Patent US4237379A successfully refreshed from Google Patents.
US4237379A
Expired / Lapsed
US
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Method for inspecting electrical devices
Assignee: RCA Corp
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Filing: 1979-06-22
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Granted: 1980-12-02
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Expires: 1999-06-22
Abstract
Abstract A method of inspecting electrical devices such as integrated circuit devices which have conductors covered by a protective layer of passivating material to determine the quality of the protective layer includes treating the circuit with a fluorescein containing dye and exposing the treated device to UV radiation while applying a voltage between two conductors. Fluorescence is observable in well passivated areas of the device but not in unpassivated or inadequately passivated areas. When a device is tested before dicing from a wafer, adjacent devices to which no voltage is applied fluoresce in both passivated and unpassivated areas.
Inventors
- 👤 Cheryl A. Deckert
- 👤 Robert B. Comizzoli
- 👤 George L. Schnable
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:36
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/28; G01R31/302; G01R31/308
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
53 words
A method for inspecting an electrical device, which has conductors covered by a protective layer of passivating material, to determine the quality of said protective layer comprising the steps of coating said device with fluorescent dye, applying electrical energy to two conductors of said device, and exposing said fluorescent dye to actinic radiation.
Claim 2
Independent Claim
53 words
A method for inspecting an electrical device, which has conductors covered by a protective layer of passivating material, to determine the quality of said protective layer comprising the steps of coating said device with fluorescent dye, applying electrical energy to two conductors of said device, and exposing said fluorescent dye to actinic radiation.
Claim 3
Dependent Claim
47 words
A method as defined in claim 1 applied to a monolithic integrated circuit device in which said two conductors are connected via at least one PN junction, in which the electrical energy is supplied by a DC voltage, the polarity of which reverse biases said PN junction.
Claim 4
Dependent Claim
13 words
A method as defined in claim 1 wherein said fluorescent dye contains fluorescein.
Claim 5
Dependent Claim
29 words
A method as defined in claim 1 further comprising carrying out said applying and exposing steps in an atmosphere of controlled relative humidity between about 0% and about 70%.
Claim 6
Dependent Claim
17 words
A method as defined in claim 1 wherein said fluorescent dye comprises fluorescein and a nonvolatile solvent.
Claim 7
Dependent Claim
15 words
A method as defined in claim 5 wherein said fluorescent dye further comprises a surfactant.
Claim 8
Dependent Claim
18 words
A method as defined in claim 6 wherein said nonvolatile solvent comprises glycerol in an excess of ethanol.
Claim 9
Dependent Claim
26 words
A method as defined in claim 7 wherein the concentration of glycerol in the ethanol is between about 0.2 volume % and about 1.0 volume %.
Claim 10
Dependent Claim
20 words
A method as defined in claim 7 wherein the concentration of glycerol in the ethanol is about 1.0 volume %.
Claim 11
Dependent Claim
19 words
A method as defined in claim 9 wherein the amount of fluorescein in said dye is about 0.6 grams/liter.
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) | 1983-12-02 | 1984-06-02 | 1984-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-02 | 1988-06-02 | 1988-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-02 | 1992-06-02 | 1992-12-02 | $7700.00 | Window Closed / Lapsed |