Patent ID: 9638589
Date: 2017-05-02
CPC Classifications: G01B,G01L,H01L

Claim:
1. A method for determining a three-dimensional stress field of an object having a flat surface, the method comprising: measuring variations in resistive values of a group of resistors on the flat surface of the object, with each resistor in the group of resistors having a same material concentration level, and with the group of resistors comprising at least four flat resistors, each resistor having a resistive value, and each resistor having a geometric shape defined by a line width and a line spacing forming the geometric shape, and at least one of the resistors having a geometric shape that is different from the geometric shape of the other resistors; and determining the three-dimensional stress field from a system of equations and based upon the measured variations in the resistive values and sensitivity parameters of the resistors, the sensitivity parameters including at least one of a longitudinal sensitivity, a transverse sensitivity and a vertical sensitivity.