US5431328A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite bump flip chip bonding
Assignee: Industrial Technology Research Institute
•
Filing: 1994-05-06
•
Granted: 1995-07-11
•
Expires: 2014-05-06
Abstract
Abstract A bonded structure comprising the physical and electrical connections between an integrated circuit element and substrate using a composite bump comprised of a single polymer body of low Young's Modulus, a conductive barrier metal coating covering the polymer body and a soldering metal coating covering the conductive barrier metal coating. When the bonded structure is formed the composite bump is deformed and the low Young's Modulus of the polymer body allows a very reliable bonded structure with very low bonding force. Due to the low Young's Modulus there is little stress tending to break the solder joint after the bonded structure is formed. The bond is formed using a soldering process so that the soldering metal forms a conductive adhesive between the composite bumps and either the substrate input/output pads or the integrated circuit element input/output pads.
Inventors
- 👤 Shyh-Ming Chang
- 👤 Chih-Chiang Chu
- 👤 Yu-Chi Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:16
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/20; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/341; H05K3/3431; H05K3/3436; H05K2201/00; H05K2201/02; H05K2201/0203; H05K2201/0206; H05K2201/0212; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/251; H10W72/252; H10W72/90; H10W72/921; H10W72/923; H10W72/951; H10W72/952; Y; Y02; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
153 words
A method for forming a bonded structure, comprising: providing an integrated circuit element with input/output pads; providing a single polymer body on each said integrated circuit element input/output pad wherein the cross section area of said single polymer body on said integrated circuit element input/output pad is smaller than that of said integrated circuit element input/output pad; providing a conductive metal coating upon said single polymer body and covering said integrated circuit element input/output pad wherein each said single polymer body and said coductive metal coating comprises a composite bump; providing a substrate with input/output pads; providing a soldering metal; bringing together said composite bumps formed on said integrated circuit element input/output pads, said substrate input/output pads, and said soldering metal; heating said soldering metal to a temperature of about 30° C. above the melting point of said soldering metal; and cooling said soldering metal below the melting point of said soldering metal.
Claim 2
Independent Claim
153 words
A method for forming a bonded structure, comprising: providing an integrated circuit element with input/output pads; providing a single polymer body on each said integrated circuit element input/output pad wherein the cross section area of said single polymer body on said integrated circuit element input/output pad is smaller than that of said integrated circuit element input/output pad; providing a conductive metal coating upon said single polymer body and covering said integrated circuit element input/output pad wherein each said single polymer body and said coductive metal coating comprises a composite bump; providing a substrate with input/output pads; providing a soldering metal; bringing together said composite bumps formed on said integrated circuit element input/output pads, said substrate input/output pads, and said soldering metal; heating said soldering metal to a temperature of about 30° C. above the melting point of said soldering metal; and cooling said soldering metal below the melting point of said soldering metal.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein said polymer is polyamic acid polyimide.
Claim 4
Dependent Claim
61 words
The method of claim 1 wherein said conductive metal coating is a composite of 500 Angstroms chrome/500 Angstroms copper/2000 Angstroms gold and said conductive metal coating and said single polymer body of said composite bumps have such material and thickness characteristics that said composite bumps are permanently deformed and crushed into permanent physical and electrical contact with said substrate input/output pads.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein said soldering metal is 95% lead-5% tin.
Claim 6
Dependent Claim
21 words
The method of claim 1 wherein said soldering metal is formed on said composite bumps prior to heating said soldering metal.
Claim 7
Dependent Claim
22 words
The method of claim 1 wherein said soldering metal is formed on said substrate input/output pads prior to heating said soldering metal.
Claim 8
Independent Claim
146 words
A method for forming a bonded structure, comprising: providing a substrate with input/output pads; providing a single polymer body on each said substrate input/output pad, wherein the cross section area of said single polymer body on said substrate input/output pad is smaller than that of said integrated circuit element input/output pad; providing a conductive metal coating upon said single polymer body and covering said substrate input/output wherein each said single polymer body and said conductive metal coating comprises a composite bump; providing an integrated circuit element with input/output pads; providing a soldering metal; bringing together said composite bumps formed on said substrate input/output pads, said integrated circuit element input/output pads, and said soldering metal; heating said soldering metal to a temperature of about 30° C. above the melting point of said soldering metal; and cooling said soldering metal below the melting point of said soldering metal.
Claim 9
Independent Claim
146 words
A method for forming a bonded structure, comprising: providing a substrate with input/output pads; providing a single polymer body on each said substrate input/output pad, wherein the cross section area of said single polymer body on said substrate input/output pad is smaller than that of said integrated circuit element input/output pad; providing a conductive metal coating upon said single polymer body and covering said substrate input/output wherein each said single polymer body and said conductive metal coating comprises a composite bump; providing an integrated circuit element with input/output pads; providing a soldering metal; bringing together said composite bumps formed on said substrate input/output pads, said integrated circuit element input/output pads, and said soldering metal; heating said soldering metal to a temperature of about 30° C. above the melting point of said soldering metal; and cooling said soldering metal below the melting point of said soldering metal.
Claim 10
Dependent Claim
12 words
The method of claim 7 wherein said polymer is polyamic acid polyimide.
Claim 11
Dependent Claim
63 words
The method of claim 7 wherein said conductive metal coating is a composite of 500 Angstroms chrome/500 Angstroms copper/2000 Angstroms gold and said conductive metal coating and said single polymer body of said composite bumps have such material and thickness characteristics that said composite bumps are permanently deformed and crushed into permanent physical and electrical contact with said integrated circuit element input/output pads.
Claim 12
Dependent Claim
13 words
The method of claim 7 wherein said soldering metal is 95% lead-5% tin.
Claim 13
Dependent Claim
21 words
The method of claim 7 wherein said soldering metal is formed on said composite bumps prior to heating said soldering metal.
Claim 14
Dependent Claim
24 words
The method of claim 7 wherein said soldering metal is formed on said integrated circuit element input/output pads prior to heating said soldering metal.
References Cited (Backward Citations)
US3401126A
Cited
US3809625A
Cited
US4402450A
Cited
US4705205A
Cited
US5134460A
Cited
US4749120A
Cited
US4963002A
Cited
US4916523A
Cited
US4903889A
Cited
US5329423A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-07-10 | 1999-01-09 | 1999-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-10 | 2003-01-09 | 2003-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-10 | 2007-01-09 | 2007-07-11 | $7700.00 | Window Closed / Lapsed |