US4053372A
Expired / Lapsed
US
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Tin-lead acidic plating bath
Assignee: TE Connectivity Corp
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Filing: 1975-10-09
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Granted: 1977-10-11
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Expires: 1995-10-09
Abstract
Abstract A method for electroplating tin-lead compositions, a bath for electroplating of tin-lead alloys and stable, solid salt compositions for make up of a bath for plating the tin-lead alloys, said bath contains, besides the two metals, thiourea, potassium, hypophosphite and hydrochloric acid with the pH of the bath being from 0.5 to 1.5.
Inventors
- 👤 Thomas Francis Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:18
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/56; C25D3/60; H; H05; H05K; H05K3/00; H05K3/30; H05K3/32; H05K3/34; H05K3/3465; H05K3/3473
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
97 words
A method for depositing tin-lead alloys from an aqueous electrolyte solution comprising electrolyzing a solution comprising from ______________________________________
Sn metal (as stannous chloride)
7.5-75 g/l
Pb metal (as lead chloride)
1-99% of total
Sn and Pb concentration
A thiourea 10-200 g/l
NH.sub.4 Cl 00-300 g/l
Na.sup.+, or K.sup.+ 10-200 g/l.- H.sub.2 PO.sub.2 . H.sub.2 O
HCl, 36% concentrated
20-500 ml/l
______________________________________ said solution being at a pH from 0.5 to 1.5, said bath being at a temperature from 130° to 200° F. and depositing said lead alloy on a cathodic work piece and recovering said work piece.
Claim 2
Independent Claim
97 words
A method for depositing tin-lead alloys from an aqueous electrolyte solution comprising electrolyzing a solution comprising from ______________________________________
Sn metal (as stannous chloride)
7.5-75 g/l
Pb metal (as lead chloride)
1-99% of total
Sn and Pb concentration
A thiourea 10-200 g/l
NH.sub.4 Cl 00-300 g/l
Na.sup.+, or K.sup.+ 10-200 g/l.- H.sub.2 PO.sub.2 . H.sub.2 O
HCl, 36% concentrated
20-500 ml/l
______________________________________ said solution being at a pH from 0.5 to 1.5, said bath being at a temperature from 130° to 200° F. and depositing said lead alloy on a cathodic work piece and recovering said work piece.
Claim 3
Dependent Claim
89 words
A method for depositing a tin-lead alloy from an aqueous electrolyte solution as defined in claim 1 wherein the electrolyte comprises: ______________________________________
Sn° (added as SnCl.sub.2 . 2H.sub.2 O) as metal
15 g/l
Pb° (added as PbCl.sub.2) as metal
1.15 g/l
NaH.sub.2 PO.sub.2 . H.sub.2 O
40 g/l
HCl, 36% concentrated 50 ml/l
NH.sub.4 Cl 40 g/l
a nonylphenoxy ethylene oxide
0.5 g/l
adduct
Thiourea 40 g/l
______________________________________ said bath being at 60° C., the current density at about 5 to 30 ASF, and said bath being agitated mechanically.
Claim 4
Dependent Claim
13 words
The method as defined in claim 1 wherein the hypophosphite is potassium hypophosphite.
Claim 5
Dependent Claim
13 words
The method as defined in claim 1 wherein the hypophosphite is sodium hypophosphite.
Claim 6
Dependent Claim
64 words
A storage stable solids composition for use to make the electrolyte solution used in the method of claim 1 consisting essentially of tin metal as a stannous salt, lead metal as a lead salt, ammonium chloride, a thiourea, and a hypophosphite wherein said lead on an elemental basis is from 1 to 99 percent based on the amount of total metal in said composition.
Claim 7
Dependent Claim
18 words
The composition as defined in claim 5 wherein the same contains as a surfactant alkylphenoxy (ethylene oxide) adduct.
Claim 8
Dependent Claim
86 words
An aqueous electrolyte suitable for deposition of tin-lead alloys from said electrolyte, said aqueous electrolyte comprising ______________________________________
Sn metal (as stannous chloride)
7.5 - 75 g/l
Pb metal (as lead chloride)
1 - 99 % of total
Sn and Pb concentration
A thiourea 10 - 200 g/l
NH.sub.4 Cl 0 - 300 g/l
Na.sup.+, NH.sub.4.sup.+ or K.sup.+ with .sup.- H.sub.2 PO.sub.2 .
H.sub.2 O 10 - 200 g/l
HCl (conc.) 20 - 500 ml/l
______________________________________ wherein the pH of said solution is from 0.5 to 1.5.
Claim 9
Dependent Claim
86 words
An aqueous electrolyte suitable for deposition of tin-lead alloys from said electrolyte, said aqueous electrolyte comprising ______________________________________
Sn metal (as stannous chloride)
7.5 - 75 g/l
Pb metal (as lead chloride)
1 - 99 % of total
Sn and Pb concentration
A thiourea 10 - 200 g/l
NH.sub.4 Cl 0 - 300 g/l
Na.sup.+, NH.sub.4.sup.+ or K.sup.+ with .sup.- H.sub.2 PO.sub.2 .
H.sub.2 O 10 - 200 g/l
HCl (conc.) 20 - 500 ml/l
______________________________________ wherein the pH of said solution is from 0.5 to 1.5.
References Cited (Backward Citations)
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US2734025A
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US3769182A
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US3785939A
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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) | 1980-10-10 | 1981-04-11 | 1981-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-10 | 1985-04-11 | 1985-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-10 | 1989-04-11 | 1989-10-11 | $7700.00 | Window Closed / Lapsed |