基于全面析因试验的塑封球栅阵列器件焊点可靠性

Solder Joint Reliability of Plastic Ball Grid Array Component Based on Design of Full Factorial Experiment

采用全面析因试验设计方法设计了多种不同工艺参数组合的1.0mm引脚间距塑封球栅阵列(PBGA)器件测试样件,进行了500h的可靠性热循环试验;基于试验数据进行了极差分析和方差分析;用有限元方法分析了PBGA器件焊点内的应力分布.试验结果和有限元分析结果均表明,失效焊点裂纹出现于焊点与芯片基板的交界面上.极差分析表明,最优的工艺参数组合为钢网厚度0.14mm,焊盘直径0.34mm,芯片配重质量11.0384g或17.1084g.方差分析表明,芯片配重质量对1.0mm引脚间距PBGA器件焊点的可靠性有显著的影响,而焊盘直径和钢网厚度对可靠性无显著影响.

The plastic ball grid array (PBGA) component test vehicles with different combinations of process parameters were designed based on full factorial experiment. A 500-hour accelerated thermal cycling test of PBGA test vehicles was carried out. Based on the test results, both range analysis and variance analysis were performed, and the stress distribution within PBGA solder joint under thermal cycle were evaluated with finite element analysis (FEA). Both the test result and the FEA result show that the cracks of failure solder joints occur at the interface between the solder joints and the bismaleimide-triazine substrate. The optimal combinations of process parameters are the stencil thickness of 0.14 mm, the pad diameter of 0.34 mm, and the chip weight of 11.0384 grams or 17.1084 grams. Chip weight has a significant effect on the reliability of solder joints, whereas pad diameter and stencil thickness have little effects on the reliability. These optimal combinations of process parameters have been applied to assemble the 1.0 mm pitch PBGA components.