PROPERTIES OF FLAT NICKEL-CHROMIUM FILM RESISTORS
Abstract
Vacuum-deposited resistors with values ranging from 35 to 4700 ohms per sq in. were prepared and studied. The resistors were made by first depositing a layer of Ni-Cr alloy on glass substrates and then a protective layer of SiO. Heating at 250 C for 10 min caused the values of the resistors to increase by 95% for the thinnest films and by 0.3% for the thickest. A shelf-life study of the test resistors showed most of them to be stable with ! 10% over a period of more than 3000 hr of storage at room temperature; for the same resistors, the change due to storage in air at 70 C for 2900 hr ranged from 4.5 to 27%. It was found that reproducible resistors were more readily obtained when the end contacts or electrodes were deposited over the resistor films than when this procedure was reversed. Power capacities up 1.7 w/sq cm were measured. Excluding annealing effects, the values of temperature coefficient of resistance varied from +4 to +220 ppm/ degree C. It is concluded that the resistors are adequate for certain circuit applications; however, with respect to power capacity, certain limitations must be taken into account. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 26, 1961
- Accession Number
- AD0263388
Entities
People
- William E. Isler