Abstract
The purpose of this study is to elucidate the microstructure of printed wiring board (PWB) under the condition of ion-migration (IM) using a three dimensional (3D) measuring system and an atomic force microscope (AFM). In order to calculate the spatial variation of the electrodes for ion migration on a glass epoxy (FR4) PWB, we applied the WDT method which is one of the IM acceleration testing methods. We also investigated the spatial shape and its variation of dendrite after short circuit for various cases of non-uniform field strength. As a result the phenomenon of immigration peak of separated matter from cathode to anode due to non-uniform was reported. From the analysis of microstructure of electrodes, we confirmed that the height of an anode electrode was decreased, on the other hand, the height of a cathode electrode was increased. From the results of nano-structure analysis of an electrode by an AFM, we found the relationship between the color of an electrode and the size of grain boundary of the electrode.
