PROSPECTS FOR AUTOMATED PWA SOLDER DEFECT INSPECTION.

The current enthusiasm for automated PWA solder defect inspection comes partly from a desire to automate the factory entirely and partly from a concern over the lack of agreement by visual inspectors. The lack of agreement is not inherent in the supposed 'subjectiveness' of the task, but from a lack of definition that makes automated, as well as visual, inspection arbitrary. It is argued here that there are really two inspections, with two concerns: inspection for product reliability (screening for risky defects), and inspection for materials and process control (for which sampling is sufficient). A discussion of all defects occurring after machine soldering is given, along with probable causes and a risk assessment. Recommendations are made on how inspection should be performed and how all defects can be prevented so that screening inspection can be dropped.