Issue link: https://iconnect007.uberflip.com/i/1508761
22 SMT007 MAGAZINE I OCTOBER 2023 3D inspection capability for the AOI machine as well. Furthermore, as PCB density increases, the proximity decreases between taller devices and lower lying discrete components, creating a challenge with shadowing. To overcome this challenge, the AOI machine must be config- ured with multi-angle 3D projection technol- ogy as well as the capability to process taller devices up to 25 mm. Lastly, the increased use of bottom terminated devices increases the requirement for X-ray inspection capability for verification of proper electrical connectivity. e good news is that the technology exists to overcome each of these challenges. Scutchfield: On the mechanical side, shiny and hidden joints can be challenging, so systems had to be created (special lighting and side camera technology) to overcome these chal- lenges. Beyond that, management and process- ing of the immense amount of 3D data being generated creates additional challenges. Again, we continue to refine everything involved with doing this, as it continues to be a moving target where more and more data will be generated as we go forward. Virani: Some common challenges associated with automatic inspection systems include: • Long programming time for each new board type, which is amplified when components on a board change • Poor suitability for covering a wide variety of inspection tasks at different stages of manufacturing (e.g., many systems are not suitable for final assembly inspection for inspecting a fully-populated board with components of different sizes, shapes, and height, and different types, such as SMT, through-hole, wires, etc.) • Highly sensitive to minor acceptable variations resulting in high false positive rates Could you describe the role of machine vision and image processing algorithms in automatic inspection systems for electronics manufacturing? D'Amico: Most automated inspection sys- tems use some form of machine vision. As the inspection process becomes more complex, these systems must be configured with high- speed, high-resolution optics, lighting, and 3D technology to capture multiple images of each region of interest for data processing. e most advanced systems use a combination of 2D and 3D algorithms to analyze this data to deter- mine the integrity of each phase of the man- ufacturing process. For solder deposition, SPI algorithms are used to analyze the area, vol- ume, shape, and offset of each deposition as well as bridging between depositions. AOI sys- tems use a combination of complex algorithms to determine the length, width, height, and coplanarity for both the body and leads of each device, as well as volumetric measurement of every solder joint. X-ray systems offer com- puted tomography (CT) scanning with spe- cialized algorithms for detailed cross-sectional 3D analysis of a given region of interest at mul- tiple different angles and levels. Scutchfield: is is probably the most impor- tant feature when it comes to capability, accu- racy, and repeatability. Image acquisition is the first big step in the inspection process, and it must be done properly for the system to have any chance of providing a reliable, trust- (Source: MIRTEC)