Patent US4646958A successfully refreshed from Google Patents.
US4646958A
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Fluxless soldering process using a silane atmosphere
Assignee: International Business Machines Corp
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Filing: 1985-10-31
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Granted: 1987-03-03
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Expires: 2005-10-31
Abstract
Abstract Solder reflow or solder chip joining can be accomplished in a fluxless system by conducting the solder reflow or chip joining procedure in a carrier gas which comprises from about 0.1 to about 10% by volume SiH 4 , based on the volume of carrier gas and SiH 4 . A preferred carrier gas for the reflow is hydrogen and a preferred carrier gas for the chip joining is nitrogen.
Inventors
- 👤 Robert T. Howard, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:21
CPC Classifications
B; B23; B23K; B23K35/00; B23K35/22; B23K35/38; H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3489; H10; H10W; H10W72/00; H10W72/071; H10W72/072; H10W72/07231; H10W72/07236; H10W72/20; H10W72/251; H10W72/252
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
60 words
In a process for joining a semiconductor chip to a substrate by soldering in a carrier gas, the improvement which comprises: performing the soldering step in the presence of SiH 4 , thereby reducing any oxide on the solder, resulting in the formation of H 2 O and SiO 2 which exit with the carrier gas and SiH 4 .
Claim 2
Dependent Claim
60 words
In a process for joining a semiconductor chip to a substrate by soldering in a carrier gas, the improvement which comprises: performing the soldering step in the presence of SiH 4 , thereby reducing any oxide on the solder, resulting in the formation of H 2 O and SiO 2 which exit with the carrier gas and SiH 4 .
Claim 3
Dependent Claim
54 words
In a process for reflowing solder in a carrier gas, the improvement which comprises: performing the reflowing step in the presence of SiH 4 , thereby reducing any oxide on the solder, resulting in the formation of H 2 O and SiO 2 which exit with the carrier gas and the SiH 4 .
Claim 4
Dependent Claim
54 words
In a process for reflowing solder in a carrier gas, the improvement which comprises: performing the reflowing step in the presence of SiH 4 , thereby reducing any oxide on the solder, resulting in the formation of H 2 O and SiO 2 which exit with the carrier gas and the SiH 4 .
Claim 5
Dependent Claim
13 words
A process as claimed in claim 1, wherein the carrier gas is nitrogen.
Claim 6
Dependent Claim
32 words
A process as claimed in claim 3, wherein there is used from about 0.1 to about 10% SiH 4 , based on the total volume of carrier gas and SiH 4 .
Claim 7
Dependent Claim
22 words
A process as claimed in claim 4, wherein the solder comprises from about 0.1 to about 5% tin, balance lead, by weight.
Claim 8
Dependent Claim
17 words
A process as claimed in claim 4, wherein the solder comprises over 50% tin, balance substantially lead.
Claim 9
Dependent Claim
13 words
A process as claimed in claim 2, wherein the carrier gas is hydrogen.
Claim 10
Dependent Claim
32 words
A process as claimed in claim 7, wherein there is used from about 0.1 to about 10% SiH 4 , based on the total volume of carrier gas and SiH 4 .
Claim 11
Dependent Claim
22 words
A process as claimed in claim 8, wherein the solder comprises from about 0.1% to about 5% tin, balance lead, by weight.
Claim 12
Dependent Claim
17 words
A process as claimed in claim 8, wherein the solder comprises over 50% tin, balance substantially lead.
Claim 13
Dependent Claim
108 words
In a process for joining a semiconductor chip to a substrate which includes a solder reflow step and joining the semiconductor chip to a substrate by soldering, both of these steps being conducted in a carrier gas, the improvement which comprises: performing the solder reflow step in the presence of hydrogen containing from about 0.1 to about 10% by volume silane, based on the total volume of hydrogen and silane; and joining the semiconductor chip to the substrate in a carrier gas which comprises nitrogen containing from about 0.1 to about 10% by volume SiH 4 , based on the total volume of nitrogen plus SiH 4 .
Claim 14
Dependent Claim
108 words
In a process for joining a semiconductor chip to a substrate which includes a solder reflow step and joining the semiconductor chip to a substrate by soldering, both of these steps being conducted in a carrier gas, the improvement which comprises: performing the solder reflow step in the presence of hydrogen containing from about 0.1 to about 10% by volume silane, based on the total volume of hydrogen and silane; and joining the semiconductor chip to the substrate in a carrier gas which comprises nitrogen containing from about 0.1 to about 10% by volume SiH 4 , based on the total volume of nitrogen plus SiH 4 .
Claim 15
Dependent Claim
22 words
A process as claimed in claim 11, wherein the solder comprises from about 0.1 to about 5% tin, balance lead, by weight.
Claim 16
Dependent Claim
17 words
A process as claimed in claim 11, wherein the solder comprises over 50% tin, balance substantially lead.
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) | 1990-03-02 | 1990-09-01 | 1991-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-02 | 1994-09-01 | 1995-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-02 | 1998-09-01 | 1999-03-03 | $7700.00 | Window Closed / Lapsed |