Homebrew PCBs

Hi Markus and all

I tried and tried tonight to make this work.  I even tried the dual 
layer of Riston technique, but I just can't seem to ever get it on 
the board without some kind of imperfection that screws up the 
traces in that area.

Markus, can you tell us what brand and model your laminator is?  I 
think you (and others who said so) are probably right on the money 
in that my laminator just doesn't have enough room between the 
rollers.  It's got a temp adjust, which is nice, but I hear a "chunk 
chunk chunk" sound, which sounds like gears slipping, probably 
because there just isn't enough clearance in there.


I also noticed very fine squares on the pcb copper layer itself that 
were causing some of the lines in the film.  A friend noted that 
these are the fiberglass underlayer's telegraphing through from 
beneath.  I got an electric sander, and used 250 then 500 grit paper 
to smooth them out.


I found that I could use a hair dryer to pre-heat the film once 
applied, and push on it with my fingers in rubber gloves and get it 
to bond a little better.  It wasn't hot enough to cure it, but if I 
then placed it on a clothes iron for about 5 seconds on the low 
setting - just enough to heat but not make it boil - that would cure 
it.


Still trying....frustrated...but trying.


-Josh



--- In Homebrew_PCBs@yahoogroups.com, Markus Zingg <homebrew-
pcb@...> wrote:
>
> Josh,
> 
> I don't know your particular film as I'm using a different product 
> (Ordyl Alpha 900). However, the one I use is also pickey. I posted 
some 
> pics to the forum a while ago showing how I feed the laminator to 
avoid 
> bubbles. From what it sounds however I have the impression that 
the 
> particular laminator you are using is just too hot even in it's 
lowest 
> setting. The other thing is the applied pressure during 
lamination. My 
> solution was to try several different laminators and I ended up 
using 
> one where I was able to adjust the pressure of the rolls with 
screws 
> (had to loosen them quite a bit) and one that also works with 
pretty low 
> temperature setting. It took quite some experimentation to find 
the 
> propper setting but overall, off the shelf laminators apply too 
much 
> pressure and usually also are too hot.
> 
> HTH
> 
> Markus
> 
> joshdewinter schrieb:
> >
> > Hi
> >
> > MG Chemicals now sells a "Negative Photoresist Film" (product 
#416-
> > DFR5) that I believe may be Riston.
> >
> > I have tried it several times now with mediocre results. The
> > traces turn out good when they turn out. The problem I'm getting 
is
> > actually getting the film to stick to the board uniformly before
> > exposure.
> >
> > Someone suggested using water between the board and the film to
> > allow rolling of any bubbles out from underneath with your thumb
> > after positioning, then drying it in an oven at about 200 
degrees for
> > 10 min to get it to stick.
> >
> > They were right, it worked great...until I tried to dry it. Small
> > mutations formed, sometimes in the form of lines, sometimes what 
look
> > like small blobs. They aren't bubbles per se, but somehow there 
are
> > areas of the film that appear to stick to the board at a deeper 
level
> > than the surrounding film, or maybe they are melting and 
deforming.
> >
> > The manufacturer recommends using a laminator to apply the film,
> > which I tried initially, but it appears to have the same 
problem. My
> > laminator is adjustable heat, and I've tried from hi to low with
> > similar results. I haven't as yet put the board between any
> > protective sheets when laminating like you might to laminate 
paper
> > items...I'm going to try that next (the manufacturer never
> > specifically said to do it).
> >
> > Here are their instructions:
> >
> > http://www.mgchemicals.com/techsupport/416dfr_inst.html 
> > <http://www.mgchemicals.com/techsupport/416dfr_inst.html>
> >
> > I clean the board ahead of time with steel wool, alcohol and
> > acetone. I am using clean gloves throughout.
> >
> > Can anyone help me with any tricks to get this stuff to adhere
> > uniformly?
> >
> > Thank you so much in advance!
> >
> > -Josh
> >
> >
>