This book is a comprehensive overview of the discoveries in composition, growth and control of gold-aluminum intermetallic compounds in microelectronic interconnects known as Purple Plague. It focuses on the history of detection, theory, and understanding of the gold/aluminum interface reliability issues.

Purple Plague in Microelectronics presents research on the phenomenon of purple plague from the earliest days to the present. The authors explain intricate scientific aspects to understand cause and effect of this reliability issue in microelectronics in a way that they are understandable by readers from various educational levels, novice to expert, while satiating the needs of the engineering personnel closely associated with work related to the gold-aluminum interfacial integrity. The discovery of void formations leading to porosity in the purple phase and the subsequent failure of the joint are outlined and detailed analyses of various phases, metallurgy and diffusion phenomenon at the gold-aluminum interface are presented. They provide detailed drawings, graphs, charts, models, and tables for easy comprehension of concepts and phenomenon. Various ways of evaluating the quality and reliability of the joint and the relative merits of the methods are explained with the introduction of shear testing and bond resistance testing. The roles of the ingredients in the packaging materials and the gold wire itself are discussed and the related mathematical models are presented.

This book is intended for electronic assembly engineers, design engineers, assembly process development engineers, material scientists, electronic industry supervisors and managers. It is an excellent reference for anyone responsible for defect control and reliability in gold wirebonding.