Anyone who has ever tried to reverse engineer a printed circuit board is familiar with the frustration of tracing out the connections by eye and by multimeter. It’s a long process, and if there are multiple layers to the board, you may not even get the full picture. It would be a lot easier if you could just see through the board. On an industrial scale, X-ray inspection machines are used for this, but as you might suspect, they’re not cheap. So, hardware hacker John McMaster built his own.

McMaster has been working on his own X-ray machine for a while now, but he was dissatisfied with the small field of view the dental X-ray head had. To fix this, he decided to build a system that would move the PCB around underneath the X-ray head and take multiple pictures, which could be stitched together into a larger picture later.


A BeagleBone Black running LinuxCNC controls the 2-axis linear stage.

With a 2-axis CNC linear stage purchased on eBay, McMaster needed only to fab a circuit board holder, mount the X-ray head, and build the system to control all of it. At the heart of the system is a laptop and a BeagleBone Black running LinuxCNC, a free and open source software for machine control. McMaster also wrote his own software to automate the capture of the board (which he also uses when imaging decapped integrated circuits with a microscope).


The completed X-ray imager (before radiation shielding).

With all the work done, McMaster now has a way to auto-image PCB traces for reverse engineering (don’t worry, he added lead shielding). Pretty impressive stuff! For more info on the build, jump over to McMaster’s website where he has all manner of awesome science-related posts, including how he built an 80kv fruit exploding machine.