This is a collection of information on electronic board and assembly cleaning in a single location. This major revision explains the relationship between materials, processes, and contaminants in fabrication and assembly operations. It also addresses cleanliness assessment and process control in relation to cleanliness. Color pictures help with understanding. 200 pages.Supersedes IPC-CH-65A, IPC-SC-60A, IPC-SA-61A, IPC-AC-62A, IPC-SM-839.