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US5346857A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for forming a flip-chip bond from a gold-tin eutectic

Assignee: NXP USA Inc
•
Filing: 1992-09-28
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Granted: 1994-09-13
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Expires: 2012-09-28
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Abstract

Abstract A method for flip-chip bonding an integrated circuit die to a substrate. A substrate (21) having conductive bonding areas (22) coated with tin (23) is secured to a bottom end effector of a flip-chip bonding apparatus. An integrated circuit die (26) having gold bumps (28) is secured to a die tool of the flip-chip bonding apparatus. A gold-tin eutectic bond is formed between the integrated circuit die (26) and the conductive bonding areas (22) of the substrate (21).

Inventors

  • 👤 Thomas A. Scharr
  • 👤 Russell T. Lee
  • 👤 Ravichandran Subrahmanyan

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 22:06
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/071; H10W72/072; H10W72/0711; H10W72/07141; H10W72/07231; H10W72/07235; H10W72/07236; H10W72/07251; H10W72/20; H10W72/251; H10W72/252

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 68 words
A method for forming a flip-chip bond from a gold-tin eutectic, comprising the steps of: providing a semiconductor integrated circuit having at least one gold bump; providing a substrate having at least one conductive bonding area, the at least one conductive bonding area coated with tin; and flip-chip bonding the at least one gold bump with the at least one conductive bonding area to form the gold-tin eutectic.
Claim 2
Independent Claim 68 words
A method for forming a flip-chip bond from a gold-tin eutectic, comprising the steps of: providing a semiconductor integrated circuit having at least one gold bump; providing a substrate having at least one conductive bonding area, the at least one conductive bonding area coated with tin; and flip-chip bonding the at least one gold bump with the at least one conductive bonding area to form the gold-tin eutectic.
Claim 3
Dependent Claim 37 words
A method for forming a flip-chip bond from a gold-tin eutectic as claimed in claim 1 wherein the step of providing a semiconductor integrated circuit includes providing the semiconductor integrated circuit in a gallium arsenide semiconductor substrate.
Claim 4
Dependent Claim 31 words
A method of forming a flip-chip bond from a gold-tin eutectic as claimed in claim 1 wherein the step of providing a substrate includes providing a substrate of an organic material.
Claim 5
Dependent Claim 29 words
A method for forming a flip-chip bond from a gold-tin eutectic as claimed in claim 3 wherein the step of providing a substrate includes providing a substrate comprising polyimide.
Claim 6
Dependent Claim 29 words
A method for forming a flip-chip bond from a gold-tin eutectic as claimed in claim 3 wherein the step of providing a substrate includes providing a substrate comprising FR-4.
Claim 7
Dependent Claim 31 words
A method for forming a flip-chip bond from a gold-tin eutectic as claimed in claim 1 wherein the step of providing a substrate includes providing a substrate comprising a ceramic material.
Claim 8
Dependent Claim 80 words
A method for forming a flip-chip bond from a gold-tin eutectic as claimed in claim 1 wherein the step of flip-chip bonding comprises: heating the substrate at approximately 50° C. per second to a temperature ranging between approximately 280° C. and 315° C.; and providing a compression load ranging between approximately 3 and 5 grams per bump, wherein the compression load serves to establish contact between the at least one gold bump and the at least one conductive bonding area.
Claim 9
Dependent Claim 79 words
A flip-chip method for bonding a semiconductor integrated circuit to a circuit board, comprising the steps of: providing a semiconductor integrated circuit having a plurality of gold bumps; providing a circuit board having a plurality of bonding areas, the plurality of bonding areas coated with tin and patterned to mate with the plurality of gold bumps; flip-chip bonding the plurality of gold bumps with the plurality of bonding areas wherein the step of flip-chip bonding forms a gold-tin eutectic.
Claim 10
Dependent Claim 79 words
A flip-chip method for bonding a semiconductor integrated circuit to a circuit board, comprising the steps of: providing a semiconductor integrated circuit having a plurality of gold bumps; providing a circuit board having a plurality of bonding areas, the plurality of bonding areas coated with tin and patterned to mate with the plurality of gold bumps; flip-chip bonding the plurality of gold bumps with the plurality of bonding areas wherein the step of flip-chip bonding forms a gold-tin eutectic.
Claim 11
Dependent Claim 60 words
A flip-chip method for bonding a semiconductor integrated circuit to a circuit board as claimed in claim 8 wherein the step of flip-chip bonding includes: providing a temperature between approximately 280° C. and 315° C.; and providing a compression load ranging between approximately 3 and 5 grams per bump for a time ranging between substantially 3 seconds and 10 seconds.
Claim 12
Dependent Claim 35 words
A flip-chip method for bonding a semiconductor integrated circuit to a circuit board as claimed in claim 8 wherein the step of providing a semiconductor integrated circuit includes providing a gallium arsenide semiconductor integrated circuit.
Claim 13
Dependent Claim 32 words
A flip-chip method for bonding a semiconductor integrated circuit to a circuit board as claimed in claim 8 wherein the step of providing a circuit board includes providing an FR-4 circuit board.
Claim 14
Dependent Claim 32 words
A flip-chip method for bonding a semiconductor integrated circuit to a circuit board as claimed in claim 8 wherein the step of providing a circuit board includes providing a polyimide circuit board.

References Cited (Backward Citations)

US3874072A Cited
US4129042A Cited
US4887760A Cited
US5108950A Cited
US5008997A Cited
US4922322A Cited
US5090609A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-09-12 1998-03-14 1998-09-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-09-12 2002-03-14 2002-09-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-09-12 2006-03-14 2006-09-13 $7700.00 Window Closed / Lapsed

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