Description

Stacked ICs with vertical interconnect containing fine-pitch micro-bumps and through-silicon vias (TSVs) are a hot-topic in design and manufacturing communities. These 2.5D- and 3D-SICs hold the promise of heterogeneous integration, inter-die connections with increased performance at lower power dissipation, and increased yield and hence decreased product cost. However, testing for manufacturing defects remains an obstacle and potential showstopper before stacked-die products can become a reality. There are concerns about the cost or, even worse, feasibility of testing such TSV-based 3D chips. In this tutorial, we present key concepts in 3D technology, terminology, and benefits. We discuss design and test challenges and emerging solutions for 2.5D- and 3D-SICs. Topics to be covered include an overview of 3D integration and trendsetting products such as a 2.5D-FPGA and 3D-stacked memory chips, test flows and test content for 3D chips, advances in wafer probing, 3D design-for-test architectures and ongoing IEEE P1838 standardization efforts for test access, and 3D test cost modeling and test-flow selection.