冲击载荷下航天用PBGA焊点的优化设计

从动力学角度考虑PBGA焊点承受不同加速度情况下冲击载荷的情况,对PBGA焊点尺寸建立了正交设计表。运用有限元分析技术对该表中各种因素和水平分别进行有限元分析,运用数理统计对正交结果进行分析,在现有尺寸结构上提出了最优化设计。对各种因素进行了显著性分析及比较,得出在动力载荷下,焊点直径、高度等参数对焊点可靠性的影响比焊点位置参数对焊点可靠性的影响要低得多。在动力载荷下,焊点位置、形状变为可靠性设计的主要考虑因素。并通过扩大参数取值范围得到二次正交设计表验证了其正确性。

Optimization Design of Astronomic PBGA Solder Joint under Shock Load

PBGA solder joint reliability under shock load is considered. According to the solder joints?shape, dimension and location, an orthotropic design table is created, and Finite Element Models are created by the data from this orthotropic design table. According to Finite Element Calculation, the maximum strain of solder joints is obtained and then according to Sta. Theory the optimization design factor is obtained. Then the next calculation to testify is accuracy. By the way, the results influenced by some factors are considered and find that the dimension (height and diameter), which is the first important factor under its thermo reliability, is not an important factor when considering its reliability under shock load. The location and shape of solder joint becomes a prime important factor.