For many years, companies have had a love it or hate it attitude to automated optical PCBA inspection systems. They know they need a less operator heavy inspection process to help them reduce manufacturing costs and improve the reliability and resultant quality of PCBA inspection, but have found traditional AOI systems temperamental with limited success.
AOI’s definitely provide a better alternative to manual inspection both in repeatability and lower operator involvement. These days, AOI systems have also reduced significantly in price enabling more companies to take the plunge and invest in this inspection technology reaping the rewards of automating the inspection process.
So what does the future for PCBA inspection look like?
It is likely that AOI systems will continue to grow in popularity as more and more companies make the switch to automation. High volume manufacturers will invest to move from using AOI’s in a quality assurance function to a fully integrated part of their production line. This will have its own challenges. False call rates are often an issue with AOI’s, where the systems identify an issue when in fact there is none. These false calls add delays into the inspection process and can be a frustrating side effect of using these types of systems.
The latest revolution in PCBA inspection systems is the use of lasers instead of traditional AOI cameras. It would seem to make a great deal of sense after all lasers have been used for many years for taking accurate measurement’s in many hi tech industry areas.
What are the benefits of using lasers for PCBA inspection?
Lasers inherently enable very fast and accurate measurements to be taken, so PCBA inspection systems built using lasers are really true metrology systems rather than the optical inspection technique used in traditional AOI’s, ie they take millions of measurements in a short period of time. As the laser scans the PCBA it sends millions of true XYZ measurements to a powerful computer to process. The result is a high resolution array of measurement points. When combined together these measurement points can provide a full 3D measurement profile of the board being tested. The benefits of taking measurements and not relying on camera pictures are very clear. Measurements are just that, they are real, they exist, they can be processed easily, are repeatable and can be used in calculating extremely accurate results.