● Light Absorption
● Tomography Technolog
For the wide use of BGA and CSP, the typical inspection method like ICT fails to check the soldering point buried by components. Automatic X-ray inspection aims to inspect these buried soldering points with X-ray. And it can be divided into two types: 2D and 3D.
Automatic X-ray Inspection
AXI examines the PCBs with the principle that different substances have different absorption of light, which mainly aims to inspect the PCB boards with ultra narrow spacing and high density. Besides, it is possible to detect the internal defect of IC components with the tomography technology. On the other hand, AXI is the only way to inspect the soldering quality of BGA and the buried soldering point. And some AXI machine not only can make 2D X-ray examination but also a 3D one with oblique of inspected PCBs.
Automatic X-Ray Inspection does well in the inspection of BGA and embedded components, and it is fixture-free. However, there are some weak points of this inspection method, such as low inspection speed, high failure rate, hard to rework and high cost in program developing.