Graphitic surface layer formation on organic substrates for electronics using a concentrated solar simulator

Heat spreading is an important attribute that improves thermal management and operation of high-performance packages, such as those for solid-state power amplifiers. This attribute can be enhanced through direct transformation of polymers into graphitic films. The present work reports a custom vacuum deposition process that synthesizes thin graphitic layers on organic substrates through direct pyrolysis via concentrated irradiation from a xenon lamp to produce a peak heated zone of approximately 3 cm diameter with a maximum heat flux of 3.2 MW/m². The light source, replaceable with concentrated terrestrial solar power, provides ultrafast heating of substrates through rapid flashes (< 0.5 s) and improves growth rates over relatively larger areas compared to laser processing, mitigating the issue of porosity in graphitic layers that deteriorate heat spreading capabilities. The enhanced organic substrates are analyzed using Raman and energy-dispersive X-ray spectroscopy, scanning electron microscopy, and thermal diffusivity measurements, indicating graphitic conversion. Graphical abstract: [Figure not available: see fulltext.]