Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, Kamal Shankar
<kbshankar2000@...> wrote:
>
> I would be interested in getting a good idea of what
> are the etchants being used.
...
> What's the reason? Financial? (The 2nd choice is a
> little bit cheaper than the first) Speed? Ease of
> storage?


I previously used ferric chloride heated to near-boiling in the
microwave for years but after I learned about HCl/H2O2 on this group I
gave it a try and haven't looked at FeCl3 since! Specifically, I use
"muriatic acid" (31.45% HCl) that I buy off the shelf at Home Depot
for $9/2Gal (that's 7.5L to you metric folks) and regular 3% hydrogen
peroxide solution from any old drugstore (although in this particular
case I bought it from Sam's Club for something like $3/2qt. (~1.9L).

Besides being at least an order of magnitude cheaper than FeCl3, it
also etches boards a lot faster and is transparent. I've even etched
some fine pitch (0.5mm) SMT boards with very good results. This
etchant is truly a no-brainer choice IF you can get the chemicals
without a lot of hassle (otherwise the "time saved" hassn't really
been saved).

-Jeff