Adjustment of thick film resistor (TCR) by laser annealing
US4703557A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1986 |
| Grant date | Nov 3, 1987 |
| Priority date | — |
| Expiry date | Oct 7, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49099
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The adjustment of the temperature coefficient of resistance (TCR) of a thick film resistor by laser annealing is disclosed. The thick film resistor is fired for a controlled time and temperature sufficient to burn off the organic material in the resistive paint, and to provide an initial adjustment of the (TCR), but prior to obtaining the desired (TCR) range. The resistor is then laser annealed to controllably adjust the (TCR) of the resistor within the desired (TCR) range. The fixture used to hold the substrate during laser annealing is preferably controllably heated to avoid thermal shock to the resistor during laser annealing. A microprocessor is preferably used to monitor the (TCR) during the laser annealing process. At least one of the laser scan speed, laser beam diameter, laser beam power, and number of annealing passes are used to controllably adjust the resistor (TCR) to within the desired (TCR) range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.