PCB Etch Disaster!!!

[raycroft]

Hi.  Second time etching for me- 2nd pedal build attempt .  The first time around I used Ferric (Ratshack 15.99 kit), this time I tried the hydrochloric/peroxide method (http://www.instructables.com/id/Stop-using-Ferric-Chloride-etchant!--A-better-etc/   great tutorial!).  It etched great, about 5 minutes using the mix cold right out of the bottle.  However, it didn't like my hand-drawn sharpie traces, and ate through most of them.  I spent all morning on this!  Oh well, live an learn.  I just bought a used laser printer last week and am waiting a delivery of toner- I will try again then. 







If it was just one or two, I could probably fix it.  I can just imagine troubleshooting bad traces on that thing for days.  No thanks! 

Fun stuff!

[Cardboard Tube Samurai]

Just get some conductive silver circuit repairer and go over the whole thing

[JOHNO]

You could probally run solder over all the traces like they did in the old days. I bet it would work ok. It doesnt take long, I do it with a lot of my pcb's that have fine traces. Good Luck with it. JOHNO

[deadspeaker]

Yeah the other day I did exactly the same thing. I think you replied to my post about it. It ate through my sharpie too. Hmmmm It's also partly my fault because I took the toner off before I had taken all the rest of the copper off. I think this etchant would work fine if I could transfer enough toner onto the board. Maybe I'll ask the officemax girl for the thinner paper next time....

P.S. My board appears worse than yours from what I can tell, but a lot of traces checked out ok with the multimeter. The solder trick works to some degree. Resistor leads across points help a lot too.

[tranceracer]

Yea, I've had this problem too using the standard sharpies.  Here's a link to my post and some helpful hints from some members on the forum...

http://www.diystompboxes.com/smfforum/index.php?PHPSESSID=93f732c0df11ff650a82c0ad74ea0c5b&topic=66306.0

[culturejam]

muriatic+H202 does *not* play nice with standard Sharpie "ink". It does work okay for fixing up small issues with your toner transfer.

Muriatic also destroys the etch resist on the presensitized positive boards (photo resist).

Raycroft: while your traces don't *look* pretty, they do look like they're all intact enough to work. If you have a DMM with audible continuity test function, you can test all the traces for continuity. I've made some really ugly, pitted boards, but they all worked.

[Minion]

Why use the sharpie method?? It takes way too long and you need to put like several layers to Ink and let it thouroughly dry befotre you can etch it without risk of traces being eaten up....

try doing an actual toner transfer...quick, simple, Reliable and works flawlessly one you got it down....

[tranceracer]

muriatic+H202 does *not* play nice with standard Sharpie "ink". It does work okay for fixing up small issues with your toner transfer.

Muriatic also destroys the etch resist on the presensitized positive boards (photo resist).

Raycroft: while your traces don't *look* pretty, they do look like they're all intact enough to work. If you have a DMM with audible continuity test function, you can test all the traces for continuity. I've made some really ugly, pitted boards, but they all worked.

Ah, I didn't know about the photo sensitive boards not working w/ muriatic.  I stopped using pre-sensitized  boards when I discovered toner transfer.  I kept screwing up the exposure times and developer times and would end up with a bunch of blank Cu boards and had to figure out how to recycle these anyway.   

Raycronft,
Maybe conductive ink will work to help patch up some of the traces and you won't have to redo the whole thing.

[culturejam]

Raycronft,
Maybe conductive ink will work to help patch up some of the traces and you won't have to redo the whole thing.

I really do think that it'll be fine as is. All it takes is the tiniest bit of connection between pads/traces to make the connection.

As I mentioned previously, those traces should be checked for continuity.

While not pretty, there's no reason to scrap the board because it doesn't look "perfect".

[Solidhex]

Yo

  Yeah, second Culturejam's statement. Bust out your multimeter and check the continuity of the traces. Stick the test probe into one pad on a net then stick the other in every other pad. If you get a beep each time you're good.

--brad

[Ed G.]

I'd "beep it out" with a continuity tester. If it beeps, it's good to go.

[raycroft]

thanks for all the replies!  after I posted yesterday, I spent a good hour taking small solid-core wire and linking it all over the "very bad" traces .  I actually have most of the board populated; and I;m thinking it'll work ok.

I will definatley be using the pnp method, as soon as my new laser printers toner arrives.  I just rushed it- I've had all the necessary components for 3 weeks to build this pedal; been too busy; then got sick of waiting.  Live and learn. 

I'll definatley have to get a touch-up pen.  Thanks again!