Bulk Expansion Effect of Gallium-Based Thermal Interface Material
Bulk Expansion Effect of Gallium-Based Thermal Interface Material
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DOI：
10.1007/s10765-017-2226-6
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发表时间：
2017-04
影响因子：
2.2
通讯作者：
Yujie Ding;Z. Deng;C. Cai;Zelin Yang;Ying-Bao Yang;Jinrong Lu;Yunxia Gao;Jing Liu
中科院分区：
文献类型：
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作者：
Yujie Ding;Z. Deng;C. Cai;Zelin Yang;Ying-Bao Yang;Jinrong Lu;Yunxia Gao;Jing Liu
首次从实验上揭示和阐明了镓基热传导界面材料(GBTIMs)的体膨胀效应。GBTIM是在低(26%)和高(96%)相对湿度下分别在短时间(2小时)和长时间(5小时)下制备的。在足够的湿度下，观察到明显的体积膨胀现象。湿度越大，膨胀率和膨胀系数越大。在96%的相对湿度下，GBTIMs的膨胀系数可以达到令人惊讶的1.5。假设体积变化与混合物中的化学反应有关，采用扫描电子显微镜和X射线衍射仪测定了样品的结构和物相组成。用气相色谱检测了膨胀过程中产生的气体，发现了大量的氢气。结果表明，GBTIMs的膨胀效应是由氧化镓与水反应产生的氢气引起的。腐蚀后的GBTIMs主要由氧化镓组成，膨胀后为疏松多孔的固体。由于成分和结构的变化，膨胀后的导热系数急剧下降。从应用的角度来看，在制备这种热界面材料时，必须控制环境湿度和氧化程度，以避免其体积膨胀效应。
The bulk expansion effect of gallium-based thermal interface materials (GBTIMs) was experimentally disclosed and clarified for the first time. GBTIMs were prepared under low (26 %) and high (96 %) relative humidity for a short (2 h) and long (5 h) time periods. An evident volume expansion phenomenon was observed with adequate humidity. Higher humidity resulted in bigger expansion rate and expansion coefficient. The expansion coefficient could reach surprisingly large value of 1.5 for GBTIMs under 96% relative humidity. Assuming that the volume change was related to chemical reactions in the mixture, SEM and XRD were adopted to determine the structure and phase components of the samples. The gases produced in the expansion process were detected with gas chromatography and a large amount of hydrogen was found. The results indicated that the hydrogen produced by the reaction between gallium oxideand water in GBTIMs caused the expansion effect. The corroded GBTIMs were mainly composed of gallium oxideand became loose and porous solids after expansion. Thermal conductivity decreased dramatically after the expansion process due to the composition and structure changes. From the view point of application, the ambient humidity and oxidation degree must be controlled during preparation of such thermal interface material to avoid its bulk expansion effect.