Jul 25 2018
Print circuit boards are mostly machine populated. But during this assembly process and soldering of electronic components production errors are inevitable. To detect defects nowadays 3D machine vision can also be used. For the detection of flaws and securing of the quality the automatic optical inspection (AOI) has been established, and 3D can also deliver new insights into that process.
With EyeVision 3D not only pins of ICs, THTs, SMDs or even BGAs can be inspected, but also the problem of lifted leads or lifted pads. First, the EyeVision 3D can determine the wobble circle. This means if the pin are not exactly centered. Also the software can recognize if the pins have the same height, if there are standing out or are too deep in the body. As well as if the pins are bent.
And to top that the EyeVision can also recognize if the pins are rest correctly on the board after the assembly. During the manufacturing of electronic components the lifted leads are among the most critical errors. This most often occurs when trying to de-solder components from the board or due to reduced wetting, when a pin is oxidized. During an operation for example, this error can lead to disruptions and therefore to malfunction of the component part. The lifted leads are not only one of the critical errors but they are also very difficult to identify. Many parameter determine the shape of a lifted lead and the solder joint. For example the length and width of the pad, as well as the height of the pin and the characteristics of the solder.
Thanks to the constantly developing 3D image processing it can now also be used to detect the lifted leads. Depending on the size of the component part, different 3D techniques are applicable, whereas shape-by-shade projection provides a very detailed and fine-grained point cloud. And on this point cloud the EyeVision 3D software can carry out various 3D measurements and evaluations to identify a faulty PCB.
The ready-to-use Pin-Inspector-Kit or an especially developed inspection program makes it even easier to handle. Both options allow the user to create the inspection program with the drag-and-drop function.