J031034 Three-dimensional and nondestructive evaluation of thermal fatigue crack propagation process in complex-shaped solder joints by synchrotron radiation X-ray microtomography

Abstract

In this work, we applied a synchrotron radiation X-ray micro-tomography system called the SP-.tCT along with a refraction-contrast imaging technique to the nondestructive evaluation of fatigue crack propagation process due to thermal cyclic loading in complex-shaped solder joints of chip type resistors mounted on FR-4 substrate. The results show that many micro-cracks appear in the thin solder layer under the chip prior to the main fatigue cracks, and using the 3D crack images, the dimensions of the crack were straightforwardly quantified by measuring the surface area of the same fatigue crack.