Nondestructive Strain Measurement of Solder Joints by Using Synchrotron Radiation X-ray CT

Abstract

In the present study, a synchrotron radiation micro CT and digital image correlation (DIC) were applied to the measurement of the strain distribution in solder joints due to thermally cyclic loading. At first, in order to verify the accuracy of the measured strains, DIC was applied to artificially deformed images. As a result, it was possible to measure the strain with an error of 18% with respect to the artificially loaded strain 0.01. Next, DIC was applied to the CT images of a flip-chip type joined specimen loaded by thermal cycles and the strain distributions were measured. Consequently, we succeeded in measuring the strain at the region where the characteristic microstructures such as the Ag₃Sn phase are distributed.