Patent US4543153A successfully refreshed from Google Patents.
US4543153A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for etching copper masked by a nickel-gold mask
Assignee: PSI Star Inc
•
Filing: 1984-05-17
•
Granted: 1985-09-24
•
Expires: 2004-05-17
Abstract
Abstract Process and apparatus for anisotropically etching copper through a nickel-gold mask on a circuit board. An electrical connection is made between the copper and the reactor wall or another electrical conductor contacted by the etching solution. The copper is removed anisotropically, without undercutting or lateral etching of the copper beneath the nickel-gold mask.
Inventors
- 👤 Norvell J. Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:04
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/02; H05K3/06; H05K3/067; C; C23; C23F; C23F1/00; C23F1/02; H05K3/061; H05K3/062; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0338
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
62 words
In a process for etching copper on a circuit board in the presence of another electrical conductor, the steps of: forming a metallic mask over portions of the copper to be retained, connecting the copper electrically to the other conductor, and contacting the exposed portions of the copper and the other conductor with a liquid etchant to effect removal of the copper.
Claim 2
Dependent Claim
62 words
In a process for etching copper on a circuit board in the presence of another electrical conductor, the steps of: forming a metallic mask over portions of the copper to be retained, connecting the copper electrically to the other conductor, and contacting the exposed portions of the copper and the other conductor with a liquid etchant to effect removal of the copper.
Claim 3
Dependent Claim
33 words
The process of claim 1 wherein the copper is contacted with the etchant in a reaction chamber having an electrically conductive metal wall, and the copper is connected electrically to the metal wall.
Claim 4
Dependent Claim
28 words
The process of claim 1 wherein the etchant comprises an aqueous solution of NO 2 or HNO 3 , Cu(NO 3 ) 2 , and a polymer additive.
Claim 5
Dependent Claim
29 words
The process of claim 1 wherein the metallic mask is formed by forming a layer of nickel over the copper and forming a layer of gold over the nickel.
Claim 6
Dependent Claim
76 words
In apparatus for removing copper from a circuit board in the presence of another electrical conductor, with a metallic mask covering portions of the copper to be retained: means for connecting the copper electrically to the other conductor to maintain the copper and the other conductor at substantially the same electrical potential, and means for contacting the exposed portions of the copper and the other conductor with a liquid etchant to effect removal of the copper.
Claim 7
Dependent Claim
76 words
In apparatus for removing copper from a circuit board in the presence of another electrical conductor, with a metallic mask covering portions of the copper to be retained: means for connecting the copper electrically to the other conductor to maintain the copper and the other conductor at substantially the same electrical potential, and means for contacting the exposed portions of the copper and the other conductor with a liquid etchant to effect removal of the copper.
Claim 8
Dependent Claim
24 words
The apparatus of claim 5 including a reaction chamber having an electrically conductive wall, and means for connecting the copper to the reactor wall.
Claim 9
Dependent Claim
21 words
The apparatus of claim 6 wherein the means for connecting the copper to the reactor wall comprises an electrically conductive wire.
Claim 10
Dependent Claim
28 words
The apparatus of claim 5 wherein the etchant comprises an aqueous solution of NO 2 or HNO 3 , Cu(NO 3 ) 2 , and a polymer additive.
Claim 11
Dependent Claim
72 words
In combination: a circuit board having a layer of electrically conductive copper on one side thereof, a nickel-gold mask covering portions of the copper, another electrical conductor in proximity to the circuit board, a liquid etchant contacting the exposed portions of the copper and the other conductor, and means connecting the copper and the other conductor electrically together to maintain the copper and the other conductor at substantially the same electrical potential.
Claim 12
Dependent Claim
72 words
In combination: a circuit board having a layer of electrically conductive copper on one side thereof, a nickel-gold mask covering portions of the copper, another electrical conductor in proximity to the circuit board, a liquid etchant contacting the exposed portions of the copper and the other conductor, and means connecting the copper and the other conductor electrically together to maintain the copper and the other conductor at substantially the same electrical potential.
Claim 13
Dependent Claim
16 words
The combination of claim 9 wherein the other conductor comprises a metal wall of a reactor.
Claim 14
Dependent Claim
21 words
The combination of claim 9 wherein the means connecting the copper and the other conductor together comprises an electrically conductive wire.
Claim 15
Dependent Claim
28 words
The combination of claim 9 wherein the etchant comprises an aqueous solution of NO 2 or HNO 3 , Cu(NO 3 ) 2 , and a polymer additive.
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) | 1988-09-23 | 1989-03-25 | 1989-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-23 | 1993-03-25 | 1993-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-23 | 1997-03-25 | 1997-09-24 | $7700.00 | Window Closed / Lapsed |