Heat-Electric Field Conversion Model for Measuring Current Density: A Combined Simulation and Experimental Study

The distribution of current density is crucial for the performance, reliability, and thermal management of electronic devices and conductive materials. Based on heat conduction theory and Joule's law, this paper establishes a model for converting the thermal field to electric field under AC heat sources and proposes a non-contact method for measuring current density. This method uses an infrared thermal camera to extract temperature distribution and indirectly derive current density, offering high spatial resolution. By separating steady-state periodic variations from transient temperature rises in the temperature distribution, finite element simulations confirmed the proposed coupling between thermal and electric fields, revealing that the amplitude of temperature variations at twice the current frequency is positively correlated with current amplitude and inversely correlated with frequency. The results show that high-resolution temperature distributions obtained via infrared thermography can quantitatively detect current density distribution, aiding in reliability analysis of electronic devices and conductive materials, with significant potential applications in materials science and electrical engineering.