further comprises sealing the MEMS die and MEMS package using soldering.

17. The method of claim 1, wherein the step of sealing the MEMS die and the MEMS package together further comprises sealing the MEMS die and MEMS package using eutectic bonding.

18. The method of claim 1, further comprising the steps of

placing the MEMS package into a bonding chamber, and

photo-registering the MEMS package subsequent to placing the MEMS package into the bonding chamber.

19. The method of claim 1, further comprising the steps of

picking the MEMS die up with a tool, and

photo-registering the MEMS die subsequent to the step of picking the MEMS die up with the tool.

20. The method of claim 1 wherein the controlled environment is at a pressure of 1.0 atmosphere or less.

21. The method of claim 1 wherein the controlled environment is at a pressure of 0.5 atmospheres or less.

22. The method of claim 1 wherein the step of inserting the MEMS die and MEMS package into the chamber further comprises the step of evacuating the chamber to a reduced pressure and then at least partially backfilling the chamber with an inert gas.

23. The method of claim 22 wherein the chamber is at least partially backfilled with an inert gas to a pressure of less than 10×

10<sup>−

2</sup> torr.

24. The method of claim 22 wherein the chamber is at least partially backfilled with an inert gas to a pressure of less than 50×

10<sup>−

3</sup> torr.

25. The method of claim 22 wherein the chamber is at least partially backfilled with an inert gas to a pressure of less than 20×

10<sup>−

3</sup> torr.

26. The method of claim 1 wherein the controlled environment is at a pressure of less than 100×

10<sup>−

5</sup> torr.

27. The method of claim 1 wherein the controlled environment is at a pressure of less than 50×

10<sup>−

5</sup> torr.

28. The method of claim 1 wherein the controlled environment is at a pressure of less than 15×

10<sup>−

5</sup> torr.

29. A method of packaging a MEMS device, comprising the steps of:

providing a MEMS die having a MEMS device, a seal ring, and bond pads;

providing a MEMS package having a seal ring and bond pads;

providing a solder pre-form between the MEMS die and the MEMS package; and

positioning the MEMS die over the MEMS package so that the seal ring and bond pads of the MEMS die are aligned with the seal ring and bond pads of the MEMS package;

inserting the MEMS die and the MEMS package into a chamber and forming a controlled environment therein;

sealing the MEMS die and the MEMS package together using the solder pre-form to form a package having a hermitically sealed interior chamber with the MEMS device therein and simultaneously forming electrical connections between the bond pads of the MEMS die and MEMS package.

30. The method of claim 29 further comprising the step of:

providing a seal ring on the MEMS die having a shape and a position to contact the solder pre-form during the sealing step.

31. The method of claim 29 further comprising the step of:

providing a seal ring on the MEMS package having a shape and a position to contact the solder pre-form during the sealing step.

32. The method of claim 29 further comprising the step of providing a getter in the hermitically sealed interior chamber.

33. The method of claim 32 further comprising the step of activating the getter.

34. The method of claim 29, further comprising the step of verifying the operability of the MEMS device prior to the step of sealing the MEMS die and the MEMS package together.

35. The method of claim 29, further comprising the step of verifying the operability of the MEMS device subsequent to the step of sealing the MEMS die and the MEMS package together.

36. A method of packaging a MEMS device, comprising:

flip-chip bonding a MEMS die having a MEMS device and a plurality of bond pads thereon to a MEMS package having a recess for receiving at least part of the MEMS device and a plurality of bond pads, to create a hermetically sealed interior chamber having the MEMS device therein, wherein the flip-chip bonding step simultaneously creates a seal between the MEMS die and the MEMS package and electrical connections between the pluralities of bond pads.

37. The method of claim 36, wherein the flip-chip bonding step includes thermo-compression bonding the MEMS die to the MEMS package.

38. The method of claim 37, wherein the flip-chip bonding step includes creating a solder seal between the MEMS die to the MEMS package.