Image capture & processing for 3D X-ray inspection system

Stemmer Imaging has supplied GÖPEL electronic with machine vision systems for use in its new OptiCon X-Line 3D X-ray inspection system for simultaneous inspection of both sides of double sided printed circuit boards. Parallel image capture allows real time 3D X-ray image reconstruction from 2D images taken at different angles at production line speeds.

At the heart of the image capture system is a 3D parallel X-Ray detector developed in-house by GÖPEL. This allows the simultaneous capture of images from nine different directions in a 12 bit grey scale with a maximum object resolution of 10 µm per pixel. The detector hardware achieves continuous data rates of up to 40 gigapixels/s.

Following hardware-based image integration and pre-processing there are 360 megapixels/s distributed over nine angles of observation available for further processing in the PC. In the reconstruction process, the image data are converted into a 3D output of typically 24 megapixels/s. As each projection captures a different region of the board, the board is moved under the X-ray beam so that all the required angles of observation are observed sequentially.

With reconstruction requiring a 64 bit PC platform, they worked closely with GÖPEL engineers. The Sales & Marketing Director, Mark Williamson, said: "This is a classic example of Stemmer working in partnership with an OEM customer. Our involvement extended far beyond the supply of the basic components. Our technical expertise was essential to ensure seamless integration of frame grabbers, 64 bit drivers and other image processing components to meet the required demands of speed and accuracy".