Comments on: Etch PCBs with ferric chloride and a sponge

By: Chassidy Chronister

Chassidy Chronister — Wed, 07 Apr 2010 11:28:44 +0000

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By: Colin mackenzie

Colin mackenzie — Thu, 01 Apr 2010 02:31:55 +0000

The Edinburg etch worked good. I don’t use sponge anymore though. I double bag the PCB in two zip lock bags and put the etchant inside and zip lock. I then use an artists rubber roller to squeeze the etchant accross the pcb surface. I submerge the whole thing in a bucket of hot water while I do this. The hot water heats the etchant through bag without diluting it and speeds up the process beyond belief!

By: Gee Wiz

Gee Wiz — Wed, 31 Mar 2010 20:38:33 +0000

@ ilyas

Yes, sulfuric works just as well…. The reason it’s use isn’t more often indicated in the USA is difficulty locating the material in most areas. It oxidizes the copper layer and forms the bright blue solution of copper sulfate.

Be careful with any method to etch circuit boards however.

By: Colin MacKenzie

Colin MacKenzie — Sun, 26 Jul 2009 16:43:23 +0000

I’ve been working with FeCl for about 25 years now (I started when I was around 10 yrs old). The stuff is safe, though it stains bad. It wont hurt or burn if get it on you but the stain will last 1-3 weeks and look strange to others. Stains on cement or floors can be permanent after it dries. Ingestion? I dont know, very small amounts probably ok, but take a good gulp and it could lead to iron poisoning.

FeCl fumes are not so much toxic as just an irritant. However, keep metal appliances and stuff nearby away, fumes could condense on them and ruin the finish. (I’ve seen it firsthand.)

I’ve been using this guys system for a few boards:
http://www.pulsarprofx.com/pcbfx/main_site/pages/

much better than regular tonor transfer. After the tonor transfer you treat it with some green leaf and then the resist pattern is *very* tough to get off…as in, sandpaper has a tough time.

I then use the sponge to etch and it is definately faster and more effecient than constant agitation. It’s all about getting the used FeCl away from the copper surface to let the fresh FeCl do its work. The sponge is also cleaner, just trust me on this. You use much less of the resist and your not adjitating it and dripping it everywhere.

Today I am trying a new ferric chloride mix with citric acid (Edinborough mix) that is supposed to facilitate the evacuation of the used FeCl from the copper surface to let fresh FeCl at the copper. I’ll post the results.

By: ilyas

ilyas — Fri, 24 Jul 2009 19:07:32 +0000

hi all,
i wanna etch the pcb…here in qatar its very hard to get the right chemical to etch the pcb like ferric chloride etc…but sufuric acid is easily available in here… my question is …is any one tried etching pcb with sulfuric acid? if so pls share your experience…will be appreciated…thanx all for reading my post…

waiting for ur response…
ilyas

By: Oren Beck

Oren Beck — Thu, 16 Jul 2009 02:21:00 +0000

surface prep is simply everything in getting resist to stick. After that it’s ultraimportant to clean/neutralize every trace of etchant. As etchants will keep on corroding. And many spent etchants are quite conductive too. Which has caused odd hard to track down intermittent flakies in high voltage or high gain circuits… Especially if humidity fluctuations make conductivity vary..

By: samurai

samurai — Wed, 15 Jul 2009 20:24:01 +0000

i have made quite a few PCBs using the ferric chloride method, and i can tell you that sharpies do not work for me. maybe its the copper clad, maybe not, but it dont work. =p

By: kanamin

kanamin — Wed, 15 Jul 2009 01:06:20 +0000

you can use A SHARPIE?????????

Sweet.

By: Jesse

Jesse — Wed, 15 Jul 2009 00:56:51 +0000

benny is likely in Australia.

the lowes in the US is a hardware store, like home depot or Bunnings.

By: Flood_of_SYNs

Flood_of_SYNs — Tue, 14 Jul 2009 22:45:26 +0000

Hydrochloric acid = Muriatic acid = Spirits of salt, it goes by a few different names.

By: cgmark

cgmark — Tue, 14 Jul 2009 21:12:58 +0000

I use the muriatic acid + peroxide combo . It is really cheap. The muriatic acid is sold to clean concrete, makes it really white. Do not get the etchant on stainless steel , it will ruin it. I unthinking washed off a board in the kitchen sink and now the sink has stains that cannot be cleaned off.

I use photo glossy paper + laser printer then just soak the board in water till the paper peels away leaving the toner.

By: Steve Watkins

Steve Watkins — Tue, 14 Jul 2009 19:04:35 +0000

Benny, Where are you?

Clothes- Really? I was at Lowes earlier today so i checked the price and found i was wrong. It is now $6.98 without tax.

By: zypher

zypher — Tue, 14 Jul 2009 16:25:08 +0000

I’m with Benny M on this, though the nearest lowes to me is a hardware store.

I’ll be trying this just for the hell of it. So wish me luck.

By: Benny M

Benny M — Tue, 14 Jul 2009 15:39:35 +0000

“hydrochloric acid… Typically sold in 2 gallon jugs at lowes” –Steve Watkins

I don’t know about you Steve, but Lowes around here sells clothes.

I’m gonna take a crack at making PCBs just for the hell of it. Wish me luck guys. Send a card to the hospital in advance, hoping that the acid burns heal up okay.

See ya

By: markps2

markps2 — Tue, 14 Jul 2009 14:11:55 +0000

i echo the warning
ferric chloride is very nasty and will stain anything it comes in contact with, including skin