细晶硅铝材料的制备及其均匀导热特性  

Fabrication of fine grain SiAl alloy and its uniform thermal conductivity

作　　者：王亚平[1] 王菲[1] 

机构地区：[1]西安交通大学理学院,物质非平衡合成与调控教育部重点实验室,西安710049

出　　处：《中国科技论文在线》2011年第2期131-136,共6页

基　　金：国家自然科学基金资助项目(50871078);陕西省自然科学基金重点项目(2009JZ011)

摘　　要：提出了均匀导热的新概念,并以细晶硅铝合金为例研究硅粒子尺寸对均匀导热性能的影响。采用高能球磨技术细化硅铝粉末并获得硅粒子尺寸为5~30μm的细晶合金,得出其宏观热传导性能与商业喷射成形合金相当。模型推导得出,硅铝合金的热传导性能受芯片热源尺寸l、硅粒子尺寸d及硅相在铝基体中的分布状态的影响。当d〈l时,遵守传统复合材料的导热规律;当d≥l时,第二相粒子导热系数及其与芯片的接触面积是决定系统导热性能的关键,硅粒子尺寸越小,材料热传导的均匀性越好。提出了均匀导热的判据：决定复合材料均匀导热性、不产生局域热传导障碍的特征尺寸为第二相粒子临界尺寸d≤热源特征尺寸l。High energy ball milling process is employed to fabricate a fine grain Al-Si alloy. The microstructure of milled powders is obviously refined and the average Si particle size in the consolidated alloy is about 20 μm. The thermal conductivity of the alloy is comparable to that of the commercial spray-formed alloys. The influence of Si particle size on the thermal conducitivity of packaging materials is investigated using a numerical analysis model. It is found that the thermal conductivity of the Al-Si alloy is affected by the size of heating area （l） and Si particles （d）. When dl, the thermal conductivity is in accordance with traditional laws for composites. When d≥l, the thermal conductivity decreases with increasing Si particle size as the heating area may totally connected with Si particles. Therefore, the critical size of Si particles is determined by the inequation of d≤l.

关 键 词：电子封装 铝合金 硅合金 球磨 晶粒细化 导热 粒子尺寸 

分 类 号：TG146.21[一般工业技术—材料科学与工程]