基于毛细填缝效应的CGA器件植柱连接

Column Planting Connection of CGA Devices Based on Capillary Filling Effect

针对CGA器件在制造过程中存在的连接质量易受辅助模具影响、辅助模具通用性差、成本高等问题,采用一种基于毛细填缝效应的CGA焊柱成型方法。以Sn58Bi+Sn37Pb为主要研究对象,研究了温度、时间、毛细间隙等因素对连接质量的影响。通过金相显微镜对焊件微观组织形貌进行观察,借助推拉力计对植柱焊点的性能进行表征。研究结果表明,随着回流时间和回流温度的增加,IMC层厚度增大,植柱焊点性能提高,融合区Bi相逐渐向锡铅相扩散。毛细间隙大小由0.025 mm增大到0.075 mm时,界面处空洞率明显降低,拉拔强度逐渐增大,界面强度提高。Sn58Bi与Sn37Pb钎料融合区处,Sn58Bi钎料合金微观组织致密网状结构改变。

Aiming at the problems of poor universality and high cost of auxiliary mould,the connection quality of CGA devices in the manufacturing process is easily affected by the auxiliary mould.A capillary filling effect-based CGA welding column shaping method was used,with Sn58Bi+Sn37Pb as the main research object.The effects of temperature,time and capillary gap on the quality of the connection were studied.The micro-structure and morphology of the weld were observed by metallographic microscope,and the properties of the post-implanted solder were characterized by push-pull force meter.The results show that with the increase of reflux time and reflux temperature,the thickness of IMC layer increases,the performance of post-implanted solder joint increases,and the Bi phase in fusion zone gradually diffuses to the tin-lead phase.When the capillary gap size increases from 0.025 mm to 0.075 mm,the void rate at the interface decreases significantly,the pulling strength increases gradually,and the interface strength increases.At the fusion zone between Sn58Bi and Sn37Pb,the dense mesh structure of Sn58Bi brazing alloy was changed.