An advanced optical diagnostic technique of IBM z990 eServer microprocessor

Abstract

In this paper, we describe an advanced optical diagnostic technique used for diagnosing the IBM z990 eServer microprocessor [1]. Time-to-market pressure demands quick diagnostic turnaround time and high diagnostic resolution while the ever increasing design complexity, density, cycle time, and shrinking technologies dramatically add difficulties to diagnostics. Although design-for-test (DFT) and design-for-diagnostics (DFD) features are implemented in the latest microprocessors to help easing the diagnostic efforts, they may still not be sufficient to diagnose certain fails. The well-known Picosecond Imaging Circuit Analysis (PICA) [2] tool, equipped with the high quantum efficiency Superconducting Single-Photon Detector (SSPD,) shows a unique diagnostic capability for optically probing the internal nodes of a chip. Several hard-to-diagnose examples will be used to demonstrate the unique capabilities of this technique. © 2005 IEEE.