The advent of 3-D package age

The three-dimensional (3D) package is one type of multi-die package (MDP). Unlike most MDPs, the dice inside 3D packages are stacked vertically. Although it is not a new concept, 3D packaging has not been widely implemented in mass production until recent years (Sidharth et al. 2000; Gannamani et al. 1999; Kada, 1999). Advanced portable products that require high spatial density as well as performance are driving this technology into a new age. However, without a solid and manufacturable assembly technology, 3D packages will still be too costly to be implemented. In this paper, the challenges in 3D packaging assembly such as backgrinding, die-attach, wire bonding and overmolding are investigated. Also, the cost-performance trade-offs of various 3D packages are discussed.