摘要: |
以QFN封装1/4模型为研究对像,通过有限元分析及实验验证的方式,分析温度循环载荷下QFN器件焊点可靠性。有限元分析结果表明,QFN的使用寿命周期为525周,其焊点应力的最大值位于拐角处的焊点上表面处,且应力值变化具有周期性,因此该位置上的焊点更容易出现失效。实验证实,温循载荷导致失效焊点内形成贯穿性裂纹,未失效焊点形成非贯穿性微小裂纹。失效焊点位置与有限元模拟结果吻合良好。 |
关键词: QFN封装;可靠性;有限元分析;显微组织 |
基金项目: |
|
Study on Reliability and Service Life of QFN’s Solder Joint |
Ding Ying1, Dong Yunsong1, Zhou Ling1, Hang Chunjin2, Fei Jingming2
|
1. Beijing Institute of Control Engineering;2. Harbin Institute of Technology
|
Abstract: |
QFN package possess good electric and thermolysis performance. Nevertheless, its package features result in it’s unable to release thermal stress. This paper found 1/4 of QFN package model, analysisng QFN’s joint reliability in the process of thermal cycling via finite element analysis and experimental verification. The result of FEA indicates that QFN service life is 525 cycles. Under thermal cycling loading, the maximum stress happened on top surface of joints which locate in the corner of chip, and stress is cycle in the process of thermal cycling, so those joints are more likely to be failure. Running through crack happened in failure joint which locate in the corner of chip due to thermal stress during thermal cycle process, there are many small cracks in other joints. |
Key words: QFN package;reliability;FEA;microstructure |