--- In
Homebrew_PCBs@yahoogroups.com, "lcdpublishing" <lcdpublishing@...> wrote:
>
> TO clarify, using the dry film type stuff, I would get blisters - sometimes. Nothing consistant about it from what I could determine. I could easily manipulate the dry film onto the board without bubbles (small boards) but after running through the laminator, blisters would appear and those never turned out good.
>
> Other times I would have a simple break in a trace as if there was a cut line in the resist material (toner or dry film).
>
I had similar problems. The wet method did not work well for me. What did work for me is a J-roller. This is normally is used for applying laminate to counter tops. You should be able to find it at any hardware store.
You do not use the roller to push the bubbles out like you would do with a counter top. Instead hold the resist at the edge of the board and off the board. Push forward with the J-roller and let it press the photoresist on to the board. No air bubbles can get trapped.
You still need to run the board though the laminator to activate the adhesive.
Once I started doing it this way, I have had no problem with air getting trapped under the photoresist.