Session: 10-01 Interactive Presentations

Paper Number: 100320

100320 - Thin Flat Boiling-Driven Heat Spreader 

High heat dissipation is facing up with a high-performance electronic component becoming miniaturized due to the development of advanced technologies. The failure in thermal management of electronic components raises the temperature of the semiconductor and affects the performance and reliability of electronic products. The current high-performance electronic components require thermal management methods for the high heat flux of more than 100 W/cm². This study presented a new concept of passive heat spreader (boiling-driven heat spreader) using phase-change heat transfer. The boiling-driven heat spreader is a flat heat spreader similar to the vapor chamber, has no wick structure, and has a simple internal design, making it easy to fabricate.

The boiling-driven heat spreader is fabricated by spot welding a copper sheet in the form of a lid to a copper plate of 90 mm x 90 mm x 2 mm with a rib structure. Since the copper plate is machined, it is possible to precisely fabricate the shape of the desired rib and the inner cavity space. Deionized degassed water is used as the working fluid in the boiling-driven heat spreader. The microporous coating that enhances boiling is applied to a copper sheet to cover the 25 mm × 25 mm area. Bubbles generated by boiling supply a large amount of working fluid to the hotspot due to the bubble pumping.

The performance of the boiling-driven heat spreader was confirmed through an experiment using a water-cooled heat sink. A 10 mm x 10 mm ceramic heater was soldered to the center of the copper sheet, and TIM was used to minimize the contact thermal resistance between the boiling-driven heat spreader and the heat sink. The cooling water temperature was set at 40°C, and an experiment was carried out by applying a heat flux up to 200 W/cm². As a result, the boiling-driven heat spreader performs evenly well in all directions, and a junction temperature was derived under 80°C at 100 W/cm². In addition, as the heat flux increased, the thermal resistance continuously decreased, and the thermal resistance was less than 0.2 K/W at 200 W/cm². Therefore, when the boiling-driven heat spreader is used, excellent heat dissipation performance might be achieved at even a high heat flux.

Presenting Author: Su-Yoon Doh Ajou University