摘要
通过对PoP的翘曲进行优化分析,采用有限元分析方法分析了PoP中FBGA和PBGA的翘曲形变,并利用Taguchi设计和有限元模拟相结合的方法进行优化设计。分析结果表明:PBGA具有较大的翘曲,增加基板厚度和塑封料热膨胀系数,减小芯片大小和厚度可以改善PBGA的翘曲。对比优化前后的翘曲,在25℃时翘曲值从53.3μm降到39.1μm,260℃时翘曲值从-112μm降到了-67.7μm。塑封料热膨胀系数和芯片尺寸在优化翘曲中起着重要作用。
In the reflow process of package assembly, PoP warpage is an important factor affecting the reliability of the interconnect solder ball owing to the thermal mismatch between the package materials. This necessitates the optimization of the warpage for PoP. The warpage of FBGA and PBGA was analyzed by finite element analysis （FEA）, and then optimization design was carried out for PBGA using Taguchi method and FEA simulation. Study results showed that PBGA had more serious warpage than FBGA, increase in thickness of the substrate and the coefficient of thermal expansion of epoxy molding compound and decrease in die size could improve the warpage of PBGA. Compared to the warpage before and after optimization, the warpage value had reduced from 53.3 μm to 39.1 μm at 25 ℃, while at the reflow temperature the warpage value had decreased from -112 μm to -67.7 μm. The coefficient of thermal expansion of epoxy molding compound and the die size played an important role in warpage optimization.
出处
《桂林电子科技大学学报》
2009年第5期385-389,共5页
Journal of Guilin University of Electronic Technology
基金
广东省自然科学基金(8151064101000014)
