**5.1. Density**

The density of a microelectronic device is very important for developing portable electronic goods. There are various reports which show a reduction in density values in nanoparticle reinforced composites. [18, 21, 41] Zhong *et al.* reported that the Al2O3 reinforced Sn matrix composite is lighter compared to monolithic matrix, while Babaghorbani *et al.* found that SnO2 reinforced Sn–3.5Ag matrix did not show any change in density. This may be due to the fact that the matrix and reinforcement have the similar values of density.[21, 25]
