Abstract: The heat dissipation device comprises a fluid direction changing part that changes a fluid traveling direction in which a fluid travels. The fluid direction changing part has a base end and a tip. The base end is fixed to a second surface facing a first surface inside a tubular body. The tip is arranged to face multiple fin ends of multiple fins of a heat sink. The fluid direction changing part is entirely or partially arranged downstream of the fluid traveling direction from an upstream end surface of the heat sink. The fluid flows into the heat sink through the upstream end surface, and also passes through a flow path without fin other than a flow path between fins for passage of a fluid formed between the multiple fins to flow into the heat sink through parts of the multiple fin ends exposed at upstream positions from the tip of the fluid direction changing part.

Abstract: The heat dissipation device comprises a fluid direction changing part that changes a fluid traveling direction in which a fluid travels. The fluid direction changing part has a base end and a tip. The base end is fixed to a second surface facing a first surface inside a tubular body. The tip is arranged to face multiple fin ends of multiple fins of a heat sink. The fluid direction changing part is entirely or partially arranged downstream of the fluid traveling direction from an upstream end surface of the heat sink. The fluid flows into the heat sink through the upstream end surface, and also passes through a flow path without fin other than a flow path between fins for passage of a fluid formed between the multiple fins to flow into the heat sink through parts of the multiple fin ends exposed at upstream positions from the tip of the fluid direction changing part.