US4536322A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorescent corrosive fluoride solution
Assignee: LONDON CHEMICAL COMPANY Inc A DE CORP
•
Filing: 1983-10-28
•
Granted: 1985-08-20
•
Expires: 2003-10-28
Abstract
Abstract A composition of matter including an aqueous solution of hydrofluoric acid or ammonium fluoride and a dye that fluoresces when illuminated by ultra-violet light. Spilled corrosive fluoride solutions are thereby rendered easily detectable by subjecting the surface onto which the solution was spilled to ultra-violet radiation.
Inventors
- 👤 Gary A. Amstutz
- 👤 Kishor D. Mayekar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:20
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/06
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
69 words
An aqueous etchant solution comprising: a corrosive fluoride etchant component and a non-metallic, organic, normally colorless dye that fluoresces in the visible region when illuminated by ultra-violet light and which is non-reactive with the corrosive fluoride etchant component said dye being an organic dye having the general formula: ##STR2## whose R 1 =NH 2 or OH R 2 =C 1 -C 18 alkyl or fluorosubstituted methyl X=O or N.
Claim 2
Dependent Claim
69 words
An aqueous etchant solution comprising: a corrosive fluoride etchant component and a non-metallic, organic, normally colorless dye that fluoresces in the visible region when illuminated by ultra-violet light and which is non-reactive with the corrosive fluoride etchant component said dye being an organic dye having the general formula: ##STR2## whose R 1 =NH 2 or OH R 2 =C 1 -C 18 alkyl or fluorosubstituted methyl X=O or N.
Claim 3
Dependent Claim
22 words
The solution of claim 1 wherein said corrosive fluoride components are selected from the group consisting of hydrogen fluoride and ammonium fluoride.
Claim 4
Dependent Claim
20 words
The aqueous solution of claim 1 wherein said dye fluoresces at a wavelength visible in wafer fabrication "safe light" conditions.
Claim 5
Dependent Claim
30 words
The solution of claim 1 wherein said dye fluoresces when radiated with ultra-violet light having a wavelength in the range of from between about 250 nanometers to about 370 nanometers.
Claim 6
Dependent Claim
23 words
The solution of claim 1 wherein the dyes are present in concentrations in the range of between 0.5 and 50 milligrams per liter.
Claim 7
Dependent Claim
20 words
The solution in claim 1 wherein the dyes are present in concentrations of between 1 and 10 milligrams per liter.
Claim 8
Dependent Claim
15 words
The solution of claim 1 including a component selected from acetic acid and nitric acid.
Claim 9
Dependent Claim
12 words
The aqueous solution of claim 1 wherein said dye is 7-Hydroxy-4-methyl coumarin.
Claim 10
Dependent Claim
12 words
The aqueous solution of claim 1 wherein said dye is 7-Amino-4-methyl coumarin.
Claim 11
Dependent Claim
12 words
The aqueous solution of claim 1 wherein said dye is 7-Amino-4-trifluoromethyl coumarin.
Claim 12
Dependent Claim
11 words
The aqueous solution of claim 1 wherein said dye is 2,6-Diaminopyridine.
Claim 13
Dependent Claim
11 words
The aqueous solution of claim 1 wherein said dye is 2-(2-Pyridyl)benzimidazole.
Claim 14
Dependent Claim
12 words
The aqueous solution of claim 1 wherein said dye is Trans-o-coumaric acid.
Claim 15
Dependent Claim
12 words
The aqueous solution of claim 1 wherein said dye is 7-Methoxycoumarin-4-acetic acid.
References Cited (Backward Citations)
US26888A
Cited
US3257167A
Cited
USRE26888E
Cited
US3773464A
Cited
US3960559A
Cited
JPS527682A
Cited
US4410396A
Cited
US4375384A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-19 | 1989-02-18 | 1989-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-19 | 1993-02-18 | 1993-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-19 | 1997-02-18 | 1997-08-20 | $7700.00 | Window Closed / Lapsed |