Tuesday, December 29, 2015

First etching attempts.


I’ve started to work on the chemical etching process to remove the copper from the laser etched paint PCBs. I’ve used the etchant solution described here:


And here are my first results. Macroscopically they look good:



But when I increase the magnification the quality is not enough:


So, there are lots of improvements to work on yet. The etching time may have been too much, the cleaning of the board may not have been so good, or the choice of paint may have been a bad one.


Please send me some feedback. I’d appreciate a lot!

Thanks for reading!

Saturday, December 26, 2015

CNC at work.

Hi. I’m posting today a video of the CNC working to draw a PCB on a black painted copper board with a 0.5W 808nm laser diode assembled as described on earlier posts.


EDIT: Watch this video too:


Friday, December 18, 2015

New laser holder.


I’ve just installed a new support for the 808nm 0.5W diode laser discussed in previous posts. It is a very simple one, using a copper tube and two PVC plumbing parts. Now the focus position can be changed by moving the Z axis.





I’ve also assembled all the electronics in a sealed plastic box, with removable connections to switches and step motors.


Thursday, June 11, 2015

Microscopic pictures of the PCB ink coating that was laser etched


I’m posting here the latest microscopic pictures of a PCB that was covered with black spray ink and illuminated by the 808nm 0.5W laser diode that was installed on my ShapeOko2 CNC. The focal point was moved by the machine to draw an insulating trace around the tracks.

As can be seen, the focal area is not round and the result is not good. I’m trying to find a laser diode with a circular profile to fix this.







Tuesday, June 9, 2015

Latest results

I’m posting the latest results, after disassembling the ShapeOko2 and reassembling it due to a change from one country to another.

A few things have changed:

1- I found an easy way to place and hold limit switches in the machine. See the pictures below for more info.

2 - The YetAnotherGCodeSender program was advanced and now it can be compiled in a Raspberry Pi and in a Mac. Probably on Linux too. The program uses a very crude text based interface and controls quite well the TinyG planner queue, sending commands to the controller only when it is able to process them;

3 - I installed a 808nm laser diode on the machine as I said I would. I tested it against black ink covered PCBs and it could remove the ink where the laser beam hit. Pictures below too;

4 - Instead of using a specific program for generating GCode from GERBER files, I decided to follow the following workflow:

a – Draw the board then export the layers to GERBER format;

b – Open gerbv, installed on a Mac through MacPorts, load the GERBER layer and export it to PNG;

c – Open MeshCAM, load the PNG layer, set the Z thickness to 0.1mm and set black to +Z. Follow the normal procedure and generate a toolpath only with the pencil pass. Save the G-Code to a file;

d – Send the GCode file to your CNC machine. I’ve used my own software here and made it translate the negative z movements to Laser ON and the positive ones to Laser OFF. Incredibly, it worked. The first result can be seen on the last picture below.