Development of a comprehensive in‐line quality control system for printed circuit board assemblies

Purpose To present an overview of the research and development carried out by an EC Framework 6 part funded consortium, known as MICROSCAN, for the implementation of an in‐line PCB inspection prototype system that is capable of offering comprehensive defect detection. Design/methodology/approach Four non‐destructive testing inspection modules based on digital radiography (X‐ray) inspection, thermal inspection, automated‐optical inspection and acoustic inspection have been integrated to form a combined inspection system. Findings A proof in principle in‐line PCB inspection system, utilising four different inspection techniques, has been developed and demonstrated. The system is based on a generic mechanical, electrical and software communications platform culminating in a flexible system that enables the inspection modules to be used separately, together or interchanged to give the best results in terms of inspection coverage and inspection throughput. Research limitations/implications In its current embodiment, the prototype is suited to inspection of high‐return PCBs, particularly those used in medical and aerospace products, rather than high‐throughput PCB production work. The X‐ray inspection module is the slowest inspection technique and combining four different inspection techniques reduces the inspection throughput of the whole system to that of the X‐ray inspection module. Further, trials and investigations need to be carried out to improve inspection throughput. Originality/value The novelty of the system is that it is the first time that four inspection techniques have been combined to give the capability of 100 per cent defect coverage.