Homebrew PCBs

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. 


--- 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