Patent EP0369566A2 successfully refreshed from Google Patents.
Patent US3617684A successfully refreshed from Google Patents.
US3617684A
Expired / Lapsed
US
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Electronic trimming of microelectronic resistors
Assignee: Datapax Computer Systems Corp
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Filing: 1970-02-24
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Granted: 1971-11-02
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Expires: 1990-02-24
Abstract
Abstract An electronic technique for changing the ohmic values of microelectronic resistors formed on a substrate, so as to either increase or decrease the values thereof without affecting their physical qualities. To bring about a decrease in value, the surface of the resistor is subjected to a corona discharge produced by radiofrequency energy having a low-frequency amplitude modulation component. The same energy source is used to effect an increase in ohmic value, this being effected by passing a heating current through the body of the resistor.
Inventors
- 👤 Alfonso Di Mino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:26
CPC Classifications
H; H01; H01C; H01C17/00; H01C17/22; H01C17/26; H01C17/265; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49099
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
131 words
An electronic technique for trimming the ohmic value of a microelectronic resistor printed on a substrate, the technique comprising the steps of: A. generating radiofrequency energy including an audiofrequency amplitude-modulation component to render the energy effectively pulsatory in nature, B. applying the energy in high-voltage form to a first probe at a level sufficient to create a corona discharge, C. applying the energy in low voltage form to a second probe at a level sufficient to effect resistive heating, D. bringing the first probe into the proximity of a point on the resistor to create a corona discharge causing a decrease in resistance value, and E. bringing the second probe into contact with a point on the resistor to produce a heating current flow therein causing an increase in resistance value.
Claim 2
Dependent Claim
131 words
An electronic technique for trimming the ohmic value of a microelectronic resistor printed on a substrate, the technique comprising the steps of: A. generating radiofrequency energy including an audiofrequency amplitude-modulation component to render the energy effectively pulsatory in nature, B. applying the energy in high-voltage form to a first probe at a level sufficient to create a corona discharge, C. applying the energy in low voltage form to a second probe at a level sufficient to effect resistive heating, D. bringing the first probe into the proximity of a point on the resistor to create a corona discharge causing a decrease in resistance value, and E. bringing the second probe into contact with a point on the resistor to produce a heating current flow therein causing an increase in resistance value.
Claim 3
Dependent Claim
22 words
A technique as set forth in claim 1 wherein said radiofrequency energy is in the range of about 800 to 1,000 kilohertz.
Claim 4
Dependent Claim
18 words
A technique as set forth in claim 1 wherein said audiofrequency component is about 2,000 to 3,000 Hz.
Claim 5
Dependent Claim
35 words
A technique as set forth in claim 1, further including the steps of measuring the value of the resistor in the course of testing and cutting off said energy when the measured value is correct.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |