Temperature-dependent electronic circuit analogy for predicting wire temperature as a function of current

A model has been developed accurately predicting the temperature along a length of wire heated by passing a current through it. The wire is modeled as a transmission line with its thermal properties mapped onto the appropriate electronic analogs. A program describing the model circuit has been written in PSPICE such that time versus temperature curves can be generated for any wire given the material, diameter, length, and stressing current. The model has been dynamically temperature corrected, and its accuracy has been demonstrated for two types of fuses and one type of bond wire. This model is useful for predicting fusing conditions of fuse elements or bond wires, assessing the reliability of a material for given operating conditions (by knowing the temperature the material would attain), derating for design, and as a failure analysis tool by providing insight into an overstress condition in which a wire has melted open.