I can't speak for how they do it in Finland, but at least in Norway you can take the paternity leave over a period of 3 years. I think most people take it out in full, but a lot of self-employed people do that in order to keep things running.
That's really smart. I get the health impacts are different for women, but I never saw the point of spending time with new borns, compared to 18-36month olds.