US5740956A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bonding method for semiconductor chips
Assignee: Amkor Technology Singapore Holding Pte Ltd
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Filing: 1995-12-12
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Granted: 1998-04-21
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Expires: 2015-12-12
Abstract
Abstract This invention is related to providing a bonding method for flip chips in which the circuit part is oriented to be face-down on a substrate after bonding bumps are formed on the semiconductor chip namely, forming Au bumps by Au wire ball bonding employing a wire ball bonding device onto aluminum bond pads of the semiconductor chips; coating the Au bumps with Sn/Pb alloy bumps also by wire ball bonding using a wire ball bonding device; with or without re-forming the Sn/Pb alloy bumps into a desired ball-shape by performing a heat treatment in a furnace after an activation solvent is applied to the Sn/Pb alloy bumps; and bonding (by the heat treatment in the furnace) the substrate to the coated bumps containing chip by a heat treatment in the furnace.
Inventors
- 👤 Seong Min Seo
- 👤 Suck Ju Jang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:04
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/071; H10W72/072; H10W72/01; H10W72/012; H10W72/20; H10W72/01221; H10W72/01225; H10W72/0711; H10W72/07141; H10W72/07231; H10W72/07236; H10W72/251; H10W72/252; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; H10W72/90; H10W72/951; H10W72/952
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
142 words
A bonding method for connecting a semiconductor chip having aluminum bond pads to a substrate having a series of lead fingers comprising: providing a wire ball bonding device; forming Au bumps by Au wire ball bonding employing the wire ball bonding device onto the aluminum bond pads of the semiconductor chip; then coating fully an outer surface of the Au bumps with Sn/Pb alloy bumps in an atmosphere of a gas mixture of H 2 --Ar or H 2 --N 2 , by stacking said Sn/Pb alloy bumps onto said Au bumps by the wire ball bonding device, the resultant Sn/Pb coating having portions adhered to the aluminum bond pads; and bonding the substrate to the semiconductor chip having said Sn/Pb alloy bumps which coat said Au bumps, said coated Au bumps being oriented face-down on the lead fingers of the substrate.
Claim 2
Dependent Claim
142 words
A bonding method for connecting a semiconductor chip having aluminum bond pads to a substrate having a series of lead fingers comprising: providing a wire ball bonding device; forming Au bumps by Au wire ball bonding employing the wire ball bonding device onto the aluminum bond pads of the semiconductor chip; then coating fully an outer surface of the Au bumps with Sn/Pb alloy bumps in an atmosphere of a gas mixture of H 2 --Ar or H 2 --N 2 , by stacking said Sn/Pb alloy bumps onto said Au bumps by the wire ball bonding device, the resultant Sn/Pb coating having portions adhered to the aluminum bond pads; and bonding the substrate to the semiconductor chip having said Sn/Pb alloy bumps which coat said Au bumps, said coated Au bumps being oriented face-down on the lead fingers of the substrate.
Claim 3
Dependent Claim
29 words
The bonding method of claim 1, following said coating step further comprising re-forming said Sn/Pb alloy bumps in a desired ball-shape by performing a heat treatment in a furnace.
Claim 4
Dependent Claim
26 words
The bonding method of claim 1 or 2, in which the Au wire which is formed to said Au bumps, contains Pd of 0.5-3.0 weight %.
Claim 5
Dependent Claim
40 words
The bonding method of claim 1 or 2, further comprising cutting off parts of said Au bumps to make shortened Au bumps, or by pressing-down said Au bumps with a capillary of the wire ball bonding device having flatting ends.
Claim 6
Dependent Claim
30 words
The bonding method of claim 1 or 2, further comprising cutting off parts of said Au bumps and forming said cut-off Au bumps in the shape of a circular arc.
References Cited (Backward Citations)
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US4875618A
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JPH02215140A
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JPH0414845A
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US5497545A
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KR940001149A
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US5439162A
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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) | 2001-04-20 | 2001-10-20 | 2002-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-04-20 | 2005-10-20 | 2006-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-04-20 | 2009-10-20 | 2010-04-21 | $7700.00 | Window Closed / Lapsed |