When x-ray inspecting BGA packages with metal heat spreaders tube voltages greater than those used for Plastic BGAs must be used. It must be recognized, however, that the tube votage required will depend on the particular sensitivity of the x-ray camera employed. A commercial CsI image intensifier may require a tube operating at 100 kV whereas a high sensitivity x-ray camera will only require 70 kV to get comparable or better x-ray image.
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