US4919752A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bath solution and process for the removal of lead/tim, lead or tin coatings from copper or nickel surfaces
Assignee: AMP-AKZO Corp A CORP OF
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Filing: 1988-11-10
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Granted: 1990-04-24
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Expires: 2008-11-10
Abstract
Abstract The invention relates to a stripping solution for the removal of lead/tin, lead or tin coatings applied to copper or nickel surfaces. The caustic solution consists of nitric acid and contains one or several inhibitor(s) such as block copolymers of propylene oxide and ethylene oxide, or polyethylene glycols, and/or polyols with a molecular weight in excess of 2000.
Inventors
- 👤 Gunter Mika
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:26
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/44; C23F1/10; C23F1/14; C23F1/16; C23F1/30; H; H05; H05K; H05K3/00; H05K3/02; H05K3/06; H05K3/067
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
84 words
Process for the removal of lead/tin, lead or tin coatings applied to nickel or copper surfaces, by contacting the coatings with an aqueous stripping solution for a period sufficient to remove the coatings from the nickel or copper surfaces, said aqueous stripping solution being characterized in that the stripping solution contains nitric acid and one or several inhibitor(s) selected from the group of block copolymers of propylene oxide and ethylene oxide, fluorocarbon surfactants, polyethylene glycols with a molecular weight more than 2000, and polyols.
Claim 2
Dependent Claim
84 words
Process for the removal of lead/tin, lead or tin coatings applied to nickel or copper surfaces, by contacting the coatings with an aqueous stripping solution for a period sufficient to remove the coatings from the nickel or copper surfaces, said aqueous stripping solution being characterized in that the stripping solution contains nitric acid and one or several inhibitor(s) selected from the group of block copolymers of propylene oxide and ethylene oxide, fluorocarbon surfactants, polyethylene glycols with a molecular weight more than 2000, and polyols.
Claim 3
Dependent Claim
100 words
Process as defined in claim 1, further characterized in that subsequent to removing the lead/tin, lead or tin coating removing an intermetallic intermediate layer, formed at the interface between the nickel or copper base and the lead/tin, lead, or tin coating applied thereto, by contacting the intermetallic layer with an aqueous stripping solution for a time period sufficient to remove the intermetallic layer, said solution containing iron-III chloride and one or several inhibitor(s) selected from the group of block copolymers of propylene oxide and ethylene oxide, fluorocarbon surfactants, polyethylene glycols with a molecular weight of more than 2000, and polyols.
Claim 4
Dependent Claim
52 words
Process as defined in claim 1, characterized in that for removing in one step the lead/tin lead or tin coating and an intermetallic intermediate layer formed at the interface between the nickel or copper base and the lead/tin, lead or tin coating applied thereto, said aqueous stripping solution further comprises iron-III chloride.
Claim 5
Dependent Claim
22 words
Process as defined in claim 1, characterized in that the aqueous stripping solution is used at a temperature not exceeding 25° C.
Claim 6
Dependent Claim
22 words
Process as defined in claim 2, characterized in that the aqueous stripping solution is used at a temperature not exceeding 25° C.
Claim 7
Dependent Claim
22 words
Process as defined in claim 3, characterized in that the aqueous stripping solution is used at a temperature not exceeding 25° C.
Claim 8
Dependent Claim
58 words
Aqueous stripping solution for the removal of lead/tin, lead or tin coatings applied to nickel or copper surfaces, characterized in that the solution contains nitric acid and one or several inhibitor(s) selected from the group of block copolymers or propylene oxide and ethylene oxide, fluorocarbon surfactants, polyethylene glycols with a molecular weight of more than 2000, and polyols.
Claim 9
Dependent Claim
58 words
Aqueous stripping solution for the removal of lead/tin, lead or tin coatings applied to nickel or copper surfaces, characterized in that the solution contains nitric acid and one or several inhibitor(s) selected from the group of block copolymers or propylene oxide and ethylene oxide, fluorocarbon surfactants, polyethylene glycols with a molecular weight of more than 2000, and polyols.
Claim 10
Dependent Claim
70 words
Aqueous stripping solution for the removal of an intermetallic intermediate layer, formed at the interface between a nickel or copper base and a lead/tin, lead or tin coating applied thereon, characterized in that the solution contains iron-III chloride and one or several inhibitor(s) selected from the group of block copolymers of propylene oxide and ethylene oxide, fluorocarbon surfactants, polyethylene glycols with a molecular weight of more than 2000, and polyols.
Claim 11
Dependent Claim
70 words
Aqueous stripping solution for the removal of an intermetallic intermediate layer, formed at the interface between a nickel or copper base and a lead/tin, lead or tin coating applied thereon, characterized in that the solution contains iron-III chloride and one or several inhibitor(s) selected from the group of block copolymers of propylene oxide and ethylene oxide, fluorocarbon surfactants, polyethylene glycols with a molecular weight of more than 2000, and polyols.
Claim 12
Dependent Claim
89 words
Aqueous stripping solution for the removal of lead/tin, lead or tin coatings applied to nickel or copper surfaces, and of an intermetallic intermediate layer formed at the interface between the nickel or copper base and the lead/tin, lead or tin coating applied thereto, in one process step, characterized in that the solution contains nitric acid, iron-III chloride and one or several inhibitor(s) selected from the group of block copolymers of propylene oxide and ethylene oxide, fluorocarbon surfactants, polyethylene glycols with a molecular weight of more than 2000, and polyols.
Claim 13
Dependent Claim
89 words
Aqueous stripping solution for the removal of lead/tin, lead or tin coatings applied to nickel or copper surfaces, and of an intermetallic intermediate layer formed at the interface between the nickel or copper base and the lead/tin, lead or tin coating applied thereto, in one process step, characterized in that the solution contains nitric acid, iron-III chloride and one or several inhibitor(s) selected from the group of block copolymers of propylene oxide and ethylene oxide, fluorocarbon surfactants, polyethylene glycols with a molecular weight of more than 2000, and polyols.
Claim 14
Dependent Claim
30 words
Aqueous stripping solution as defined in claim 7, characterized in that such solution contains from 20 to 35% by weight nitric acid, from 0.03 to 0.06 g/L inhibitor, and water.
Claim 15
Dependent Claim
29 words
Aqueous stripping solution as defined in claim 8, characterized in that such solution contains from 5 to 8 g/L iron-III chloride, from 0.03 to 0.06 g/L inhibitor, and water.
Claim 16
Dependent Claim
37 words
Aqueous stripping solution as defined in claim 9, characterized in that such solution contains from 20 to 35% by weight nitric acid, from 5 to 8 g/L iron-III chloride, from 0.03 to 0.06 g/L inhibitor, and water.
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) | 1993-04-23 | 1993-10-23 | 1994-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-23 | 1997-10-23 | 1998-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-23 | 2001-10-23 | 2002-04-24 | $7700.00 | Window Closed / Lapsed |