This book is about how to design the most complex types of digital circuit boards used inside servers, routers and other equipment, from high-level system architecture down to the low-level signal integrity concepts. It explains common structures and subsystems that can be expanded into new designs in different markets. The purpose of this book is to show all aspects of a hardware design engineer’s job in the more high-end digital board segments. This individual is sometimes called a hardware engineer, hard- ware design engineer, electrical engineer, electronics design engineer, CCA, or PCA engineer. The book is focused mainly on low-level detailed circuit implementation, but it also discusses high-level aspects like systems and manufacturing. This book is about advanced hardware design, so it is assumed that the reader has an EE degree and has already designed some lower-complexity digital circuit boards. There are short introductions to all topics, but the focus is on more advanced material. The book is targeted at all levels of hardware engineers. There are shorter, lower-level introductions to every topic, while the book also takes the reader all they way to the most complex and most advanced topics of digital circuit design, layout design, analysis, and hardware architecture.