TSVs/ Bumps

VIAs are introduced to provide electrical connections through a silicon substrate. Given the packing densities commonly encountered in present-day semiconductor production, these through connections have diameters down to a few µm and aspect ratios of up to 20/1. Connection between the silicon layers to form complex circuits is made by tiny balls of solder known as bumps. These too are becoming smaller and smaller as a result of the ever-increasing complexity of components; bumps with diameters below 30 µm are far from rare.