Low impedance power distribution structure for a semiconductor chip package

• US 6,661,100 B1
• Filed: 07/30/2002
• Issued: 12/09/2003
• Est. Priority Date: 07/30/2002
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Anderson, Brent A., Knarr, Randolph F., Knickerbocker, Sarah H., Srivastava, Kamalesh K., Sprogis, Edmund J.
• Primary Examiner(s): CLARK, JASMINE JHIHAN B
• Application Number:
  US10/210,631
• Time in Patent Office: 497 Days
• Field of Search: 257/784, 257/778, 257/723, 257/777, 257/691
• US Class Current: 257/784
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• 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 2225/06527 Special adaptation of electrical connections, e.g. rewiring, engineering changes, pressure contacts, layout
• CPC Class Codes: H01L 2225/06555 Geometry of the stack, e.g. form of the devices, geometry to facilitate stacking
• CPC Class Codes: H01L 2225/06586 Housing with external bump or bump-like connectors
• CPC Class Codes: H01L 23/13 characterised by the shape
• CPC Class Codes: H01L 23/49816 Spherical bumps on the substrate for external connection, e.g. ball grid arrays [BGA]
• CPC Class Codes: H01L 23/5286 Arrangements of power or ground buses
• CPC Class Codes: H01L 25/0657 Stacked arrangements of devices
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/3011 Impedance

Abstract

A low impedance power distribution structure and method for substrate packaging of semiconductor chips containing very large scale integrated circuit (VLSI) circuits, such as microprocessors and associated memory, is presented. The power distribution structure incorporates under bump metallurgy (UBM) solder bump forming technology to produce not only solder bump connections that are vertically oriented, but also low impedance distribution wires that are horizontally oriented, and which provide electrical interconnection between various selected electrical contact points, such as solder bumps. These low impedance distribution wires introduce the benefits of low characteristic impedance to the substrate'"'"'s power distribution structure.

Claims

1. A wire structure made from an under bump metallurgy (UTBM) process, said wire structure comprising:

a substrate having a plurality of first features, wherein, said first features are under bump metallurgy;

a plurality of second features situated over at least one of said first features, said second features operatively connected to said first features;

at least one electrical wire interconnecting said plurality of first features, wherein said electrical wire is under bump metallurgy, said electrical wire comprising a metal structure having a low impedance and characterized by having substatiantially the same composition as the first features; and

wherein said first features and said electrical wire are formed in substantially the same plane.

2. The wire structure of claim 1, said electrical wire further comprising a modified under bump metallurgy, said modified tinder bump metallurgy including a capping layer, said capping layer disposed on the surface of the electrical wire.

3. The wire structure of claim 1, wherein said first features are solder bumps, said solder bumps being formed with UBM processing.

4. The wire structure of claim 1, wherein said electrical wire is used for power distribution.

5. The wire structure of claim 1, wherein said electrical wires are about 10 to about 150 microns wide, and wherein said electrical wires are about 1 to about 50 microns tall.

6. An electronic package comprising:

a first substrate having a first surface, said first surface including a plurality of first features;

a second substrate having a second surface, said second surface including a plurality of second features, wherein said second substrate is positioned substantially parallel to said first substrate, and wherein said second surface is located proximal to and facing said first surface;

first electrical wires located on said first surface, said first electrical wires connecting selected ones of said plurality of first features on said first surface, wherein said first features and said first electrical wires are formed in substantially the same first plane;

second electrical wires located on said second surface, said second electrical wires connecting selected ones of said second plurality of second features on said second surface, wherein said second features and said second electrical wires are formed in substantially the same second plane;

wherein said first substrate and said second substrate are operationally bonded together; and

wherein said first electrical wires, said second electrical wires, and said first features are under bump metallurgy (UBM).

7. The electronic package of claim 6, wherein selected ones of said first electrical wires, said second electrical wires, and said first features further comprise a modified under bump metallurgy, said modified under bump metallurgy including a capping layer, said capping layer disposed on the surface of selected ones of the first electrical wires, the second electrical wires, and the first features.

8. The electronic package of claim 6, wherein said first features are solder bumps.

9. The electronic package of claim 6, wherein at least one of said first substrate and said second substrate comprises a semiconductor chip.

10. The electronic package of claim 6, wherein said electronic package comprises a flip-chip package.

11. The electronic package of claim 6, wherein said plurality of electrical wires are selected from the group consisting of rectilinear wires, curvilinear wires, and a combination of rectilinear and curvilinear wires.

12. The electronic package of claim 6, wherein said first electrical wires and said second electrical wires are power distribution wires.

13. The electronic package of claim 6, wherein said first substrate and said second substrate are a master chip and a slave clip, respectively.

14. A method of forming an electronic package comprising:

providing a first substrate having a first surface, said first surface including a plurality of first features;

providing a second substrate having a second surface, said second surface including a plurality of second features, wherein said second substrate is positioned substantially parallel to said first substrate, and wherein said second surface is located proximal to and facing said first surface;

providing first electrical wires located on said first surface, said first electrical wires connecting selected ones of said plurality of first features on said first surface, wherein said first features and said first electrical wires are formed in substantially the same first plane;

providing second electrical wires located on said second surface, said second electrical wires connecting selected ones of said plurality of second features on said second surface, wherein said second features and said second electrical wires are formed in substantially the same second plane;

wherein said first substrate and said second substrate are operationally bonded together; and

forming said first electrical wires, said second electrical wires, said first features, and said second features with under bump metallurgy (UBM) processing.

15. The method of claim 14, wherein said step, of forming said first electrical wires, said second electrical wires, said first features, and said second features with under bump metallurgy (UBM) processing, further includes the step of forming a capping layer on at least one of said first electrical wires, said second electrical wires, said first features, and said second features.

16. The method of forming an electronic package of claim 14, wherein said first features are solder bumps.

17. The method of forming an electronic package of claim 14, wherein at least one of said first substrate and said second substrate comprises a semiconductor chip.

18. The method of forming an electronic package of claim 14, wherein said electronic package comprises a flip-chip package.

19. The method of forming an electronic package of claim 14, wherein said plurality of electrical wires are selected from the group consisting of rectilinear wires, curvilinear wires, and a combination of rectilinear and curvilinear wires.

20. The method of forming an electronic package of claim 14, wherein said first electrical wires and said second electrical wires are power distribution wires.