US5776551A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of plasma activated NF3 to clean solder bumps on a device
Assignee: Bell Semiconductor LLC
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Filing: 1996-12-23
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Granted: 1998-07-07
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Expires: 2016-12-23
Abstract
Abstract A method for cleaning solder bumps on a substrate that may be employed in a flip-chip design, for example, is described. The method of cleaning includes placing the substrate having the solder bumps into a plasma reactor, introducing a source gas including nitrogen trifluoride gas into the plasma reactor, striking a plasma from the source gas in the plasma reactor, and forming a fluoride compound on the surface of the solder bump.
Inventors
- 👤 Nicholas F. Pasch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:34
CPC Classifications
H; H10; H10W; H10W72/00; H10W72/01; H10W72/012; C; C23; C23C; C23C8/00; C23C8/06; C23C8/36; C23G; C23G5/00; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3489; H10W72/20; H10W72/251; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24752; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
58 words
A method for cleaning solder bumps on a substrate, said method comprising: placing said substrate having said solder bumps into a plasma reactor; introducing a source gas including nitrogen trifluoride gas into said plasma reactor; striking a plasma from said source gas in said plasma reactor; and forming a fluoride compound on the surface of said solder bump.
Claim 2
Independent Claim
58 words
A method for cleaning solder bumps on a substrate, said method comprising: placing said substrate having said solder bumps into a plasma reactor; introducing a source gas including nitrogen trifluoride gas into said plasma reactor; striking a plasma from said source gas in said plasma reactor; and forming a fluoride compound on the surface of said solder bump.
Claim 3
Dependent Claim
28 words
The method of claim 1, wherein said step of striking said plasma comprises generating said plasma under a pressure of between about 5 milliTorr and about 1 Torr.
Claim 4
Dependent Claim
26 words
The method of claim 1, wherein said step of striking said plasma comprises generating said plasma at a power of between about 50 and 1000 Watts.
Claim 5
Dependent Claim
15 words
The method of claim 3, wherein said power is between about 300 and 500 Watts.
Claim 6
Dependent Claim
32 words
The method of claim 1, wherein said step of introducing said source gas comprises introducing nitrogen trifluoride gas at a flow rate of between about 10 cubic centimeter/minute to 1 standard liter/minute.
Claim 7
Dependent Claim
20 words
The method of claim 1, wherein said step of introducing said source gas comprises introducing nitrogen trifluoride gas and helium.
Claim 8
Dependent Claim
30 words
The method of claim 1, wherein said source gas comprises between 0 and about 95% by volume of helium gas and up to about 5% by volume of nitrogen trifluoride.
Claim 9
Dependent Claim
63 words
A method for attaching a solder bump to a surface having a connection region, said method comprising: cleaning said solder bump according to claim 1; bringing into close proximity said solder bump to a connection region of a surface; and heating said solder bump such that said solder bump melts and flows into said connection region to establish a contact with said surface.
Claim 10
Dependent Claim
21 words
The method of claim 8, wherein said step of cleaning and said step of bringing are conducted in said plasma reactor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-07-06 | 2002-01-05 | 2002-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-07-06 | 2006-01-05 | 2006-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-07-06 | 2010-01-05 | 2010-07-07 | $7700.00 | Window Closed / Lapsed |