Micro focus x-ray tube for examining printed circuit board in electronic industry, has screen body consisting of material for delimitation of cross section of electron beam, and provided with layer of another material in section wise

摘要

The x-ray tube has a unit for directing an electron beam on a target (2), and a screen (4) arranged in a propagation path of the electron beam, where target is designed as a transmission target. A screen body (6) consists of material i.e. metal, for delimitation of a cross section of the electron beam. The screen body is provided at its surfaces (14, 16) with a layer of another material e.g. aluminum, in section wise, where the surfaces are set to the electron beam. A reference number of the latter material is smaller than a reference number of the former material.