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US4319955A
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Ammoniacal alkaline cupric etchant solution for and method of reducing etchant undercut
Assignee: C P INORGANICS Inc
•
Filing: 1980-11-05
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Granted: 1982-03-16
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Expires: 2000-11-05
Abstract
Abstract An improved ammoniacal alkaline etchant solution and method of reducing etchant undercut for use in etching copper and copper-containing alloy traces on substrates having resist-coated areas and non-coated areas, which reduces the amount of undercutting beneath the resist-coated areas that lie above the copper traces. The improved etchant solution contains an organic undercut inhibitor which can be either 5-nitro-1H indazole or pyrazole and the improved method includes the step of incorporating said organic undercut inhibitor in a standard ammoniacal alkaline cupric etchant solution. The organic undercut inhibitor causes the formation of a bath-insoluble, physically weak, etch-resistant film on the copper substrate. Said film serves to protect the side walls of an etched depression and thereby diminishes undercutting.
Inventors
- 👤 Kenneth J. Murski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:22
CPC Classifications
C; C23; C23F; C23F1/00; C23F1/10; C23F1/14; C23F1/32; C23F1/34; H; H05; H05K; H05K3/00; H05K3/02; H05K3/06; H05K3/067
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
53 words
In an improved ammoniacal alkaline etchant solution for etching copper and copper-containing alloy traces on substrates having resist-coated areas and non-coated areas, the improvement comprising, an organic undercut inhibitor for reducing the amount of undercutting beneath the resist-coated areas that lie above the copper traces, said organic undercut inhibitor being 5-nitro-1 H indazole.
Claim 2
Dependent Claim
53 words
In an improved ammoniacal alkaline etchant solution for etching copper and copper-containing alloy traces on substrates having resist-coated areas and non-coated areas, the improvement comprising, an organic undercut inhibitor for reducing the amount of undercutting beneath the resist-coated areas that lie above the copper traces, said organic undercut inhibitor being 5-nitro-1 H indazole.
Claim 3
Dependent Claim
51 words
In an improved ammoniacal alkaline etchant solution for etching copper and copper-containing alloy traces on substrates having resist-coated areas and non-coated areas, the improvement comprising, an organic undercut inhibitor for reducing the amount of undercutting beneath the resist-coated areas that lie above the copper traces, said organic undercut inhibitor being pyrazole.
Claim 4
Dependent Claim
51 words
In an improved ammoniacal alkaline etchant solution for etching copper and copper-containing alloy traces on substrates having resist-coated areas and non-coated areas, the improvement comprising, an organic undercut inhibitor for reducing the amount of undercutting beneath the resist-coated areas that lie above the copper traces, said organic undercut inhibitor being pyrazole.
Claim 5
Dependent Claim
57 words
An improved ammoniacal alkaline etchant solution for etching copper and copper-containing alloy traces on substrates, having resist-coated areas and non-coated areas consisting essentially of: ______________________________________
cupric ions as metallic copper
1.0-2.8
moles/liter
ammonium chloride 2.2-6.2
moles/liter
ammonium hydroxide 2.0-9.0
moles/liter
ammonium phosphate-mono-basic,
0.001-0.10
NH.sub.4 H.sub.2 PO.sub.4
moles/liter
5-nitro-1H Indozole 0.096-0.24
g/liter
Water g.s. to 1 liter
______________________________________
Claim 6
Dependent Claim
57 words
An improved ammoniacal alkaline etchant solution for etching copper and copper-containing alloy traces on substrates, having resist-coated areas and non-coated areas consisting essentially of: ______________________________________
cupric ions as metallic copper
1.0-2.8
moles/liter
ammonium chloride 2.2-6.2
moles/liter
ammonium hydroxide 2.0-9.0
moles/liter
ammonium phosphate-mono-basic,
0.001-0.10
NH.sub.4 H.sub.2 PO.sub.4
moles/liter
5-nitro-1H Indozole 0.096-0.24
g/liter
Water g.s. to 1 liter
______________________________________
Claim 7
Independent Claim
85 words
A method of reducing the amount of undercutting beneath the resist-coated areas that lie above the copper and copper-containing alloy traces, on substrates, comprising the steps of: (a) providing an ammoniacal alkaline etching solution consisting essentially of: cupric ions ammonium chloride; ammonium hydroxide; ammoniun phosphate-mono basic and water, and (b) incorporating into said ammoniacal alkaline etching solution an organic undercut inhibitor for reducing the amount of undercutting beneath the resist-coated areas that lie above the copper traces, said organic undercut inhibitor being 5-nitro-1 H indazole.
Claim 8
Independent Claim
85 words
A method of reducing the amount of undercutting beneath the resist-coated areas that lie above the copper and copper-containing alloy traces, on substrates, comprising the steps of: (a) providing an ammoniacal alkaline etching solution consisting essentially of: cupric ions ammonium chloride; ammonium hydroxide; ammoniun phosphate-mono basic and water, and (b) incorporating into said ammoniacal alkaline etching solution an organic undercut inhibitor for reducing the amount of undercutting beneath the resist-coated areas that lie above the copper traces, said organic undercut inhibitor being 5-nitro-1 H indazole.
Claim 9
Independent Claim
83 words
A method of reducing the amount of under-cutting beneath the resist-coated areas that lie above the copper and copper-containing alloy traces, or substrates, comprising the steps of: (a) providing an ammoniacal alkaline etching solution consisting essentially of: cupric ions; ammonium chloride; ammonium hydroxide; ammonium phosphate-mono basic and water, and (b) incorporating into said ammoniacal alkaline etching solution an organic undercut inhibitor for reducing the amount of undercutting beneath the resist-coated areas that lie above the copper traces, said organic undercut inhibitor being pyrazole.
Claim 10
Independent Claim
83 words
A method of reducing the amount of under-cutting beneath the resist-coated areas that lie above the copper and copper-containing alloy traces, or substrates, comprising the steps of: (a) providing an ammoniacal alkaline etching solution consisting essentially of: cupric ions; ammonium chloride; ammonium hydroxide; ammonium phosphate-mono basic and water, and (b) incorporating into said ammoniacal alkaline etching solution an organic undercut inhibitor for reducing the amount of undercutting beneath the resist-coated areas that lie above the copper traces, said organic undercut inhibitor being pyrazole.
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) | 1985-03-15 | 1985-09-14 | 1986-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-03-15 | 1989-09-14 | 1990-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-03-15 | 1993-09-14 | 1994-03-16 | $7700.00 | Window Closed / Lapsed |