Abstract
In electronic devices, a crack initi ation and propagation of solder joints lead to failure. A cross-sectional observation and bonding
strength test (pull or shear) are often carried out to confirm whether a crack exists or not. However, it has been known that bonding
strength of solder joints depends on various factors so that it is unidentified the condition of a crack contributes to the value of
strength. In this study, we obtained a 3-dimentional crack structure from X-ray CT data by using deep-learning technique before pull
strength test and investigated their correlation.