X-Ray Tomography is a non-destructive contactless imaging technique, which can be used to visualize the internal structure of electronic devices.
The component is rotated and a series of two-dimensional X-Ray images is produced. A 3D image of the device is reconstructed from these using advanced algorithms. X-Ray Tomography is often used in combination with other techniques during the Failure Analysis process. The tool we use is a Phenyx V|tome|xs240, which is equipped with two x-ray sources, a nanofocus and microfocus dual tube.
As X-Rays do not interfere with the defects, this is a unique technique for obtaining three dimensional information about the internal structure of a device without de-processing it. Once the 3D image has been acquired, many types of post-treatment can be performed, such as virtual cross-sections in any direction. By using a greyscale image it is also possible to distinguish between the different materials in the component.
X-Ray tomography is particularly useful when CAD information of the component assembly is not available. While standard X-Ray images can reveal the presence of broken or shorted bonding wires, by using the reconstructed 3D image it is also possible to visualize voids in the solder bumps. In cases where a defect has been localized using other techniques, X-Ray images can often be used to validate the localization results before de-packaging the component.