Patent ID: 6888725

Claim:
An electronics device unit, comprising: a circuit board; a plurality of semiconductor components that are dispersedly mounted on the circuit board, the plurality of semiconductor components generating heat, heat sinks being mounted on the plurality of semiconductor components, respectively; and a cover member that is provided for covering the heat sinks and forms a tunnel on the circuit board, a cooling medium flowing in the tunnel, wherein the plurality of semiconductor components are cooled via the heat sinks by forcing the cooling medium to flow so as to pass through the tunnel, and the plurality of semiconductor components are arranged on the circuit board such that in a section of the tunnel orthogonal to a flow of the cooling medium in the electronics device unit, a ratio of a sectional area of a clearance at a downstream part of the flow of the cooling medium to a sectional area of the tunnel is smaller than a ratio of a sectional area of a clearance at an upstream part of the flow of the cooling medium to the sectional area of the tunnel, the sectional area of the clearance at the upstream part being obtained by subtracting from the sectional area of the tunnel a sectional area at the upstream part occupied by members that block the flow of the cooling medium, the sectional area of the clearance at the downstream part being obtained by subtracting from the sectional area of the tunnel a sectional area at the downstream part occupied by members that block the flow of the cooling medium.