Semiconductor flip-chip assembly with pre-applied encapsulating layers

• US 6,297,560 B1
• Filed: 08/21/1998
• Issued: 10/02/2001
• Est. Priority Date: 10/31/1996
• Status: Expired due to Term

• Current Assignee: Invensas Corporation
• Original Assignee: Miguel Albert Capote
• Inventors: Zhu, Xiaoqi, Capote, Miguel A.
• Primary Examiner(s): Lee, Eddie
• Assistant Examiner(s): Warren, Matthew E.
• Application Number:
  US09/137,971
• Time in Patent Office: 1,138 Days
• Field of Search: 257/778, 257/777, 257/780, 257/782, 257/786, 257/773, 257/701, 257/779, 257/783, 257/785, 257/789, 257/795
• US Class Current: 257/778
• CPC Class Codes: B23K 35/025 Pastes, creams, slurries
• CPC Class Codes: B23K 35/3613 Polymers, e.g. resins
• CPC Class Codes: B23K 35/3618 Carboxylic acids or salts
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: C08F 222/104 of tetraalcohols, e.g. pentaerythritol tetra(meth)acrylate
• CPC Class Codes: C08F 222/20 Esters containing oxygen in addition to the carboxy oxygen
• CPC Class Codes: C09J 4/00 Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16
• CPC Class Codes: H01L 21/563 Encapsulation of active face of flip-chip device, e.g. underfilling or underencapsulation of flip-chip, encapsulation preform on chip or mounting substrate
• CPC Class Codes: H01L 2224/02379 Fan-out arrangement
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/06102 the bonding areas being at different heights
• CPC Class Codes: H01L 2224/1147 using a lift-off mask
• CPC Class Codes: H01L 2224/1148 Permanent masks, i.e. masks left in the finished device, e.g. passivation layers
• CPC Class Codes: H01L 2224/1182 Applying permanent coating, e.g. in-situ coating
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/13111 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/1403 Bump connectors having different sizes, e.g. different diameters, heights or widths
• CPC Class Codes: H01L 2224/16105 the bump connector connecting bonding areas being not aligned with respect to each other
• CPC Class Codes: H01L 2224/16108 the bump connector not being orthogonal to the surface
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/274 : by blanket deposition of the material of the layer connector
• CPC Class Codes: H01L 2224/27436 : Lamination of a preform, e.g. foil, sheet or layer
• CPC Class Codes: H01L 2224/27602 : Mechanical treatment, e.g. polishing, grinding
• CPC Class Codes: H01L 2224/27614 : by chemical means only
• CPC Class Codes: H01L 2224/27618 : with selective exposure, development and removal of a photosensitive layer material, e.g. of a photosensitive conductive resin
• CPC Class Codes: H01L 2224/29 : of an individual layer connector
• CPC Class Codes: H01L 2224/29082 : Two-layer arrangements
• CPC Class Codes: H01L 2224/29099 : Material
• CPC Class Codes: H01L 2224/29101 : the principal constituent melting at a temperature of less than 400°C
• CPC Class Codes: H01L 2224/29111 : Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/2919 : with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29199 : Material of the matrix
• CPC Class Codes: H01L 2224/2929 : with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29299 : Base material
• CPC Class Codes: H01L 2224/29562 : On the entire exposed surface of the core
• CPC Class Codes: H01L 2224/2969 : with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/32225 : the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73104 : the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73204 : the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/81011 : Chemical cleaning, e.g. etching, flux
• CPC Class Codes: H01L 2224/81024 : Applying flux to the bonding area
• CPC Class Codes: H01L 2224/8121 : using a reflow oven
• CPC Class Codes: H01L 2224/81815 : Reflow soldering
• CPC Class Codes: H01L 2224/83101 : as prepeg comprising a layer connector, e.g. provided in an insulating plate member
• CPC Class Codes: H01L 2224/83191 : wherein the layer connectors are disposed only on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/83192 : wherein the layer connectors are disposed only on another item or body to be connected to the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/83193 : wherein the layer 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 2224/83856 : Pre-cured adhesive, i.e. B-stage adhesive
• CPC Class Codes: H01L 23/293 : Organic, e.g. plastic
• CPC Class Codes: H01L 23/4334 : Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 23/49827 : Via connections through the substrates, e.g. pins going through the substrate, coaxial cables H01L23/49822, H01L23/49833, H01L23/4985, H01L23/49861 take precedence
• CPC Class Codes: H01L 23/49883 : the conductive materials containing organic materials or pastes, e.g. for thick films for printed circuits H05K1/092
• CPC Class Codes: H01L 24/11 : Manufacturing methods for bumps on insulating substrates H01L21/4853
• CPC Class Codes: H01L 24/29 : of an individual layer connector
• CPC Class Codes: H01L 24/81 : using a bump connector
• CPC Class Codes: H01L 24/83 : using a layer connector
• 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 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00013 : Fully indexed content
• 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 2924/01004 : Beryllium [Be]
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01018 : Argon [Ar]
• CPC Class Codes: H01L 2924/0102 : Calcium [Ca]
• CPC Class Codes: H01L 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01025 : Manganese [Mn]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/0103 : Zinc [Zn]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01039 : Yttrium [Y]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01045 : Rhodium [Rh]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01051 : Antimony [Sb]
• 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 2924/0132 : Binary Alloys
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/01327 : Intermediate phases, i.e. intermetallics compounds
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/0781 : being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/1579 : with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2924/3511 : Warping
• CPC Class Codes: H01L 2924/3512 : Cracking
• CPC Class Codes: H05K 1/095 : for polymer thick films, i.e. having a permanent organic polymeric binder
• CPC Class Codes: H05K 3/321 : by conductive adhesives

Abstract

A simplified process for flip-chip attachment of a chip to a substrate is provided by pre-coating the chip with an encapsulant underfill material having separate discrete solder columns therein to eliminate the conventional capillary flow underfill process. There is also provided a flip-chip configuration having a flexible tape lamination for underfill encapsulation. With this configuration, the complaint solder/flexible encapsulant understructure absorbs the strain caused by the difference in the thermal coefficients of expansion between the chip and the substrate and provides enhanced ruggedness.

Claims

1. An electrical component assembly, comprising:

(a) a substrate having a plurality of pads on a first surface thereof;

(b) an integrated circuit chip having an encapsulant on an active surface thereof, the encapsulant comprising a first encapsulant portion laminated film having a plurality of holes there through filled with an electrically conductive material that extends from contacts on the active surface aligned with the holes through the encapsulant to the plurality of pads on the substrate; and

(c) a second encapsulant portion of flux adhesive between the substrate and a subassembly comprising the encapsulant and the electrically conductive material.

2. The electrical component assembly of claim 1 wherein the electrically conductive material in the plurality of holes comprises solder.

3. The electrical component assembly of claim 1 wherein the first portion of the encapsulant and the electrically conductive material are located on the integrated circuit chip and the second portion is located on the substrate.

4. The electrical component assembly of claim 3 wherein the first portion comprises a polymeric adhesive and a filler.

5. The electrical component assembly of claim 1 wherein the first portion of the encapsulant and the electrically conductive material are located on the integrated circuit chip and the second portion is coated on the first portion.

6. The electrical component assembly of claim 1 wherein the encapsulant includes a polymer layer that can be remelted after assembly of the electrical component assembly to allow removal of the integrated circuit chip for repair or replacement.

7. The electrical component assembly of claim 1 wherein the encapsulant includes a printed circuit layer having electrical circuitry thereon.

8. An electrical component assembly, comprising:

(a) a substrate having a plurality of pads on a first surface thereof; and

(b) an integrated circuit chip having an encapsulant on an active surface thereof, the encapsulant having a plurality of holes therethrough filled with an electrically conductive material that extends from contacts on the active surface aligned with the holes through the encapsulant to the plurality of pads on the substrate, wherein a first portion of the encapsulant and the electrically conductive material are located on the integrated circuit chip and a second portion is located on the substrate, the first portion comprising a first encapsulant portion laminated film and the second portion comprises a flux adhesive.

9. The electrical component assembly of claim 8 wherein the electrically conductive material in the plurality of holes comprises solder.

10. The electrical component assembly of claim 8 wherein the first portion comprises a polymeric adhesive and a filler.

11. The electrical component assembly of claim 8 wherein the first portion of the encapsulant and the electrically conductive material are located on the integrated circuit chip and the second portion is coated on the first portion.

12. The electrical component assembly of claim 8 wherein the encapsulant includes a polymer layer that can be remelted after assembly of the electrical component assembly to allow removal of the integrated circuit chip for repair or replacement.

13. The electrical component assembly of claim 8 wherein the encapsulant includes a printed circuit layer having electrical circuitry thereon.

14. An electrical component assembly, comprising:

(a) a substrate having a plurality of pads on a first surface thereof; and

(b) an integrated circuit chip having an encapsulant on an active surface thereof, the encapsulant having a plurality of holes therethrough filled with an electrically conductive material that extends from contacts on the active surface aligned with the holes through the encapsulant to the plurality of pads on the substrate, and wherein the encapsulant includes a first portion comprising a printed circuit layer having electrical circuitry thereon and the first portion comprises a laminated film.

15. The electrical component assembly of claim 14 wherein the electrically conductive material in the plurality of holes comprises solder.

16. The electrical component assembly of claim 14 further comprising a second portion of flux adhesive between a subassembly comprising the encapsulant, the electrically conductive material, and the substrate.

17. The electrical component assembly of claim 14 wherein the first portion comprises a polymeric adhesive and a filler.

18. The electrical component assembly of claim 14 wherein the first portion of the encapsulant and the electrically conductive material are located on the integrated circuit chip and the second portion is located on the substrate.

19. The electrical component assembly of claim 18 wherein the second portion comprises an adhesive material with solder fluxing properties.

20. The electrical component assembly of claim 14 wherein the first portion of the encapsulant and the electrically conductive material are located on the integrated circuit chip and the second portion is coated on the first portion.

21. The electrical component assembly of claim 14 wherein the encapsulant includes a polymer layer that can be remelted after assembly of the electrical component assembly to allow removal of the integrated circuit chip for repair or replacement.

22. An electrical component assembly, comprising:

(a) an integrated circuit chip having a plurality of pads on an active surface thereof; and

(b) a substrate having an encapsulant on a first surface thereof, the encapsulant having a plurality of holes therethrough filled with an electrically conductive material that extends from contacts on the first surface aligned with the holes through the encapsulant to the plurality of pads on the integrated circuit chip, wherein a first portion of the encapsulant and the electrically conductive material are located on the substrate and a second portion is located on the integrated circuit chip, the first portion comprises a laminated film and the second portion comprises an adhesive flux.

23. The electrical component assembly of claim 22 wherein the electrically conductive material in the plurality of holes comprises solder.

24. The electrical component assembly of claim 22 wherein the first portion comprises a polymeric adhesive and a filler.

25. The electrical component assembly of claim 22 wherein the first portion of the encapsulant and the electrically conductive material are located on the substrate and the second portion is coated on the first portion.

26. The electrical component assembly of claim 22 wherein the encapsulant includes a polymer layer that can be remelted after assembly of the electrical component assembly to allow removal of the integrated circuit chip for repair or replacement.

27. The electrical component assembly of claim 22 wherein the encapsulant includes a printed circuit layer having electrical circuitry thereon.

28. An integrated circuit assembly comprising:

(a) at least one integrated circuit device having an active surface with a plurality of separate discrete solderable contacts thereon;

(b) a plurality of discrete solder bumps positioned on the active surface of the integrated circuit device such that one or more of the solderable contacts has a solder bump associated with it, said solder bumps electrically interconnected with its associated contact pad; and

(c) an encapsulant comprising at least two portions wherein

(i) a first portion comprises a laminated film; and

(ii) a second portion comprises an adhesive flux.

29. The integrated circuit assembly of claim 28 wherein the first portion comprises a polymer and an inorganic filler.

30. The integrated circuit assembly of claim 28 wherein the second portion encapsulant contains little or no filler.

31. The integrated circuit assembly of claim 28 wherein the first portion covers at least a portion of the surface of the integrated circuit device and lies between the solder bumps.

32. The integrated circuit assembly of claim 28 wherein the solder bumps protrude beyond the first portion.

33. The integrated circuit assembly of claim 28 wherein the encapsulant comprises at least one portion that can be remelted sufficiently to allow removal of the device after it has been assembled to the substrate.

34. The electrical component assembly of claim 28 wherein the encapsulant includes a printed circuit layer having electrical circuitry thereon.

35. The integrated circuit assembly of claim 28 wherein the second portion comprises an adhesive flux encapsulant comprising carboxylic acid moieties for fluxing and polymerizable moieties for crosslinking.