I want to panelize my boards by myself. When I do the panelization is there need for gap between the boards borders?
Yes. Please panelize your boards with 0.254 mm (10 mils) gap between outer outside of their borders (NOT between the centers of your board borders i.e. take into account the border line width too!) if you choose guilotinee cut and panelize with 2 mm (78 mils) gap between outer outside of their borders if you choose disk cut. Boards that are panelized must have a minimum border width of 10mils. Please have look at this picture which explains how to place the boards.