Homebrew PCBs

I use negative "dry-film" resist. I got about 20meters off a old 
roll from a local PCB shop. New film only sold in pair of rolls 
152.4 meter length 305mm width, price $AU600.

Application is tricky without the help from some basic tools. No 
need to buy a hot roll laminator. I got two rubber ink rollers 
from a old printing machine. I built a mounted frame so they roll 
against each other. I manually feed the PCB through the rollers 
while the film wraps around the top half of a roller, hanging 
down on the outside. Both the film and PCB go through the 
rollers. While laminating, warm water is slowly poured at the 
interface between the film and PCB as its feed through. This 
gives a lamination that is free from trapped air bubbles, dusk 
particles and wrinkles.
The PCB is then heated in drying oven at 90\ufffdC for 5 minutes and 
the film 'bakes' on. Its impossible to peel away the film after 
that. Developing and stripping are processed as normal.

The difficult part is finding a cheap printing press rubber 
roller. One of the rollers can be hard, like that from a old dot 
matrix, inkjet or laser printer.



gregben wrote:

> Does anyone have any experience applying, exposing,
> developing, etc. with Seno 1000 photoresist? This
> is a positive-acting, dyed, aqueous developed and
> stripped liquid photoresist. The only place that I've
> found that sells it is Mega Electronics in the UK.
> 
> I'm interested in this because I have easy access to high
> resolution laser photoplots and want to use photoresist
> for board-making instead of toner transfer.
>