高效能、高亮度及長壽命之發光二極體(LED)已被廣泛應用，其中約15% 能量可應用於可見光頻譜，但受限於約85% 熱量之導、散熱問題，若無法有效移除，將大幅降低LED的壽命及穩定度。相對於傳統強制對流的散熱方式，利用相轉換之均熱板(vapor chamber)更能有效地提升導、散熱效率。
利用製程簡易、成本低廉的碳化法(carbonization)合成奈米核殼(Cu@C)材料，並藉由銅碳比值的調整以控制奈米銅顆粒大小，將其負載於超薄均熱板內層表面，透過蒸氣轉化反應(steam reforming) (Cu@C + H2O → Cu + CO + H2) 移除碳環，以構築奈米毛細泵結構。超薄奈米毛細泵均熱板在自製真空腔體中填充工作流體(例如：甲、乙醇混合溶液)及壓合密封。另外，也探討均熱板之工作流體填充量、奈米毛細泵負載量、甲乙醇混合比例、奈米核殼顆粒大小、均熱板材質、與離子熔鹽添加等之導熱係數影響。
藉由X射線繞射儀、電子顯微鏡、與同步輻射X射線吸收光譜分析，得知奈米核殼材料之粒徑介於8.9~35 nm，且以奈米銅型式存在。此奈米核殼材料也可由回收電鍍或化學機械研磨廢水中的銅離子研製。透過蒸氣轉化反應移除部分碳環，奈米核殼材料仍維持奈米銅之晶相，碳環厚度由3~5 nm減少至1.0~2.2 nm。經由聚焦離子束顯微鏡及接觸角測量儀觀察，顯示負載量為50~300 g之奈米毛細泵厚度皆維持於25 nm，負載量達100 g可有效增加均熱板之潤濕性，使內部工作流體得以快速循環。
新穎之奈米毛細泵超薄均熱板應用於LED散熱，其結果指出：(1)負載重量為100 g之奈米毛細泵，並且填充80 torr之甲醇蒸氣作為工作流體，可獲得熱擴散率3.65 cm2/sec及熱傳導係數668.1 W/m-K；(2)應用8.9~35 nm粒徑大小之核殼材料構築奈米毛細泵結構，其中粒徑為14 nm，而且填充甲醇蒸氣作為工作流體時，可獲得相對較佳之熱擴散率及熱傳導係數，分別為11.68 cm2/sec及2230 W/m-K，可獲得優於純鋁片9倍以上之散熱效率。

Recently, the high efficiency, high brightness, environmental friendly, and long lifetime light-emitting diodes (LED) have been widely applied in lighting. However, LEDs which have relatively high energy (15%) used in lighting have suffered problems of heat dissipation, which also lead to decrease their lifetime and stability. Compared with the traditional forced heat convection, the liquid/vapor phase change for vapor chambers is more effective to enhance the heat dissipation.
The core-shell (Cu@C) nanoparticles can be prepared by a simple method which was developed in our laboratory. The size (Dp) of the Cu@C nanoparticles in the range of 7-40 nm can be selected by simply changing the Cu/C ratio during preparation. A ultra-thin vapor chamber containing nano capillary pump loops (CPLs) can be prepared by removing the carbon-shell of the coated Cu@C with steam reforming (Cu@C + H2O → Cu + CO + H2). Methanol (MeOH) and ethanol (EtOH) were used as the working fluid in the Al vapor chambers. Experimentally, the LED heat dissipation associated with the partial pressures of the working fluid in vapor chambers, structures of the nano Cu CPLs, MeOH/EtOH ratios, Dp of the Cu@C nanoparticles, material of vapor chambers, and the amount of the ionic liquid added were investigated.
By XRD and TEM, it is clear that the nanostructured Cu encapsulated in carbon-shell has a Dp range of 8.9-35 nm. Note that the thickness of the carbon-shell in the Cu@C was reduced from 3-5 nm to 1.0-2.2 nm during steam reforming, and without a perturbation of the core Cu. The wettability of the vapor chambers is increased in the presence of the nano Cu CPLs coated on the internal surface of the Al vapor chambers, which can accelerate the circulation of working fluid.
The novel ultra-thin Al vapor chambers with nano Cu CPLs have been applied in the enhanced LED heat dissipation. For instance, for the vapor chamber containing nano Cu CPLs, in the presence of 80 torr of MeOH vapor, have a high thermal diffusivity (3.65 cm2/sec) and thermal spreading conductivity (668.1 W/m-K). The best thermal diffusivity (11.68 cm2/sec) and thermal spreading conductivity (2230 W/m-K) for the Al vapor chamber can be obtained, which greater than the bulky Al by at least nine times. The ionic liquids can play the role of preventing the thermal shock for the ultra-thin Al vapor chambers.

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