This book introduces the reader to the widely dispersed reliability literature of microelectronic and electro-optical devices. It integrates a treatment of chip and packaging level failures within the contexts of the atomic mechanisms and models used to explain degradation, and the statistical handling of lifetime data. Electromigration, dielectric breakdown, hot-electron effects, electrostatic discharge, corrosion, radiation damage and the mechanical failure of contacts and solder joints are among the failure mechanisms considered. An underlying book thread concerns product defects - their relation to yield and reliability, the role they play in failure, and the way they are experimentally exposed. The book can be used as an advanced undergraduate/graduate textbook for materials scientists and electrical engineers, and as a reference for reliability professionals.