FOW在叠层CSP封装中的应用

FOW Die Attach Method Application in Stack CSP Package Assembly

随着电子封装微型化、多功能化的发展,三维封装已成为封装技术的主要发展方向,叠层CSP封装具有封装密度高、互连性能好等特性,是实现三维封装的重要技术。针对超薄芯片传统叠层CSP封装过程中容易产生圆片翘曲、金线键合过程中容易出现OBOP不良、以及线弧(wire loop)的CPK值达不到工艺要求等问题,文中简要介绍了芯片减薄方法对圆片翘曲的影响,利用有限元(FEA)的方法进行芯片减薄后对悬空功能芯片金线键合(Wirebond)的影响进行分析,Film on Wire(FOW)的贴片(Die Attach)方法在解决悬空功能芯片金线键合中的应用,以及FOW贴片方式对叠层CSP封装流程的简化。采用FOW贴片技术可以达到30%的成本节约,具有很好的经济效益。

With the increasing of multi-function and mini-sized packaging demand, the 3D packaging is becoming a development direction for packaging technology. As stacked chip scale package （SCSP） has many good properties, such as higher packaging density and better interconnection, it is one important technique of realiz- ing 3D packaging. Due to traditional SCSP assembly process have some issues, such as grinding result in wafer warpage, OBOP defect occur on extra thin overhang die during wirebonding process, and wire loop CPK can＇t achieve process requirements. Use FEA tools analysis gold wire wirebondability on extra thin overhang function die, introduce how to use Film on Wire （FOW）die attach methodology to solve overhang function die wirebond constrain and simplify SCSP assembly process flow reduce around 30% cost.