[Tips & Tricks] PCB Etching with(out) chemicals

Frequently asked question on the subject of designing, creating, producing printed boards, veroboards or perfboads and on point-to-point construction techniques.
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lolbou
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Post by lolbou »

Ok, I won't bother with strong chemistry here (the title of the topic shows I'm OT), but from the equations and values, here's what happening:

Peroxyde "sees" two reactants: chloride ions (from the chlorhydric acid) and copper. The values in the tables indicates that the copper reaction is done far more easily than the chloride one, which is good for us (peroxyde will mostly interact with copper). The green color appearing is due to copper chloride...

BUT the chloride reaction happens at all times, and produce chlorine gas, which is extremely harmful. So I haven't tested it yet, but do prepare your etchant short before etching, and don't leave it around you when the PCB is removed, cause it will continue. The two reactions need protons (H+ = acidity), so if you spill your etchant in a big bucket of water, pH will rise to almost 7, and these H+ ions won't be enough to let the reaction happening fastly... I bet the quantities of copper chloride produces aren't big, but I still have to look if it's not too bad for environment...

I hope this helps and avoids intoxications, event if it's off topic :D

Be safe, fellas!

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Post by uncleboko »

Judging by what it does to our grass, female dog urine should be good!

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Post by steelplayer »

soulsonic wrote:I've used ExpressPCB before. They are very high quality boards; but I do not like their layout program. Since I've started using Eagle, I don't want to use anything else.

I've asked this before, but I'm going to ask again; has anyone tried Futurlec for boards? They say that they accept Eagle .brd files directly without the need to export; that's great for a pcb noob like me, and their prices are dirt cheap.
Anyone?
Bump for a great question.....

I've had good luck ordering parts from these guys, but I'd also like to hear if anyone has had experience with their board service. Seems really cheap, like under $40US for 6 single sided boards. May have to try this. Heh, as soon as my Eagle skills get a bit better. :oops:

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Post by rocklander »

uncleboko wrote:Judging by what it does to our grass, female dog urine should be good!
:lol: I hear ya.. goes for male dogs too... how the hell? brown patches of death all over the lawn.
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Post by JiM »

[smilie=bump.gif] because i've found a tutorial about RnFR's technique for etching a PCB with very few chemicals :
http://www.instructables.com/id/Sponge- ... ircuit-Bo/

It's so simple, i don't understand why it's not widely used.
But i'm thinking right now at a small improvement for the ferric-chloride impregnated sponge : why not use a foam paint brush (with a convenient handle), or better still, a foam paint roller ?

You'll just need a shallow plastic tray or plate, tape the toner-enabled PCB in it, and gently roll the etchant-impregnated foam roller over. No need for gloves, little risk of splashing/spilling etchant, little risk of damaging the toner as you don't scrub it, just let the roller dry until next time ...

I'll try that the next time i etch a board !

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Post by RnFR »

yeah man, it works great! it's just that whenever i etch, i do a number of circuits, and i'm just sick of rubbing those damn boards! it's great for doing just a few boards though and uses a minimal amount of etchant. not sure about the painting supplies, it's worth a shot though, i don't see why it wouldn't work!

i built myself a heated, aerated etching tank, and that thing rocks. but if i want to do a single board quick, i'll probably go back to this method.
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Post by Mr. G. »

Thanks for the link! I think I'll give that method a try next time I do up a board.

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