US6082610A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming interconnections on electronic modules
Assignee: Visteon Global Technologies Inc
•
Filing: 1997-06-23
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Granted: 2000-07-04
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Expires: 2017-06-23
Abstract
Abstract A method which utilizes flip chip technology to provide interconnection between printed circuit boards and integrated circuits is disclosed. The method involves metallization of the bond pad and multiple, novel bump compositions and coating compositions to provide an interconnection which is reliable and which withstands differences in the coefficient of thermal expansion between the silicon device and the bump material.
Inventors
- 👤 Dongkai Shangguan
- 👤 Mohan Paruchuri
- 👤 Achyuta Achari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:23
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/20; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/346; H10W70/00; H10W70/60; H10W70/62; H10W70/66; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/251; H10W72/252; H10W72/90; H10W72/921; H10W72/923; H10W72/941; H10W72/9415; H10W72/951; H10W72/952; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49144
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
109 words
A method of forming an interconnection between a printed wiring board and an integrated circuit for automotive applications, comprising: forming a via bond pad on the integrated circuit; forming a flip chip bump with a first metal on said via bond pad wherein said first metal is zinc; providing a substrate pad on the printed wiring board; applying a coating of a second metal on said substrate pad wherein said second metal is tin; and forming an interconnection between said first metal and said second metal to bond the printed wiring board and the integrated circuit wherein said interconnection is lead-free and has a eutectic temperature above 170° C.
Claim 2
Independent Claim
109 words
A method of forming an interconnection between a printed wiring board and an integrated circuit for automotive applications, comprising: forming a via bond pad on the integrated circuit; forming a flip chip bump with a first metal on said via bond pad wherein said first metal is zinc; providing a substrate pad on the printed wiring board; applying a coating of a second metal on said substrate pad wherein said second metal is tin; and forming an interconnection between said first metal and said second metal to bond the printed wiring board and the integrated circuit wherein said interconnection is lead-free and has a eutectic temperature above 170° C.
Claim 3
Dependent Claim
17 words
The method of claim 1, wherein said first metal is zinc and said second metal is tin.
Claim 4
Dependent Claim
16 words
The method of claim 2, wherein said zinc has a thickness between 25 and 75 μm.
Claim 5
Dependent Claim
17 words
The method of claim 2, wherein said tin coating has a thickness between 7.62 and 10.16 μm.
Claim 6
Dependent Claim
38 words
The method of claim 2, wherein said step of forming an interconnection comprises forming a eutectic phase between said first and second metal by heating to obtain a temperature in the range of 240° C. and 290° C.
Claim 7
Dependent Claim
23 words
The method of claim 1, wherein a barrier layer is sandwiched between said substrate pad and said second metal to prevent diffusion therebetween.
Claim 8
Dependent Claim
19 words
The method of claim 6, said barrier layer comprising nickel with a thickness in the range of 2.29-7.62 μm.
Claim 9
Dependent Claim
22 words
The method of claim 1, wherein an oxidation prevention layer is placed in contact with said second metal layer to prevent oxidation.
Claim 10
Dependent Claim
20 words
The method of claim 8, wherein said oxidation prevention layer comprises gold having a thickness between 0.13 and 0.51 μm.
Claim 11
Dependent Claim
11 words
The method of claim 1, wherein said substrate pad comprises copper.
Claim 12
Dependent Claim
19 words
The method of claim 1, wherein a gold coating is applied to said flip chip bump for oxidation protection.
Claim 13
Dependent Claim
16 words
The method of claim 1, wherein an epoxy underfill is used on said flip chip bump.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-07-04 | 2004-01-03 | 2004-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-07-04 | 2008-01-03 | 2008-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-07-04 | 2012-01-03 | 2012-07-04 | $7700.00 | Window Closed / Lapsed |