小尺寸Sn63Pb37和Sn3.0Ag0.5Cu焊球可靠性焊接研究

Reliability Soldering Technology of Small Size Sn63Pb37 and Sn3.0Ag0.5Cu Solder Balls

微型化趋势下,宇航及武器产品中BGA封装器件焊球尺寸不断减小,这对产品长寿命、高可靠性要求提出了严峻挑战。分析了模板厚度、再流焊温度曲线峰值温度、印制板焊盘镀层等焊接参数对0.3 mm小尺寸焊球Sn63Pb37和Sn3.0Ag0.5Cu(SAC305)形成焊点的微观组织形貌和力学性能的影响,确定了该两种成分焊球使用有铅焊膏高可靠性焊接的工艺参数。研究发现,0.3 mm的Sn63Pb37和SAC305焊球应选用Cu镀Ni/Au的焊盘,0.08 mm厚度模板印刷焊膏,相应的再流焊温度曲线也应进行优化。SAC305混装焊点剪切强度明显大于Sn63Pb37焊点,Sn63Pb37焊球更易受焊接参数的影响。

With the miniaturization of aerospace and weapon products, the diameter of solder balls in BGA would be continuous reduced. As a result, more serious challenges have been raised for long-time and high reliability requirements of products. The influence of soldering parameter adjustment（printed solder paste with stencil thickness, peak temperature of reflow curve, PCB pad plating） on microstructure and mechanical properties of formed solder joints used small size solder balls（0.3 mm） Sn63 Pb37 and Sn3.0 Ag0.5 Cu（SAC305） was analyzed, and determined the parameters for high reliability soldering of these two kinds of solder ball. It was found that the soldering of small size（0.3 mm） Sn63 Pb37 and SAC305 solder balls should be used plated Ni/Au pads and 0.08 mm thick steel mesh reflow, while the corresponding reflow curve optimization. In addition, the shear strength of SAC305 solder joints was obviously greater than Sn63 Pb37, and Sn63 Pb37 solder ball was more susceptible to the soldering parameters.