| dc.description.abstract | ABSTRACT
Diffusion barrier plays an important role in soldering, it can prevent fast reaction between tin and copper. Beside nickel and platinum, nickel-copper alloy is a possible diffusion barrier in the future. In the past, our labortoary investigated liquid/solid reaction between SnAgCu solder and nickel, it found that little copper added in solder can reduce consumption of nickel. Additionally, intermetallic compound at interface can also changed with copper added in solder.
In the experiment, we electroplated nickel-copper alloy on copper and investigated reaction between Sn3Ag solder and different concentration nickel-copper alloy. Beside liquid/solid reaction, we also investigated solid/solid reaction. According to the result, change of concentration in nickel-copper alloy will affect intermetallic compound phase and consumption.
Beside copper and nickel,we also electroplated Ni-15 at.%Cu,Ni-40 at.%Cu and Ni-54 at.%Cu. After 120 sec liquid/solid reaction, intermetallic compound between tin and Ni-15 at.%Cu is (Ni1-xCux)3Sn4；intermetallic compound between tin and Ni-40 at.%Cu is (Ni1-xCux)3Sn4；intermetallic compound between tin and Ni-54 at.%Cu is (Ni1-xCux)3Sn4 and (Cu1-xNix)6Sn5.After solid/solid reaction, intermetallic compound between tin and Ni-15 at.%Cu is (Ni1-xCux)3Sn4；intermetallic compound between tin and Ni-40 at.%Cu is (Ni1-xCux)3Sn4 and (Cu1-xNix)6Sn5；main intermetallic compound between tin and Ni-54 at.%Cu is (Cu1-xNix)6Sn5.
After 120 sec liquid/solid reaction, consumption of nickel-copper alloy will increase with copper concentration in alloy.Surprisingly, consumption of Ni-54 at.%Cu is faster than copper after 300 sec liquid-state reaction. After solid/solid reaction, consumption of Ni-40 at.%Cu and Ni-54 at.%Cu is even faster than copper.
In the research, we found that a little sulfur copper added in electrolyte will great affect copper concentration in nickel-copper alloy, intermetallic compound phase and consumption. | en_US |