CT Reconstruction with Good-Orientation and Layer Separation for Multilayer Objects

Nowadays, multilayer designs such as temperature co-fired c eramic (LTCC) and stacked IC packaging are increasingly popular in electronics and semiconductor industr ies. For these multilayer structures, X-ray CT is thought as one of the essential tools for inspecting the ir internal defects. A common requirement for X-ray CT inspection of multilayer objects is to visualize the re constructed CT results in separated layers so that defec t analysis can be conducted layer-wise and conveniently corresponded to manufacturing process. One characteristic of multilayer objects is that the layers are usually t hin and have a large area-to-thickness aspect ratio. This property sometimes may lead to failure in inspecting thin defects. For example, thin and large delamination-like defects in a multilayer packaging are in many cases inv isible to X-ray 2D imaging. If the user has no prior knowledge about their existence, they are also quit easy to be missed with CT images if the reconstructed object has a tilted orientation. In this paper, we demonstrate t hat a good-oriented CT reconstruction for planar object can make layer separation much more simple and effective. Through the study of a 5 ‐ layer packaging sample, we also show that more detailed information of the delamina tion-like defects can be observed.