Crack and Failure Analysis with Fluorescence

Fluorescence is a valuable tool for failure analysis, helping investigators see what they might otherwise miss. Fluorescence indicators of various types – including fluorescent penetrants, magnetic particles, and other fluorescent dyes – are commonly used to highlight cracks or defects that would otherwise be difficult or impossible to see. The fluorescence makes them stand out in high contrast. The NIGHTSEA fluorescence adapter systems can be used with microscopes at a variety of scales for detailed examination of these features. Here we show images made with a stereo microscope and with a Keyence digital microscope. (Relevant links at the bottom of this article.)

Note that all of the images below were made using the Royal Blue excitation/emission option. While this kind of analysis is normally associated with Ultraviolet, we find that the Royal Blue option is an excellent choice for working with a wide variety of fluorescent indicators.

First, some small cracks highlighted with fluorescent penetrants and fluorescent magnetic particles. Images made with a Unitron Z650HR Stereo Zoom microscope with Excelis AU-600-HD digital camera.

(Click image for larger view)

Next we show some cross sections of electronic components that were embedded in epoxy, cross-sectioned, and polished, after which indications were highlighted with an epoxy-like dye with Morton Fluorescent Yellow G as the fluorescent ingredient.

Stereo microscope images made with the Unitron Z650HR Stereo Zoom microscope and Excelis AU-600-HD digital camera.

Now the same samples at higher magnification, imaged with the Keyence VHX-5000 with the NIGHTSEA fluorescence adapter.