Hello Hans,
I didn't give any details on the process I was using only because I
haven't got it working good as I like and it would take me all day to
write up :). Basically I'm using a variation of the proprietary
BLACKHOLE process by Macdermid. Search the web for "blackhole pcb".
Macdermid hold the exact chemistry a secret but I've managed to get some
good results by investigating all the patents on the subject. A long
time ago I looked into electroless copper and found it was an expensive
and difficult process to run, so I didn't bother with it. Electroless
copper is widely used by platers and has been around since 40's (I
think) so you won't have trouble finding info in a good library.
Tom is absolutely right in that most chemicals are only available in
bulk. A bulk quantity for hobbyist is 25 kg, but that's about a minimum
sale for any chemical from any chemical supplier. I was lucky enough to
get some of my chemicals in small quantity. Others such as 98% sulfuric
acid, and 25% aqua ammonia I could get in 25 liter, fortunately these
are cheap.
Waste disposal is discussed in many plating books. The carbon black
solutions are non-toxic and I regularly dump them on the garden with
zero effect to the plants (just makes the soil a bit blacker :).
If you want to do electroless copper then your best bet is to contact
your local plating supplier and ask them to supply you with the
chemicals. They know exactly how their chemicals behave and how to use
them so all the hard work is done for you. You will find it difficult
obtaining all the individual ingredients and trying to make it work for
your self.
The bottom line is that if you don't like handing chemicals and not
interested in the chemistry then I think it would be a waste of time for
anyone trying to make through hole boards as part of their hobby.
The electroless is only a fraction of the whole process. It took me a
about year before I could successfully plate copper and tin on PCBs.
Each step in the process is completely different to learn and
understand. Unfortunately PCB making involves so many of these steps.
If you are still interested in making holes platable then I'd be happy
to sometime write about the carbon black process. But it won't be of
much use unless you can also do dry film photoresist lamination, hot
soak cleaning, acid copper plating, acid tin plating, persulfate micro
etching and alkaline ammonia etching and photoresists stripping.
Hans Wedemeyer wrote:
> Adam,
> I just posted a message about solutions, and would like to know what is
> in the "super activated palladium catalyst" and "electroless copper
> bath" ?
> Also what is the "daily process" for testing and maintaining them ?
> How long can these solution be stored ?
> How does one get rid of used solutions?
> Hans W
>
>
> "twb8899 " wrote:
>
>
>> Adam and the group,
>>
>>If you want to make plated through boards you should consider asking
>>a board fabricator to sell you some of their existing chemistry. The
>>cost of this stuff is higher than you would think because of the
>>minimum quantities that must be purchased when starting new. These
>>chemical baths require almost daily testing and replenishment with
>>the main culprit being the catalyst and electroless copper baths.
>>Some systems don't require an electroless copper bath and use a super
>>activated palladium catalyst which is a little easier to maintain.
>
>
>
> [Non-text portions of this message have been removed]
>
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