Estimated reading time: 9 minutes

An Inside Look: 3D AOI of Electronic Assemblies Seminar

This capability assessment had concluded that the 3D AOI system as described was capable of inspecting 03015 and 0201 micro-components and of detecting defective symptoms such as component shift, component lifted, component missing, insufficient or excess solder or bridging, solder balls, and solder splash.

Pierre Williams from Yamaha discussed new technology available in SMT equipment and software to help raise production yield and reduce waste in a presentation entitled “Boosting Quality Control and Productivity through Closed-Loop AOI.” The goals were to produce more good units and achieve a higher end-of-line inspection pass rate, with fewer line stoppages and faster fault resolution. To achieve these goals, the requirements were high-quality inspection data, real-time information and feedback of defect data, and access to detailed reports, either at the machine or on the move.

In a typical SMT line there was only one AOI and this was located post reflow so that defects were not found until after board has been soldered, meaning that several defective boards could be in reflow by the time the first defect was found, and significant human intervention was needed to monitor reports and stop the line. On a short production run, the run could be finished before the defect was found and there was no benefit from feedback. Until recently, there was no facility for the AOI to communicate with the pick-and-place machine, so quality information was not shared between the inspection area and the production area and there was no scope to eliminate a problem whilst it was occurring.

In the knowledge that reflow could correct minor placement errors, Williams suggested locating the AOI machine after placement and before reflow as the first stage in the transition to closed-loop feedback so that defects could be detected before boards were reflowed. Large amounts of manual rework and repair could be avoided and high-value components could be retrieved and reused. With suitable software, this gave the option to automatically feed-back data from the AOI to the pick-and-place and pinpoint the origin of the defect, and conversely, close the loop to feed forward data from the mounter to optimise AOI performance.

Page 3 of 4

• < Previous Page
• Next Page >