铝渗碳化硅泡沫电子封装材料

The continuing increase in electronic packaging density has pushed the requirement for advanced packaging materials with such properties as low tailorable coefficients of thermal expansion(CTEs) matching those of ceramic substrates and semiconductors,high thermal conductivity（HTC）, high stiffness, low density and low cost. Traditional materials used in electronic packaging do not meet all of these requirements.In this project, HTC aluminum infiltrated silicon carbide（SiC/Al）packaging materials were fabricated by infiltrating molten aluminum into porous SiC. The infiltration and solidification of molten aluminum alloys in the porous SiC, and the thermophysical properties of SiC/Al packaging materials has been investigated in detail.A hybrid SiCp-PCS porous SiC with controllable （10～100μm） and uniform pore size was fabricated; The comparison between the theoretical calculations and experimental results indicates that the CTEs of the SiC/Al and the porous SiC/Al do not agree with Kerner's and Turner's model, and the thermal conductivity（TC） of the SiC/Al and the porous SiC/Al can be estimated using models of Hasselman and Johnson, and Maxwell. Computer simulation of the thermal conductivity by ANSYS software shows that effect of interface TC on effective TC of the SiC/Al is related to the interface thickness, and the effect is small as the thickness is very small（such as the ratio of the thickness to the diameter of the SiC is smaller than 1/1000）. The developed SiC/Al can provide great advantages over conventional materials for electronic packaging thermal management, including high thermal conductivity(170～200W/mK); low tailorable coefficients of thermal expansion（6×10-6/°C～8×10-6/°C）matching those of ceramic substrates and semiconductors; extremely high stiffness（220～240GPa）; low density（3g/cm） and low cost. The achievements in this research are of theoretical significance in guiding the interface and thermophysical properties of HTC composites for electronic packaging, and the SiC/Al packaging materials will find broad applications in microprocessor lids, high density microwave packaging substrates, microwave housing, high performance IGBT and MOSFET power modules, PWB cores, carriers and package bases, power module heat sinks,etc.

将高导热的液态铝渗入低热膨胀的碳化硅泡沫，凝固后获得高导热，低热膨胀的铝渗碳化硅泡沫电子封装材料。研究碳化硅泡沫预制型的快速制备工艺，考察铝渗碳化硅泡沫的低压浸渗排气与凝固补缩规律，并探索其在冷热循环下的热膨胀特性及热导率。本项目对制备热物理性能优异，轻质且廉价的新型电子封装材料具有重要的科学意义和实用价值。