热循环加载条件下PBGA叠层无铅焊点可靠性分析

Reliability analysis of plastic ball grid array double-bump lead-free solder joint under thermal cycle

建立了塑料球栅阵列(plastic ball grid array,PBGA)器件叠层焊点应力应变有限元分析模型,基于该模型对叠层无铅焊点在热循环载荷条件下的应力应变分布进行了分析,计算其热疲劳寿命,分析焊点材料、焊点高度和焊点最大径向尺寸对叠层焊点热疲劳寿命的影响.结果表明,与单层焊点相比,焊点叠加方式能有效提高焊点热疲劳寿命;采用有铅焊料Sn62Pb36Ag2和Sn63Pb37的叠层焊点比采用无铅焊料Sn-3.5Ag和SAC305的叠层焊点热疲劳寿命高;叠层焊点的高度由0.50 mm增加到0.80 mm时,焊点的热疲劳寿命随其高度的增加而增加;叠层焊点的最大径向尺寸由0.30 mm增加到0.45 mm时,焊点的热疲劳寿命随焊点的最大径向尺寸增加而减小.

The plastic ball grid array( PBGA) doublebump lead-free solder joint stress and strain distribution under the thermal cyclic loading was analyzed based on the stress-strain finite element analysis model,and then the thermal fatigue life was calculated. The impacts of solder joint height,solder joint maximum radial size on fatigue life were also studied. The results show that compared with the single-layer solder joint,the stacking solder joint can effectively improve the solder joint thermal fatigue life. The thermal fatigue lives of double-bump solder joint by using of lead solder Sn62Pb36Ag2 and Sn63Pb37 are longer than that using the lead-free solder Sn-3. 5Ag and SAC305.Solder joint thermal fatigue life increases when the height of the double-bump solder joint increases from 0. 50 mm to 0. 80 mm.The thermal fatigue life of double-bump solder joint decreases when the maximum radial dimension of the double-bump solder joint increases from 0. 30 mm to 0. 45 mm.