Luca , 03-08-2020, 01:33 AM
It depend about your PCB assembly process will be and how you/your company has defined.
Tipically i do footprint as the manufacturer specify in the datasheet, so with paste mask reduction especially for fine pitch IC and connector.
This will allow to suggest/specify to your assembly house "only" the stencil thickness, surface treatment and in some cases kind of solder paste. But, for clarity, i also specify components, mainly for fine pitch IC and connectors, where my paste layer are already correct so they don't need to adjust the opening.
By the way I STRONGLY recomend to talk with your assembly house because there are a lot of different topics to know and concordate for best soldering phase, for example stencil thickness, surface treatment for stencil and PCB copper, polishing type for stencil surface, kind of solder paste and so on