倒装芯片放置工艺的设计分析

对倒装芯片不流动底部填充胶进行压迫流动填充,底部填料会对倒装芯片产生流体静态压力,阻碍芯片向下放置。根据牛顿流体挤压流动的静态近似分析估算出底部填料对芯片的作用力,分别计算在两种不同工艺条件下放置压力达到最大时,两种不同规格芯片与基板的间隔距离,比较与芯片凸点高度,然后计算使芯片凸点与基板键合区实现接触所需放置压力的最小保持时间,从正反两个方面讨论关键参数等对倒装芯片工艺设计影响。

Design analysis of flip chip placement process

When using a compression flow fill process on no flow underfills of flip chip, underfills under the chip produces a hydrostatic pressure resisting the placement head motion. The effect force engendered by the underfills can be estimated approximately basing on quasi-steady-state of a Newtonian fluid squeeze flow. Calculating the distance above the substrate of two different specifications in two different technics conditions when the placement force is maximal, and comparison with high of the chip bumps. Then calculating the minimum dwell time required to ensure the chip bumps touch the substrate bonding pads. Discuss from the pros and cons of some key parameters to the effect of flip chip design.