Warning: This tutorial is just an overview of my experience with home etched circuit boards. Use at your own risk. Therefore I cannot be held responsible for accidents with the etching acid or damaged laser cutters.
In my previous etching tutorial I described the toner-tranfser method to transfer the etching mask onto the circuit board.
That method has some limitations. Especially small circuits are difficult because the small toner traces get easily damaged when removing the soaked paper.
This time the laser cutter was used to remove the excessive spray paint. This worked out really great!
The etching process is the same as the previously mentioned tutorial.
The process:
Get some copper clad without photo sensitive layer.
Spray-paint a thin layer of paint onto the circuit board after cleaning and sanding it! We’ve tried both ordinary cheap black paint and heat resistant Motip paint (to reduce the flow of melted paint) but it didn’t make a big difference.
Prepare a negative of the to be etched mask file.
Put the copper clad (painted) in the laser cutter. Make sure you focus the lens properly! This is very important to ensure a high resolution. We used an engraving setting. Make sure not to put the power too high or the speed to low or you may damage your laser cutter due to reflection.
After the laser cutter is finished brush off the residue that still sticks to the board. I used toothpaste and a towel to polish off the residue till it’s shiny again.
Then your board is ready to be etched. Check out the other tutorial for the etching details.
A few impressions:
The lasercutter at work (sorry for the crappy quality (Iphone 3G camera)).
Completed board.
This is what the board looks like after the laser cutter.
While etching you’ll see the color of the copper turn reddish.
The board gets transparent when the copper is removed.
Make sure you use gloves and plastic tools while etching.
Completed board without holes.
Fully assembled board, even the TLC5940PWP (SMD) was soldered without problems.
This board was used to drive 5 High Power RGB LEDs.
Final application.
Same board as above but this time to drive normal LEDs.
Fully assembled.
Final Result:
Philips was the client of the Philips Creative Challenge.
More on this project will be put online later.
This prototype was not built by Philips.
All the 5 LEDs inside the “lamp” can get any color.