Beginner looking for advice
Cat
Please excuse the beginner questions; this is my first attempt at
etching a PCB.
I bought some 2oz dbl sided boards, and will be etching them using
Sodium Persulphate. I've done the traces using press-n-peal blue. I do
not yet have an elaborate set up, and I'm looking for any advice your
willing to share.
I've read that I should add 1/2lb Sodium Persulphate crystals to 1
gallon of warm water. The board should be submerged until the copper
that is not protected is dissolved. Am I missing anything? Any tips or
tricks that would be helpful? will this solution be strong enough? How
does one dispose of the remaining etching solution?
Lastly the board is a breakout of sorts, taking a db25 and directing
the individual wires to terminal connectors. The board will be exposed
to short pulses (1-3 seconds) of 24VDC @ up to 5 amps. The traces are
1/16th of an inch thick and separated by only 1/32th of an inch in
many places. This board will not be used for transferring signals,
just on or off for short durations. Does this sound ok?
Thanks,
Brian
D from BC
There's no directions on the Na2S2O8? Is it straight from the chemical
plant? I use ammonium persulfate.
Agitation and heating will speed up the etch.
I've preheat my etch in a microwave oven.
About PCB trace capacity..
If the traces glow from the current...that's bad...
If the traces burn the epoxy...that's bad..
I've never checked if traces will blow...I've gotten lucky.
If a trace blows..then I google for a strip current capacity chart or
formula.
D from BC
a7yvm1...@netzero.com
Are you a summer intern? It's possible someone is making fun of you.
http://www.winfordeng.com/products/brk25.php
20$. I repeat: 20 bucks.
You could have spent the time waiting for the delivery guy reading the
datasheet to your connector and figure out if they're rated for 5A per
contact, if you're using one contact at a time that is.
Cat
> Are you a summer intern? It's possible someone is making fun of you.
>
> http://www.winfordeng.com/products/brk25.php
> 20$. I repeat: 20 bucks.
I searched and found several places one can buy them online, but I
thought this would be a good get my feet wet project. I've always been
interested in electronics just need the experience.
D from BC
You're getting experience that there's better experiences in
electronics.
Make something special..
D from BC
JeffM
>Please excuse the beginner questions;
>
Those usually go in sci.electronics.basics.
>this is my first attempt at etching a PCB.
>
Those question (if advanced) usually go in sci.electronics.cad.
>I've done the traces using press-n-peal blue.
http://www.google.com/search?q=define:peal
http://www.google.com/search?q=define:peel
>[...]will be etching them using Sodium Persulphate.
>
>I do not yet have an elaborate set up,
>and I'm looking for any advice your willing to share.
>
A quite comprehensive PCB Resources page (link farm).
http://www.google.com/search?q=cache:_Wsrv2f9wHwJ:www.smps.us/pcb-design.html+fundamentals+Best-*-practices+GNU+Lazar.Rozenblat+DEMOs+guide+Tutorial+tips+design.rules+*-*-calculator-*-*-*-*-*&strip=1
>Lastly the board is a breakout of sorts, taking a db25
>and directing the individual wires to terminal connectors.
>
As a7yvm109gf5d1 has noted,
there are vendors who have these readily available off the shelf.
--
Several weeks in the lab can save a few hours in the library.