具V形溝槽鰭片熱沉之性能分析

Abstract

本研究將改良可應用於電子產品的熱沉，希望在電子產品有限的體積下，可使較小的熱沉也有能力達成電子產品的散熱需求。本研究最初嘗試了在平板鰭片上加入水平溝槽，傾斜溝槽與垂直溝槽等熱傳增強方式；結果顯示，這些熱傳增強方式最有效的為垂直溝槽，其約可提升平板鰭片熱傳性能16%左右。 接著，本研究再進一步改良垂直溝槽結構，希望使其熱傳增益可以更為顯著。嘗試了增加凸點導流，於鰭片上打出三角翼、六角形凹槽，移動熱管，於溝槽邊緣處開孔與放入導流管模擬交錯管陣排列等方式。模擬結果初步顯示，此些改良方式並無顯著增強效果，或是製作模組所需的費用增加太多，並不適合本研究所需。 最後，本研究於平板鰭片上打出V字溝槽，希望可以藉此改良平板鰭片熱傳性能。結果顯示，此改良模組可在減少熱沉約30%體積前提下，仍使熱沉基底(base)溫度與總熱阻低於原先使用平板鰭片的熱沉；也因為體積減小的緣故，改良過後的縮小體積熱沉將可降低空氣流經熱沉的壓降40%左右。

In typical applications of electronic cooling, keeping the volume of the cooling module as small as possible is a must due to space confinement; however, as the volume gets smaller, the accommodated area required for heat transfer also suffers appreciably. In the cases where raising the effective heat transfer area is constrained, based on the Newton’s cooling law, to maintain the same heat transfer rate without raising the heat transfer area, we need to raise the heat transfer coefficient, effective temperature difference or both. The present study proposed a V-shaped cannelure structure applicable for electronic cooling thermal module. The proposed modified thermal module can appreciably reduce the heat sink volume (up to 30%) and still maintain a lower base temperature than the original plain fin design. Based on the foregoing discussions, the following conclusions are made. In summary of the experiment, the redesigned V-shaped cannelure structure thermal module is able to maintain the same performance (even better) as plain fin thermal module when the heat sink volume is reduced by 30% and also able to lower the pressure drop by about 40%.