关键词: CGA, 毛细填缝, Sn58Bi钎料, Sn37Pb钎料

Abstract: 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.

Key words: CGA（Column Grid Array）, column planting method, Sn58Bi, Sn37Pb