Microelectronic assemblies having compliancy

• US 20060194365A1
• Filed: 02/23/2006
• Published: 08/31/2006
• Est. Priority Date: 02/25/2005
• Status: Active Grant

• Current Assignee: Tessera, Inc. (Adeia Inc.)
• Original Assignee: Tessera, Inc. (Adeia Inc.)
• Inventors: Haba, Belgacem
• Granted Patent: US 7,999,379 B2
• Time in Patent Office: Days
• US Class Current: 438/106
• CPC Class Codes: G01R 31/2896 Testing of IC packages; Test features related to IC packages containers per se H01L23/02, encapsulations per se H01L23/28
• CPC Class Codes: H01L 2224/0231 Manufacturing methods of the redistribution layers
• CPC Class Codes: H01L 2224/0233 Structure of the redistribution layers
• CPC Class Codes: H01L 2224/0236 Shape of the insulating layers therebetween
• CPC Class Codes: H01L 2224/0239 Material of the redistribution layers
• CPC Class Codes: H01L 2224/024 Material of the insulating layers therebetween
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/0554 External layer
• CPC Class Codes: H01L 2224/1132 Screen printing, i.e. using a stencil
• CPC Class Codes: H01L 2224/1147 using a lift-off mask
• CPC Class Codes: H01L 2224/13016 in side view
• CPC Class Codes: H01L 2224/13023 the whole bump connector protruding from the surface
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/13147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/29099 Material
• CPC Class Codes: H01L 2224/81801 Soldering or alloying
• CPC Class Codes: H01L 23/3114 the device being a chip scale package, e.g. CSP
• CPC Class Codes: H01L 23/3171 the coating being directly applied to the semiconductor body, e.g. passivation layer H01L23/3178 takes precedence
• CPC Class Codes: H01L 23/525 with adaptable interconnections
• CPC Class Codes: H01L 24/03 : Manufacturing methods
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• CPC Class Codes: H01L 24/11 : Manufacturing methods for bumps on insulating substrates H01L21/4853
• CPC Class Codes: H01L 24/13 : of an individual bump connector
• CPC Class Codes: H01L 24/16 : of an individual bump connector
• CPC Class Codes: H01L 24/81 : using a bump connector
• CPC Class Codes: H01L 2924/00013 : Fully indexed content
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01024 : Chromium [Cr]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01076 : Osmium [Os]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/014 : Solder alloys

Abstract

A microelectronic assembly includes a microelectronic element, such as a semiconductor wafer or semiconductor chip, having a first surface and contacts accessible at the first surface, and a compliant layer overlying the first surface of the microelectronic element, the compliant layer having openings in substantial alignment with the contacts of the microelectronic element. The assembly desirably includes conductive posts overlying the compliant layer and projecting away from the first surface of the microelectronic element, the conductive posts being electrically interconnected with the contacts of the microelectronic element by elongated, electrically conductive elements extending between the contacts and the conductive posts.

Claims

1. A microelectronic assembly comprising:

a microelectronic element having a first surface and contacts accessible at the first surface;

a compliant layer overlying the first surface of said microelectronic element;

conductive posts overlying said compliant layer and projecting away from the first surface of said microelectronic element, wherein said conductive posts are electrically interconnected with said contacts of said microelectronic element.

2. The assembly as claimed in claim 1, wherein said conductive posts have tips that define the highest point on said assembly.

3. The assembly as claimed in claim 1, wherein said compliant layer has openings in substantial alignment with said contacts of said microelectronic element.

4. The assembly as claimed in claim 3, further comprising conductive traces passing through the openings in said compliant layer for electrically interconnecting said conductive posts and said contacts of said microelectronic element.

5. The assembly as claimed in claim 1, wherein said microelectronic element is a semiconductor wafer.

6. The assembly as claimed in claim 1, wherein said microelectronic element is a semiconductor chip.

7. The assembly as claimed in claim 1, further comprising a dielectric passivation layer disposed between the first surface of said microelectronic element and said compliant layer.

8. The assembly as claimed in claim 1, wherein said compliant layer comprises a material having a low modulus of elasticity.

9. The assembly as claimed in claim 1, wherein said compliant layer comprises a dielectric material.

10. The assembly as claimed in claim 1, wherein said compliant layer comprises a material selected from the group consisting of silicones, flexibilized epoxies, polyimides, thermosetting polymers, fluoropolymers and thermoplastic polymers.

11. The assembly as claimed in claim 1, wherein said compliant layer has a top surface and a sloping surface extending between the top surface of said compliant layer and the first surface of said microelectronic element.

12. The assembly as claimed in claim 11, wherein the top surface of said compliant layer is substantially flat.

13. The assembly as claimed in claim 12, wherein said compliant layer has a sloping transition surface extending between the substantially flat top surface of said compliant layer and the first surface of said microelectronic element, and wherein the sloping transition surface includes at least one curved surface.

14. The assembly as claimed in claim 13, wherein the at least one curved surface includes a curved surface extending from the first surface of said microelectronic element.

15. The assembly as claimed in claim 13, wherein the at least one curved surface includes a curved surface extending from the top surface of said compliant layer.

16. The assembly as claimed in claim 1, further comprising elongated, electrically conductive elements for electrically interconnecting said conductive posts and said contacts of said microelectronic element.

17. The assembly as claimed in claim 16, wherein said elongated, electrically conductive elements comprises materials selected from the group consisting of copper, gold, nickel and alloys, combinations and composites thereof.

18. The assembly as claimed in claim 16, wherein said elongated, electrically conductive elements are selected from the group consisting of bond ribbons and traces.

19. The assembly as claimed in claim 16, wherein said elongated, electrically conductive elements extend over said compliant layer.

20. The assembly as claimed in claim 1, wherein said compliant layer comprises a plurality of compliant bumps overlying the first surface of said microelectronic element.

21. The assembly as claimed in claim 20, wherein at least one of said conductive posts is disposed atop at least one of said compliant bumps.

22. The assembly as claimed in claim 20, wherein said conductive posts are disposed atop said compliant bumps.

23. The assembly as claimed in claim 1, wherein each said conductive post has a base adjacent said compliant layer and a tip remote from said compliant layer.

24. The assembly as claimed in claim 1, wherein each said conductive post has a height of about 50-300 micrometers.

25. The assembly as claimed in claim 23, wherein at least one of said conductive posts has a frustoconical shape with the base having a diameter of about 100-600 micrometers and the tip having a diameter of about 40-200 micrometers.

26. The assembly as claimed in claim 1, wherein said conductive posts comprise an electrically conductive material.

27. The assembly as claimed in claim 1, wherein said conductive posts comprise materials selected from the group consisting of copper, copper alloys, gold and combinations thereof.

28. A microelectronic assembly comprising:

a microelectronic element having a first surface and contacts accessible at the first surface;

a compliant layer overlying the first surface of said microelectronic element, said compliant layer having a top surface spaced from the first surface of said microelectronic element;

conductive posts overlying the top surface of said compliant layer and projecting away from the first surface of said microelectronic element;

elongated, conductive elements electrically interconnecting said conductive posts and said contacts of said microelectronic element.

29. The assembly as claimed in claim 28, wherein said microelectronic element is a semiconductor wafer.

30. The assembly as claimed in claim 28, wherein said microelectronic element is a semiconductor chip.

31. The assembly as claimed in claim 28, wherein said compliant layer comprises a plurality of compliant bumps and each said conductive post is disposed atop one of said conductive bumps.

32. The assembly as claimed in claim 28, wherein said compliant layer has openings in alignment with said contacts of said microelectronic element, said openings defining sloping surfaces of said compliant layer extending from the first surface of said microelectronic element to the top surface of said compliant layer, wherein said elongated, conductive elements overlie the sloping surfaces of said compliant layer.

33. A microelectronic assembly comprising:

a microelectronic element having a first surface and contacts accessible at the first surface;

a plurality of compliant bumps overlying the first surface of said microelectronic element, each of said compliant bumps being disposed adjacent one of said contacts of said microelectronic element;

conductive posts overlying said microelectronic element and projecting away from the first surface of said microelectronic element;

conductive traces electrically interconnecting said conductive posts and said contacts of said microelectronic element, wherein said compliant bumps enable said conductive posts to move relative to said contacts of said microelectronic element.

34. The assembly as claimed in claim 33, wherein said compliant bumps have top surfaces that are spaced from the first surface of said microelectronic element and sloping surfaces that extend between the top surfaces of said compliant bumps and the first surface of said microelectronic element.

35. The assembly as claimed in claim 34, wherein said conductive traces extend over the sloping surfaces of said compliant bumps.