Case Studies

Customer S. needed to examine the voids in a BGA (ball grid array) package mounted on an electronics circuit board.   Although this can be done quite satisfactorily with a 2D X-ray system, he wanted to be able to see at what height within the balls each void occurred, to be certain that none were near the two soldered interfaces on each ball.   With the aid of ProCon, Systegration arranged for planar tomography X-ray of the package, without in any way damaging the board.   33 slices were taken through the balls, of which three are shown here :                           Top interface to package, no voids     Slice 25 in lower quarter of balls, showing some voids      Lower interface to board, no voids

Customer G., a manufacturer of electronic connectors, wished to have a means of closely examining the goodness of his products after final assembly.   ProCon's CT-Mini provided the answer.   Shown is a study of one particular connector, showing damage to the central ceramic plate in the right-hand reconsructed image.

In palaeontological research, fossils are generally found still in a rock matrix.   Ideally, one could simply remove the matrix, revealing the fossil for further study, e.g. brain case shape and size studies.   However, attempts to do this often result in destruction of part or all of the fossil, and even when successful take considerable time and can result in a very fragile specimen easily damaged by further work.   Today, removal of the rock matrix is becoming unusual due to he availability of CT X-ray systems.   Until now, only very large and very expensive systems have been available to do this, but it is now possible to use ProCon's CT-Mini or CT-Compact to X-ray the vast majority of small specimens.   The image show is of a diictodon skull, a two-toothed vegetarian animal from South Africa about 290 million years ago.   The image is from a first reconstruction of the slices made by the X-ray system, but it is possible to make out jaw line, teeth, nostrils, eye sockets and brain case.   Thanks to the Natural History Museum, London, for permission to use this case study. Image ©The Natural History Museum, London, 2005

Carbon fibre laminate is an important material today for use in aerospace, where it is used to form helicopter rotor blades or aircraft skins, for example.   It is important to study how the material behaves under load, in terms of fibre bundle damage as well as layer delamination.   This is often studied using X-ray, but there are difficulties when 2D X-ray is used, as the contrast between spaces caused by damage and surrounding fibre is sharply reduced by the remainder of the laminate through which the X-rays must travel.   Until now, the contrast has been enhanced by injecting an iodide solution, but it is not always certain that this has penetrated sufficiently.   Further, it is not possible to tell from a 2D X-ray image exactly where in the laminate the damage has occurred.   ProCon's CT-Mini again provides the answer below we show a slice section from a small sample loaded by a sharp impact, completely untreated with iodide.   Delaminations and fibre bundle breaks are both clearly visible, and the position can be determined.

Application Notes

PDF files to download : Cracked Ceramic Capacitor