摘要
针对LCCC封装器件在温度循环载荷下焊点开裂的问题,首先分析其失效现象和机理,并建立有限元模型,进行失效应力仿真模拟。为降低焊点由封装材料CTE不匹配引起的热应力,提出了两种印制板应力释放方案,并分析研究单孔方案中不同孔径和阵列孔方案中不同孔数量对热疲劳寿命的影响。之后,为降低对PCB布局密度的影响,提出一种新型的叠层焊柱应力缓冲方案,进行了不同叠层板厚度和焊柱间距的敏感度分析。结果表明,更大的开孔面积、更小的叠层板厚度、更密的焊柱可有效降低焊点应力,提高焊点热疲劳寿命,使得LCCC封装器件焊点热疲劳可靠性得到有效提高。
To address the problem of solder joint cracking in low-cost chip carrier(LCCC)packaging devices under temperature cycling loads,we first analyze the failure phenomenon and mechanism and establish a finite element model for simulating failure stress.Two stress relief schemes for the printed circuit board(PCB)are proposed to reduce the thermal stress caused by the mismatch in the coefficient of thermal expansion(CTE)between packaging materials.The impact of different hole sizes in the single-hole scheme and different hole quantities for the array-hole scheme on the thermal fatigue life were analyzed and studied.Subsequently,a novel stacked solder column stress buffering scheme is proposed to mitigate the impact on PCB layout density.Sensitivity analysis was performed for different stacked board thicknesses and solder column spacings.The results indicate that larger opening areas,thinner stack boards,and denser solder columns effectively reduce the solder joint stress,enhance the solder joint thermal fatigue life,and significantly improve the thermal fatigue reliability of LCCC packaging devices.
作者
刘敏
陈轶龙
李逵
李媛
曾婧雯
LIU Min;CHEN Yilong;LI Kui;LI Yuan;ZENG Jingwen(Xi’an Microelectronics Technology Institute,Xi’an 710000,P.R.China)
出处
《微电子学》
CAS
北大核心
2024年第2期311-316,共6页
Microelectronics
