Kermit E Sonney

US Patent:

41594614, Jun 26, 1979

Filed:

Nov 22, 1977

Appl. No.:

5/854049

Inventors:

Frederick H. Kost - Raleigh NC
Kermit E. Sonney - Raleigh NC
Timothy M. Kougher - Raleigh NC

Assignee:

Stackpole Components Co. - Raleigh NC

International Classification:

H01C 1000

US Classification:

338195

Abstract:

A film resistor network horizontal geometry having extended trim ratio and improved trimming and operating characteristics and method of using the same. The film resistor network comprises an insulating substrate having at least one film resistor formed thereon and a pair of opposed film conductor electrodes disposed on opposite sides of the film resistor. The side edges of the film resistor engaged by the film conductor electrodes flare outwardly from the bottom edge of the film resistor, at least on one side, and terminate in a dome-shaped top region that preferably is elongated semi-cylindrical in configuration. The dome-shaped top region is not engaged by the film conductor electrodes and the film resistor is trimmed by removal of a notch from the film resistor starting from the bottom edge and extending upwardly along a line substantially centered beneath the apex of the dome. With a film resistor thus formed, the trim ratio (TR) will conform to the expression TR=(1+%. DELTA. R/laser bite). sup.