US5280414A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Au-Sn transient liquid bonding in high performance laminates
Assignee: International Business Machines Corp
•
Filing: 1990-06-11
•
Granted: 1994-01-18
•
Expires: 2010-06-11
Abstract
Abstract A method is disclosed of simultaneously laminating circuitized dielectric layers to form a multilayer high performance circuit board and making interlevel electrical connections. The method selects two elements which will form a eutectic at one low temperature and will solidify to form an alloy which will only remelt at a second temperature higher than any required by any subsequent lamination. The joint is made using a transient liquid bonding technique and sufficient Au and Sn to result in a Au-Sn20wt% eutectic at the low temperature. Once solidified, the alloy formed remains solid throughout subsequent laminations. As a result, a composite, multilayer, high performance circuit board is produced, electrically joined at selected lands by the solid alloy.
Inventors
- 👤 Charles R. Davis
- 👤 Richard Hsiao
- 👤 James R. Loomis
- 👤 Jae M. Park
- 👤 Jonathan D. Reid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:34
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/24; B23K35/30; B23K35/3013; B23K35/001; H; H01; H01R; H01R4/00; H01R4/02; H05; H05K; H05K3/00; H05K3/46; H05K3/4611; H05K3/4614; H05K2201/00; H05K2201/03; H05K2201/0302; H05K2201/0305; H05K3/22; H05K3/28; H05K3/30; H05K3/32; H05K3/328; H05K3/40; H05K3/4038; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T156/00; Y10T156/10; Y10T156/1052; Y10T156/1056; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49126
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
100 words
An apparatus, comprising: at least a first dielectric layer including a through hole, containing electrically conductive material, terminating in a first electrically conductive land; at least a second dielectric layer including a second electrically conductive land, which second dielectric layer is laminated to said first dielectric layer; and means for electrically connecting said first and second lands, said means including a region of material having a composition which includes a metallic, non-eutectic alloy, essentially free of flux, said region of material having a melting point which is higher than the lamination temperature associated with said first and second dielectric layers.
Claim 2
Independent Claim
100 words
An apparatus, comprising: at least a first dielectric layer including a through hole, containing electrically conductive material, terminating in a first electrically conductive land; at least a second dielectric layer including a second electrically conductive land, which second dielectric layer is laminated to said first dielectric layer; and means for electrically connecting said first and second lands, said means including a region of material having a composition which includes a metallic, non-eutectic alloy, essentially free of flux, said region of material having a melting point which is higher than the lamination temperature associated with said first and second dielectric layers.
Claim 3
Dependent Claim
15 words
The apparatus recited in claim 1, further comprising at least one semiconductor device mounted thereupon.
Claim 4
Dependent Claim
13 words
The apparatus recited in claim 1, wherein said region of material includes gold.
Claim 5
Dependent Claim
13 words
The apparatus recited in claim 1, wherein said region of material includes tin.
Claim 6
Dependent Claim
14 words
The apparatus recited in claim 1, wherein said apparatus is a printed circuit board.
Claim 7
Independent Claim
91 words
An apparatus, comprising: at least a first dielectric layer including a first electrically conductive land; at least a second dielectric layer including a second electrically conductive land, which second dielectric layer is laminated to said first dielectric layer; and means for electrically connecting said first and second lands, said means including a region of material having a composition which includes a metallic, non-eutectic alloy, essentially free of flux, said region of material having a melting point which is higher than the lamination temperature associated with said first and second dielectric layers.
Claim 8
Independent Claim
91 words
An apparatus, comprising: at least a first dielectric layer including a first electrically conductive land; at least a second dielectric layer including a second electrically conductive land, which second dielectric layer is laminated to said first dielectric layer; and means for electrically connecting said first and second lands, said means including a region of material having a composition which includes a metallic, non-eutectic alloy, essentially free of flux, said region of material having a melting point which is higher than the lamination temperature associated with said first and second dielectric layers.
References Cited (Backward Citations)
US3417461A
Cited
GB1204052A
Cited
US3648357A
Cited
US3660726A
Cited
US3678570A
Cited
US3922777A
Cited
US3993238A
Cited
US4157932A
Cited
DE3316017A1
Cited
US4727633A
Cited
US4875617A
Cited
US4788766A
Cited
US4935584A
Cited
US4998665A
Cited
US5008997A
Cited
US5038996A
Cited
US5031308A
Cited
US5090609A
Cited
US4965702A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-17 | 1997-07-19 | 1998-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-17 | 2001-07-19 | 2002-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-17 | 2005-07-19 | 2006-01-18 | $7700.00 | Window Closed / Lapsed |