Hermetically sealing using a cold welded tongue and groove structure

• US 8,191,756 B2
• Filed: 11/04/2005
• Issued: 06/05/2012
• Est. Priority Date: 11/04/2004
• Status: Active Grant

• Current Assignee: DARE MB Incorporated
• Original Assignee: MicroCHIPS Inc.
• Inventors: Coppeta, Jonathan R., Shelton, Kurt, Sheppard, Norman F. Jr., Snell, Douglas, Santini, Catherine M. B.
• Primary Examiner(s): Stoner, Kiley
• Assistant Examiner(s): GAMINO, CARLOS J
• Application Number:
  US11/267,541
• Publication Number:
  US 20060115323A1
• Time in Patent Office: 2,405 Days
• Field of Search: 228/115, 228/116
• US Class Current: 228/115
• CPC Class Codes: A61K 9/0097 Micromachined devices; Microelectromechanical systems [MEMS]; Devices obtained by lithographic treatment of silicon; Devices comprising chips intradermal microneedle arrays A61K9/0021; MEMS in general B81B7/02
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 2207/00 Methods of manufacture, assembly or production
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: B23K 20/02 by means of a press ; Diffusion bonding B23K20/001, B23K20/04 take precedence
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: B81B 2201/06 Bio-MEMS
• CPC Class Codes: B81C 1/00047 Cavities
• CPC Class Codes: B81C 1/00095 Interconnects
• CPC Class Codes: B81C 1/00269 Bonding of solid lids or wafers to the substrate
• CPC Class Codes: B81C 2203/0109 Bonding an individual cap on the substrate
• CPC Class Codes: B81C 2203/019 characterised by the material or arrangement of seals between parts
• CPC Class Codes: B81C 2203/038 Bonding techniques not provided for in B81C2203/031 - B81C2203/037
• CPC Class Codes: F16B 11/004 by cold pressure welding
• CPC Class Codes: F16B 4/004 Press fits, force fits, interference fits, i.e. fits without heat or chemical treatment F16B4/002 takes precedence
• CPC Class Codes: F16B 5/08 by means of welds or the like welding B23K
• CPC Class Codes: H01L 2224/05001 Internal layers
• CPC Class Codes: H01L 2224/05023 the whole internal layer protruding from the surface
• CPC Class Codes: H01L 2224/051 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/056 : with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/16237 : the bump connector connecting to a bonding area disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/81193 : wherein the bump connectors are disposed on both the semiconductor or solid-state body and another item or body to be connected to the semiconductor or solid-state body
• CPC Class Codes: H01L 23/10 : characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 23/3142 : Sealing arrangements between parts, e.g. adhesion promotors
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/1461 : MEMS
• CPC Class Codes: H01L 2924/16315 : Shape
• CPC Class Codes: Y10T 403/477 : Fusion bond, e.g., weld, etc.

Abstract

Compression cold welding methods, joint structures, and hermetically sealed containment devices are provided. The method includes providing a first substrate having at least one first joint structure which comprises a first joining surface, which surface comprises a first metal; providing a second substrate having at least one second joint structure which comprises a second joining surface, which surface comprises a second metal; and compressing together the at least one first joint structure and the at least one second joint structure to locally deform and shear the joining surfaces at one or more interfaces in an amount effective to form a metal-to-metal bond between the first metal and second metal of the joining surfaces. Overlaps at the joining surfaces are effective to displace surface contaminants and facilitate intimate contact between the joining surfaces without heat input. Hermetically sealed devices can contain drug formulations, biosensors, or MEMS devices.

Claims

1. A method of hermetically sealing at least two substrates together, the method comprising:

providing a first substrate having at least one first joint structure which comprises a first joining surface, which surface comprises a first metal, the at least one first joint structure comprising at least one groove structure defined within a recess formed in the first substrate, the at least one groove structure having an open end, and an inner bottom surface distal to the open end, and inner side walls between the open end and the inner bottom surface;

providing a second substrate having at least one second joint structure which comprises a second joining surface, which surface comprises a second metal, the at least one second joint structure comprising at least one tongue structure, the at least one tongue structure having a tip end portion;

aligning the at least one first joint structure relative to the at least one second joint structure so as to impart one or more overlaps of the at least one tongue structure relative to the at least one groove structure; and

after the step of aligning, compressing the at least one tongue structure at least partially into the at least one groove structure to locally deform and shear the second joining surface at one or more interfaces created by the one or more overlaps in an amount effective to plastically deform at least a portion of the second joining surface into a space between the first substrate and the second substrate outside the at least one groove structure and form at least one metal-to-metal bond between the first metal and second metal of the joining surfaces,

wherein the at least one metal-to-metal bond is a cold weld which comprises a portion of the second joining surface deformed into the space between the first substrate and the second substrate outside the at least one groove structure, and the tip end portion of the at least one tongue structure does not extend into the at least one groove structure enough to contact the inner bottom surface of the at least one groove structure.

2. The method of claim 1, wherein the one or more overlaps are effective to displace surface contaminants and facilitate intimate contact between the joining surfaces without heat input.

3. The method of claim 1, wherein the at least one tongue structure has a tongue height ranging from 1 micron to 100 microns and a tongue width ranging from 1 micron to 100 microns and wherein the at least one groove structure has a groove depth ranging from 1 micron to 100 microns and a groove width ranging from 1 micron to 100 microns.

4. The method of claim 1, wherein the first metal, the second metal, or both, comprise gold or platinum.

5. The method of claim 1, wherein the first metal, the second metal, or both, comprise a metal selected from the group consisting of gold, indium, aluminum, copper, lead, zinc, nickel, silver, palladium, cadmium, titanium, tungsten, tin, and combinations thereof.

6. The method of claim 1, wherein the first metal and the second metal are different metals.

7. The method of claim 1, wherein the first substrate, the second substrate, or both, comprise a material selected from the group consisting of silicon, glasses, ceramics, polymers, metals, and combinations thereof.

8. The method of claim 1, wherein the first joint structure, the second joint structure, or both, comprise a material selected from the group consisting of metals, ceramics, glasses, silicon, and combinations thereof.

9. The method of claim 1, wherein the first joint structure, the second joint structure, or both, comprise indium, aluminum, gold, chromium, platinum, copper, nickel, tin, alloys thereof, and combinations thereof.

10. The method of claim 1, wherein the at least one first joint structure is formed by bonding at least one pre-formed structure to the first substrate.

11. The method of claim 1, wherein the first joining surface is formed by an electroplating process, evaporation, a chemical vapor deposition process, sputtering, electron beam evaporation, or a wet etch process.

12. The method of claim 1, wherein the first joint structure and first joining surface are a layer of metal covering at least part of a surface of the first substrate.

13. The method of claim 1, further comprising clamping or soldering together the first substrate and the second substrate.

14. The method of claim 1, wherein the bonded substrates comprise at least one cavity defined therein.

15. The method of claim 1, wherein the first or second substrate comprises a plurality of discrete reservoirs containing reservoir contents, each reservoir being hermetically sealed from each other and from an exterior environment.

16. The method of claim 15, wherein the reservoir contents comprises a bio sensor or other secondary device.

17. The method of claim 15, wherein the reservoir contents comprises a drug formulation.

18. The method of claim 15, wherein the reservoir contents comprises fragrance or scent compounds, dyes or other colorants, sweeteners, or flavoring agents.

19. The method of claim 1, wherein the deformation is conducted under vacuum or in an inert gas atmosphere effective to reduce oxidation of the joint structure relative to that which would occur if conducted in atmospheric air.

20. The method of claim 1, wherein the first or second substrate comprises a cavity in which a third substrate is located before the first and second joint structures are compressed together.

21. The method of claim 20, wherein the third substrate comprises a sensor, a MEMS device, or combination thereof.

22. The method of claim 1, wherein the at least one tongue structure has a height up to about 50 micron, and the at least one groove has a depth corresponding to the height of the at least one tongue structure.

23. The method of claim 1, wherein the at least one tongue structure defines a portion having a height of 50 micron.

24. The method of claim 1, wherein the at least one tongue structure has an aspect ratio of height to width of up to 5:

1, and the at least one groove structure has a depth corresponding to the height of the at least one tongue structure.

25. The method of claim 1, wherein the step of compressing is performed at ambient temperature.

26. The method of claim 1, wherein the step of compressing is performed without the addition of heat.

27. The method of claim 25, wherein the ambient temperature is less than 40°

C.

28. The method of claim 1, wherein the second substrate is formed of a monolithic material.

29. The method of claim 1, wherein the second substrate comprises a silicon wafer.

30. The method of claim 28, wherein the second substrate comprises a silicon wafer.

31. The method of claim 1, wherein the at least one tongue structure has a cross-sectional shape chosen from the group of shapes consisting of rectangular, triangular and hemispherical.

32. The method of claim 1, wherein the hermetic sealing is effected without the need for providing additional holding structures or sealing material.

33. The method of claim 1, further comprising, subsequent to the step of compressing, providing an additional seal holding the first substrate and the second substrate together.

34. The method of claim 33, wherein the step of providing an additional seal is chosen from the group consisting of clamping, clamping using a shape memory alloy, screwing, riveting, soldering, applying heat shrinking polymers, and applying opposed magnets.

35. The method of claim 1, wherein the one or more overlaps are imparted by providing the tongue structure wider in a lateral dimension than a width of the corresponding groove structure receiving the tongue structure.

36. The method of claim 1, further comprising the step of defining a containment space between the first substrate and the second substrate within the hermetic seal such that the containment space is hermetically sealed from an exterior environment.

37. The method of claim 1, wherein the metal-to-metal bond has a seal path parallel to a surface of one or both of the first substrate and the second substrate.

38. The method of claim 1, wherein the tongue structure overlaps the groove structure at two opposed sides of the tongue structure.

39. The method of claim 1, wherein the at least one interface comprises two interfaces, and the at least one overlap comprises two overlaps.

40. The method of claim 1, wherein the one or more overlaps are between 1 micron and 20 microns.

41. The method of claim 1, wherein the at least one tongue structure has a trapezoidal cross-sectional shape.

42. A method of hermetically sealing at least two substrates together, the method comprising:

providing a first substrate having at least one first joint structure which comprises a first joining surface, which surface comprises a first metal, the at least one first joint structure comprising at least one groove structure defined within a recess formed in the first substrate, the at least one groove structure having an open end, and an inner bottom surface distal to the open end, and inner side walls between the open end and the inner bottom surface;

providing a second substrate having at least one second joint structure which comprises a second joining surface, which surface comprises a second metal, the at least one second joint structure comprising at least one tongue structure, the at least one tongue structure having a tip end portion;

aligning the at least one first joint structure relative to the at least one second joint structure so as to impart at least two overlaps of the at least one tongue structure relative to the at least one groove structure; and

after the step of aligning, compressing the at least one tongue structure at least partially into the at least one groove structure to locally deform and shear the second joining surface at one or more interfaces created by the at least two overlaps in an amount effective to plastically deform at least a portion of the second joining surface into a space between the first substrate and the second substrate outside the at least one groove structure and form at least two metal-to-metal bonds, at least one of the bonds being on each side of the groove structure,

wherein the at least two metal-to-metal bonds are cold welds which comprise a portion of the second joining surface deformed into the space between the first substrate and the second substrate outside the at least one groove structure, and the tip end portion of the at least one tongue structure does not extend into the at least one groove structure enough to contact the inner bottom surface of the at least one groove structure.