Homebrew PCBs

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

  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