Anchor for device package

• US 6,992,375 B2
• Filed: 11/13/2001
• Issued: 01/31/2006
• Est. Priority Date: 11/30/2000
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Fisher, Edward Carl, Robbins, Roger A., Liu, Jwei Wien, Smith, Jack C., Holton, Joyce Wong
• Primary Examiner(s): Williams, Alexander Oscar
• Application Number:
  US10/007,964
• Publication Number:
  US 20020063322A1
• Time in Patent Office: 1,540 Days
• Field of Search: 257/682, 257/419, 257414-416, 257/732, 257/774, 257/680, 331/167, 359/290, 359/291, 359/224, 359/298, 156/345.43, 438/50, 438/22, 438/52, 361/762, 361/761, 174/256, 174/52.4
• US Class Current: 257/682
• CPC Class Codes: B81B 2203/0307 Anchors
• CPC Class Codes: B81B 7/0038 using materials for controlling the level of pressure, contaminants or moisture inside of the package, e.g. getters
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/484 Connecting portions
• CPC Class Codes: H01L 2224/48599 Principal constituent of the connecting portion of the wire connector being Gold (Au)
• CPC Class Codes: H01L 2224/48997 Reinforcing structures
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 23/13 characterised by the shape
• CPC Class Codes: H01L 23/26 including materials for absorbing or reacting with moisture or other undesired substances , e.g. getters
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15153 : the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/15165 : Monolayer substrate
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/16195 : Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H04N 5/7458 : the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]

Abstract

An anchor to hold getter materials in place within a micromechanical device package substrate. First and second cavity faces define an anchor cavity and mechanically retain a getter away from a region holding the micromechanical device. The getter anchor may be formed in a substrate comprised of at least three layers. The layers form a cavity in the substrate with a wide bottom portion—formed in the middle layer and a relatively narrower top portion—formed by the top layer. The narrow portion helps to retain the getter in the cavity by creating a mechanical lock on the wide portion of getter in the bottom of the cavity.

Claims

1. An anchor to hold material in place within a micromechanical device package substrate, said anchor comprising:

a first cavity face; and

a second cavity face, said first and second cavity faces defining an anchor cavity and arranged to mechanically retain material away from a region holding said micromechanical device.

2. The anchor of claim 1, said anchor cavity having a narrow top portion and a relatively wide bottom portion.

3. The anchor of claim 2, said narrow top portion having at least one wide end.

4. The anchor of claim 1, said micromechanical package substrate having a floor portion and a wall portion, said first face recessed in said floor portion and said second face recessed in said wall portion.

5. The anchor of claim 1, said micromechanical package substrate having a floor portion and a cover portion, said first face recessed in said floor portion and said second face formed by said cover.

6. The anchor of claim 1, said anchor cavity formed by laminating at least three layers of substrate material.

7. The anchor of claim 1, said package substrate having a wall portion and a floor portion, said anchor cavity formed at a junction between said wall and floor portions.

8. The anchor of claim 1, said package substrate having a wall portion and a floor portion, said anchor cavity formed at a junction between said wall and floor portions by the formation of a recess in said floor portion, wherein said wall portion overhangs said recess.

9. The anchor of claim 1, said package substrate having a wall portion and a floor portion, said anchor cavity formed at a junction between said wall and floor portions by the formation of a recess in said wall portion, wherein said floor portion extends beyond a portion of said recess.

10. The anchor of claim 1, said package substrate having a wall portion and a floor portion, said anchor cavity formed at a junction between said wall and floor portions.

11. The anchor of claim 1, further comprising:

a third cavity face opposing said first cavity face; and

a fourth cavity face opposing said second cavity face.

12. The anchor of claim 11, said first cavity face defined by a floor of said anchor cavity.

13. The anchor of claim 11, said third cavity face defined by a transition between a narrow top portion and a relatively wider bottom portion of said anchor cavity.

14. The anchor of claim 11, said second and fourth cavity faces defined by the sides of a recess in said package substrate.

15. The anchor of claim 11, said package substrate having a wall portion and a floor portion, said anchor cavity comprising a recess in said floor portion, a floor of said recess forming said first cavity face, and a side portion of said recess forming said second cavity face.

16. The anchor of claim 11, said package substrate having a wall portion and a floor portion, said anchor cavity comprising a recess in said floor portion, a floor of said recess forming said first cavity face, and opposing side portions of said recess forming said second and fourth cavity faces.

17. The anchor of claim 11, said package substrate having a wall portion and a floor portion, said anchor cavity formed by a recess in said floor portion, said fourth cavity face comprising the underside of an overhanging portion of said wall portion.

18. The anchor of claim 11, said package substrate having a wall portion and a floor portion, said anchor cavity formed at a junction between said wall and floor portions by the formation of a recess in said wall portion, wherein said floor portion extends beyond a portion of said recess.

19. An anchor to hold material in place within a microelectronic device package, said anchor comprising:

a substrate having an anchor cavity;

a first cavity face; and

a second cavity face, said first and second cavity arranged to mechanically retain material in said anchor cavity away from a region holding said microelectronic device.

20. The anchor of claim 19, said anchor cavity having a narrow opening portion and a relatively wide cavity portion.

21. The anchor of claim 20, said narrow portion having at least one wide region.

22. The anchor of claim 19, said micromechanical package substrate having a floor portion and a wall portion, said first face recessed in said floor portion and said second face recessed in said wall portion.

23. The anchor of claim 19, said micromechanical package substrate having a floor portion and a cover portion, said first face recessed in said floor portion and said second face formed by said cover.

24. The anchor of claim 19, said anchor cavity formed by laminating at least three layers of substrate material.

25. The anchor of claim 19, said package substrate having a wall portion and a floor portion, said anchor cavity formed at a junction between said wall and floor portions.

26. The anchor of claim 19, said package substrate having a wall portion and a floor portion, said anchor cavity formed at a junction between said wall and floor portions by the formation of a recess in said floor portion, wherein said wall portion overhangs said recess.

27. The anchor of claim 19, said package substrate having a wall portion and a floor portion, said anchor cavity formed at a junction between said wall and floor portions by the formation of a recess in said wall portion, wherein said floor portion extends beyond a portion of said recess.

28. The anchor of claim 19, said package substrate having a wall portion and a floor portion, said anchor cavity formed at a junction between said wall and floor portions.

29. The anchor of claim 19, further comprising:

a third cavity face opposing said first cavity face; and

a fourth cavity face opposing said second cavity face.

30. The anchor of claim 29, said first cavity face defined by a floor of said anchor cavity.

31. The anchor of claim 29, said third cavity face defined by a transition between a narrow top portion and a relatively wider bottom portion of said anchor cavity.

32. The anchor of claim 29, said second and fourth cavity faces defined by the sides of a recess in said package substrate.

33. The anchor of claim 29, said package substrate having a wall portion and a floor portion, said anchor cavity comprising a recess in said floor portion, a floor of said recess forming said first cavity face, and a side portion of said recess forming said second cavity face.

34. The anchor of claim 29, said package substrate having a wall portion and a floor portion, said anchor cavity comprising a recess in said floor portion, a floor of said recess forming said first cavity face, and opposing side portions of said recess forming said second and fourth cavity faces.

35. The anchor of claim 29, said package substrate having a wall portion and a floor portion, said anchor cavity formed by a recess in said floor portion, said fourth cavity face comprising the underside of an overhanging portion of said wall portion.

36. The anchor of claim 29, said package substrate having a wall portion and a floor portion, said anchor cavity formed at a junction between said wall and floor portions by the formation of a recess in said wall portion, wherein said floor portion extends beyond a portion of said recess.