Homebrew PCBs

Hi Stefan,

I tried baking in the oven and that is an insane process... Then I 
tried to use a 'flat grill' and I did get a great transfer in one 
area but hardly anything in another. The root cause seems to be what 
you said about 'flatness'. I bet I wolud never have any of the 
problems if my board was smaller than my iron. I'll read thru your 
psots and maybe thre is something I missed.

What paper are you using? I am using HP high gloss laser paper.


Happy New Year! Mike


--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan 
<stefan_trethan@g...> wrote:
> On Thu, 01 Jan 2004 03:33:46 -0000, mikezcnc <marabu@c...> wrote:
> 
> > Stefan,
> >
> > Thank you for such an extensive description of your process. You 
nailed 
> > my problems: lousy printer, one iron only and the rest. I clean 
my board 
> > with acetone (to remove leftovers and I have always plenty of 
those, 
> > don't ask why...), then water with dishwasher soap, tehn 
sandpaper 600, 
> > then brillo pad with detergent. Then all is well flushed with 
water.
> >
> > Your process is interesting, but it takes s much time toand full 
> > attention. I am for the idea of Ron Peopeil: set it and forget 
it. Which 
> > brings me to another idea: chicken grill, just kidding. I agree 
with your 
> > supposition that higher temperature is more forgiving than lower 
and that 
> > two high pressure is not good for narrow traces.
> >
> > I ahve one of those $2 grills for hamburgers but their footpriny 
is just 
> > too small.
> >
> > The problem with iron is that I suspect that temperature is not 
evenly 
> > distributeed and therefore it must be set higher to compensate 
for the 
> > uneveness. However, that higher (than neccessary temperature -
> > someone mentioned 130 being needed for fusing..) causes problems 
in areas 
> > with widened lines due to pressure. In other words the correct 
pressure 
> > and slightly higher temperature in one area becomes correct 
pressure and 
> > incorrect temperature in another, due to a temperature gradient 
within a 
> > PCB. My next trial will be a Singer iron press that I picked up 
from a  
> > garage sale 2 summers ago for this convenient moment of being 
able to 
> > laminate PCBs... Right now I am baking that PCB in an oven after 
I 
> > finished pizza and New Year's ham...  Mike
> >
> >
> 
> Hi
> 
> In some dark corner i should have a iron press, maybe i try that..
> 
> to the press ideas:
> 
> PCBs are not compeltely flat ask the milling guys.
> If you have a flat plate (heated and press it against the pcb
> i doubt you get a even distribution of  the pressure.
> 
> 
> you would need a flexible plate with flexible backing, which again 
leaves 
> you
> with much harder pressed edges.
> 
> 
> I can only speak from experience, my iron seems to be flat, but if 
i only
> press it on flat (without moving around with the curved edge)
> there are always areas that don't adhere.
> 
> 
> I will measure for you the distribution of the heat in an iron.
> But i strongly suspect that there is no more than 2° difference.
> (in a solid aluminium iron, not stainless steel sheetmetal coated 
bottom)
> 
> 
> I don't really experience your problems, i get fairly good results
> in a wide pressure range (and i suspect also in a wide temp. range)
> 
> Stefan