US4260451A
Expired / Lapsed
US
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Method of reworking substrates, and solutions for use therein
Assignee: International Business Machines Corp
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Filing: 1980-03-17
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Granted: 1981-04-07
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Expires: 2000-03-17
Abstract
Abstract A solution for dissolving noble metal alloys which include tin, and other metals commonly used in semiconductor package substrates, having significant concentrations of KI, iodine and halogen ions selected from the group consisting of chloride and bromide ions.
Inventors
- 👤 Arnold F. Schmeckenbecher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:14
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/01; H10W70/05; C; C23; C23F; C23F1/00; C23F1/10; C23F1/14
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
70 words
A solution for dissolving noble metal alloys which include Sn from substrates in presence of refractory metal which must be retained on the substrate consisting essentially of (1) KI in an amount of at least 0.3 moles/liter, (2) I 2 in an amount of at least 0.195 moles/liter, and (3) halogen ions selected from the group consisting of chloride and bromide ions in an amount of at least 0.3 moles/liter.
Claim 2
Dependent Claim
70 words
A solution for dissolving noble metal alloys which include Sn from substrates in presence of refractory metal which must be retained on the substrate consisting essentially of (1) KI in an amount of at least 0.3 moles/liter, (2) I 2 in an amount of at least 0.195 moles/liter, and (3) halogen ions selected from the group consisting of chloride and bromide ions in an amount of at least 0.3 moles/liter.
Claim 3
Dependent Claim
50 words
The solution of claim 1 wherein said KI is present in an amount in the range of 0.6 to 3.6 moles/liter, said iodine is present in the range of 1.5 to 2.1 moles/liter, and said halogen ions are present in an amount in the range of 0.75 to 4.0 moles/liter.
Claim 4
Dependent Claim
50 words
The solution of claim 1 wherein said KI is present in an amount in the range of 1.5 to 2.1 moles/liter, said iodine is present in the range of 0.98 to 1.36 moles/liter, and said halogen ions are present in an amount in the range of 1.0 to 1.75 moles/liter.
Claim 5
Dependent Claim
12 words
The solution of claim 2 wherein said halogen ions are chloride ions.
Claim 6
Dependent Claim
12 words
The solution of claim 2 wherein said halogen ions are bromide ions.
Claim 7
Dependent Claim
87 words
A re-work method of removing from a substrate features formed of noble metal alloys containing Sn while having features formed of refractory metals intact comprising subjecting the substrate to the action of a solution consisting essentially of (1) KI in an amount in the range of 0.6 to 3.6 moles/liter, (2) Iodine in an amount in the range of 1.5 to 2.1 moles/liter, (3) Halogen ions selected from the group consisting of chloride and bromide ions in an amount in the range of 0.75 to 4.0 moles/liter.
Claim 8
Dependent Claim
87 words
A re-work method of removing from a substrate features formed of noble metal alloys containing Sn while having features formed of refractory metals intact comprising subjecting the substrate to the action of a solution consisting essentially of (1) KI in an amount in the range of 0.6 to 3.6 moles/liter, (2) Iodine in an amount in the range of 1.5 to 2.1 moles/liter, (3) Halogen ions selected from the group consisting of chloride and bromide ions in an amount in the range of 0.75 to 4.0 moles/liter.
Claim 9
Dependent Claim
52 words
The re-work method of claim 6 wherein KI is present in said solution in an amount in the range of 1/5 to 2.1 moles/liter, said iodine in an amount in the range of 0.98 to 1.36 moles/liter, and said halogen ions in an amount in the range of 1.0 to 1.75 moles/liter.
Claim 10
Dependent Claim
13 words
The re-work method of claim 6 wherein said halogen ions are chloride ions.
Claim 11
Dependent Claim
13 words
The re-work method of claim 6 wherein said halogen ions are bromide ions.
Claim 12
Dependent Claim
21 words
The re-work method of claim 6 wherein the temperature of said solution is in the range of 65 to 80° C.
References Cited (Backward Citations)
US3634159A
Cited
US4190489A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-04-06 | 1984-10-06 | 1985-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-04-06 | 1988-10-06 | 1989-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-04-06 | 1992-10-06 | 1993-04-07 | $7700.00 | Window Closed / Lapsed |