US4451327A
Expired / Lapsed
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Process and structure for etching copper
Assignee: PSI Star Inc
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Filing: 1983-05-25
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Granted: 1984-05-29
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Expires: 2003-05-25
Abstract
Abstract Process and structure for etching copper, as in the manufacture of printed circuit boards. The copper is exposed to a gaseous or liquid oxidant in the presence of a catalyst which promotes the reaction of copper with the oxidant. In some embodiments, the catalyst is carried by a medium which also serves as a receiver for oxidized copper species produced by the reaction, and in one preferred embodiment, the medium comprises a laminated structure having a first layer which contains a catalyst and a second layer which receives the oxidized copper species. The etching is substantially anisotropic, which alleviates the problem of undercutting.
Inventors
- 👤 Norvell J. Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:21
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/12; H; H05; H05K; H05K3/00; H05K3/02; Y; Y10; Y10T; Y10T442/00; Y10T442/60; Y10T442/654; Y10T442/656
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
54 words
A dry process for etching copper, comprising the steps of exposing the copper to a gaseous oxidant in the presence of a catalyst which promotes the reaction of copper with the oxidant, adsorbing oxidized copper produced by the reaction into a receiver, and carrying the oxidized copper away from the reaction in the receiver.
Claim 2
Dependent Claim
54 words
A dry process for etching copper, comprising the steps of exposing the copper to a gaseous oxidant in the presence of a catalyst which promotes the reaction of copper with the oxidant, adsorbing oxidized copper produced by the reaction into a receiver, and carrying the oxidized copper away from the reaction in the receiver.
Claim 3
Dependent Claim
27 words
The process of claim 1 wherein the gaseous oxidant is selected from the group consisting of a nitrogen oxide, a nitrogen oxyhalide, a halogen and combinations thereof.
Claim 4
Dependent Claim
19 words
The process of claim 1 wherein the oxidant is nitrogen dioxide, and the catalyst is a polar organic solvent.
Claim 5
Dependent Claim
25 words
The process of claim 3 wherein the polar organic solvent is carried by a non-liquid medium in close proximity to the copper to be etched.
Claim 6
Dependent Claim
10 words
The process of claim 1 wherein the oxidant is chlorine.
Claim 7
Dependent Claim
26 words
The process of claim 5 wherein the catalyst is nitrogen oxide, and a liquid transport agent is present in the receiver to remove the oxidized copper.
Claim 8
Dependent Claim
17 words
The process of claim 6 wherein the nitrogen oxide is introduced as a gaseous oxide of nitrogen.
Claim 9
Dependent Claim
14 words
The process of claim 6 wherein the nitrogen oxide is introduced as a salt.
Claim 10
Dependent Claim
45 words
The process of claim 1 wherein the catalyst is carried by a non-liquid medium positioned in close proximity to the copper, and an oxidized copper species produced by the reaction is received by the non-liquid medium and carried away from the copper by said medium.
Claim 11
Dependent Claim
81 words
The process of claim 9 wherein the medium comprises a solid support having first and second layers of material through which the gaseous oxidant can pass, the catalyst is carried by the first layer, the first layer is positioned in close facing relationship with the surface of the copper to be etched, the second layer is positioned away from the surface of the copper, and the oxidized copper species passes through the first layer and is received by the second layer.
Claim 12
Dependent Claim
13 words
The process of claim 9 wherein the medium comprises a particulate solid material.
Claim 13
Dependent Claim
16 words
The process of claim 9 wherein the medium comprises a fluidized bed of particulate solid material.
Claim 14
Dependent Claim
23 words
The process of claim 1 wherein the catalyst is applied to the surface of the copper in the form of a solid film.
Claim 15
Dependent Claim
19 words
The process of claim 1 wherein the catalyst comprises a polymer film applied to the surface of the copper.
Claim 16
Dependent Claim
19 words
The process of claim 1 wherein the catalyst comprises a polymerized gel applied to the surface of the copper.
Claim 17
Dependent Claim
67 words
In a process for etching copper, the steps of exposing the copper to a gaseous oxidant selected from the group consisting of a nitrogen oxide, a nitrogen oxyhalide, a halogen and combinations thereof in the presence of a catalyst which promotes the reaction of copper with the gaseous oxidant, and removing an oxidized copper species produced by the reaction with a receiver in a substantially dry form.
Claim 18
Dependent Claim
67 words
In a process for etching copper, the steps of exposing the copper to a gaseous oxidant selected from the group consisting of a nitrogen oxide, a nitrogen oxyhalide, a halogen and combinations thereof in the presence of a catalyst which promotes the reaction of copper with the gaseous oxidant, and removing an oxidized copper species produced by the reaction with a receiver in a substantially dry form.
Claim 19
Dependent Claim
21 words
The process of claim 16 wherein the catalyst is carried by a nonliquid medium positioned in close proximity to the copper.
Claim 20
Dependent Claim
25 words
The process of claim 17 wherein the oxidized copper species is received and carried away from the copper as a solid by the nonliquid medium.
Claim 21
Dependent Claim
76 words
The process of claim 16 wherein the nonliquid medium comprises a laminated support having first and second layers of material through which the gaseous oxidant can pass, the catalyst is carried by the first layer, the first layer is positioned in close facing relationship with the surface of the copper to be etched, the second layer is positioned away from the surface of the copper, and the oxidized copper species is received by the second layer.
Claim 22
Dependent Claim
14 words
The process of claim 16 wherein the non-liquid medium comprises a particulate solid material.
Claim 23
Dependent Claim
16 words
The process of claim 16 wherein the medium comprises a fluidized bed of particulate solid material.
Claim 24
Dependent Claim
23 words
The process of claim 16 wherein the catalyst is applied to the surface of the copper in the form of a solid film.
Claim 25
Dependent Claim
19 words
The process of claim 16 wherein the catalyst comprises a polymer film applied to the surface of the copper.
Claim 26
Dependent Claim
19 words
The process of claim 16 wherein the catalyst comprises a polymerized gel applied to the surface of the copper.
Claim 27
Dependent Claim
73 words
In a structure for use in the etching of copper with a gaseous oxidant: a first layer of material through which the gaseous oxidant can pass, a catalyst carried by the layer for promoting the reaction of copper with the oxidant, and a second layer of material through which the gaseous oxidant can pass positioned in proximity to the first layer for collecting and holding an oxidized copper species produced by the reaction.
Claim 28
Dependent Claim
73 words
In a structure for use in the etching of copper with a gaseous oxidant: a first layer of material through which the gaseous oxidant can pass, a catalyst carried by the layer for promoting the reaction of copper with the oxidant, and a second layer of material through which the gaseous oxidant can pass positioned in proximity to the first layer for collecting and holding an oxidized copper species produced by the reaction.
Claim 29
Dependent Claim
21 words
The structure of claim 25 wherein the first layer comprises a hydrophobic material and the second layer comprises a hydrophilic material.
Claim 30
Dependent Claim
13 words
The structure of claim 25 wherein the first layer comprises a polymeric fabric.
Claim 31
Dependent Claim
13 words
The structure of claim 25 wherein the second layer comprises a cellulose mat.
Claim 32
Dependent Claim
47 words
In a chemical process, the steps of exposing a material to a gaseous oxidant in the presence of a catalyst which promotes the reaction of the material with the oxidant, and removing an oxidized species produced by the reaction with a receiver in a substantially dry form.
Claim 33
Dependent Claim
47 words
In a chemical process, the steps of exposing a material to a gaseous oxidant in the presence of a catalyst which promotes the reaction of the material with the oxidant, and removing an oxidized species produced by the reaction with a receiver in a substantially dry form.
Claim 34
Dependent Claim
21 words
The process of claim 29 wherein the catalyst is carried by a non-liquid medium positioned in close proximity to the material.
Claim 35
Dependent Claim
24 words
The process of claim 30 wherein the oxidized species is received and carried away from the material as a solid by the non-liquid medium.
Claim 36
Dependent Claim
78 words
The process of claim 30 wherein the non-liquid medium comprises a laminated support having first and second layers of material through which the gaseous oxidant can pass, the catalyst is carried by the first layer, the first layer is positioned in close facing relationship with the surface of the material to be etched, the second layer is positioned away from the surface of the material to be etched, and the oxidized species is received by the second layer.
Claim 37
Dependent Claim
14 words
The process of claim 30 wherein the non-liquid medium comprises a particulate solid material.
Claim 38
Dependent Claim
17 words
The process of claim 30 wherein the non-liquid medium comprises a fluidized bed of particulate solid material.
Claim 39
Dependent Claim
23 words
The process of claim 29 wherein the catalyst is applied to the surface of the material in the form of a solid film.
Claim 40
Dependent Claim
19 words
The process of claim 29 wherein the catalyst comprises a polymer film applied to the surface of the material.
Claim 41
Dependent Claim
19 words
The process of claim 16 wherein the catalyst comprises a polymerized gel applied to the surface of the material.
Claim 42
Dependent Claim
62 words
In a process for etching copper on a substrate, the steps of: premixing a liquid oxidant with a catalyst which promotes the reaction of copper with the oxidant, applying the mixture to the copper as a thin film, maintaining the mixture in contact with the copper until the copper is dissolved, and removing the mixture and the dissolved copper from the substrate.
Claim 43
Dependent Claim
62 words
In a process for etching copper on a substrate, the steps of: premixing a liquid oxidant with a catalyst which promotes the reaction of copper with the oxidant, applying the mixture to the copper as a thin film, maintaining the mixture in contact with the copper until the copper is dissolved, and removing the mixture and the dissolved copper from the substrate.
Claim 44
Dependent Claim
14 words
The process of claim 38 wherein the oxidant comprises N 2 O 4 .
Claim 45
Dependent Claim
14 words
The process of claim 38 wherein the reaction is carried out at room temperature.
Claim 46
Dependent Claim
24 words
The process of claim 38 wherein the mixture comprises approximately 5.0% cellulose, 21.6% N 2 O 4 , 30.7% acetonitrile and 42.7% dimethyl esters.
Claim 47
Dependent Claim
27 words
The process of claim 38 wherein the mixture comprises approximately 9.19 parts a 10% cellulose acetate in acetonitrile, 0.36 parts surfactant and 2.9 parts liquid nitrogen dioxide.
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) | 1987-05-29 | 1987-11-28 | 1988-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-29 | 1991-11-28 | 1992-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-29 | 1995-11-28 | 1996-05-29 | $7700.00 | Window Closed / Lapsed |