US3882324A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for combustibly destroying microelectronic circuit board interconnections
Assignee: United States Department of the Navy
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Filing: 1973-12-17
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Granted: 1975-05-06
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Expires: 1993-12-17
Abstract
Abstract Metallized interconnections conventionally are used to interconnect active and passive components of MOS (metal-oxide semiconductor) circuits and the like. These and other similar metal interconnections can be formed of electrically-conductive, self-destruct aluminum and tungstic oxide films or other similar metal oxide films, which, when ignited, produce a selfdestructive, violent, exothermic chemical reaction. Ignition of the self-destruct interconnections is achieved by enclosing the circuit board in a box which also mounts a sheet of pyrofuse foil. The enclosed metallized connections are directly exposed to the foil so that, when the foil is ignited, the high heat of its thermite reaction ignites the self-destruct film interconnections. The violent reaction of the foil also produces a sputtering of high temperature metal particles which strike the metallized interconnections at various points to positively assure ignition and the desired destruction of these interconnections.
Inventors
- 👤 Gary Smolker
- 👤 Leon Chernick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:15
CPC Classifications
H; H10; H10W; H10W42/00; H10W42/40; F; F41; F41H; F41H13/00; H10W20/00; H10W20/40; H10W20/49; H10D; H10D89/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
129 words
Self-destruct apparatus for combustibly destroying circuit board electrical interconnectors comprising: a box-like enclosure, a microelectronic circuit board provided on one of its surfaces with electrical circuit interconnectors formed of superimposed films of metallized electrically-conductive exothermicallyreactive materials adapted when ignited to self-destructively maintain combustion, an ignitable and combustible sheet formed of exothermically reactive materials having an auto-ignition temperature approximating that of said interconnector materials, and remotely-controllable means of igniting said sheet, said circuit board and said ignitable sheet being disposed in a spaced relationship within said box-like enclosure with said circuit board interconnectors spanned by and directly exposed to said sheet, whereby ignition and combustion of said exothermic sheet directly and indirectly applies to said interconnectors a temperature sufficient to produce the auto-ignition and the desired destruction of said interconnectors.
Claim 2
Dependent Claim
129 words
Self-destruct apparatus for combustibly destroying circuit board electrical interconnectors comprising: a box-like enclosure, a microelectronic circuit board provided on one of its surfaces with electrical circuit interconnectors formed of superimposed films of metallized electrically-conductive exothermicallyreactive materials adapted when ignited to self-destructively maintain combustion, an ignitable and combustible sheet formed of exothermically reactive materials having an auto-ignition temperature approximating that of said interconnector materials, and remotely-controllable means of igniting said sheet, said circuit board and said ignitable sheet being disposed in a spaced relationship within said box-like enclosure with said circuit board interconnectors spanned by and directly exposed to said sheet, whereby ignition and combustion of said exothermic sheet directly and indirectly applies to said interconnectors a temperature sufficient to produce the auto-ignition and the desired destruction of said interconnectors.
Claim 3
Dependent Claim
18 words
The apparatus of claim 1 wherein said interconnectors are formed by adjacently-deposited films of aluminum and tungstic oxide.
Claim 4
Dependent Claim
17 words
The apparatus of claim 2 wherein said ignitable sheet is a pyrofuse foil formed lead and aluminum.
Claim 5
Dependent Claim
32 words
The apparatus of claim 3 wherein said circuit board includes a metal-oxide semiconductor substrate and said metallized interconnectors are employed to complete an electronic circuit incorporating circuit elements formed in said substrate.
Claim 6
Dependent Claim
29 words
The apparatus of claim 4 wherein the aluminum film is about 1000 A, the tungstic oxide film is about 1200 A and the pyrofuse foil is about .0008 inch.
Claim 7
Independent Claim
74 words
A method of combustibly destroying microelectronic circuit board interconnectors comprising: forming the interconnectors of superimposed films of metallized electrically-conductive exothermically-reactive materials adapted when ignited to self-destructively maintain combustion, and igniting said interconnectors by combustibly disintegrating a pyrofuse-like film in close proximity to the interconnectors, the ignition and combustion of said interconnectors being promoted by the heat of combustion of said pyrofuse-like film and by the direct contacts of hot film fragments with the interconnectors.
Claim 8
Independent Claim
74 words
A method of combustibly destroying microelectronic circuit board interconnectors comprising: forming the interconnectors of superimposed films of metallized electrically-conductive exothermically-reactive materials adapted when ignited to self-destructively maintain combustion, and igniting said interconnectors by combustibly disintegrating a pyrofuse-like film in close proximity to the interconnectors, the ignition and combustion of said interconnectors being promoted by the heat of combustion of said pyrofuse-like film and by the direct contacts of hot film fragments with the interconnectors.
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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |