Aside from the presence of the stress created from the indentation of load, it can be deduced that the presence of the copper-based substrate can also act as the precursor of the formation of pure tin growth. Both samples of different load are stored together in the same ambient temperature but within different period of storage. Based on the several current studies, the formation of pure tin whisker involved the grain boundary sliding movement which start with the critical pressure about -15 MPa 32. Eventually, the stress gradient is created to drive out the pure tin atoms from the surrounding undeformed areas to the base of hillock and push up the hillock outwards.The thin layer of pure tin solder plating need less time for the movement of intermetallic compound towards the pure tin grain boundaries plating to generate the compressive stress 58. According to Horváth et. al, the manipulation of the size of the pure tin grain will cause the alteration in the rate of grain boundary diffusion and the level of exerted compressive stress.


I'm Casey!

Would you like to get a custom essay? How about receiving a customized one?

Check it out