Printed circuit board or card thermal mass design

A multi-layer printed circuit board or card including a plurality of conductive planes, including ground and power planes, and insulating planes, said circuit board or card having a plurality of through holes formed through at least one of said planes, said through holes having an electrically conductive material plated onto the inside surface, at least one integrated chip or component being attached to said circuit board or card such that pins made of an electrically conductive material and attached to a surface of said chip or component extend into said plated through holes, said circuit board or card comprising:

• at least one thermal relief passage in at least one of said planes for preventing the diffusion of heat throughout said circuit board or card during the securing or removal of said pins in said plated through holes by the heating of said plating material to a temperature above a melting point of the plating material, said at least one thermal relief passage located in the vicinity of at least one of said plated through holes and being free from connection with said pins.