Researchers from Motorola worked with TPUC staff to develop a fast inspection technique of welds within a Ball Grid Array (BGA) for electronic circuits.  The defective (weak) welds are between the circuit board and ceramic substrate.  If the component passes the electrical continuity test, it is very hard to locate the weak welds. The only techniques previously known to be useful are X-ray tomography or destructive inspection.  Utilizing the IR imaging facility at TPUC, a new NDE technique using IR imaging was developed. The traditional flash lamp heating and step heating methods could not locate the welds.  However, using a high voltage pulser, the welds can be seen clearly after a 1 ms, 150 V – 300 V pulse. As shown in the pictures below, the hot spots revealed missing connections that heated up after the pulse.  For BGAs that passed continuity tests, the welds showed up nicely when 1000V pulses were applied.  More tests are planned at TPUC when a series of weak welds are prepared at Motorola.