超声波振动辅助高密度倒装芯片塑封下填充工艺与机理研究

项目名称： 超声波振动辅助高密度倒装芯片塑封下填充工艺与机理研究

项目编号： No.51305318

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 机械、仪表工业

项目作者： 王辉

作者单位： 武汉理工大学

项目金额： 25万元

中文摘要： 下填充已经成为改善倒装芯片封装可靠性的关键工艺。随着高密度倒装芯片的发展，传统的下填充工艺在成型方面遇到了毛细驱动填缝力不足和固化过程复杂缓慢的问题，在成性方面遇到了润湿不足导致胶/壁界面粘结强度差和填料非均分布导致封胶层性能下降的问题。采用一种成型方法综合解决目前下填充工艺中所遇到成型和成性方面的四个问题，本项目提出超声波振动辅助高密度倒装芯片塑封下填充工艺，并对其过程机理进行了研究。由于目前对相关的超声辅助成型机理的认识仍不清楚，本项目结合超声波振动理论和毛细驱动下填充工艺模型，建立超声波振动辅助下填充工艺的物理模型，分析超声空化和声流效应对下填充过程中诱导填缝、加速固化、胶/壁界面增润增强以及封胶层匀质强化的作用过程，通过与实验结果进行因果关联分析，从成型和成性两个方面研究超声波振动作用对改善下填充工艺的机理，定量分析超声工艺参数对下填充工艺的影响，指导超声波振动辅助下填充工艺。

中文关键词： 超声波振动；辅助；强化；塑料封装；固化

英文摘要： Underfill is an important process of flip-chip encapsulation because of its great impact on the reliability of the packagings. With the development of flip-chip technologies, the capillary-driven underfill process is suffering from the manufacturing problems of insufficient filling force and long curing cycle, and from the performance problems of low interface adhesion caused by poor wetting and inhomogeneous layer strength caused by filler distribution. In order to overcome the four problems in the capillary-driven underfill process, a novel ultrasonic vibration assisted underfill process for hight density flip-chip encapsulation is proposed, and the mechanisms of this process are studied in this project.However, the mechanisms of the associated ultrasonic vibration assisted processing are not well understood so far. In this project, a physical model for the ultrasonic vibration assisted underfill process is firstly proposed based on the theories of the ultrasonic vibration and the capillary-driven underfill. And then, the effects of the cavitation and the streaming on inducing fill gap, reducing cure cycle, enhancing interfacial wetting and homogenizing particle fillers are simulated using this model. So the mechanisms of the ultrasonic vibration assisted underfill process are studied by analyzing the simulati

英文关键词： ultrasonic vibration；assisted；strengthen；plastic encapsulation；cure