Computer Tomography of Electronics.

摘要

The application of Computed Tomography (CT) and laminography has been tested on a variety of electronic components. The effort was performed as a preliminary testing task assignment in the Advanced Development of X-ray Computed Tomography Application program. A key area for testing was printed circuit boards for the inspection of solder bonds and in particular for leadless chip carrier devices. During the course of the task assignment several other categories of electronic devices were examined including transformers, connectors, switches from solution and contrast sensitivity phantoms developed for the programs were used to establish quantitative measures of capability used to generate images. This preliminary testing of electronics lead to the conclusion that higher resolution CT scanning is needed to resolve details of interest. CT testing on commercially available system could resolve high contrast details in the range of 2 to 4 lp/mm; however, in many electronic components finer resolution is needed to detect microcracking, voiding and other features. Further testing on high-resolution system is recommended. Two areas of immediate potential economic payback for electronics inspection have been identified; the inspection of high volume printed circuit board production using high speed laminography and nondestructive failure analysis studies components using high-resolution CT. (JHD)