Derivation of dynamic constitutive equation of lead-free solder and clarification of impact characteristics of area-array pac

为了研究无铅钎料在高应变率下的拉伸特性，在直接拉伸分离式Hopkinson杆技术的基础上，研制了钎料小瓶冲击拉伸试验装置。利用该装置，在应变速率为1.66 × 103时，高精度地测量了Sn-3.0Ag-0.5Cu无铅钎料和Sn-Pb常规钎料的拉伸应力-应变特性数据，并与1.2和1.2× 103准静态应变速率下的数据进行了比较<-2>。结果表明，证明。Sn-3.0Ag-0.5Cu无铅钎料的应力和抗拉强度与Sn-Pb常规钎料相比，随应变速率的增加而显著提高。随着应变速率的增加，Sn 3.0Ag-0.5Cu钎料的断裂形态由韧性断裂向脆性断裂转变

In order to investigate the tensile characteristis of lead-free solder at high strain rates, impact tensile test equipment far solder Vials was developed, on the basis bf the direct tension split Hopkinson bar technique. By using this equipment,.tensile stress-strain characteristics data of the Sn-3.0Ag-0.5Cu lead-free solder and the Sn-Pb conventional solder up to fracture were measured with a high accuracy at strain rate of 1.66 x 103 and compared with those at quasi-static strain rates of 1.2 and 1.2×10^<-2>. The results show that the proof. stress and tensile strength of the Sn-3.0Ag-0.5 Cu lead-free solder increase significantly with ending strain rate comparing with the Sn-Pb conventional solder. It is also shown that the fracture morphology of Sn 3.0Ag-0.5Cu solder changes from ductile fracture to brittle fracture with increase in the strain rates