The semiconductor industry has followed Moore’s law in the last four decades. However, transistor performance improvement will be limited, and designers will not see doubling of frequency every two years. The need for increased performance and further miniaturization has driven the development of advanced packaging solutions, such as fan-in wafer-level chip-scale packaging, fan-out wafer-level packaging, wire-bonded stacked dice, and package-on-package. These technologies are used in mass production and provide significant benefits in form factor but may not give the desired improvement in die-to-die bandwidth. Recently, 3-D integrated circuits (ICs) that employ vertical through-silicon vias (TSVs) for connecting each die have been proposed. It is an alternative solution to existing package-on-package and system-in-package processes. This column addresses some of the challenges in implementing new TSV techniques.