Semiconductor package, printed board mounted with the same, and electronic apparatus having the printed board

A semiconductor package that can be mounted on a printed board, said semiconductor package comprising:

• a package board that is mounted with an exoergic circuit element;
• a heat spreader that transmits heat from the exoergic circuit element;
• and
• a jointing layer that joints said exoergic circuit element to said heat spreader and is made of a solid jointing material that has substantially no elasticity,
• wherein said heat spreader includes a first surface jointed to the exoergic circuit element, and a second surface as a rear surface of the first surface, and
• wherein said heat spreader has a slit that extends in a substantially radial direction from an inner side to an outer side with respect to a first area that is jointed to the exoergic circuit element on the first surface or a second area that is an orthogonal projection of the first area onto the second surface, when said heat spreader is transparently viewed from the first or second surface.