US4419183A
Expired / Lapsed
US
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Etchant
Assignee: Shipley Co Inc
•
Filing: 1983-01-18
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Granted: 1983-12-06
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Expires: 2003-01-18
Abstract
Abstract An etchant, especially for copper, comprising sulfuric acid and hydrogen peroxide and characterized by the inclusion of a small amount of tungsten in an amount sufficient to increase the surface area of the etched metal.
Inventors
- 👤 Michael Gulla
- 👤 Marc Connelly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:11
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/16; C23F1/18; H; H05; H05K; H05K3/00; H05K3/02; H05K3/06; H05K3/067; H05K3/22
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
62 words
In a composition for etching a metal surface comprising sulfuric acid in an amount of at least 0.5 moles per liter and hydrogen peroxide in an amount of at least 0.1 moles per liter, the improvement comprising as an additive to the solution, a solution soluble source of tungsten in an amount sufficient to increase the surface area of the metal surface.
Claim 2
Dependent Claim
62 words
In a composition for etching a metal surface comprising sulfuric acid in an amount of at least 0.5 moles per liter and hydrogen peroxide in an amount of at least 0.1 moles per liter, the improvement comprising as an additive to the solution, a solution soluble source of tungsten in an amount sufficient to increase the surface area of the metal surface.
Claim 3
Dependent Claim
20 words
The composition of claim 1 where the tunsten is present in an amount of at least 0.00005 moles per liter.
Claim 4
Dependent Claim
18 words
The composition of claim 2 where the peroxide content varies between about 0.1 and 3.5 moles per liter.
Claim 5
Dependent Claim
18 words
The composition of claim 3 where the peroxide content varies between about 0.2 and 1.0 mole per liter.
Claim 6
Dependent Claim
18 words
The composition of claim 2 where the sulfuric acid content varies between 0.5 and 7.5 moles per liter.
Claim 7
Dependent Claim
18 words
The composition of claim 5 where the sulfuric acid content varies between 1 and 2.5 moles per liter.
Claim 8
Dependent Claim
41 words
The composition of claim 2 having a composition comprising 0.2 to 1.0 moles per liter of hydrogen peroxide, 1.0 to 2.5 moles per liter of sulfuric acid and from 0.0001 to 0.001 moles per liter of a solution source of tunsten.
Claim 9
Dependent Claim
15 words
The composition of claim 7 where the solution soluble source of tungsten is sodium tunstate.
Claim 10
Dependent Claim
11 words
The composition of claim 7 containing a stabilizer for hydrogen peroxide.
Claim 11
Dependent Claim
13 words
The composition of claim 9 where the stabilizer is an aryl sulfonic acid.
Claim 12
Dependent Claim
12 words
The composition of claim 9 where the stabilizer is phenol sulfonic acid.
Claim 13
Dependent Claim
77 words
A process for preparing a copper surface for metal deposition, said process comprising contact of the surface with an etchant comprising sulfuric acid in an amount of at least 0.5 moles per liter, hydrogen peroxide in an amount of at least 0.1 moles per liter and a solution soluble source of tungsten in an amount of at least 0.00005 moles per liter, said contact being for a time sufficient to form a matte surface over the copper.
Claim 14
Dependent Claim
77 words
A process for preparing a copper surface for metal deposition, said process comprising contact of the surface with an etchant comprising sulfuric acid in an amount of at least 0.5 moles per liter, hydrogen peroxide in an amount of at least 0.1 moles per liter and a solution soluble source of tungsten in an amount of at least 0.00005 moles per liter, said contact being for a time sufficient to form a matte surface over the copper.
Claim 15
Dependent Claim
43 words
The process of claim 12 where the etchant comprises from 0.2 to 1.0 moles per liter of hydrogen peroxide, 1.0 to 2.5 moles per liter of sulfuric acid and from 0.0001 to 0.001 moles per liter of a solution soluble source of tungsten.
Claim 16
Dependent Claim
17 words
The process of claim 13 where the copper surface is a copper clad circuit board base material.
Claim 17
Dependent Claim
18 words
The process of claim 14 including the step of depositing an electroless metal over the etched copper surface.
Claim 18
Dependent Claim
11 words
The process of claim 15 where the electroless metal is copper.
Claim 19
Dependent Claim
14 words
The process of claim 13 where the etchant contains a stabilizer for hydrogen peroxide.
Claim 20
Dependent Claim
13 words
The process of claim 17 where the stabilizer is an aryl sulfonic acid.
Claim 21
Dependent Claim
12 words
The process of claim 17 where the stabilizer is phenol sulfonic acid.
Claim 22
Dependent Claim
33 words
The process of claim 14 where the electroless copper is deposited on the surface of the copper and onto walls of holes drilled through the copper clad and the circuit board base material.
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) | 1986-12-05 | 1987-06-06 | 1987-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-05 | 1991-06-06 | 1991-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-05 | 1995-06-06 | 1995-12-06 | $7700.00 | Window Closed / Lapsed |