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wanna start etching the best way, but dont know how.....

wanna start etching the best way, but dont know how.....

2003-07-20 by mumin55555

hallo everybody!
im making a lot of pcb's, but the old way (photo paper, ironing...).
i want to start etch using photo resist and everything, only i dont
know how...
my problem is that im not an english speaker, and in my languege
there is nothing about it. i was wondering- can somebody help me
find a place where it is explained good and easy to read and
understand, with lots of pictures???

thanks a lot,
mumin.

Re: wanna start etching the best way, but dont know how.....

2003-07-21 by Ben H. Lanmon

Not too sure about instructions in other languages. I use M.G.
Chemicals positive borads. Best place I have found to buy the M.G.
Chemical products is Circuit Specialist
www.web-tronics.com

M.G. Chemicals has some instructions on their site, think it has
pictures with it, if I remember correctly. www.mgchemicals.com

Depending on how many and how offen you make PCB's and how much room
you have to do the work.

Myself I have a 5 gallon homemade etch tank can do upto (6) 8"x12"
single sided boards at once,
Homemade exposure for single sided board, soon to change where I
can do (2) single 8"x12" boards at once.
Use Dremel in drill presses with vacumn, have several setup with
most common drill sizes. The Dremel bits are OK for low volume but
should get Carbide bits I buy from www.thinktink.com
To cut the boards to size use a table saw with a diamond blade,
(note put a filter on the motor air intake) also use a vacumn system
to keep the dust down.
You will need a good printer or copier. I use the HP ink jet
transparencies with good results, other brands did not work as will
but where cheaper but normally had to double up so there goes the
cheaper per sheet. Right now use a HP 855 ink jet.
Use Ivex Winboard layout software.

If you need supplies and PCB equipment between Circuit Specialist
and ThinkTink you can find most of what you need. They do carry
premade etch tanks and exposure systems. For small production they
sell kits with most everything needed.

Myself I never had very good results with the iron-on's.

--- In Homebrew_PCBs@yahoogroups.com, "mumin55555" <MUMIN55555@H...>
wrote:
> hallo everybody!
> im making a lot of pcb's, but the old way (photo paper,
ironing...).
> i want to start etch using photo resist and everything, only i
dont
> know how...
> my problem is that im not an english speaker, and in my languege
> there is nothing about it. i was wondering- can somebody help me
> find a place where it is explained good and easy to read and
> understand, with lots of pictures???
>
> thanks a lot,
> mumin.

[Homebrew_PCBs] Again a warning that HCl and H2O2 may corrode tools

2003-07-22 by Stefan Trethan

Hi

I know i am telling you something you already know but please be aware that
HCl is very corrosive.
i forgot a small char of hcl plus h2o2 on my workbench, it made a set of
hss drill bits rusty in two days.
when i discovered it the jar was almost dried out. the rust wasn't too
serious, i didn't think it would be a problem.
when drilling it would simply diasppear (if you rubbed it with your finger
it disapeared without traces.

so i removed the etchant char and thought everything is alright.
today (~three days after removing the jar) i discovered the drill bits have
rusted MUCH MORE.
there was already some rust falling down from them in the case where they
are stored (this was open all the time).

i decided to put them in a jar with NaOH in water. then i dried them with
paper and brushed of the rust with a steelwire brush.
finally i oiled them with thin oil (they were almost new and most had the
factory oil still on them - it didn't prevent rusting.

only a 4mm banana plug is another victim of the acid so nothing serious is
damaged.
but the cleaning of the drills took some time and i fear now they may be
less precise because the shafts
were corroded only at one side. there were expensive good drills and i
think i will never forget the etchant char again......



so please be cautious


regards
stefan

note:
i store the etchant in a 1 liter glass bottle.
it has a plastic cap with a 1mm hole punched through.
the hole is covered on the outer side by a 1cm wide and 2cm high plastic
"cap". the cap is filled with some flexible foam and is open at the top.
this forms a "overpressure valve with anti-spill if the bottle accidentally
falls on one side".

i always kept this bottle amongst some toos and it never caused any
corrosion.
so this small opening and maybe the foam prevents too much acid getting
into the air.