Let's Make Robots!

First foray into homemade PCBs

**Update at the bottom.

  Alright guys/gals, it has been a coons age since I posted anything even remotely useful of my own. I have managed to break that trend with this 'bitty blog, somewhat. I say somewhat, because, everyone and their brother has posted a how to about DIY PCBs. I will attempt to offer some bit of information that others have not, doubtful. :)

  My foray started with a need to make an easy to set up brain for some smaller bots that I want to build. I am a PIC guy, because, I started looking at microcontrollers a good many years ago. And, to begin my robotic journey I had planned to build a hexapod controlled by an 8 pin PIC. I wrote a quick program to control the servos and found I would need a 12f683. With those thoughts in mind I made some decisions about the layout of the board. Hindsight, I failed to include bolt holes to mount the board.

**Note: many of the following images can be clicked for larger images.

  Onward, I often use Ubuntu as my OS. That said, I ran across gEDA a few years back and had not heard of KiCAD. With my board idea in my mind I laid out a schematic that should meet my requirements.
Black and White schematic 
Nothing terribly exciting there. Voltage regulator up top fed by a 2 pin header. 3 pin headers on all of the I/O. An 8 pin PIC in the center, and an In Circuit Serial Programming (ICSP) port at the bottom. Time to make artwork.

  A few commands later and ...
PCB screenshot  

Now I have artwork for a board that is 1.62" x 1" (41.1mm x 25.4mm) and it holds all of the bits and pieces that I hoped for it to.

  I used Inkscape to lay out a sheet to print. With my sheet, I have 12 copies of said board laid out to fit on the board I purchased at Radio Shack. **Note to self: don't use double sided copper clad to make single sided boards, if you don't have to. The etching process takes FOREVER.

  With the printing done, it is time to layout all the assorted materials, copper clad, scuffing material, alcohol, Muratic acid, Hydrogen Peroxide.
copper clad
Radio Shack double sided copper clad

Artwork
I figured I should cover the board, because, A) I don't have an easy way to cut it, and, B) the more attempts I make, the better the chance of getting one or more good images. :)

Artwork ironed onto copper clad
Obligatory artwork on copper clad pic. This pic looks like it was taken before the iron set to Cotton setting was mashed all over it and then a 3/4" dowel rod was used as a make shift laminator roller with the iron on top. After 3 to 5 minutes, closer to the 3, the board was allowed to cool and then tossed in some cold water for a minute or so and off came the paper.

board just out of water
The after water pic. If you look close, there are still drops of water on the board. Also, if you look close, you will see errors here and there. Second closer pic.

After many minutes of etching
Once the artwork was etched, I used a copper pot scrubber to remove the artwork to reveal the purdy copper underneath. If one pic isn't enough, check this out.

silkscreen artwork
The final bit is the silkscreen for the top of the boards. I sure hope I didn't need to mirror that part as well. :|

UPDATE: upon inspection, I did indeed need to mirro the silkscreen so that it will be able to be ironed on in the proper orientation.

This is it for now. I will get back with you once I have some more useful info. Like actual parts in boards.

Update 9-18-2012

 Between kariloy and hoff70, I decided I better get off my lazy butt and finish up at least one of my boards. Using kariloy's idea of pins to align the silkscreen, I managed to get the silkscreen layer on pretty straight.


The holes are mal-aligned, because I drilled them by hand with my dremel. I can't be as much of a man and use an Archemedes drill like kariloy did. :)


And now, the top view.

One final pic that I am a bit ashamed of.

I will update this if I make something go *POOF* . Otherwise, I will call this a reasonably complete blog. 

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I consider the blog as complete, if the backside of the board looks as nice as the front side and there are mounting holes in it...Not that I want to push you :D

Nice tutorial bird. My experience is that the filled fields are not well covered by the toner but keep some blank spots. I used a permanent marker to cover them. 

Also i am using a laminator to transfer the toner to the copper, it's more reliable than an iron. If you are going to use toner transfer paper then you don't need to remove the paper with water, it will come off very smooth. What I still have to try is if you can use the toner transfer paper twice or more.
Very slick... a sharpie pen may repair gaps after the paperworktransfer. I clamp my boards in a vice with a metal edge along the cut line and hacksaw it with a finetoothed metal saw blade.

Looks nice!!

thay look grate at first glance