The figure 4.1 above shown the indentation crater after the 10 days indented by 200 g weigh at ambient condition.
After 240 hours indentation, there are several grain boundaries appeared changed position around the indentation crater and a few pores formed on the surface of pure tin solder. Each of the indented sample have clear formed carter. Meanwhile, the figure 4.2 show the SEM images of the formation of hillock on the pure tin solder deposited onto the copper plate after the indentation of 400 g load after the 24-hour period in the room temperature. As shown in the figure 4.
2 of the surface morphology of the 1mm steel ball indentation with load of 400 g onto the pure tin solder deposited on the copper plate was under observation by using SEM. In the figure 4.2(i), shown the formation of hillock about 5 µm. Meanwhile, in the figure 4.1(ii), shown the initial peak of rounded hillock.
The mean average of the formation of the hillock observed are about 209 µm. This prove that within 24-hour period with the applied stress of 12.6 kPa can formed about less than 5µm. The other pure tin solder sample is indented with the 200 g for the 240 hours.