X-Ray Systems for Optimizing PCB Inspection

摘要

The need to incorporate x-ray inspection into today's printed circuit board (PCB) assembly line is now a foregone conclusion for many manufacturers. It is no longer a question of if, but where in the line, how often to test and what features are needed in the x-ray system. Like every other question on quality improvement, the answers depend on the types of components, the density of components, production throughput and the product application. Automated optical inspection (AOI), both visual and laser, is typically positioned early in the assembly process to identify missing or misplaced components, improper paste applications and wrong components. In contrast, x-ray inspection systems are used after reflow to verify the mechanical integrity of the assembly process and identify errors such as solder bridges (shorts), missing or undersized solder joints (voids), misalignments, open solder joints and bad wetting. However, not every x-ray system can do all these inspections, and, just because a specific system has a higher price, cost does not ensure an accurate test.