不同I/O端数金凸点倒装焊的预倒装工艺研究  

Research on Pre-Flip Process of Gold Bump Flip Chip with Different Numbers of I/O Terminals

作　　者：赵竟成 周德洪 钟成 王晓卫 何炜乐 ZHAO Jingcheng;ZHOU Dehong;ZHONG Cheng;WANG Xiaowei;HE Weile(Shenzhen Institute for Advanced Study,University of Electronic Science and Technology of China,Shenzhen 518028,China;Shenzhen Zhenhua Microelectronics Co.,Ltd.,Shenzhen 518063,China)

机构地区：[1]电子科技大学(深圳)高等研究院,广东深圳518028 [2]深圳市振华微电子有限公司,广东深圳518063

出　　处：《电子与封装》2023年第11期47-53,共7页Electronics & Packaging

摘　　要：金凸点热压超声倒装焊中涉及的主要工艺参数,如压力和超声功率,会随着I/O端数的改变产生较大差异。对具有不同数量I/O端的金凸点倒装焊工艺参数进行研究和优化,有助于透析产生差异的根源,指导实际生产。通过对I/O端数分别为121、225、361的金凸点倒装焊工艺参数进行研究,发现随着I/O端数量的增加,单位凸点上的最大平均剪切力依次减小,达到最大平均剪切力时所需单位凸点上的平均超声功率和平均压力依次减小。工艺窗口依次缩窄的主要原因是热压超声过程中传递的能量不均匀。在倒装焊工艺中,使用预倒装的方法可使各凸点在倒装焊中的能量分布更均匀,使用此方法对具有361个I/O端的芯片进行倒装焊,单位凸点上的平均剪切力达到了0.54 N,比未使用此方法时的平均剪切力(0.5 N)提高了8%。The main process parameters involved in hot-press ultrasonic flip chip of gold bumps,such as pressure and ultrasonic power,will vary considerably with the number of I/O terminals.Research and optimization of gold bump flip chip process parameters with different numbers of I/O terminals are helpful to analyze the root causes of the differences and guide the actual production.By studying the flip chip process parameters of gold bumps with 121,225 and 361 I/O terminals respectively,it is found that as the number of I/O terminals increases,the maximum average shear force per unit bump decreases sequentially,and the average ultrasonic power and the average pressure per unit bump that are required to reach the maximum average shear force per unit bump decreases sequentially.The main reason for the sequential narrowing of the process window is the uneven energy transfer during the hot pressing ultrasonic process.The method of pre-flip in the flip chip process results in a more uniform energy distribution across the bumps in the flip chip.Using this method to flip chip a chip with 361 I/O terminals,the average shear force per unit bump reaches 0.54 N,which is an 8%increase in the average shear force per unit bump(0.5 N)compared to the average shear force without the method.

关 键 词：I/O端数 金凸点 倒装焊 预倒装 

分 类 号：TN305.94[电子电信—物理电子学]