Strain gauge strip element and method of its manufacture

US4310823A · kind A · utility

Assignee

• W. C. Heraeus GmbH · DE

Inventors

• Norbert Rucker · Northeim, DE
• Michael Sellschopp · Hammersbach, DE
• Hans-Ullrich Fuchs · Hanau, DE

Key dates

• Filing date: Jan 14, 1980
• Grant date: Jan 12, 1982
• Expiry date: Jan 14, 2000

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L1/2287
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

To permit adhesion of a strain gauge grid applied to a high temperature plastic, such as a polyimide, the side of the strip of polyimide which is to be attached to the support frame, the strain of which is to be measured, has a solderable surface applied thereto which consists, essentially, of three sublayers, as follows: PA1 A first sub-layer of from 1 to 8 .mu.m thickness of chromium nickel alloy, containing, for example, about 20% (by weight) of chromium, or an iron chromium nickel alloy containing, for example, about 50% iron, 49% nickel and 1% chromium (by weight); PA1 a second sub-layer of at least about 5 .mu.m thickness, preferably about 7.5 .mu.m thickness of nickel and a third outer sub-layer of gold, for example, between about 4 to 10 .mu.m thick, preferably, about 7 .mu.m. The various sub-layers are applied, for example, after cleaning of the element with a volatile hydrocarbon, or toluol, by vapor deposition, for example, vaporization from a tungsten boat of the respective materials.