Nikon's High.Contrast Filter

A new filter has been developed by the Industrial Metrology Business Unit of Nikon Corporation that greatly enhances the contrast in images produced by its X-ray inspection machines. Aptly named High.Contrast Filter, its principal application is quality control of PCBAs (printed circuit board assemblies) and other electronic circuitry such as BGAs (ball grid arrays), capacitors and through-holes. However, its power may be used equally well in mechanical engineering for non-destructive examination of castings, 3D-printed components, or welds, and for failure analysis of assemblies such as inhalers in the medical industry.

Unlike in computed tomography, where a component can be visualized in 3D, a single radiograph has to reveal all details that are present in 2D, from front to back. Typically, visualizing features in high-density areas of a radiograph involves increasing the brightness of the whole image, which risks overexposing the lower-density areas. The strength of High.Contrast Filter is that it can normalize the contrast across the whole image, revealing detail in high-density regions without washing out those of lower density. Defects in all areas may therefore be visualized alongside each other in the same image, resulting in less operator interpretation, easier decision-making, and more productive, reliable and repeatable inspection.

High.Contrast Filter has innovative processing capability for use within Nikon's automated inspection programs and C.Clear real-time imaging engine. The latter intelligently adapts to changing X-ray conditions and variations in sample position, automatically adjusting parameters to provide clear radiographs. With their powerful microfocus sources and industry-leading detectors with high dynamic range, Nikon's X-ray machines have always been able to capture the smallest defects in raw radiographs. With the new filter, contrast and sharpness are taken to the next level, revealing in much starker detail any voids, cracks and other flaws that may be present.