Are you trying to lay the film on all at once? That may be why you are getting bubbles.
Start at one edge, holding the other end of the film up and working your way across the board, pushing the film down.
The general idea can be seen here:
http://www.youtube.com/watch?v=tiBUE-tjwlc (When I tried it this way, I used my fingertip, never tried a card though, but it might work well.)
Once you get it all on flat, give it a quick heat with the iron on low. You might want to try leaving the iron off until you get to this point so it doesn't get too hot.
Then leave it to cure for 10 minutes or so before you expose it.
--- In Homebrew_PCBs@yahoogroups.com, Hari Hendaryanto <hari.h@...> wrote:
>
> good day,
>
> i'm a newbie on photoresist method. i've read homebrew's archives/forum
> about how to stick dry film to pcb, all methods involving laminator. is
> there some way for me to stick dry film without laminator?. i've tried
> without it, just by hand and pressed it with warm iron. the result is
> like this one. my exposure time is about 2 - 3 minutes.
>
> http://img39.imageshack.us/img39/3923/joharbaru2013032300273.jpg
>
> so many wrinkles here and there. and i have no confidence to develop it
> too long, sodium carbonate will dissolve the traces i'm afraid.
> if laminator is a must, what kind of laminator should i buy?what kind of
> spec? (roller thickness)
>
> i need many enlightenment here..
>
> thanks in advance
>
> regards
> hari
>