镀镍多壁碳纳米管对Sn-3.0Ag-0.5Cu无铅钎料焊点界面行为的影响

采用机械混合法制备了不同含量(0、0.05、0.1、0.2、0.5wt%)镀镍多壁碳纳米管(Ni-CNTs)复合Sn-3.0Ag-0.5Cu(SAC305)无铅钎料。采用F4N回流炉对SAC305-x(Ni-CNTs)钎料进行回流焊,利用电热鼓风干燥箱对焊点试样进行170 ℃时效(t=0、48 h)处理。结合DTA、SEM、EDS等分析手段研究了不同镀镍碳纳米管含量对Sn-3.0Ag-0.5Cu钎料润湿性、熔点和焊点界面金属间化合物(IMC)层的影响。结果表明:Ni-CNTs可以显著改善钎料的润湿性,降低钎料熔点;此外,Ni-CNTs可以有效抑制界面IMC层的生长,同时改变界面IMC组成。综合比较得出Ni-CNTs最佳添加量为0.05%,与Sn-3.0Ag-0.5Cu钎料相比,润湿角降低49.76%,熔点降低0.331 ℃;时效后界面IMC层厚度4.292 μm(t=0 h)、5.238 μm(t=48 h)相对于SAC305钎料界面IMC厚度6.529 μm(t=0 h)、8.255 μm(t=48 h)分别降低了34.26%(t=0 h)、36.55%(t=48 h),界面IMC层相组成转变为(Cu_1-xNi_x)₆Sn₅和(Cu_1-xNi_x)₃Sn。

Effect of Ni-CNTs on interface behavior of Sn-3.0Ag-0.5Cu lead-free solder joints

Lead-free solder Sn-3.0Ag-0.5Cu with different contents(0,0.05,0.1,0.2,0.5wt%)of nickel-plated multi-walled carbon nanotubes (Ni-CNTs) was fabricated by mechanical mixing method, and reflow soldered with F4N furnace. The solder joints were aged in a vacuum drying oven at 170 ℃ for 0 and 48 h. The effect of Ni-CNTs content on wettability, melting point of Sn-3.0Ag-0.5Cu solder and the intermetallic compound (IMC) layer at the solder joints was studied by means of DTA, SEM, EDS and other analytical methods. The results show that the Ni-CNTs can significantly improve the wettability of the composite solder and reduce the melting point, also inhibit the growth of the interface IMC layer and change its composition. The optimal addition amount of Ni-CNTs is 0.05%. Compared with Sn-3.0Ag-0.5Cu solder, the wetting angle of Sn-3.0Ag-0.5Cu-0.05(Ni-CNTs) is reduced by 49.76%, the melting point is reduced by 0.331 ℃. The thickness of the interface IMC layer after aging is 4.292 μm (t=0 h) and 5.238 μm (t=48 h), which is reduced by 34.26%(t=0 h) and 36.55% (t=48 h), respectively, compared with Sn-3.0Ag-0.5Cu solder joints interface IMC thickness of 6.529 μm (t=0 h) and 8.255 μm (t=48 h), and the phase composition of the interface IMC layer changes to (Cu_1-xNi_x)₆Sn₅ and (Cu_1-xNi_x)₃Sn.