Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, Markus Zingg <m.zingg@n...> 
wrote:
> 
> Bungard, but since it dates back to the sixties I figure the patent
> protection is meanwhile void. I'm however not experienced, that 
said I
> don't know if a patent is protecting "forever" or if it's only
> effective for some years.
> 

17 years