Reducing the Possibility of Subjective Error in the Determination of the Structure-Function-Based Effective Thermal Conductivity of Boards

TL;DR

This paper introduces a method to determine the effective thermal conductivity of boards using a wide-range structure function, reducing subjective errors compared to traditional point-based methods, validated through simulations and measurements.

Contribution

A novel approach applying a wide section of the structure function for thermal conductivity determination, minimizing subjective point selection errors.

Findings

The method reduces subjective error in thermal conductivity measurement.

Validated effectiveness through simulated and experimental thermal responses.

Achieves 2-5% accuracy in determining thermal conductivity.

Abstract

The thermal response function given to a unit-step dissipation accurately characterizes the thermal system. Instead of the thermal response function the so-called structure function describing three-dimensional as the equivalent model of one-dimensional heat-spreading, created from the thermal response function with the help of complex mathematical procedures, is often used. Using the structure function the partial thermal capacity and partial heat resistance of certain elements of the thermal system can be identified. If the geometrical measurements of a thermal system of simple geometry and homogeneous material (such as a homogeneous rod or board, etc.) are known, the coefficient of thermal conductivity of the material in question can be determined from two points of the structure function at 2-5 per cent of accuracy. In this paper a method is presented which applies a wide range/section instead of two points of the cumulative structure function to determine the thermal coefficient, thus reducing the subjective error deriving from the selection of the two points. The above method is presented and illustrated in simulated as well as measured thermal transient responses.