An improved heat sink within a thermal flask comprising a liquid
Publication Date: 2016-Jul-29
The IP.com Prior Art Database
A liquid heat sink fills up all available space within a thermal flask thus maximizing heat sink volume, heat transfer, and minimizing hot spots.
Title: An improved heat sink within a thermal flask comprising a liquid
Abstract: A liquid heat sink fills up all available space within a thermal flask thus maximizing heat sink volume, heat transfer, and minimizing hot spots.
Description: To keep printed circuit boards, or other electronics or sensors, within a thermal flask, such as a downhole thermal flask, below the outside ambient temperature for an extended period of time, fill the flask with a nonconductive liquid such as the high-voltage transformer fluid, Biotemp (comprising mostly sunflower or safflower seed oil), so that the circuit boards are immersed within this electrically nonconductive liquid. Biotemp’s specific heat is 0.57 to 0.67 calories/gram-Kelvin. A liquid heat sink maximizes the volume of heat sink within the flask by filling every nook and cranny and it also greatly improves heat transfer from the circuit board to the liquid heat sink because it has no thermally-nonconductive air gap between the circuit board and the heat sink as would occur when simply using a nearby solid heat sink made out of metal. Also, as a heat spreader, a liquid heat sink is a much more effective way to prevent hot spots around heat-generating components on the circuit board. Biotemp has a thermal conductivity of 0.17 to 0.36 Watts/meter-Kelvin, where anomalously, the higher thermal conductivity occurs at higher temperatures. Alternatively, if a circuit board is hermetically sealed within a very thin, high-temperatur...