Impact Properties of Lead-Free Sn-Ag-Cu-Ni-Ge Solder Joint with Cu Electrode

Abstract

The impact properties of solder ball joints with Sn-Ag-Cu-Ni-Ge lead-free solders and Cu electrodes were investigated in the aged conditions at 393 K. The impact properties evaluated was compared with Sn-Ag and Sn-Ag-Cu solder joints. The impact properties of Sn-AgCu-Ni-Ge joints were superior to those of Sn-Ag and Sn-Ag-Cu joints. In the cases of Sn-Ag and Sn-Ag-Cu joints, fracture mainly occurred in the intermetallic compounds (IMC) layer formed in the joint interface regardless of aging treatment. On the contrary, main fracture mode was solder fracture in as-reflow Sn-Ag-Cu-Ni-Ge joints. Although the main fracture mode gradually changed from solder fracture to IMC fracture upon aging, Sn-Ag-Cu-Ni-Ge joints had excellent impact reliability compared with Sn-Ag and Sn-Ag-Cu joints even after aging at 393 K for 1000 h.

Interfacial reactions and mechanical properties between Sn–4.0Ag–0.5Cu and Sn–4.0Ag–0.5Cu–0.05Ni–0.01Ge lead-free solders with the Au/Ni/Cu substrate

“…That is why the SACNG/Au/Ni/Cu solder joint has better mechanical strength than the SAC/Au/Ni/Cu solder joint. Several studies had similar results [23][24][25][27][28][29][30][31].…”

“…Massive research groups have studied interfacial reactions between Sn-Ag and Sn-Ag-Cu alloys with Ni or Cu or Au/Ni/Cu substrates [5,[11][12][13][14][15][16][17][18][19][20][21][22], and several literatures had regarded with interfacial reactions and the mechanical properties of Sn-Ag-Cu alloys by adding a minor amount of Ni or Ge elements to the Au/Ni/Cu substrate [8,21,[24][25][26][27][28][29][30][31]. The Sn-4.0Ag0.5-Cu alloy is one of popular lead-free solders and the Au/Ni/Cu multi-layer is the common UBM structure in electronic packaging.…”

Effect of Shear Speed on the Ball Shear Strength of Sn-3Ag-0.5Cu Solder Ball Joints

“…Since the increasing popularity of mobile products has made the impact reliability of the solder ball joint a critical issue, [14] impact tests have been used to examine the impact strength of solder ball joints at higher shear speeds. [14][15][16][17][18] However, studies which systematically investigated the effect of shear speed on joint strength over a broad shear speed range have not been found.…”

Effect of Trace Ge on Wettability and High-Temperature Oxidation Resistance of Sn-0.7Cu Lead-Free Solder

“…However, these studies generally are centered on low temperature around 260 C. Electronics manufacturers sometimes need to use the same solder in a wider temperature range in the actual production process, such as 250 C 400 C. So the research on wettability and oxidation resistance of solder at high temperature is particularly important. Ge element can not only improve the density of the interfacial IMC to increase the strength of soldering joints, but can also improve the oxidation-resistance of solders at high temperature [8][9][10][11] . But the research about Ge element is insuf cient, so the in uence of adding trace Ge on the wettability and the oxidation resistance of Sn-0.7Cu leadfree solder at high temperature were researched to solve this problem in the paper.…”