注射速度对塑封成型过程芯片热流固多场耦合变形的影响

Influence of melt injection rate on thermal-fluid-structure multi-field coupling deformation of chip plastic encapsulation process

塑封成型中芯片翘曲变形的控制是保障电子芯片品质的技术关键,为了准确预测其翘曲变形,基于Castro-Macosko固化动力学模型,建立了描述塑封填充过程及其芯片热流固多场耦合翘曲变形形成过程的理论模型,并揭示了其变形机制。研究结果表明:芯片热流固耦合翘曲变形先随熔体充填流动时间的增加而快速增加,达到最大值之后逐渐减小,并趋于恒定。当熔体注射速度由0.1 m/s增至2 m/s,芯片上下表面热流固耦合最大压差由9.562 34 k Pa增至18.022 43 k Pa,增幅高达88.5%,导致芯片热流固耦合翘曲变形随着注射速度增大而增大,且最大热流固耦合翘曲变形出现在芯片中心下游附近区域,减小注射速度有利于减小芯片的热流固耦合翘曲变形。

The warpage deformation control in plastic encapsulation filling process is the technical key of chip quality guarantee,in order to predict accurately chip thermal fluid-structure coupling warpage deformation,based on the Castro-Macosko cure kinetic model,theoretical model describing plastic encapsulation filling process and thermal fluid-structure coupling warpage deformation formatting process was established,and the formation mechanism of thermal fluid-structure coupling warpage deformation was revealed. Research results showed that the chip thermal fluid-structure coupling warpage increased rapidly at first with increasing melt filling flow time,after reaching the maximum value decreased gradually and tended to be constant. When the melt injection rate was increased from 0. 1m/s to 2 m/s,difference of chip up and down surface,the maximum thermal fluid-structure coupling pressure difference of chip up and down surface increased from 9. 562 34 k Pa to 18. 022 43 k Pa. Increasing of up to 88. 5%,which caused the chip thermal fluid-structure coupling warpage deformation to increase with the increase of the injection rate,and the maximum thermal fluid-structure coupling warpage deformation occurred near the chip central downstream region. It will help to reduce the chip thermal fluid-structure coupling deformation that decreases melt injection rate.