Research On Physical Properties Of Sn-Ag-Cu-Sb Solder

Because lead and lead compounds on the environment and human health hazards, international legislation has been banned in the electronic devices,as well as surface mount (SMT) process in the use of lead solder. solder, Sn-Ag-Cu ternary system eutectic solder good mechanical properties, and weldability, thermal fatigue is also better, most likely to be Sn-Pb lead material alternatives.Through nearly a decade of research and development, the researchers found that:Among the many lead-free solder,Sn-Ag-Cu ternary system eutectic solder good mechanical properties,and weldability,thermal fatigue is also better,most likely to be Sn-Pb lead material alternatives.However, Sn-Ag-Cu lead-free solders there are a lot of deficiencies,such as its melting point higher than lead-free Sn-Pb solder and wettability poorer than the Sn-Pb solder. So Sn-Ag-Cu lead-free solder performance to be further improved.Currently people are constantly seeking to improve an element doped Sn-Ag-Cu lead-free solder performance,For example,in Sn-Ag-Cu lead-free solders doped Bi, and doped Ce.The topics to Sn-Ag-Cu lead-free solder-based material,doped with different content of Sb (0 ~ 1wt%)elements,preparation of Sn-Ag-Cu-Sb Lead-free solder test samples,testing doped solder density,Young's modulus,hardness,thermal expansion coefficient of the changes,to study its physical properties.Through the test sample results show that:Sb-doped after the Sn-Ag-Cu-Sb than the density of lead-free solder Sn-Ag-Cu lead-free solder decreased significantly,when the doping ratio of 0.5%,the density decreased to reach a minimum value,the decline in density,making the solder with a low weight advantage;Amplification method using optical lever after the Sb-doped Sn-Ag-Cu-Sb Lead-free solder alloy of the Young's modulus testing,the Young's modulus increases with the doping ratio of the upward trend in the effective toughness of the solder increases;The use of HB-3000 Brinell hardness testing machine type test hardness, after the Sb-doped Sn-Ag-Cu-Sb Lead-free solder a marked increase in hardness,effectively improved the anti-deformation performance of solder;Using Netzsch DIL 402C high-temperature thermal expansion instrument coefficient of thermal expansion of the specimen was tested after the Sb-doped Sn-Ag-Cu-Sb Lead-free solder thermal expansion coefficient decreased significantly,so that the expansion coefficient of solder is closer to the base material Cu,so the solder and Cu can be a better match,but also can effectively reduce the risk of solder joint failure.