Refers to the non-destructive testing of solder, sintered or adhesive layers using X-ray technology. Defects appear lighter in the X-ray images than the materials due to the differences in density between air and metals.

Modern X-ray inspection systems also offer an automatic analysis of the void area and calculate the percentage of individual voids and total voids. The disadvantage of X-ray analysis, however, is that various defects are superimposed in the images for multilayer structures, resulting in optical effects such as circular intensity differences in the color distribution. It is therefore complex to develop algorithms for automatic analysis for such products and artificial intelligence must also be trained extensively before satisfactory results can be achieved.