Optimization of Baking Temperature for Minimization of Interfacial Thermal Resistance in Polymer/SiC Bilayer Structure Using Optical-Interference Contactless Thermometry (OICT)

Interfacial thermal resistance is a critical issue in thermal management for power device packaging. This study investigates the influence of baking temperature on interfacial thermal resistance at the polymer/SiC interface using optical-interference contactless thermometry. By controlling the solidification process of SU-8 through a combination of pre-heating, UV exposure, and baking, SU-8/SiC bilayer samples were fabricated with baking temperatures ranging from 75 to 200°C. Increasing baking temperature gives rise to an initial reduction to interfacial thermal resistance, reaching a minimum of 6 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>KW<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> at 100°C. As the baking temperature continuous to rise to 200°C, interfacial thermal resistance increases significantly to 320 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>KW<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup>. These results highlight the profound influence of fabrication conditions on thermal interface performance and offer a practical strategy to minimize interface thermal resistance by optimizing the baking temperature during fabrication.