| 摘要: | 隨著光電產品小型化裝置的應用趨勢，經常出現熱飄移影響電氣特性或熱應力破壞裝置的問題，故需要使用有導熱性添加物之複合材料協助系統傳熱與散熱，同時也要考慮電氣絕緣性與機構上可撓柔軟性安裝，進而簡化生產程序也提高產品的可靠度。
不同配比添加物之複合材料具有不同熱阻抗值RM與熱傳導係數kM，本研究論文中選擇1~4μm粒度尺寸及120~150[W/m∙℃] 熱傳導值範圍之黑石墨Graphite、碳化矽SiC與氮化鋁AlN等三種市場常見添加物材料，其中黑石墨與碳化矽為導體，氮化鋁為絶緣體。
相關複合材料可使用標準ASTM D5470進行量測，但需要二小時以上的時間穩定熱流狀態才能得知RM與kM之正確性量測值，同時比對於用熱傳遞學理論與熱容積原理所推導RM或kM理論計算值，可得知ΔRM的最大誤差是0.20[℃/W] ，最小誤差是0.01[℃/W]，而ΔkM的最大誤差是0.11[W/m∙℃] ，最小誤差是0.01[W/m∙℃] ，其可證明所推導出理論公式具有學術研究參考價值，在相關產業界上可以提供快速計算而事先預知複合矽膠的熱傳導特性。
本研究結論發現複合矽膠的熱傳導物理新特性： 若添加小於30wt% 導電性材料Graphite或SiC，kM無明顯影響變化量，當添加大於40wt%時 kM成正比增加，直至68wt%的kM值優於同樣配比之AlN的kM，若持續添加至85wt%以上則複合矽膠的機構強度脆弱。若添加非導電性AlN達到75wt% 以上之RM較同樣配比SiC小，傳熱性良好。若持續添加至80wt% AlN，則kM值為0.85傳熱效果更佳。
;The optoelectronic device with the trending minimization of application, often affect the electrical properties on thermal drift or breakdown device by thermal stress, it is required the compound silicone with thermal conductive components to transfer heat and to assist heat from the device, that consider simultaneously the electrically insulating or install with flexibility on mechanism, thereby simplifying the production process also improves the reliability of the product.
Different proportions of the compound silicone has a different thermal resistance RM and thermal conductivity kM, this research paper, in accordance with 1 ~ 4μm particle size and 120 ~ 150[W/m℃] thermal conductivity value range, to selecting the Graphite, Silicon carbide (SiC) and Aluminum nitride (AlN) that three additive materials is common in market, which the black graphite and silicon carbide is a conductor, aluminum nitride is an insulator.
Compound silicone were measured by using standard ASTM D5470, it must take more than two hours to steady state heat, then get the correct measured value of RM and kM , Derived formula of RM and kM with heat transfer theory and the principles of derived heat volume for calculate the theoretical value to comparing measured value.
Then can be available the maximum ΔRM is 0.20 [℃/W], the smallest tolerance is 0.01 [℃/W] ,while the maximum tolerance ΔkM is 0.11[W/(m∙℃)], the minimum tolerance is 0.01[W/(m∙℃)], that can be proved which the theoretical formula have useful reference in academic, and this can provide a quick calculation to predict heat transfer characteristics of the compound silicone in the relevant industry.
The conclusion that physical properties of the thermal conductive compound silicone: kM is no significant effect changes within mixing less than 30wt% conductive material as Graphite or SiC, then proportional increase kM until adding conductive material more than 40wt%, this is superior to AlN until more than each 68wt% mixing ratio. But the mechanical strength of the compound silicone is fragile when more than 85wt% mixing ratio. The RM of more than 75wt% AlN compound silicone less than the same ratio of SiC is good thermal conductivity. The 80wt% AlN compound silicone is better transferable heat and kM = 0.85. |
