The printed circuit industry has achieved maturity and universal accep­ tance. No known interconnection technology threatens to render it obso­ lete in the foreseeable future. It offers two unique advantages that are important for any assembly technology: quality (reliability) and economy. The mode of component attachment to printed circuit boards, however, is undergoing a radical change. Technical and economic pressures are forcing the industry to convert some or all of its assembly to surface­ mounting techniques. We are moving away from the traditional large through-the-hole connection with its mechanical security. It is being re­ placed by a small surface butt and/or lap joint, sometimes with no added mechanical support to the solder. This change requires a complete reas­ sessment of design, production, and inspection techniques. A major por­ tion of this book is devoted to the changes imposed by surface mounting. This recent development is an extension of the established hybrid (thick­ and thin-film) industry. Yet when it is applied to conventional printed circuits, there are major differences. One must view the printed circuit board as a planar surface designed to provide interconnections between electronic devices. The electronic in­ dustry is using them for mass-production techniques to join discrete, integrated, and special components (leaded and leadless). This book ap­ plies to all board variations including single-sided, double-sided, multi­ layer, and flexible circuits.