Pcb etching

[micahdunn]

Hi people. I've done a few random DIY project now and figure it's time to expand my knowledge and am wondering of anyone can give me some pointers on making my own pcb's. I've done some research, but didn't help to much. Easy ways, what works, what doesn't, best places to buy stuff to use. Any help would be greatly appreciated. Thanks alot.

[Davefx]

Well you have a couple options.  You  can do the positive photo resist method, which requires a dark room, special chemicals, etc.. It's nice, but by far the simplest, and most inexpensive method is the iron-on toner transfer method.  Which requires a laser printer or photocopier that uses toner (most public libraries have them).
I bought a simple monochrome Brother printer that I use only to make PCBs.  You will also need either glossy inkjet photo-paper or magazine paper to print your layout on.  There is a product available called PnP Blue.  It's a blue film that you can print on as well.  I personally hate the stuff, because it's fussy about iron temp, and it's a bit pricey at around $2 an 8x11 sheet, and I plain just suck with the stuff!
With the paper it's so much easier and all you have to do is crank the iron to the highest temp (make sure there is no water in the iron, you do NOT want steam!).  You then cut your board to size, flawlessly clean the blank board with cleanser under running water.  I use Bon Ami cleanser, it's real cheap. You don't want something with bleach like Comet has.  Clean it until water no longer beads on it. Make you sure you get the edges of the board really clean too. Then, DO NOT TOUCH CLEAN BOARD WITH YOU FINGERS!  When I print my layout, I first print it with my inkjet printer, then I cut the magazine or photo paper a bit larger than the printed layout, then i lay it on where it printed, take 2 pieces of scotch tape and tape the blank paper on, you want to have the blank paper enough wider than the layout so you can tape it without the toner printing on the tape. Just tape it with a piece on each side, no need to tape the top or bottom, just make sure it's nice and flat when you tape it on.  Then I feed into the manual feed of the laser printer, (set to the DARKEST setting) and print.
  You then align your printed toner layout onto the board and kind of work the iron on without letting the paper slide and press down FIRMLY for at least 3 minutes over the whole board, then I will spend pressing the edges as that is the most common place transfer errors happen.  After about 3 to 4 minutes of ironing I will lay a heavy book on the board for like 10 minutes, this helps the paper from bubbling up too bad.  Then soak the board in a bowel of warm water for a couple hours.  Then rub of the soaked paper with your fingers. If you did it right you should see the complete layout transferred. There will be a paper residue thats kind of a pain, but if you take VERY fine scotch brite to it, not too hard, it will clean it without harming the traces.  If you have a few missing pieces of trace or pad, use a black sharpie to draw them in again.
Then you etch in whatever sollutions you want to use that are available for the purpose. Muratic Acid, Ammonium Persulfate, Sodium Persulfate, or Ferric Chloride.  I use the Ferric.  Radio Shack sell bottles of it For $10. I put a pan of water on the stove and pour just enough sollution in a plastic Cool Whip bowel and warm the sollution a bit then put the board in.  You don't want the Ferric too hot though, then agitate it constantly until you see the copper start to disappear around the traces, and when it's gone immediately flush with cold water.  Then you're done.  I drill with my Dremel drill press, then tin mine in Tinnit Bright plate, which you can get from All Electronics and several other sources.  It protects the copper, looks cool, and makes soldering much easier!

  I'm assuming you never etched a board before, but if you have, ignore the redundant info..  Just how I do it.

Dave

[Davefx]

Oh and by the way, you should wear plastic surgical type gloves as Ferric stains and I'm sure it's not good to have absorb into your skin!. I also run the stove exhaust fan when warming the Ferric. The fumes are nasty.
And it depends on how large your board is as far as ironing times go. Little boards about 4 minutes, larger longer.

Dave

[micahdunn]

Thanks alot Dave. And yes I never have etched a board before. This really helps out alot. I appreciate the detail. Where do you get the copper sheets?

[Davefx]

I get them at Mouser. I get the 1oz per inch or centimeter.. they have 1/2 oz too but I figure more is better since it may be more forgiving of heat.
But I am sure there are better and cheaper sources. P
erhaps someone could chime in where they get theirs. 

Dave

[micahdunn]

Maybe somewhere. Thanks alot for the input though. I appreciate it.

[irmcdermott]

Maybe somewhere. Thanks alot for the input though. I appreciate it.

I usually buy all my stuff from the link below, however, it appears as though his ebay store is down right now. Not sure what is happening there though. Great source, good prices, good product and selection. I'd keep checking it.

http://stores.ebay.com/pcblaminatescopperclad

[chromesphere]

hi micahdunn,
Posted this in the tutorial section, not sure if you'd seen it? this is how i do it.  It's a dam easy process.  Anyway hope it helps!
Paul

DIY Guitar Pedal Tutorial 1 - Etch your own PCB (Print, Transfer, Etch)
http://www.youtube.com/watch?v=DBq1QKY5beQ

DIY Guitar Pedal Tutorial 2 - Etch your own PCB (cleaning, testing, drilling)
http://www.youtube.com/watch?v=UcM6Ll7Og30

[Davefx]

That would be it!  At least i got some good typing practice! 

[micahdunn]

Thanks for all the help guys, I'll post pick after my first try. We'll see how it goes.