Strength Evaluation of Plastic Packages During Solder Reflow Process Using Stress Intensity Factors of V-Notch
Strength Evaluation of Plastic Packages During Solder Reflow Process Using Stress Intensity Factors of V-Notch
复制标题
使用 V 型切口的应力强度因子评估回流焊过程中塑料封装的强度
DOI：
10.1115/1.1525244
复制
发表时间：
2003
影响因子：
1.6
通讯作者：
Mitsuru Sato
中科院分区：
文献类型：
--
作者：
T. Ikeda;Isao Arase;Yuya Ueno;N. Miyazaki;N. Ito;M. Nagatake;Mitsuru Sato
从模制树脂中的V形切口拐角（例如管芯焊盘拐角）开始的裂纹是塑料封装失效的主要原因之一。利用异质材料焊接接头拐角处应力强度因子的渐近解，对四方扁平封装（QFP）中的回流焊裂纹进行了评估。首先，我们估计的临界蒸汽压力，这会导致裂纹从一个角落的模塑树脂，使用的临界应力强度因子的V形切口角落。通过V形切口三点弯曲试验和位移外推法沿着与三维（3-D）有限元法（FEM）测量该临界因子。分析了吸收后QFP中的水分浓度，并估算了回流焊工艺引起的蒸汽压。使用这种评估技术，可以预测的临界吸湿时间，这导致在回流焊过程中出现裂纹。此外，我们进行红外回流焊测试的QFP验证目前的故障评估技术。
A crack initiated from a V-notch corner in the molding resin, such as a corner of die pad, is one of the main causes of the failure in plastic packages. The stress intensity factors of the asymptotic solution of a corner of jointed dissimilar materials are utilized for the evaluation of a solder reflow crack in a quad flat package (QFP). First, we estimate the critical vapor pressure, which causes a crack from a corner in the molding resin, using the critical stress intensity factor of a V-notch corner. This critical factor was measured by V-notched three-point bending tests and the displacement extrapolation method along with the three dimensional (3-D) finite element method (FEM). Moisture concentration in the QFP after absorption is analyzed, and vapor pressure caused by the solder reflow process is estimated. The critical moisture absorption time, which results in crack occurrence during the solder reflow process, can be predicted using this evaluation technique. Furthermore, we perform infrared solder reflow tests of the QFP for verifying the present failure evaluation technique.