ABSTRACT
Having accepted inspection, the most important question to answer is, "where in the processes is inspection the most cost-effective?" Like test, inspection may take place at various points in the assembly process. As examples, inspection points in the surface mount assembly process may include
• Bare boards • Parts • After solder paste deposition • After parts placement • After reflow • After rework
It is also important to note that the inspection criteria and the pass-fail criteria will depend on the type of product being inspected. In IPC-A-610, "Acceptability of Electronic Assemblies" the IPC defines the following three classes of electronic assemblies:
• Class 1: General Consumer Products, such as audio and video products • Class 2: Dedicated Service Electronic Products, such as communications equipment where failures
are undesirable but not critical. • Class 3: High Performance Electronic Products, such as pacemakers and weapons systems, where
downtime is unacceptable and/or the operating environment is harsh.
