Progress of microfocus X-ray systems for fluoroscopic and computed tomography

Microfocus X-ray systems for fluoroscopic and computed tomography (CT), which emerged in 1990s, are now becoming widely used for the cutting edge industrial fields such as semiconductor testing and failure analysis, because of its high magnification and nondestructive inspection capability. A novel microfocus X-ray fluoroscopic system with lanthanum hexaboride (LaB6) electron gun is successfully developed with minimum resolution as fine as 0.4 μm with maximum voltage capability of 160 kV. The system is dedicated for superfine fluoroscopic inspection of highly integrated semiconductors. For more detailed inspection, a cone beam CT technique is exploited. The technique is applied for ball grid array (BGA) or chip scale packaging (CSP) in complex large-scale integration (LSI) device inspection. The current status and performance of these microfocus X-ray fluoroscopic and CT system is reviewed.