Thin-film resistor anodization
Abstract
Abstract A method for adjusting the electrical resistance of thin-film metallic resistors by anodization is disclosed. The method includes the steps of: (1) supplying an electrolyte between a thin-film resistor and a cathode spaced therefrom; (2) applying a measuring voltage across the resistor for a period of time sufficient to determine the resistance of the resistor; (3) removing the measuring voltage, and if the resistance is below a desired value, passing an anodizing direct current between the resistor and the cathode for a time sufficient to anodize a surface of the resistor and thereby increase its resistance, the magnitude of the anodizing current and period of time being selected so as to produce an increase in resistance by an increment proportional to the difference between the desired value and the measured value of the resistance; (4) repeating step (2); and (5) terminating the anodizing of the resistor when the measured electrical resistance reaches a desired value.
Inventors
- 👤 Frederick C Livermore
- 👤 Graham Albert Neathway
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |