Exposing electronic products

High-resolution X-ray computer tomography, developed at the Siemens research laboratories in Munich-Perlach, has made it possible to examine the inside of such products in a non-destructive test. Mark Fletcher reports Many electronic products contain individual components which are only a few millimetres in size, inter-linked with each other in a highly complex structure. High-resolution X-ray computer tomography enables the examination of the inside of such products – producing images that appear in 3D and with a spatial resolution of a few thousandths of a millimetre. X-ray CT is a well proven and extremely useful tool for in medical diagnostics producing a three-dimensional image of the inside of the body. As a rule, resolutions of up to 0.6mm are adequate for this kind of medical application. However, such a resolution is not sufficient to examine highly integrated microsystems. Starting with existing medical procedures, researchers of the Corporate Technology Department of Siemens have now succeeded in enhancing the resolution of CT scanners to the micrometre range. This advance was made possible by combining X-ray tubes of a focus diameter of one micrometer with planar X-ray detector arrays with approximately 7million pixels and a 64-bit architecture computer cluster to process the enormous data volume involved. The new high-resolution CT scanner picks up structures of a few micrometres and presents them in a three-dimensional image. This allows non-destructive access to the inside of electronic modules and microtechnological devices during the various stages of their production phase, and to obtain images in a resolution and definition quality hitherto deemed unimaginable. In a typical image of an inner ear hearing aid, the hairline connecting wires are clearly visible in 3D. A special feature of the software can be used to display any type of material at any place or position in a transparent mode. This means that even covered, hidden, or enclosed structures and elements become accessible in such a non-destructive test. Detailed information provided on any deviation of the actual structure from the design data considerably accelerates product development as a whole. Moreover, it leads on to continuing optimisation of technological processes, thereby effectively supporting quality assurance. MF