Electronic device and heat sink

An electronic device, comprising:

• a casing, comprising an accommodation space;
• an electronic assembly, located in the accommodation space, wherein the electronic assembly comprises a circuit board and a heat source, the circuit board is mounted on the casing, and the heat source is mounted on the circuit board;
• a heat sink, located in the accommodation space, comprising:
• a base portion, comprising a thermal contact surface, a rear surface, and a plurality of mount holes, wherein the thermal contact surface is in thermal contact with the heat source, and the rear surface faces away from the thermal contact surface, the plurality of mount holes penetrate through the thermal contact surface and the rear surface;
• a plurality of fin portions, protruding from the rear surface of the base portion;
• a wall portion, protruding from the rear surface of the base portion and surrounding the plurality of fin portions;
• and
• a plurality of partition portions, wherein the plurality of partition portions protrude from the rear surface and are respectively connected to different sides of the wall portion, the plurality of partition portions and the wall portion respectively surround the plurality of mount holes;
• and
• a cover, comprising a plurality of through holes, wherein the plurality of through holes are configured for a passage of a coolant to drop on the heat sink.