Performance improvement of stacked graphite sheets for cooling applications

We realized a thin slice of vertically stacked pyrolytic graphite for the thermal interface use. The maximum size of the slice achieved was 37 times 37 mm² with a thickness about 500 mum. This system shows a heat resistance better than 20 mm²C/W, which is almost independent of the thickness. The heat resistance can be drastically improved by modifying the surface structure and/or small amount of fluorinated chemical. We report the characteristics and improvement of the thermal performance of this material.