This sounds good. I assume that this is just for hole activation and
standard electroplating is done next to build up the holes. What is
the success rate at home? And estimated costs? I don't want to dive
into something that would be so hard to replicate. Thanks for the
Info Adam.
standard electroplating is done next to build up the holes. What is
the success rate at home? And estimated costs? I don't want to dive
into something that would be so hard to replicate. Thanks for the
Info Adam.
--- In Homebrew_PCBs@y..., Adam Seychell <adam_seychell@y...> wrote:
> The BLACKHOLE processes is fast, cheaper and safer to run than
conventional
> electroless copper. This is expected since its aim is to replace the
> electroless copper line in the PCB fabrication plant. The low
toxicity is the
> reason I choose to develop a carbon black processes myself at home.
However
> the chemistry of BLACKHOLE is a trade secret and your not going to
replicate
> the same results at home. BLACKHOLE SP is the latest process from
MacDermid
> and performs many times better than the process explained below. Of
course
> the hobbyist doesn't need the reliability of a multimillion dollar
plant
> producing a hundreds of panels a day. Its taken me about 6 months
of fiddling
> around with carbon black dispersions, conditioning solutions and
circuit
> board material to get a working process suitable for home use.
Basically my
> process can be written down as follows;
>
> 1) drill PCB
> 2) clean copper surface with week solution of detergent/NaOH and
600 emery
> paper.
> 3) rinse well with tap water
> 4) immerse in a "hole wall conditioner" 1 min
> 5) rinse well with with tap water
> 6) immerse in "carbon dispersion" 1 min
> 7) sponge off excess dispersion with sponge, so all holes are fully
empty.
> 8) hot air dry
> 9) repeat steps 4 to 8
> 10) immerse in "activator" for 1 minute
> 11) rinse well with with tap water
> 12) microetch in a conventional non-chloride etching solution
> 13) spray rinse with with tap water to remove all traces of carbon
on copper
> surface.
> 14) air dry (optional)
>
>
> Bath compositions/conditions;
>
> hole wall conditioner:
> 5 to 10 g/l gelatine
> 0.04 to 0.06 g/l CuSO4.5H20 (as a biocide)
> temperature between 26°C and 32°C
> agitation: unnecessary
>
>
> carbon dispersion:
> 2 to 4% (w/w) of non-ionic surfactant based
> conductive carbon black dispersion paste*
> 6 to 10 g/l acetic acid
> room temperature
> agitation: unnecessary
>
>
> activator:
> 1 g/l of dye D&C Green No.5 , C.I 61570.
> room temperature
> agitation: not known
>
> non-chloride etchant:
> 100 to 200 g/l ammonium persulfate
> or
> 1% hydrogen peroxide
> 10% sulfuric acid.
> both baths may be used at room temperature.
>
>
> * The carbon black dispersion paste is FLEXOBRITE BLACK 258/86
manufactured
> by Degussa Coatings & Colorants.
>
> You will have to phone around and get a 500g sample for aqueous
based
> non-ionic surfactant conductive carbon black dispersion. Many of
the colorant
> manufactures will have these. 500g will last you forever. There is
still a
> whole range of information I left out, either because I haven't
worked it out
> yet or I missed it. The D&C Green No5 is available from food, drug
& cosmetic
> dye suppliers, either as a sample or in small volume (1 kg). Good
luck
>
> Adam