The modern PCB features almost countless joints, thus making the manual inspection a challenging task. Keep in mind that even in the years of simpler PCB circuit boards, manual testing was still hard and resulted in imperfect outcomes.

Think of the human factor. Human inspectors get tired, lose attention, or accidentally overlook some defects. It’s clear that with more advancement in these products, manual testing can’t keep pace with the exacting demands required. Moreover, vast quantities of PCBs are needed to satisfy the large and growing demand for electronic circuits. So, one needs more rapid and accurate methods. For all this, the only answer is an automatic optical inspection system.

How does AOI PCB accomplish its stunning results? Here we list three basic approaches

• Template matching – this method compares the image captured with that of the “golden board,” which acts as a benchmark. So anything that is a mismatch to this board is flagged
• Pattern matching – the system keeps a store of the image of the ideal PCB board and to match the actual output with the stored image in order to identify flawed products
• Statistical pattern matching – This technique resembles pattern matching but uses large numbers of board images. Following this, It then applies methods of statistics to identify flaws. Consequently, this method will also not reject all board errors, as some are too minor to need flagging.