Homebrew_PCBs

On Tue, 06 Jan 2004 05:28:53 -0000, dkesterline <desterline@...> wrote:

>> for a start you make a 15% HCl solution (tap water is fine)
>>
> Like 850cc water and 150cc hydrochloric acid? (clearifing weight /
> volume, and initial strength of the acid.)

i did it by volume, it is not critical.
i think the recepie i read was 12% by volume.
it doesn't change much.

many recepies call for 30% HCl diluted 1:1 (volume) with water.
i think i did exactly that.

As it was said you can keep the acid amount low, and only let the CuCl2 do
all the
work. but then you might experience the "blue" effect more often.

>
>> Then you put a pcb in it.
>>
> One you want to etch, or just some scrap to start the proccess?

one you want to etch.
but you can try it with scrap if you have too much ;-)
no, it workes like always, also with the first pcb.
i used the first one.

>
>> then you put H2O2 in it.
>> for the first pcb you may need more than usual.
>
> Approx how much? (please specify strength for that amount)

I don't remember clearly.
if you have have 250ml etchant the smallest amount you can pour out of the
bottle will do.
maybe a teaspoon full, or two.
start slow, if it doesn't work use more, agitate in between.

>
> Any attempt to remove the copper in the long run? Or do you dispose and
> start over every so often?
>

no attempt yet.
maybe some electroplating could work.
but maybe all you get is cloring gas....

i think it would require carbon electrodes, stainless steel is definitely
etched (ask the sink, now it has "freckles" where the tiny splatters around
the
bowl landed...)

>> For me this etchant is ideal with toner transfer - as it is as easy
> and
>> fast.
>> the toner takes no harm in the etchant.
>> photoresist works too.
>> Most ohp markers (edding etc) don't work too well.
>> the best is the red staedtler ohp pen ink.
>
> (assuming ohp = overhead projector) I thought OHP makers were water
> based. I've always used permanent markers like sharpies for this job.
> (though my toner transfer is almost good enough to not need it anymore :-)
>

i used it once in my first 5 or so toner transfer boards.
and then it was for the board outline ;-).

> I'm probably being overly analytical about this, it's likley the proccess
> is more forgiving and tolerant. But it's better to before I stir up a
> mess.
>

i think so..
the german recepies are rather crude, and i am always up for experiments...


wear the proper protective things, goggles and maybe gloves.
old clothes maybe, but if you mess around enough to stain your clothes
maybe this is not the best thing to do...

but still - even if you ruin your clothes, not much harm done,
if you ruin your eyes - you can't dispose of them and wear a new pair.
so take the google thing serious.

Stefan

> Thanks
> -Denny
>
>