>
> I read in one of the pages in the links/acid etch section about washing
> the boards in 5% HCL solution after etching, do you do this? or do you
> just water rinse?
what is this good for?
i never do.
>
> Horizontal etching, Have you actualy researched/experimented and decided
> to go that way, or is it just one of those things where "this works"? Do
> you get even etching on both sides? Do you need to flip it part way
> through the proccess?
> I've never set up an "official" etch system. In the past it's "find a
> bowl/dish/tray, throw some etchant in and swish it arround till it
> etches". Recently I've switched to the baggie method, but my board
> production has been increasing (couple a week now) and it's getting
> tedious.
same for me for the second part. i am tired of it.
the photo process was so complicated that the work for getting the tray
etc. was not much bother (i did that in the exposure time).
But with tt it is so much simpler and the messing around with the trays
started to disturb me.
to the horizontal etch:
I had the following experience:
I put a rather large (10x10) blank pcb in the acid, in a flat tray.
(i needed a blank board).
i used no separators or so to hold it up.
the bottom side was etched in nearly the same time, only a bit slower.
(you could see the copper "patch" remaining in the center on both sides,
the top one was some 20% smaller.
i did never turn around the board at all.
i agitated the tray from time to time by moving it slightly around.
the pcb was actually held up enough by the bubbles (or uneven tray bottom)
that it etched nearly same speed at the bottom.
it still started on the outer edges first to completely remove the copper,
but i think this also happens in vertical etching and the toner holds up
well.
so, you see, i see no reason why it should not work perfectly if i support
the board 5 to 10 mm above
the tray bottom.
i think it should be equal speed on top and bottom then.
i am not sure if the vertical tank has many advantages if you need no air
bubbling...
ST
>
> Thanks
> -Denny
>
>
> --- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan
> <stefan_trethan@g...> wrote:
>> 0,5mm to 1mm bubbles i have normally.
>> YES this is precious metric SI.
>> dunno how you live without it.
>> under the board may accumulate larger bubbles in tray etching.
>>
>> with too much h2o2 i get bubbles, 2mm to 4mm in size.
>>
>>
>>
>>
>> yes, it gets warm, 60°C i think (you may convert that too ;-) ).
>> but only if i have too much h2o2. with just enough there is not
> much
>> heating, maybe 40°C.
>>
>>
>> tray etching.
>>
>> my "permanent horizontal etching machine" is in work.
>> this will be a tupperware container where the etchant stays in all
> the
>> time.
>> the lid seals it off enough to prevent corrosion of your whole shop.
>>
>> until now i used different trays and poured it back in the bottle
> each
>> time.
>>
>
>
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