There are a number of fault conditions that can arise on boards for which optical and electrical test may not be adequate.
Prima uses a Nordson Ruby X-Ray machine with the X-Plane tilt facility. This gives a 360 degree inspection of hidden problems inside boards. Looking obliquely at the board highlights such issues as bond wires inside devices, co-planarity issues with BGA’s, plating variation of vias or micro vias, Inner layer track widths, and many more fault conditions.
X Plane, using the ability to, in effect, tilt the board as well as X-Ray through the board gives a full inspection all the way through top to bottom, thereby eliminating the effects of images of side two components when trying to inspect side 1 parts.