热冲击下Sn2.5Ag0.7Cu0.1RE0.05Ni/Cu钎焊接头组织与性能

Interfacial Microstructure and Mechanical Properties of Sn2.5Ag0.7Cu0.1RE0.05Ni/Cu Solder Joint under Thermal Shock

摘要:

借助于SEM、EDS、XRD等检测手段对Sn2.5Ag0.7Cu0.1RE0.05Ni/Cu钎焊接头进行观察分析,研究了钎焊工艺参数及热冲击条件对Sn2.5Ag0.7Cu0.1RE0.05Ni/Cu钎焊接头界面金属间化合物和力学性能的影响。结果表明：添加0.05 wt% Ni能细化Sn2.5Ag0.7Cu0.1RE钎料合金的初生β-Sn相和共晶组织；钎焊温度270 ℃和钎焊时间240 s时,钎焊接头剪切强度最大达26.9 MPa,较未添加Ni的钎焊接头提高8.9%；随着热冲击周期的增加,钎焊接头界面金属间化合物层平均厚度增加,界面粗糙度先增大后减小,钎焊接头强度降低；添加0.05wt%Ni能够抑制接头界面金属间化合物的成长、钎焊接头强度的降低,有利于改善接头可靠性。

Abstract:

To study the effect of solder process parameters and thermal shock on Sn2.5Ag0.7Cu0.1RE0.05Ni/Cu of soldered joints, the interface intermetallic compounds and strength of the joints were observed and analyzed with the help of SEM, EDS, XRD. The results showed that adding 0.05 wt% Ni can refine the primary β-Sn phase and eutectic of the Sn2.5Ag0.7Cu0.1RE solder alloy. The maximum shear strength was 26.9MPa, which obtained from the joint under the soldering temperature of 270℃ and soldering time of 240s. The maximum shear strength increased 8.9% than Sn2.5Ag0.7Cu0.1RE/Cu joint. The interface roughness, the average thickness of the Sn2.5Ag0.7Cu0.1RE0.05Ni/Cu joint rased with the increasing of temperature and time. The shear strength of the joints increased and then decreased. The interface IMC of the solder joints irregular growth with the rasing of thermal shock cycle. At the same time, the strength of the joint was decreasing. The added 0.05 wt% Ni can inhibite the quick decrease of the reliability of soldered joint in the process of the thermal shock.