大功率芯片高精度自动共晶焊接工艺技术研究

以固态发射机大功率芯片为研究对象,从自动共晶焊接专用吸嘴设计、大功率芯片载体表面可焊性、焊料片尺寸、焊接温度等方面研究了大功率芯片高精度自动共晶焊接工艺技术,测试了大功率芯片外观、空洞率、共晶焊接强度、共晶焊接精度。结果表明,使用合适的共晶焊接吸嘴、选取适宜的芯片焊接载体、采用优化尺寸的焊料片以及适宜的焊接参数完成焊接的大功率芯片,每个边长的75%以上有焊料溢出,焊接层总空洞率≤10%,有源区焊接层空洞率≤3%,剪切强度满足标准要求,自动共晶焊接精度优于15μm,实现了大功率芯片高精度、高可靠性自动共晶焊接工艺技术的应用。

Influence of solidification mode on pore structure of directionally solidified porous Cu-Mn alloy

By the directional solidification of metal-gas eutectic method（GASAR）,porous Cu-Mn alloy with oriented pores was fabricated successfully.The variation of pore structure was studied by experiments.The results show that the pore structure is primarily dependent on the solidification mode（planar,columnar cellular,columnar dendritic,equiaxed dendritic）,which is controlled by the solidification process.By numerical simulation,it is noted that along with solidification,the solidification mode of the alloy transforms from cellular to columnar dendritic and finally to equiaxed dendritic.Through increasing melt temperature and mold preheating,the range of equiaxed dendrite could be decreased,which helps to extend the region of oriented pore structure.

高性能宽带低噪声放大器的研制

以薄膜混合集成电路为基础,采用AL2O3精细陶瓷做衬底和国际上较先进的共晶工艺,运用宽带内补偿网络和负反馈并用的设计方法,结合理论计算和仿真技术,实现了高指标C波段宽带低噪声放大器的设计,测试结果验证了设计的正确性,为高性能宽带低噪声放大器研制提供了新的设计依据和理论基础。