After changing my Laptop to a Lenovo T540p, I was constantly making screen shot since some mad engineer had placed the key between the right AltGr and Ctrl key. The Settings in Cinnamon have no possibility to change the behaviour of the Print Key.
After some searching I found a thread in the Linux Mint Forum which describes how to disable the Print Screen key.
$ sudo apt-get install dconf-editor
dconf-editor and go to "org -> cinnamon -> settings-daemon ->
plugins -> media-keys". Voila, you are able to change the settings..