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automatic X-ray inspection (AXI)

During the assembly and manufacture of printed circuit boards, interruptions, soldering faults and short circuits are the most common causes of faults, followed by component faults and component misalignment. These faults make up about 80% of all faults that occur. All these defects can be automatically detected by the AXI test (Automatic X-ray Inspection) with a probability between 80% and 99%.

The AXI test belongs to the structural tests and is an optical test procedure that works with X-rays and shines through the components and their connections. In combination with the in-circuit test, the defect detection rate for most placement and soldering defects can be increased to 90% to 100%, as the ICT test and the AXI test usefully complement each other. Only missing or defective non-electrical components are not detected.

X-ray image of a component during the AXI test. Photo: Göpel Electronic GmbH

X-ray image of a component during the AXI test. Photo: Göpel Electronic GmbH

The AXI test is based on the brightness comparison of a PCB under test with existing reference values. The brightness values of each individual solder joint, whose thickness causes different brightness values, are compared. The AXI test causes difficulties when checking assemblies that are populated on both sides with overlapping components, since both sides can be seen and overlap each other. In this case, an exact inspection can only be performed with AXI test equipment that can be axially offset.

Englisch: automatic X-ray inspection - AXI
Updated at: 14.03.2014
#Words: 220
Links: assembly, make up, test, procedure, indium (In)
Translations: DE

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