Heat sink

A heat sink comprising:

• a base plate;
• at least one first heat radiating fin thermally connected to the base plate;
• and
• at least one second heat radiating fin disposed adjacently to a side end portion of the side close to the first heat radiating fin, and thermally connected to the base plate,
• at least one third heat radiating fin disposed adjacently to a side end portion of the side close to the third heat radiating fin of the second heat radiating fin, and thermally connected to the base plate,
• wherein
• a surface of the first heat radiating fin is not parallel to a surface of the second heat radiating fin, a surface of the third heat radiating fin is not parallel to the surface of the second heat radiating fin,
• the first heat radiating fin is thermally connected to the base plate through a same heat conductive member as the third heat radiating fin,
• a lower end portion of the second heat radiating fin comes into contact with the base plate so that the second heat radiating fin is thermally connected to the base plate, and
• the free end of the second heat radiating fin is disposed at a position closer to the base plate than the first heat radiating fin positioned at the uppermost portion and the third heat radiating fin positioned at the uppermost portion.