Electrical resistance element with a semiconductor overlay
Abstract
Abstract A thin film overlay of a semi-conductive material, such as germanium, silicon, indium antimonide, titanium oxide or ferric oxide, covers the resistor track of a film resistance element. A resistance element incorporating this improvement, as compared with one having a noble metal overlay, has a much lower temperature coefficient of resistance. A germanium overlay may be provided by evacuating the space about the resistive element to a pressure of about 2 X 10 5 torr, supplying the germanium material in granular particles ranging in fineness between 180320 mesh by vibration and gravity in a steady and even flow thereof to the evacuated space at a point with respect to which the resistor track is exposed, and then evaporating the germanium at the point by electrical resistance heating to vaporization temperature at about 1,850* C. When used in a potentiometer with a movable contact, a resistance element so made exhibits superior wear stability, and good contact resistance variation characteristics.
Inventors
- 👤 Robert M Healy
- 👤 Robert Marshall
Bibliographic Details
Claims Analysis
Total Claims: 5References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |