From your description our methods differ very little.
What copper foil thickness do you have on your boards?
Do you have any photos or scans of boards with such thin runs?
You can see a picture of a test PCB i did some time ago here:
<
http://i40.tinypic.com/fk7dir.jpg>
As you can see the 3.33mil line already starts to break up, this is on
18um copper.
Thanks,
ST
On Mon, Feb 23, 2009 at 8:10 PM, Derward Myrick <wdmyrick@...> wrote:
> Stefan,
>
> This is how I make the boards.
>
> The best solution I have ever used is one part
> muriatic acid(27% the kind used to clean bricks)
> and two parts hydrogen peroxide ( 3 % , the
> kind you can get at Walmart or drug stores).
> I only use it once I want it to etch fast.
> This will etch in 5 - 6 minutes and does not need heat.
> You mix only enough to cover the board in a small plastic tray.
> Rock it back and to untill etched.
>
> The printer you use is very important(at least the toner is).
> A brother printer will not work.
> I use an HP P1505 and it works the best I have seen.
> I think HP printer is part of why I get good resolution.
>
> I clean the board very good with BAR KEEPERS FRIEND
> that you can get at Walmart. The cleaner the board
> the better. Do not get finger prints(oil from fingers)on
> the board. You might want to use latex gloves starting
> at this point. After you scrub the board good with
> BAR KEEPERS FRIEND wash it good with soap
> and cold water. Now take some 91% alcohol and
> wipe the board clean. Wipe until there is no residue
> left on the wipe cloth. Now put the board in an oven that
> is preheated to 350 degrees and let it stay for
> 3 minutes.
>
> Take the board out of the oven and put the toner paper
> on the board. Be careful at this point and lay the paper
> down easy because it will stick to the hot board.
> Apply very light pressure (almost no pressure) as you
> move the iron all over the board. Iron for one minute.
>
> Now put the board in water and let it soak for about 20
> minutes the paper will float off the board with very little help.
> (I print the circuit on some Laser Jet color paper that
> I bought at Sams. It is made by a company named
> Royal Brights, 108 Main Street, Norwalk, CT 06851
> phone 1-800-526-4280. It is Glossy Ink Jet Paper 200
> sheets per box, this is all I can find on the box. You could
> call them and find out where to get it) THIS IS THE ONLY
> PAPER I HAVE SEEN THAT FLOATS OFF THE BOARD
> WHEN SOAKED.
> Now after the paper is off put the board back in the hot oven
> for about 3 minutes. It is now ready to etch.
>
> This works very good for going under smd but is harder to do
> for long runs.
>
>
> Derward Myrick KD5WWI
>
>
>
>
> ----- Original Message -----
> From: Stefan Trethan
> To: Homebrew_PCBs@yahoogroups.com
> Sent: Monday, February 23, 2009 11:54 AM
> Subject: Re: [Homebrew_PCBs] Re: Surface Mount
>
>
> Well you seem to be the only one able to make 1 to 3 mil lines with TT.
>
> Please describe what printer you use, what etchant, and what
> precedure. I'm sure most people here are interested to hear about your
> method.
>
> Personally 6.66mil is the limit of what i am comfortable with. Much
> thinner and i don't get continuity because of under-etching.
>
> ST
>
> On Mon, Feb 23, 2009 at 5:29 PM, Derward Myrick <wdmyrick@...> wrote:
> > PHIL,
> >
> > I make my regular run up to the smd and then I go with a 1 to 3 mil
> > line through the smd and then go back to the regular trace.
> > This will eliminate nost jumpers.
> >
> > Derward myerick KD5WWI
> >
> >
>
>
>
> [Non-text portions of this message have been removed]
>
>
>
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>
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