Laser resistance trimmer
US4184062A · kind A · utility
Inventor
Key dates
| Filing date | Oct 25, 1977 |
| Grant date | Jan 15, 1980 |
| Priority date | — |
| Expiry date | Oct 25, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49099
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
This invention relates to an apparatus and method for adjusting the resistance value of an elongated resistance film of typically inconsistent density which has been deposited on an insulative substrate. The resistance incremental of this film is measured between a start point and a wiper point. This resistance is then compared with a specified resistance, and an error signal is generated responsive to any error between the measured resistance and the specified resistance. The error signal is used to regulate the relative motion between a laser beam and the resistance film, with the motion being generally transverse to a longitudinal axis of the resistance film. This motion causes the finely focused laser beam to burn an insulative separation path in the resistance film, thereby regulating the effective width of the resistance film. This regulation of the effective width progresses in a continuous manner over the entire length of the active portion of the resistive element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.