Laser etched circuit boards

By tjh1, Apr 12, 2019

Tristan, another one of our students, continues to do amazing work with custom etched circuit boards using the laser engraver.  For a robotics project, he’s been working on a camera slider for fancy YouTube recordings that the human hand couldn’t possibly recreate.  With his project, smooth cinematic shots will be possible due to the bot’s three stepper motors along with multiple sensors which will be implemented to make it user friendly.  But how could all of the components fit in one small little box?  Well a PCB (printed circuit board), of course!

Around 1950, PCBs were being manufactured for commercial use.  But the expense of having them produced detoured many electronics enthusiasts away from them.  So hobbyists did what they do best, they made their own!  While a handful of websites today allow you to purchase a PCB for low-cost, many hands on people found it satisfying to make their own.  All it requires is copper plated fiber board, Rustoleum high heat spray paint, diluted ferric chloride (etching solution), and a high wattage laser.

The concept involves etching away copper with the ferric chloride solution.  An image is carefully drawn on a computer (Tristan used Microsoft Paint) where the copper needs to be etched away from.  Once that’s done, the laser engraver is used to “retrace” the image onto the board.  By laser engraving the image onto the board, paint is removed and copper is exposed.  The PCB is stuck into a ferric chloride solution until the visible copper is dissolved.  Lastly, steel wool is used to clean-off the remaining paint and holes are drilled.  An old school PCB with new tech!