| Summary: | 碩士 === 國立臺灣科技大學 === 材料科學與工程系 === 105 === Au and Ni are widely used in Under Bump Metallurgy. Au is widely used as a anti-oxidation layer, because it has many advantages, such as good anti-oxidation, corrosion resistance and solderability. And Ni is widely used as a diffusion barrier to avoid interfacial reaction between solders and the substrate. Sn is a common material because it has good wetting properties with metal surfaces.And Cu is a substrate. Therefor the Au/Sn/Ni/Cu multilayer structure is a common structure at the solder joint in electronic packaging. So in this study we prepared the Au/Sn/Ni/Cu multilayer structure by depositing a Ni/Sn two-layer structure onto the Cu substrate through electroplating. In order to understand the IMC evolution with various of reaction time at different temperatures,these couples will undergo the solid-solid interfacial reaction at 150, 180 and 200 oC. At the mean time the phase equilibria of Au-Ni-Sn ternary system at 180, 240 oC were experimentally investigated.The result shows that there is no homogenous range from the Ni3Sn2 phase to the AuSn phase, but a large solubility of Au in the Ni3Sn2 phase. There is a ternary compound AuNi2Sn4 in this system, and large solubility of Ni in the AuSn4 phase. In the Au/Sn/Ni/Cu multilayer interfacial reaction shows that the thickness of IMC increased with the increasing temperature ; however, the category of the IMC weren’t change with the different temperature. As the reaction time increased, the Sn-rich phases AuSn4 and AuSn2 gradually became thinner and finally disappeared because the phase transformation. The voids caused by volume shrinkage decreased with the increasing temperature. Ni layer prevented the formation of Cu-Sn IMC, and formed (Ni,Au)3Sn2 phase between Au-Sn IMC /Ni interface.
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