Patent US2942117A successfully refreshed from Google Patents.
US4784785A
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Copper etchant compositions
Assignee: MacDermid Acumen Inc
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Filing: 1987-12-29
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Granted: 1988-11-15
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Expires: 2007-12-29
Abstract
Abstract The etching rate of an alkaline ammonium copper etching bath is accelerated by inclusion therein of an etchant accelerating amount of a mixture comprising an ammonium halide, a water-soluble salt containing sulfur, selenium or tellurium in the anion, an organic thio compound containing the group <IMAGE> and, optionally, a water-soluble salt of a noble metal (e.g. silver).
Inventors
- 👤 John L. Cordani
- 👤 Raymond A. Letize
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:40
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/32; C23F1/34
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
47 words
An etchant for copper and copper alloys which comprises an alkaline ammoniacal copper salt solution and an etchant accelerating amount of a mixture comprising an ammonium halide, a water-soluble salt containing sulfur, selenium or tellurium in the anion, and an organic thio compound containing the group ##STR5##
Claim 2
Dependent Claim
47 words
An etchant for copper and copper alloys which comprises an alkaline ammoniacal copper salt solution and an etchant accelerating amount of a mixture comprising an ammonium halide, a water-soluble salt containing sulfur, selenium or tellurium in the anion, and an organic thio compound containing the group ##STR5##
Claim 3
Dependent Claim
18 words
An etchant according to claim 1 wherein said mixture also comprises a water-soluble salt of a noble metal.
Claim 4
Dependent Claim
13 words
An etchant according to claim 1 wherein said copper salt is copper sulfate.
Claim 5
Dependent Claim
16 words
An etchant according to claim 1 having a pH in the range of 8.0 to 10.0.
Claim 6
Dependent Claim
77 words
An etchant according to claim 1 wherein said ammonium halide is present in an amount in the order of 0.5 g to 5 g per liter of etchant, said water-soluble salt is present in an amount to provide from 0.001 g to 0.02 g per liter of etchant of sulfur, selenium or tellurium and said organic thio compound is present in an amount in the range of about 0.001 g to 0.02 g per liter of etchant.
Claim 7
Dependent Claim
38 words
An etchant according to claim 1 which also comprises a water-soluble salt of a noble metal in an amount sufficient to provide from 0.001 g to 0.02 g per liter of etchant of the anion of said metal.
Claim 8
Dependent Claim
13 words
An etchant according to claim 1 wherein said ammonium halide is ammonium chloride.
Claim 9
Dependent Claim
18 words
An etchant according to claim 1 wherein said water soluble salt is an metal salt of selenious acid.
Claim 10
Dependent Claim
15 words
An etchant according to claim 1 wherein said organic thio compound is dithiobiuret or thiourea.
Claim 11
Dependent Claim
41 words
An etchant for copper and copper alloys which comprises an alkaline ammoniacal copper sulfate solution and an etchant accelerating amount of a mixture comprising an ammonium halide, an alkali metal selenite and a thio compound selected from thiourea, dithiobiuret and dithiobiurea.
Claim 12
Dependent Claim
41 words
An etchant for copper and copper alloys which comprises an alkaline ammoniacal copper sulfate solution and an etchant accelerating amount of a mixture comprising an ammonium halide, an alkali metal selenite and a thio compound selected from thiourea, dithiobiuret and dithiobiurea.
Claim 13
Dependent Claim
13 words
An etchant according to claim 10 wherein said mixture also comprises silver nitrate.
Claim 14
Dependent Claim
24 words
An etchant according to claim 10 wherein said ammonium halide is present in an amount from 0.5 to 5 g per liter of etchant.
Claim 15
Dependent Claim
33 words
An etchant according to claim 10 wherein said alkali metal selenite is present in an amount such that there is from about 0.001 g to 0.02 g of selenium per liter of etchant.
Claim 16
Dependent Claim
29 words
An etchant according to claim 10 wherein said thio compound is present in an amount in the range of about 0.001 g to 0.02 g per liter of etchant.
Claim 17
Dependent Claim
29 words
An etchant according to claim 11 wherein said silver nitrate is present in an amount to provide from about 0.001 g to 0.02 g per liter of silver anion.
Claim 18
Dependent Claim
121 words
An etchant for copper and copper alloys in the form of an aqueous solution comprising from about 100 to about 400 g per liter of copper sulfate, ammonium hydroxide in an amount sufficient to provide a pH in the range of about 8.5 to 9.5, from about 0.5 to 5 g per liter of an ammonium halide, from about 0.001 g to 0.02 g per liter of sulfur, selenium or tellurium in the form of a water-soluble salt in which said sulfur, selenium or tellurium is present in the anion, from 0.001 g to 0.02 g per liter of an organic thio compound containing the grouping ##STR6## and from 0 to 0.2 g of a water-soluble salt of a noble metal.
Claim 19
Dependent Claim
121 words
An etchant for copper and copper alloys in the form of an aqueous solution comprising from about 100 to about 400 g per liter of copper sulfate, ammonium hydroxide in an amount sufficient to provide a pH in the range of about 8.5 to 9.5, from about 0.5 to 5 g per liter of an ammonium halide, from about 0.001 g to 0.02 g per liter of sulfur, selenium or tellurium in the form of a water-soluble salt in which said sulfur, selenium or tellurium is present in the anion, from 0.001 g to 0.02 g per liter of an organic thio compound containing the grouping ##STR6## and from 0 to 0.2 g of a water-soluble salt of a noble metal.
Claim 20
Dependent Claim
13 words
An etchant according to claim 16 wherein said ammonium halide is ammonium chloride.
Claim 21
Dependent Claim
23 words
An etchant according to claim 16 wherein said water-soluble salt having sulfur, selenium or tellurium in the anion is an alkali metal salt.
Claim 22
Dependent Claim
15 words
An etchant according to claim 18 wherein said water-soluble salt is an alkali metal selenite.
Claim 23
Dependent Claim
12 words
An etchant according to claim 16 wherein said thio compound is dithiobiuret.
Claim 24
Dependent Claim
17 words
An etchant according to claim 16 wherein said water-soluble salt of a noble metal is silver nitrate.
Claim 25
Dependent Claim
40 words
An etchant for copper and copper alloys which comprises an alkaline ammoniacal copper salt solution and an etchant accelerating amount of a mixture comprising ammonium chloride, an alkali mixture comprising ammonium chloride, an alkali metal selenite, dithiobiuret and silver nitrate.
Claim 26
Dependent Claim
40 words
An etchant for copper and copper alloys which comprises an alkaline ammoniacal copper salt solution and an etchant accelerating amount of a mixture comprising ammonium chloride, an alkali mixture comprising ammonium chloride, an alkali metal selenite, dithiobiuret and silver nitrate.
Claim 27
Dependent Claim
56 words
In a process for etching copper and copper alloys using an alkaline ammoniacal copper salt solution as etchant the improvement comprising incorporating into said etchant an etchant accelerating amount of a mixture comprising an ammonium halide, a water-soluble salt containing sulfur, selenium or tellurium in the anion, and an organic thio compound containing the group ##STR7##
Claim 28
Dependent Claim
56 words
In a process for etching copper and copper alloys using an alkaline ammoniacal copper salt solution as etchant the improvement comprising incorporating into said etchant an etchant accelerating amount of a mixture comprising an ammonium halide, a water-soluble salt containing sulfur, selenium or tellurium in the anion, and an organic thio compound containing the group ##STR7##
Claim 29
Dependent Claim
18 words
A process according to claim 23 wherein said mixture also comprises a water-soluble salt of a noble metal.
Claim 30
Dependent Claim
13 words
A process according to claim 23 wherein said copper salt is copper sulfate.
Claim 31
Dependent Claim
21 words
A process according to claim 23 wherein the pH of the etchant solution is in the range of 8.0 to 10.0.
Claim 32
Dependent Claim
77 words
A process according to claim 23 wherein said ammonium halide is present in an amount of the order of 0.5 g to 5 g per liter of etchant, said water-soluble salt is present in an amount to provide from 0.001 g to 0.02 g per liter of etchant of sulfur, selenium or tellurium and said organic thio compound is present in an amount in the range of about 0.001 g to 0.02 g per liter of etchant.
Claim 33
Dependent Claim
37 words
A process according to claim 24 wherein said salt of a noble metal is present in an amount sufficient to provide from 0.001 g to 0.02 g per liter of etchant of the anion of said metal.
Claim 34
Dependent Claim
13 words
A process according to claim 23 wherein said ammonium halide is ammonium chloride.
Claim 35
Dependent Claim
19 words
A process according to claim 23 wherein said water soluble salt is an alkali metal salt of selenious acid.
Claim 36
Dependent Claim
15 words
A process according to claim 23 wherein said organic thio compound is dithiobiuret or thiourea.
Claim 37
Dependent Claim
42 words
A process according to claim 23 wherein the copper being etched is that in the exposed areas of a copper clad substrate on which photoresist images of circuit patterns have been formed as a step in the fabrication of printed circuit boards.
References Cited (Backward Citations)
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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) | 1991-11-15 | 1992-05-16 | 1992-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-15 | 1996-05-16 | 1996-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-15 | 2000-05-16 | 2000-11-15 | $7700.00 | Window Closed / Lapsed |