Using backgrind wafer tape to enable wafer mounting of bumped wafers

• US 6,949,158 B2
• Filed: 05/14/2001
• Issued: 09/27/2005
• Est. Priority Date: 05/14/2001
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Sanchez, Jose L., Ball, Michael B.
• Primary Examiner(s): Haran, John T.
• Application Number:
  US09/854,759
• Publication Number:
  US 20020166625A1
• Time in Patent Office: 1,597 Days
• Field of Search: 156/153, 156/154, 156/247, 156/285, 156/344, 438/459, 438/460, 438/464, 438/977
• US Class Current: 156/154
• CPC Class Codes: B24B 21/04 for grinding plane surfaces
• CPC Class Codes: H01L 21/67132 Apparatus for placing on an insulating substrate, e.g. tape
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 21/6838 with gripping and holding devices using a vacuum; Bernoulli devices
• CPC Class Codes: H01L 2221/68386 Separation by peeling
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/11003 for holding or transferring the bump preform
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 24/11 Manufacturing methods for bumps on insulating substrates H01L21/4853
• 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 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01032 Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01047 Silver [Ag]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/014 Solder alloys
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: Y10S 156/941 Means for delaminating semiconductive product
• CPC Class Codes: Y10T 156/1179 : with poking during delaminating [e.g., jabbing, etc.]
• CPC Class Codes: Y10T 156/19 : Delaminating means

Abstract

A method and apparatus are disclosed for mounting a wafer on a mount and thinning the wafer. The wafer includes a front surface having bumps with an adhesive tape having a backing attached thereto and a back surface. The front surface of the wafer is mounted facedown on a suction surface with the backing of the adhesive tape abutting the surface. The wafer is then suctioned, after which the back surface of the wafer undergoes a grinding process to thin the wafer. Since the backing attached to the bumps on the wafer is substantially planar and sits substantially flat on the suction surface of the wafer mount, the force exerted on the wafer from the thinning process does not overcome the suction force holding the wafer on the wafer mount. Thus, the bumped wafer may be thinned without damaging the bumps and the active surface of the wafer.

Claims

1. A method of attaching a wafer having bumps on a surface thereof, comprising:

attaching a tape having an adhesive and a backing on to solely a portion of said bumps of said surface having bumps thereon of said wafer;

conforming at least a portion of said adhesive of said tape to said bumps, said backing of said tape has a substanially planar surface after said conforming;

providing a wafer mount having a suction surface;

applying a suction force to said backing of said tape;

removing wafer material from a back surface of said wafer while applying said suction force; and

cutting said wafer to form at least one semiconductor die after said removing wafer material from said back surface.

2. The method of claim 1, removing said adhesive from said wafer prior to said cutting.

3. The method of claim 1, wherein said applying said suction force to said backing of said tape comprises applying a suction force to said substanially planar surface of said backing.

4. The method of claim 1, wherein said applying said suction for to said backing of said tape includes abutting said backing to said suction surface of said wafer mount.

5. The method of claim 1, wherein said wafer comprises a wafer having a thickness of at least about 12 mils.

6. The method of claim 1, wherein said removing comprises thinning said wafer to a thickness in a range of between about 6 mils and about 12 mils.

7. The method of claim 1, wherein said removing comprises thinning said wafer to one of about 6 mils thickness and less than about 6 mils thickness.

8. The method of claim 1, wherein said removing comprises grinding said back surface of said wafer.

9. The method of claim 1, wherein said removing comprises thinning said wafer by chemical-mechanical polishing said back surface of said wafer.

10. A method of holding a wafer having bumps on at least a portion of a surface thereof, comprising:

applying an adhesive to solely a portion of said bumps on said surface of said wafer;

attaching a backing to at least a portion of said adhesive;

conforming at least a portion of said adhesive of said tape to said bumps, said backing of said tape has a substanially planar surface after said conforming;

providing a wafer mount having a suction surface;

holding said backing to said suction surface of said wafer mount using a suction force;

removing wafer material from another surface of said wafer while holding said backing to said suction surface; and

cutting said wafer to form at least one semiconductor die after said removing wafer material from said another surface.

11. The method of claim 10, further comprising:

removing said adhesive from said wafer prior to said cutting.

12. The method of claim 10, wherein said holding said backing to said suction surface of said wafer mount comprises applying said suction force to said substantially planar surface of said backing.

13. The method of claim 10, wherein said holding said backing to said suction surface of said wafer mount comprises abutting at least a portion of said backing to said suction surface of said wafer mount.

14. The method of claim 10, wherein said wafer comprises a wafer having a thickness of at least about 12 mils.

15. The method of claim 10, wherein said removing comprises thinning said wafer to a thickness in a range of about 6 mils to about 12 mils.

16. The method of claim 10, wherein said removing comprises thinning said wafer to one of a thickness of about 6 mils and a thickness of about less than 6 mils.

17. The method of claim 10, wherein said removing comprises grinding said another surface of said wafer.

18. The method of claim 10, wherein said removing comprises thinning said wafer by chemical-mechanical polishing said another surface of said wafer.

19. A method of thinning a wafer comprising:

providing a wafer having bumps on at least a portion of a surface thereof;

attaching an adhesive having a backing to solely a portion of said bumps on said surface of said wafer;

conforming at least a portion of said adhesive of said tape to said bumps, said backing of said tape has a substantially planar surface after said conforming;

providing a wafer mount having a suction surface;

attaching said backing of said adhesive to at least a portion of said suction surface of said wafer mount using a suction force;

removing wafer material from another surface of said wafer while said backing of said adhesive attached to at least a portion of said suction surface; and

cutting said wafer to form at least one semiconductor die after said removing wafer material from said another surface.

20. The method of claim 19, wherein said attaching said backing to at least a portion of said suction surface of said wafer mount comprises applying said suction force to said substantially planar surface of said backing.

21. The method of claim 19, wherein said attaching said backing to at least a portion of said suction surface of said wafer mount comprises abutting at least a portion of said backing to said at least a portion of said suction surface and wherein said suction force attaches said wafer to said wafer mount.

22. The method of claim 19, wherein said wafer comprises a wafer having a thickness of at least about 12 mils.

23. The method of claim 19, wherein said removing comprises thinning said wafer to a thickness in a range of between about 6 mils and about 12 mils.

24. The method of claim 19, wherein said removing comprises thinning said wafer to one of about 6 mils and less than about 6 mils.

25. The method of claim 19, wherein said removing comprises grinding said another surface of said wafer.

26. The method of claim 19, wherein said removing comprises thinning said wafer by chemical-mechanical polishing said another surface of said wafer.

27. A method of fabricating a wafer having a front surface having bumps thereon and a back surface, comprising:

applying an adhesive having a backing onto solely a portion of said bumps;

conforming at least a portion of said adhesive of said tape to said bumps, said backing of said tape has a substantially planar surface after said conforming;

providing a wafer mount having a suction surface;

attaching at least a portion of said backing to at least a portion of said suction surface of said wafer mount using a suction force;

removing wafer material from said back surface of said wafer while said at least a portion of said backing attached to at least a portion of said suction surface; and

cutting said wafer to form at least one semiconductor die after said removing wafer material from said back surface.

28. The method of claim 27, wherein said attaching at least a portion of said backing to at least a portion of said suction surface of said wafer mount comprises applying said suction force to at least a portion of said substantially planar surface of said backing.

29. The method of claim 27, wherein said attaching at least a portion of said backing to at least a portion of said suction surface of said wafer mount comprises abutting at least a portion of said backing to said suction surface and wherein said suction force to attach said wafer to said wafer mount.

30. The method of claim 27, wherein said wafer comprises a wafer having a thickness of at least about 12 mils.

31. The method of claim 27, wherein said removing comprises thinning said wafer to a thickness in a range of between about 6 mils and about 12 mils.

32. The method of claim 27, wherein said removing comprises thinning said wafer to a thickness of one of about 6 mils and less than about 6 mils.

33. The method of claim 27, wherein said removing comprises grinding said back surface of said wafer.

34. The method of claim 27, wherein said removing comprises thinning said wafer by chemical-mechanical polishing said back surface of said wafer.

35. The method of claim 27, further comprising:

removing said adhesive from said wafer.

36. The method of claim 35, wherein said cutting said wafer comprises forming a plurality of semiconductor dies.

37. A method of mounting a bumped wafer having bumps on at least a portion of a surface thereof to a wafer mounting chuck, comprising:

applying an adhesive having a backing to solely a portion of said bumps;

conforming at least a portion of said adhesive of said tape to said bumps, said backing of said tape has a substantially planar surface after said conforming;

mounting said wafer to said wafer mounting chuck using a suction force communicated through said wafer mounting chuck;

removing wafer material from a back surface of said wafer while said wafer mounted to said wafer mounting chuck; and

cutting said wafer to form at least one semiconductor die after said removing wafer material from said back surface.

38. The method of claim 37, wherein said mounting said wafer to said wafer mounting chuck comprises applying said suction force to at least a portion of said substantially planar surface.

39. The method of claim 37, wherein said mounting said wafer to said wafer mounting chuck comprises abutting at least a portion of said backing to a suction surface of said wafer mounting chuck.

40. The method of claim 37, wherein said wafer comprises a wafer having a thickness of at least about 12 mils.

41. A method of using a vacuum to hold a bumped wafer having a front surface having bumps thereon and a back surface, comprising:

applying an adhesive having a backing to solely a portion of said front surface of said wafer covering a portion of at least one bump of said bumps thereon;

conforming at least a portion of said adhesive of said tape to said bumps, said backing of said tape has a substantially planar surface after said conforming;

holding at least a portion of said front surface of said wafer using a vacuum applied through at least a portion of a surface of a wafer mount;

removing wafer material from a back surface of said wafer while holding said at least a portion of said first surface of said wafer using said vacuum; and

cutting said wafer to form at least one semiconductor die after said removing wafer material from said back surface.

42. The method of claim 41, wherein said holding comprises applying said vacuum to said substantially planar surface of said backing.

43. The method of claim 41, wherein said holding comprises abutting at least a portion of said backing to said surface of the wafer mount and wherein said vacuum holds said wafer to said wafer mount.

44. The method of claim 41, wherein said wafer comprises a wafer having a thickness of at least about 12 mils.

45. A method of attaching a wafer having bumps on a surface thereof, comprising:

attaching a tape having an adhesive and a backing on at least a portion of said surface having bumps thereon of said wafer, said tape contacting about 10% to about 60% of the surface area of said bumps;

conforming at least a portion of said adhesive of said tape to said bumps, said backing of said tape having a substantially planar surface after said conforming;

providing a wafer mount having a suction surface;

applying a suction force to said backing of said tape;

removing wafer material from a back surface of said wafer while applying said suction force; and

cutting said wafer to form a plurality of semiconductor dies after removing said wafer material from said back surface.

46. The method of claim 45, further comprising:

removing said adhesive from said wafer prior to said cutting.

47. The method of claim 45, wherein said applying said suction force to said backing of said tape comprises applying a suction force to said substantially planar surface of said backing.

48. The method of claim 45, wherein said applying a suction force to said backing of said tape includes abutting said backing to said suction surface of said wafer mount.

49. The method of claim 45, wherein said wafer comprises a wafer having a thickness of at least about 12 mils.

50. The method of claim 46, wherein said removing comprises thinning said wafer to a thickness in a range of between about 6 mils and about 12 mils.

51. The method of claim 46, wherein said removing comprises thinning said wafer to one about 6 mils thickness and less than about 6 mils thickness.

52. The method of claim 46, wherein said removing comprises grinding said back surface of said wafer.

53. The method of claim 46, wherein said removing comprises thinning said wafer by chemical-mechanical polishing said back surface of said wafer.