Solid state lighting module with improved heat spreader

A solid state lighting device comprising a solid state lighting module and a socket for receiving the solid state lighting module through rotation around an axis of rotation, said solid state lighting module comprising:

• at least one solid state light-source;
• a heat spreading member having a first surface and a second surface arranged opposite each other and in thermal connection with each other, said first surface being in thermal connection with said at least one solid state light-source,
• said socket comprising:
• a heat sink;
• and
• receiving fastening means co-operating with corresponding extending fastening means comprised in said solid state lighting module and providing a thermal connection between a surface of said heat sink and the second surface of the heat spreading member comprised in said solid state lighting module,
• wherein the second surface of said heat spreading member has a surface topography with a plurality of peaks and valleys arranged substantially concentrically in relation to said axis of rotation and wherein the surface topography of the surface of the heat sink is substantially an inverse of the surface topography of the second surface of the heat spreading member.