Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "James Bishop" <bishopaj@...> wrote:
>
> This gave me an idea.. I wonder if it would be possible to replace the
> laser diode in a laser printer with a uv one, and then run a
> sensitised board through in place of the drum..
> 
> What do you guys think? Am i crazy?

Not crazy. I recall a past conversation on this but don't recall the
outcome.

I suspect exposure time would be a problem. Photoconductor drums are
very sensitive, whereas photoresist is not.

Aha... found something relevant. Someone calculated how much exposure
time from a 2mW UV laser diode. Says approximately 25 seconds per
square cm minimum. Way to slow for a laser printer. High sensitivity
photoresist would require darkroom procedures.

http://tech.groups.yahoo.com/group/Homebrew_PCBs/message/1933

It would also take a very large change in the mechanics of a laser
printer. A laser printer works by shining laser or LED light onto a
charged photoconductor drum, which causes charge to drain from the
exposed areas. The unexposed, still charged areas then attract toner
from another roller, then the paper is rolled across the
photoconductor drum with a high voltage behind the paper to attract
the toner to the paper. The paper then has a hot fuser roller melt the
toner onto it.

It seems that direct inkjet conversion would be much simpler,
comparatively.

But don't let anyone stop you from trying! There used to be lots of
nay-sayers about direct inkjet printing, some of them quite vehement.
All it really took to happen was the advent of pigmented ink and for
someone to keep trying.

Steve Greenfield