[chbot] Anyone making PCBs?

[Andrew Errington]

On Tue, May 31, 2011 16:05, Richard Jones wrote:
> Kind of you to post the details Andrew,
>
>
> I've made several attempts at the toner transfer method using .020 inch
> tracks and 0.020 inch gaps and failed miserably. I don't recall how I did
> the cleaning, stainless steel cleaning pads I think, so maybe the
> additional detail is in the acetone. What size tracks and gaps are you
> using? I finally gave up and used photo sensitive PCBs instead. With your
> encouragement it deserves another try :-)
>

Hi Richard,

I don't know what size I'm actually using- whatever are KiCAD's defaults. 
I just measured one of the traces on the board and it looks like 0.5mm
track/space, so probably 0.02"

Visually, all the lands are separated (I did a flood fill to reduce how
much copper needed to be removed) so I'll see if I can actually solder
1206 parts and a SOT-23 without bridging the gaps.  I might be being a bit
ambitious.

The thing about it is that you can inspect the toner transfer before you
etch.  It's frustrating when it doesn't work, due to smudging or poor
adhesion, but you can just wipe it off and start again.  It's sufficient
to know that one works, therefore more are possible.

As for the etchant, the ingredients are easier to get than Ferric Chloride
(and slightly less nasty), and extremely cheap.

I'd be happy to discuss it in more detail off-list, but there's not much
more to say.

Keep the copper clean.
Use the blackest toner setting.
Don't move the artwork when you're ironing.
Don't push too hard.
Be careful with the chemicals- wear gloves and goggles, and add the Acid
to the Water, the way you know you oughta.

Best wishes,

Andrew

PS I'll be trying again soon, but my next board needs some holes drilled.