What Is 3-D Test and How Do IEEE Standards Help?

3-D silicon integration is reaching the point where it may be deployed. 3-D silicon integration is different from 3-D packaging in that 3-D packaging involves whole packaged chips, and each chip can still be tested individually throughout the manufacturing and assembly process, such as at wafer test, before and after packaging, and before and after integration into a complex chip assembly. Thus, methods used to test, debug, and verify multichip modules are generally extensible into the 3-D packaging space. For 3-D silicon integration using through-silicon vias, the issue is debug or test access to an individual die in the stack. This article reports on efforts by an IEEE P1838 Working Group to develop a per die standard.