NDTnet 1998 Aug, Vol.3 No.8

Abstract

Main requirement for 3D reconstruction by tomographical methods corresponding to complete displacement of object inside the field of view during rotation. Most electronic devices and boards represents as a planar structure and cannot be completely rotated around axle in the device plane. In the same time the internal 3D-structure can be visualized layer by layer during rotation around axle orthogonal to the object surface by laminography methods. Recently commercially available X-ray systems for laminography have a spatial resolution limited to hundreds of microns that not enough formodem multilayer structures like PCBs, flip-chips, BGA-connections etc. To rich better spatial resolution a new microlaminography approach has been developed. Main differences in comparison to existing systems are using of microfocus sealed X-ray tube(130kV, 10µm spot size) and image acquisition by immovable X-ray camera (see fig). After images acquisition in all rotation positions the final micro laminography section calculated by contrary rotation of all images in the computer memory.Image rotation in the memory allows avoiding any camera movements and eliminating all corresponding errors from vibration and misalignment. During testing the depth resolution of 50-80 µm. and lateral resolution of 20-30 µm was achieved.

Fig. : Microlaminography block-diagram

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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