Homebrew PCBs

On Thu, 08 Dec 2005 00:54:43 +0100, soffee83 <soffee83@...> wrote:

> Stefan,
>
>
> Thanks again. Man, you take a damn good picture!

I reckon it is actually a scan. I did it ages ago and i don't remember.

> That transfer looks
>
> about a hundred times better than mine did too. On my double-sided
>
> boards, I'm supposedly dealing with 1oz of copper per side. The
>
> transitions look more troublesome than yours. The material is the less
>
> translucent greenish-brown colored stuff too, if that had any affect.

Usually the freshly etched epoxy takes toner very well, if it reaches it.  
So the material shouldn't matter.
I dunno why my boards are such strange material, i'm not sure if it is  
FR4, it sure has all the required glass but the resin might be something  
else.


>
> The Staples unit was supposed to have been the same one Pulsar bundles
>
> for PCB transfers (you probably already knew). I don't know if it has
>
> any rubber in it either. I've got a couple long rubber rollers here,
>
> one of which I've mounted by it's axles to a square aluminum bar via
>
> standoffs. That one was from a big Xerox machine. I use it with a drum
>
> finishing thing I made (manual feed between two sets of rollers). I
>
> know nothing about printer/laminator guts, but depending on where and
>
> how the heat source factors into that, I wonder if that idea would be
>
> half as functional as it is fun to think about.

If you put your board transfer up on a iron, and the "roll" a heat-proof  
rubber roller over the top of it it might just work.
Allow a bit higher temp and some time to heat through the PCB, maybe a  
second iron on top that is removed just before rolling.

I reckon a paper that releases without soak makes things easier here  
(althought the picture was made with normal inkjet i'm sure).


> I also wonder if the "wipe the back of the paper down with acetone-
>
> soaked cotton balls" method would work for that. I've always imagined
>
> that process blurring the prints, but it would have the same "squish"
>
> you describe with the rubber.
>
>
>                             -George

Well, that sure couldn't be done on a hot board as the acetone would cool  
it or instantly evaporate. I really don't think it would do much.
I have never heard of that method, what's it do?

But a dry balled-up towel or rag might be useable to squish the paper down  
on the upside-down iron.

ST