Automatic optical inspection of electronic assemblies using using new 3D AOI machine.
Most AOI machines function by taking a digital image in the 2 dimensions, and do a comparison between a good board and a board under a test. It can also recognise characters on a surface - letters or numbers - to check that the right component is fitted and that the orientations are correct to the right rotation.
A 3D machine like this one can do all of this and also take measurements in the 3 dimensional state of the board. On the pitch of 20 microns it measures the height of every feature on the circuit board so this creates an enormous database of dimensions. From this database the operator can programme specific test which measure the volume of solder joints on a particular component or the height of a Gullwing leg for example, to identify whether it’s been lifted or not, or it might be the height of a board grid array to check that its soldered perfectly flat.