US3596039A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Trimming thin-film capacitors by spark erosion
Assignee: Sprague Electric Co
•
Filing: 1969-07-14
•
Granted: 1971-07-27
•
Expires: 1989-07-14
Abstract
Abstract Both electrodes of a thin film capacitor are shorted to ground. A high-voltage pulse is applied to a needle electrode that is separated from the electrodes a sufficient distance to permit formation of a spark which burns away a portion of both electrodes.
Inventors
- 👤 Michael Edmond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:38
CPC Classifications
H; H01; H01G; H01G4/00; H01G4/002; H01G4/255; H05; H05K; H05K1/00; H05K1/16; H05K1/162; H05K3/00; H05K3/02; H05K3/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
90 words
A technique for fine tRimming of thin-film capacitors having a thin dielectric layer between thin film electrodes, whereby small portions of said capacitor electrodes are removed by means of an electrical spark, both of said capacitor electrodes being short-circuited and earthed, high voltage from an earthed Teslatransformer being on a needle electrode which is spaced from the capacitor without touching either of said capacitor electrodes a distance such that a spark is produced between said capacitor and said needle electrode, by which means portions of both said electrodes are removed.
Claim 2
Dependent Claim
90 words
A technique for fine tRimming of thin-film capacitors having a thin dielectric layer between thin film electrodes, whereby small portions of said capacitor electrodes are removed by means of an electrical spark, both of said capacitor electrodes being short-circuited and earthed, high voltage from an earthed Teslatransformer being on a needle electrode which is spaced from the capacitor without touching either of said capacitor electrodes a distance such that a spark is produced between said capacitor and said needle electrode, by which means portions of both said electrodes are removed.
Claim 3
Dependent Claim
21 words
A technique as in claim 1 in which said capacitor has a substrate which is place on an earthed metal plate.
Claim 4
Dependent Claim
26 words
A technique as in claim 1 in which the spark gap between said capacitor and said needle electrode is set between 0.2 mm. and 1 mm.
Claim 5
Dependent Claim
16 words
A technique as in claim 1 in which the level of the high voltage is varied.
Claim 6
Dependent Claim
18 words
A technique as in claim 4 in which the high voltage lies between 40 kv. and 60 kv.
Claim 7
Dependent Claim
15 words
A technique as in claim 1 in which the capacitor is alternately trimmed and measured.
Claim 8
Dependent Claim
40 words
A technique as in claim 6 in which said earthed Tesla-transformer, a measuring bridge, said needle electrode, two contacts, and a switch are so arranged that the capacitor can be alternately connected to a measuring bridge or the high voltage.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |