Fracture mechanism of QFP micro-joints soldered with Sn-Pb and SnAgCu solders

来源期刊：中国有色金属学报(英文版)2005年第z3期

论文作者：薛松柏 史益平 胡永芳

文章页码：311 - 316

Key words：QFP； micro-joints； tensile strength； fracture mechanism

Abstract: Tensile strengths of QFP micro-joints with different pitches were tested by means of micro-joints tester. On the basis of those results, the effects of QFP pitches’ numbers on the mechanical properties were studied and the microstructures of cracks of micro-joints were analyzed based on facts of SEM and EDS. The results indicate that of tensile strengths micro-joint of 48 pitches are lower than that of 100 pitches and the tensile strength of soldered joint is higher than that of solder itself. The fracture mechanism of QFP soldered joint with Sn-Pb solder acts as the interface cavity impair ductile rupture while the fracture mechanism of QFP soldered joint with lead-free solder shows trans-crystalline toughness rupture which belongs to micro-holes coalescence fracture.