INTEGRAL STRAIN TRANSDUCER AND METHOD OF ITS MANUFACTURE Russian patent published in 1995 - IPC

FIELD: semiconductor strain gauges. SUBSTANCE: principle of strain transducer operation is based on dependence between resistance of semiconducting material and internal stresses arising inside this material. With the respective shape of resistance strain gauge, these internal stresses may exceed stresses arising in material of strain gauge backing 1. Strain sensing elements 2 are made integral with current carrying paths 3 in the form of a layer, strain-sensitive axis of which is oriented along specified axis X of semiconducting material strip of varying width. Boundaries of this strip are symmetrical relative to specified axis X and are formed by sections of concave and convex curves alternating with constant pitches. Radius of curvature of concave curves at points nearest to specified axis is the least tolerable for strength of material used and for distance between these points, and thickness of backing 1 exceeds thickness of semiconducting material. In compliance with the method of manufacture of integral strain transducer, layer of strain sensing material is formed before application of protective mask. Protective mask shall cover only area of future strain sensing elements and current carrying paths and unprotected sections of strain sensing material are etched through its entire depth. EFFECT: improved accuracy in measuring low values of strain with high degree of linearity and stability. 3 cl, 1 dwg