Thin stacked integrated circuit device

• US 6,137,164 A
• Filed: 09/22/1999
• Issued: 10/24/2000
• Est. Priority Date: 03/16/1998
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Low, Siu Waf, Chan, Min Yu, Yew, Chee Klang
• Primary Examiner(s): Guay, John
• Assistant Examiner(s): Chambliss, Alonzo
• Application Number:
  US09/401,568
• Time in Patent Office: 398 Days
• Field of Search: 257/686, 257/737, 257/738, 257/773, 257/774, 257/777, 257/778, 257/723, 257/779, 257/780, 257/724, 174/258, 174/260, 174/261, 174/262, 361/748, 361/760, 361/767, 361/770, 361/771, 361/792, 361/795
• US Class Current: 257/686
• CPC Class Codes: H01L 2224/05001 Internal layers
• CPC Class Codes: H01L 2224/05026 the internal layer being disposed in a recess of the surface
• CPC Class Codes: H01L 2224/05099 Material
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/4824 Connecting between the body and an opposite side of the item with respect to the body
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73215 Layer and wire connectors
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 2225/0651 Wire or wire-like electrical connections from device to substrate
• CPC Class Codes: H01L 2225/06513 Bump or bump-like direct electrical connections between devices, e.g. flip-chip connection, solder bumps
• CPC Class Codes: H01L 2225/06517 Bump or bump-like direct electrical connections from device to substrate
• CPC Class Codes: H01L 2225/06586 Housing with external bump or bump-like connectors
• CPC Class Codes: H01L 23/49816 Spherical bumps on the substrate for external connection, e.g. ball grid arrays [BGA]
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 25/0657 : Stacked arrangements of devices
• 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 2924/00014 : 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 2924/00015 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01087 : Francium [Fr]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/07811 : Extrinsic, i.e. with electrical conductive fillers
• 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 2924/1532 : the connection portion being formed on the die mounting surface of the substrate
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/16195 : Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 2924/207 : Diameter ranges
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H05K 2201/0212 : Resin particles
• CPC Class Codes: H05K 2201/10234 : Metallic balls solder balls H05K2203/041
• CPC Class Codes: H05K 2203/047 : Soldering with different solders, e.g. two different solders on two sides of the PCB
• CPC Class Codes: H05K 3/3463 : Solder compositions in relation to features of the printed circuit board or the mounting process

Abstract

A thin, stacked face-to-face integrated circuit packaging structure includes a chips attached to both major surfaces of a rigid interposer, and interconnected by printed wiring traces and vias to external solder ball contacts attached to the interposer.

Claims

1. A thin face-to-face stacked integrated circuit packaging structure comprising:

a rigid interposer board having a first surface and a second surface with printed wiring circuits disposed on each surface for mounting an integrated circuit chip on each surface; and

said two integrated circuit chips having an array of electrical terminals connected electrically and mechanically to contact pads on the first and the second surfaces of said interposer board by a conductor having low alpha emissivity; and

said integrated circuits terminals electrically interconnected by printed metal traces on said interposer board to conductive vias between the first and second surfaces; and

said vias terminate in external connectors which comprise solder on the lower (or second) surface of the structure which comprise solder balls; and

said structure having perimeters slightly greater than the larger chip, and the thickness of the structure is in the range of 1.25 mm to 1.5 mm, and the space between said chips and interposer filled with an underfill polymer formulated with an electrically insulating, thermally conductive powder.

2. A device as in claim 1, wherein the electrical terminals of the integrated circuit are connected to the interposer by flip chip reflowed solder.

3. A device as in claim 1, wherein the electrical terminals of the integrated circuit are connected to the interposer by anisotropic conductive adhesive.

4. A device as in claim 3, wherein the anisotropic conductive adhesive has low alpha particle emission.

5. A device as in claim 1, wherein an underfill polymer formulated with an electrically insulating, thermally conductive powder occupies the space between said chips and said interposer.

6. A device as in claim 2, wherein said electrical terminals of each chip are located in an area array, around the perimeter, in the center or any combination thereof.

7. A device as in claim 1, wherein said interposer board comprises a filled polymeric material made of FR-4.

8. A device as in claim 1, wherein said interposer includes more than two levels of printed wiring circuitry.

9. A device as in claim 8, wherein said vias provide a means of interconnection between selected terminals of the two integrated circuits, a means of contact to inner level conductor layers on a circuit board, as well as to the external contacts.

10. A device as in claim 1, wherein one of said integrated circuit chips has a smaller area than the other and the smallest chip is attached to the second or lower surface of said interposer and the largest chip is attached to the upper surface of the interposer.