The demand for smaller-sized, high-speed, high-density multi-chip packages (MCP) is growing by the day . Stacking Silicon to increase packing density in IC’s is not a new concept, but recently stacking has gained a new level of importance as the process is being introduced to make microprocessors and is slated to come into the mainstream by 2008,Currently chip components are connected by wire bonding, requiring vertical spacing between dies that is tens of microns deep and horizontal spacing on the package board hundreds of microns wide for the die-connecting wires.Stacked silicon, rather than placed side-by-side shortens on chip data travel distances, ultimately saving a whole lot of space on chip and offering an opportunity to drive Moore’s law forward .

“Through-silicon vias” (TSV) is the technology employed for stacking ,which uses vertical connections etched through the silicon wafer and filled with metal. This concept has been described by other chip manufacturers before . Intel revealed thier plans for TSV at the spring IDF 2005 and most recently Samsung announced that it has developed the first all-DRAM stacked memory package using TSV technology, which will soon result in memory packages that are faster, smaller and consume less power, Samsung’s technology forms laser-cut micron-sized holes that penetrate the silicon vertically to connect the memory circuits directly with a copper filling, eliminating the need for gaps of extra space and wires protruding beyond the sides of the dies.
While TSV is still in its early stages, the technology represents the next step in innovative packaging solutions which have become increasingly important to enable high-speed, high-density and high- performance Semiconductor solutions .